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Aims Remote monitoring by implantable devices substantially improves management of heart failure (HF) patients by providing diagnostic day-to-day data. The use of thoracic impedance (TI) as a surrogate measure of fluid accumulation is still strongly debated. The multicenter HomeCARE-II study evaluated clinically apparent HF events in the context of remote device diagnostics, focusing on the controversial role of TI. Methods and results We followed 497 patients (66.6 ± 10.1 years, 77% male, QRS 139.8 ± 36.0 ms, ejection fraction 26.8 ± 7.0%) implanted with a CRT-D (67%) or an ICD (33%) for 21.4 ± 8.1 months. An independent event committee confirmed 171 HF events of which 82 were used to develop a TI-based algorithm for the prediction of imminent cardiac decompensation. Highly inter-individual variations in patterns of TI trends were observed. The algorithm resulted in a sensitivity of 41.5% (50.0%) with 0.95 (1.34) false alerts per patient year, and a positive predictive value of 7.9% overall and 27.9% in the HF event group of patients. Averaged ratio statistics showed a significant pre-hospital decrease and a highly significant in-hospital increase in TI after intensified diuresis. Recurrent decompensations turned out to be preceded by a significantly stronger decrease of TI compared to first events with a higher chance for detection (63.6% sensitivity, p Conclusions Overall performance in predicting imminent decompensation by monitoring TI alone is limited due to its high inter-patient variability. TI stand-alone applications should be redirected towards a target population with more advanced symptoms where post-hospital observation aimed to maintain the patient's discharge status might be the most valuable approach. Clinical trial registration ClinicalTrials.gov Identifier NCT00711360 (HomeCARE-II) and NCT01221649 (J-HomeCARE-II).

Aims Non-compaction cardiomyopathy (NCCM) is associated with high rates of mortality and morbidity. Knowledge regarding risk stratification, arrhythmogenesis, therapy, and prognosis is limited. The aim of this study was to analyse the outcome of patients suffering from NCCM and ventricular arrhythmias (VAs) focusing on a treatment with implantable cardioverter-defibrillator (ICD) therapy and catheter ablation. Methods and results We conducted a multicentre observational study on 18 patients with NCCM, who underwent ICD implantation for secondary (n = 12) and primary (n = 6) prevention. In patients with multiple symptomatic episodes of VAs catheter ablation was performed. During a follow-up of 62 ± 42 months, 12 patients (67%) presented with appropriate ICD therapies [ventricular tachycardia (VT): n = 8; ventricular fibrillation (VF): n = 4; VT/VF: n = 3]. Ten patients underwent catheter ablation for VT/VF. Solely endocardial ablation was conducted in eight patients, and in two patients endo- and epicardial ablation was performed within the same procedure. Acute procedural success was achieved in 9/10 patients. Ventricular tachycardia recurrence was observed in two patients and the median arrhythmia free interval was 9.5 months (interquartile range 5.3-21 months). One patient underwent reablation, four patients died due to the underlying NCCM, and one patient received a left ventricular assist device. Conclusion Ventricular arrhythmias are common in patients suffering from NCCM and ICD therapy may be effective for primary and secondary prevention. In our cohort, consisting of patients with multiple VA episodes and recurrent ICD therapy, catheter ablation offered a safe and effective therapeutically option.

With the rapid development of new mapping and imaging technologies as well as catheter ablation technologies, it is increasingly important to understand the basic concepts of conventional mapping and ablation of cardiac arrhythmias. Prerequisite for successful ablation is the exact identification of the tachycardia mechanism and subsequent localization of the origin or tachycardic substrate. Only intracardiac electrograms provide decisive information regarding activation time and signal morphology. In some arrhythmias, it is necessary to supplement conventional mapping with so-called pace and/or entrainment mapping. This article aims to discuss and demonstrate the fundamentals of intracardiac mapping as it relates to the mapping and ablation of supraventricular and ventricular arrhythmias based on representative clinical cases. Modern three-dimensional mapping methods make it possible to individually optimize established ablation strategies with significantly better spatial resolution. The authors aimed to demonstrate that intracardiac uni- and bipolar electrograms provide essential information about timing and morphology guiding successful catheter ablation. Furthermore, our article provides useful information about conventional cardiac mapping techniques including activation mapping, pace mapping, and individual substrate mapping.

This study aimed to evaluate the impact, safety, and success of atrial fibrillation (AF) ablation in adults with congenital heart disease (ACHD) transferring ablation strategies established in normal hearts.AF is an emerging arrhythmia in ACHD.Fifty-seven consecutive ACHD (median age 51.1 ± 14.8 years) with drug-refractory AF were analyzed who underwent catheter ablation between 2004 and 2017. CHD was classified according to its complexity into mild (61.4%), moderate (17.5%), and severe (21.1%) lesions. AF ablation was performed in 104 procedures following a sequential ablation approach.Of the 57 patients, 30 underwent corrective surgery, 6 underwent palliative surgery, 5 had catheter interventions, and 16 were natural survivors. Follow-up was available for all patients (median 41 ± 36 months). The median duration of cyanosis was 9.2 ± 19.7 years, and the time of volume or pressure overload prior to corrective surgery or intervention was 26.1 ± 21.2 years and 18.1 ± 15.8 years, respectively. The Kaplan-Meier estimate for arrhythmia-free survival following the index ablation procedure was 63% for 1 year and 22% for 5 years. Performing subsequent ablation procedures (2.0 ± 0.5), the Kaplan-Meier estimate significantly improved, with 99% for 1 year and 83% for 5 years (p 0.01). Five patients died during follow-up due to their underlying CHD condition or underwent transplantation.AF ablation strategies established in normal hearts can be transferred to ACHD. The treatment is safe and effective with acceptable long-term results. Varying anatomical pre-conditions and the heterogeneous population itself are challenging and contribute toward a higher reablation rate. Therefore, AF ablation in ACHD should be reserved for dedicated and highly specialized teams.

Background— The implantable cardioverter–defibrillator (ICD) is the standard therapy to prevent sudden cardiac death in patients with coronary artery disease and unstable ventricular tachyarrhythmias. The prospective multinational SMS (Substrate Modification Study) was designed to assess whether prophylactic ablation of the arrhythmogenic substrate reduces or prevents the recurrence of ventricular tachycardia/ventricular fibrillation in such patients. Methods and Results— Of 111 patients included in an intention-to-treat analysis, 54 were randomly assigned catheter ablation plus ICD implantation (ablation group: 68±8 years; 47 men), whereas 57 were assigned ICD implantation without catheter ablation (ICD-only group: 66±8 years; 46 men). Primary study end point was the time to first recurrence of ventricular tachycardia/ventricular fibrillation. ICD episodes were assessed and verified by an independent board. Patients were followed up for 2.3±1.1 years. The primary end point was reached by 25 ablation patients and 26 ICD-only patients. Two-year event-free survival was estimated at 49.0% (95% confidence interval, 33.3%–62.9%) in the former and 52.4% (36.7%–65.9%) in the latter groups. Comparison of episode incidence revealed no significant difference in the primary end point ( P =0.84). In an Andersen–Gill regression model with multiple end point recurrences, the difference between the study arms significantly favored catheter ablation for both the primary end point and all but one of the predefined subgroups of detected arrhythmia events. Conclusions— SMS failed to meet the primary end point of time to first ventricular tachycardia/ventricular fibrillation recurrence. However, catheter ablation did reduce the total number of ICD interventions during the duration of follow-up. Clinical Trial Registration— https://clinicaltrials.gov . Unique identifier: NCT00170287.

Aims Although Eustachian valves and recesses have been related to resistance to block, the effect of convective cooling by the right coronary artery (RCA) has not been evaluated in the clinical setting. Methods and results The distance and course of the RCA in relation to the cavotricuspid isthmus (CTI) in addition to variants of CTI anatomy and the presence of Eustachian valves were analysed from computed tomography scans of 54 patients. Ablation power was titrated using a step-up protocol. Invasive follow-up was available for 34 patients. The RCA came closest to the CTI inferiorly separated by a mean of 5.3 ± 2.5 mm compared with 7.3 ± 3.3 mm septally and 5.7 ± 2.3 mm anteriorly ( P < 0.01). The maximum power required for CTI block correlated inversely with the distance of the RCA to the CTI, whereas the cumulative energy was highest in the presence of recesses. Neither failure of acute block nor a higher rate of conduction recurrence could be attributed to variants of CTI anatomy or the presence of a Eustachian valve. Using multivariate analysis, a position of the RCA underneath the central part of the CTI was the only significant predictor for late conduction recurrence. These patients showed a 2.7 mm larger distance of the RCA to the tricuspid valve plane ( P = 0.05). Conclusion The RCA affects CTI ablation as higher power settings are required at closer distances to the ablation site. Late conduction recurrences were observed in patients with a variation of the RCA, leaving the atrioventricular groove towards the atrial aspect.

Objectives: The effect of angiotensin-converting enzyme inhibitors (ACE-I) and angiotensin II receptor blockers (ARBs) on the long-term outcome after pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (PAF) is unknown. Methods: This matched-pair study included 102 patients with PAF treated with ACE-I or ARBs (group 1) and 102 control subjects (group 2) after standardized PVI. Tele-ECG recorders were used to detect the end point of the first PAF recurrence after a 3-month blanking period. Results: Median follow-up was 2.1 years (range 0.3–6.3). In group 1, 51 (50%) patients suffered recurrences, with a mean time to recurrence of 3.2 years (95% CI 2.6–3.8). In group 2, 67 (65.7%) patients presented PAF after a mean period of 2.2 years (95% CI 1.7–2.8; p = 0.009). A second ablation was performed in 31 (50%) patients from the treatment group and in 48 (66.7%) patients from the control group (p = 0.02). Multivariate Cox analysis showed treatment with ACE-I and ARBs to be the only significant predictor of a reduced recurrence rate (HR 0.49, 95% CI 0.32–0.75). Conclusion: ACE-I and ARBs were effective for the preservation of sinus rhythm after PAF ablation, and they reduced the reablation rate.

Background— Termination of chronic atrial fibrillation (CAF) can be achieved by catheter ablation using a stepwise approach. However, there are limited data on the contribution of the right atrium to the CAF process. Furthermore, the prognostic value of CAF termination remains unclear. Methods and Results— Eighty-eight patients (61�10 years of age) underwent de novo ablation of CAF in 2006 at our institution. The ablation procedure was performed sequentially in the following order: pulmonary vein isolation, defragmentation of the left atrium, coronary sinus, and right atrium. Attempted procedural end point was termination of CAF. Consecutive arrhythmias occurring after AF termination were mapped, and ablation was attempted. AF termination was achieved in 68 (77%) patients: in 37 (55%) patients it occurred in the left atrium, in 18 (26%) patients in the right atrium, and in 13 (19%) patients in the coronary sinus. In 54 patients, at least one redo was performed (total number of procedures: 154). After the first redo, another 30 patients were in sinus rhythm (total 63), 8 patients were in atrial tachycardia (AT), and 17 patients were in AF. Another 11 patients underwent a second redo. After a mean follow-up of 20�4 months, 71 (81%) patients were in sinus rhythm, 1 (1%) patient was in AT, and 16 (18%) patients were in AF. Patients with CAF termination had predominantly ATs as recurrent arrhythmias (83%), whereas those without mainly presented with recurrent CAF (85%). The overall success rate in patients with CAF termination was 95% compared with 5% of patients without CAF termination in 2 procedures (n=12). In almost all redo procedures attributable to AT, at least 1 AT during redo was documented previously. Conclusions— AF termination is a prognostic important end point of catheter ablation for CAF. Termination of AF was achieved in both atria and the coronary sinus, suggesting a biatrial substrate of CAF. Subsequent arrhythmias often recur during follow-up and, therefore, should be targeted for ablation.

Objective: Catheter ablation of ventricular tachycardia (VT) after myocardial infarction (MI) can be complex and time-consuming. We only targeted the previously documented VTs and those with similar or longer cycle lengths. Methods: 30 patients with VTs after MI were included in the study. Voltage mapping was performed using an electro-anatomic mapping system (CARTOT). Stable VTs were mapped during tachycardia and unstable VTs during sinus rhythm. Results: Clinical VTs were stable in 16 (53%) and unstable in 14 (47%) patients, and ablation was successful in 11 (69%) and 9 patients (64%), respectively (p = 0.42). During follow-up (14 ± 6 months), 4 patients (25%) treated for stable and 6 (43%) for unstable VTs had recurrences (p = 0.82); ablation was successful in none and 2 (33%) of them, respectively. Non-target VTs were inducible in 11 (55%) of 20 patients after successful ablation and non-inducible in 9 (45%). During follow-up, inducibility of non-target VTs did not predict recurrences (9 vs. 11%, p = 0.88). Conclusions: Catheter ablation of VTs after MI can be successfully performed. Acute success rates seem to be similar for stable and unstable VTs. VTs faster than those documented clinically exert a minor effect on VT recurrences during follow-up.

Background— Insights gained from noncontact mapping of ventricular tachycardia (VT) have not been systematically applied to contact maps. This study sought to unify both techniques for an individualized approach to the patient with multiple ischemic VTs irrespective of cycle length. Methods and Results— For 12 consecutive patients with chronic myocardial infarction and recurrent VT, bipolar contact maps were acquired during sinus or paced rhythm. Additional noncontact maps were obtained during 48 induced VTs (cycle length 192 to 579 ms). Endocardial exit sites were superimposed on contact maps and verified by pace-mapping. Radiofrequency lesions were extended for critical borders defined by multiple neighboring exits and followed the isovoltage contour line of contact maps. Nine critical borders were identified in 8 patients and constituted the substrate for 31 VTs. The voltage at exit sites was 0.8 mV (range 0.1 to 2.3). Noncontact maps revealed 23±18% of isthmus conduction. Thirty-seven (77%) of all and 83% of clinically documented VTs were rendered noninducible irrespective of cycle length by application of 27 radiofrequency lesions (range 18 to 56). Spontaneous transitions between distinct VTs along critical borders were demonstrated in 4 patients. Pace-mapping reproduced the QRS morphology of 81% of VTs and was associated with successful ablation ( P P Conclusion— The combined approach of contact and noncontact mapping effectively defines critical borders as the substrate of multiple VTs without limitation for unstable VTs.

With increasing advances in technology, cardiac pacemakers have become highly sophisticated devices that allow diagnostic and therapeutic functions beyond conventional antibradycardic therapy. This review discusses the most promising developments in antibradycardic device therapy, such as novel diagnostic functions, telemonitoring, autoadjustment of programmed parameters, algorithms for support of intrinsic atrioventricular conduction, pacing algorithms for the prevention of atrial arrhythmias and cardiac resynchronization therapy. A short overview of the basic principles of antibradycardic device therapy is also provided.

Background: Vasovagal syncope is triggered by complex cerebral and cardiovascular reflex mechanisms leading to general vasodilatation and bradycardia resulting in cerebral hypoperfusion. Methods: We prospectively studied the correlation of postural blood pressure test (PBT) and head-up tilt table test (TT) in patients with recurrent vasovagal syncope. Sixty-eight patients (37 male, 52.4 ± 18.6 years) were included in the trial. They were asked to participate in a PBT and a TT. Independent samples t-test, ANOVA and Fisher’s exact test were used for statistical analysis. p values Results: Thirty patients (44%) showed a positive TT and thirty-four patients (50%) had a positive PBT. PBT did not show any correlation with TT, although pathophysiological mechanisms in vasovagal syncope and orthostatic hypotension are supposed to be similar. Furthermore neither TT nor PBT nor their combination had any predictive value for the patient’s risk of syncope recurrence. Conclusions: TT and PBT are not correlated with each other. Both investigations cannot predict the patient’s risk of syncope recurrence.

Aims To investigate the effectiveness of additional substrate modification (SM) by left atrial (LA) linear lesions as compared with pulmonary vein isolation (PVI) alone in patients with persistent atrial fibrilla- tion (AF) in a prospective randomized study. Percutaneous PVI has evolved as an accepted treatment for paroxysmal AF but seemed to be less effective in patients with persistent AF. The benefit of PVI alone and additional linear lesions has not been validated in a randomized study so far. Methods and results Sixty-two patients with persistent AF (median duration 7, range 1-18 months) were randomly assigned to either PVI alone (n ¼ 30) or additional SM (n ¼ 32) consisting of a roof line connecting both left superior and right superior PV and LA isthmus ablation between left inferior PV and mitral annulus. Procedures including SM were performed using a three-dimensional mapping system (EnSite NavX TM , St Jude Medical, St Paul, MN, USA). Anti-arrhythmic drugs were discontinued within 8 weeks after ablation in both groups. Follow-up included daily trans-telephonic ECG transmitted irrespective of the patient's symptoms. PVI was successful in 98% of all targeted veins in both groups. Additional SM did not increase fluoroscopy time (72.1+ 18.7 vs. 72.9+ 17.3 min, P ¼ 0.92) because of the use of three-dimensional navigation in the PVI þ SM group. AF recurrences within the first 4 weeks following ablation were more common after PVI alone (77%) than additional SM (44%, P ¼ 0.002). After a follow-up time of 487 (429-570) days, only 20% of patients undergoing stand alone PVI remained in sinus rhythm when compared with 69% following PVI combined with SM (P ¼ 0.0001). Two patients assigned to PVI þ SM experienced procedure-related complications (cardiac tamponade and minor stroke) which resolved without sequelae. Conclusion PVI alone is insufficient in the treatment of persistent AF. However, additional left linear lesions increase the success rate significantly. Early AF-relapses are associated with a negative outcome after PVI alone but not following additional SM.

Introduction: Currently, definition of success following atrial fibrillation (AF) ablation is commonly based on the lack of symptoms. The purpose of this study was to evaluate the correlation between symptoms and the underlying rhythm after AF ablation. Methods and Results: Eighty consecutive patients (pts) were treated for paroxysmal episodes of AF by segmental ostial ablation of all pulmonary veins and right atrial isthmus ablation. For 6 months pts transmitted transtelephonic (T-) ECG recordings in combination with comments daily or in the event of symptoms. Eligible comments were classified as: (1) asymptomatic, (2) symptomatic. Analysis was performed at 1-month intervals, defining an acute (first month) and chronic period (second to sixth month) after ablation. Overall 6,835 T-ECGs were analyzed. Of these 5,437 (79.5%) showed sinus rhythm (SR) and 1,398 (20.5%) showed AF. Pts in SR reported symptoms for 593 (10.9%) episodes, whereas 4,844 (89.1%) episodes were asymptomatic. During AF, 646 (46.2%) episodes were associated with symptoms, and 752 (53.8%) episodes remained asymptomatic. Exclusively asymptomatic were 7 (8.8%) pts. In 30 (52.6%) of 57 pts with AF, arrhythmic events were confined to the acute phase. Of the remaining 27 pts 14 (52%) reported an improvement, 12 (44%) the same, and 1 (4%) worsened symptoms after 3 months. A significant change (P < 0.01) toward more asymptomatic episodes from the acute (43.5%) to the chronic (57.5 ± 4.5%) period was evident. Conclusion: Assessment of success after AF ablation cannot be based on the absence of symptoms due to a high prevalence of asymptomatic episodes.

Simultaneous occurrence of narrow and broad QRS complex tachycardias in patients with WPW syndrome usually indicates a macroreentry in an orthodromic atrioventricular reentry-tachycardia using the AV node as antegrade and the accessory pathway as retrograde conduction and vice versa in an antidromic circuit. We report on a 32-year-old woman with WPW syndrome presenting with both a narrow and a broad QRS complex tachycardia using two accessory pathways with different unidirectional conduction properties in combination of an exclusively antegrade conducting AV node. This case report describes conventional mapping techniques and ablation of this unusual entity of a WPW syndrome.

Amiodarone Effect on PV Electrophysiologic Properties. Introduction: Pulmonary veins (PVs) are the predominant location of triggers for atrial fibrillation (AF), but little is known about the electrophysiologic propertiesof PVs. In addition, the influence of amiodarone on the electrophysiologic properties of PVs has not been elucidated. Methods and Results: Fifty-five patients with symptomatic and drug-resistant AF were divided into two groups: group 1 patients (n = 29) without antiarrhythmic drug therapy at the time of electrophysiologic study (EPS), and group 2 patients (n = 26) undergoing continuous long-term treatment with amiodarone. EPS including programmed stimulation of both atria and within the PVs was performed in both groups. In group 1, the effective refractory period (ERP) of all PVs (174 ′ 62 msec) was significantly shorter than the ERP of the left atrium ([LA] 254 ′ 30 msec, P = 0.0001) and right atrium ([RA] 221 ′ 29 msec, P = 0.0001). The same pattern was observed in group 2 (PV: 210 ′ 58 msec; LA: 259 ′ 35 msec, P = 0.0001; RA: 246 ′ 37 msec, P = 0.0255). The ERP of all stimulated PVs was significantly lower in group 1 (174 ′ 62 msec) than in group 2 (210 ′ 58 msec; P = 0.0001). The ERP of the left superior and right superior PVs and RA but not the left inferior PV and LA were significantly increased in patients treated with amiodarone. Decremental conduction properties were observed in all stimulated PVs, and there were no significantly differences between the maximal decrement of both groups. Conclusion: The distinctive electrophysiologic properties of PVs are emphasized by amiodarone therapy. Long-term amiodarone treatment is responsible for heterogeneous alteration of the PV electrophysiology, which may account for the individual antiarrhythmic responses in a subset of patients with paroxysmal AF.

Cooled Versus Large-Tip Catheters for Flutter Ablation. introduction: Open cooled-tip and solid 8-mm-tip catheters have demonstrated safety and effectiveness for radiofrequency current (RFC) ablation of typical atrial flutter (AFL). However, data from prospective and randomized studies in this setting are lacking. Methods and Results: One hundred thirty consecutive patients (104 men; 61 ′ 11 years) with AFL were randomized to undergo RFC catheter ablation either using a solid 8-mm-tip catheter (group A, 65°C, 70 W, 60 s) or an open irrigated-tip catheter (group B, 65°C, 50 W, 60 s, 17 mL/min flow). Endpoint was bidirectional conduction isthmus block. In cases of repeated (two times) transient isthmus block; the catheter was changed (crossed over) to the catheter used in the other randomization arm, but patients remained in the original group following intention-to-treat analysis. The selected endpoint could be achieved in all patients after 12 ′ 6 RFC pulses in group A and 10 ′ 7 RFC pulses in group B (P = 0.11). Procedure times were longer (159 ′ 38 min vs 138 ′ 37 min, P = 0.002) and x-ray exposures higher in group A (fluoroscopy time 25 ′ 17 min vs 21 ′ 10 min, P = 0.08; x-ray dosage 3,133 ′ 2,576 cGy.cm 2 vs 2,326 ′ 1,405 cGy.cm 2 , P = 0.03). Transient isthmus block was observed in 23 group A patients and 12 group B patients (P = 0.03). Onset time of transient isthmus block ranged from 0.5 to 27 minutes. Repeated transient isthmus block occurred in 8 of the 23 patients in group A after 19 ′ 3 RFC applications. After crossover to the cooled-tip catheter, the endpoint was reached another 5 ′ 1 RFC pulses. In group B, all patients could be treated without change of ablation catheter. After a follow-up of 14 ′ 2 months, 2 patients (3%) in group A and 1 patient (1.5%) in group B presented with AFL recurrence. Conclusion: Open cooled-tip catheters are more effective than solid large-tip catheters for AFL ablation. The greater effectiveness is evident in cases showing repeated conduction recovery within the cavotricuspid isthmus. Primary use of open irrigated-tip catheters should be considered for AFL ablation.

Aim Sub-threshold stimulation (STS) applied during atrioventricular nodal re-entrant tachycardia (AVNRT) of the common (slow–fast) type has been shown to effectively characterise target sites suitable for slow pathway (SP) ablation but has not been investigated in the setting of fast–slow and slow–slow variants. Methods and results Seventeen consecutive patients (52±16 years, 12 female) with sustained uncommon type AVNRT (fast–slow: \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(n=13\) \end{document}, slow–slow: \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(n=4\) \end{document}) were investigated. Mapping of the SP was started postero-septally close to the coronary sinus ostium and continued toward mid-septal sites, if required. Target sites for STS were selected according to established criteria including the recording of the earliest retrograde atrial activation during AVNRT. Long duration (5 s) constant current STS during AVNRT variants was performed in a stepwise manner (max 5 mA) at each site eligible for SP ablation until termination or capture occurred. Radiofrequency current (RFC) was delivered following successful STS termination of tachycardia (65 °C, 60 s) and exclusion of catheter dislodgement. Uncommon AVNRT with a mean cycle length of 405±70 ms was induced without spontaneous termination in all patients. Interruption of AVNRT variants due to selective STS-induced block of the retrograde (\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(n=12\) \end{document}) or anterograde (\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(n=2\) \end{document}) SP occurred without capture in 14/17 (82%) patients. This was exclusively observed at sites with successful subsequent RFC application. AVNRT was rendered non-inducible in all patients after a median of 1 (1–11) RFC pulses without complications. Conclusions Uncommon AVNRT can be interrupted by STS delivered at subsequently successful target sites for SP ablation in most patients (82%). The high positive and negative concordance between the effects of STS and following RFC application indicates that STS-mapping is also useful in the setting of AVNRT variants.

The present study sought to investigate the electrophysiological properties of isolated pulmonary veins following successful radiofrequency (RF) catheter ablation in patients with paroxysmal atrial fibrillation (PAF). Overall, 71 pulmonary veins in 37 consecutive patients (age:56 ± 9 years) with recurrent PAF were targeted for RF ablation at the ostial region in order to achieve a complete functional block. Following disconnection, the incidence of dissociated pulmonary vein (PV) activity and its response to orciprenalin were studied. RF ablation abolished conduction in 67 (94%) of 71 potentially arrhythmogenic PVs after a mean of10.7 ± 6.4 RFapplications for each PV. After ablation, spontaneous dissociated automatic activity (9 to 52 beats/min, median 27) was found in 6 out of 67 isolated PVs (left superior:n = 1, left inferior:n = 1, right superior:n = 2, common left PV:n = 2). Slight acceleration (13 to 68 beats/min, median 29) of dissociated PV activity was observed during infusion of orciprenalin. Following isolation, initiation of sustained or nonsustained local fibrillation was recorded in only two cases of the common left sided PV with preceding automatic activity. In one patient PV fibrillation occurred during orciprenalin infusion following a repetitive response to a dissociated automatic rhythm with increasing duration as well as destabilization. In the other patient, PV fibrillation occurred immediately after the occurrence of PV automaticity. Slow dissociated automatic rhythms are detectable within 9% of disconnected PVs. The unique anatomic substrate of common left PVs seem to favor the occurrence of local fibrillation following isolation. The initiation pattern of fibrillation within the isolated PV has pathophysiological implications and underlines the contribution of multiple factors to the onset and sustenance of PAF. (PACE 2003; 26:1363–1370)

OBJECTIVES This randomized prospective study sought to assess the value of slow pathway (SP) mapping and ablation guided by subthreshold stimulation (STS) in comparison with a strategy based on conventional criteria. BACKGROUND Previous studies have demonstrated that STS can be used as a highly specific and sensitive marker for successful SP ablation in the setting of atrioventricular nodal re-entrant tachycardia (AVNRT). Nonetheless, thus far this mapping strategy has not been investigated in contrast with the conventional approach. METHODS One hundred patients with sustained AVNRT were included. Fifty patients (group A) were randomly assigned to endocardial mapping and SP ablation using currently established criteria. In the other 50 patients (group B), SP ablation was guided by STS mapping. In group B patients, only radiofrequency current (RFC) was applied if additionally constant current STS (up to 5 mA) during AVNRT interrupted the tachycardia due to selective block within the SP. RESULTS Termination of AVNRT without apparent capture was observed during STS in 47 of 50 group B patients (94%). In all cases, this effect was indicative for successful subsequent SP ablation. The mean number of RFC pulses required for successful SP ablation was significantly lower in patients assigned to the STS-guided strategy (1.6 ± 1.3 vs. 3.9 ± 3.4; p = 0.0003). Similarly, the mean procedure duration was shorter in the STS group (156.9 ± 33.5 vs. 173.2 ± 49.7 min; p = 0.0221); the fluoroscopy time was comparable between both groups (14.1 ± 8.7 vs. 16.9 ± 10.6 min; p = 0.1278). CONCLUSIONS Subthreshold stimulation is an effective method for detection of target sites for selective SP ablation. This technique helps to minimize the number of RFC pulses without prolongation of the overall procedure and fluoroscopy time required for SP ablation.

AVNRT in the Elderly. Introduction: Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common regular supraventricular tachycardia in the general population as well as in elderly patients. The purpose of thestudy was to investigate the success and complication rate particularly regarding the induction of an atrioventricular (AV) block by radiofrequency (RF) ablation in elderly patients with and without a preexisting AV block. Methods and Results: Between February 1998 and July 2004, all patients with symptomatic AVNRT referred for slow-pathway ablation in our institution were included and divided into two groups: group 1 patients younger than 75 years (n = 508) and group 2 patients >75 years (n = 70). A preexisting prolonged PR interval was present in 17 (3.3%) patients of group 1 and in 26 (37%, P < 0.0001) patients of group 2. Following successful slow-pathway ablation (follow-up time group 1: 37 ′ 22, group 2: 37 ′ 24 months) no induction of an AV block was observed in group 2 but in four patients of group 1 (0.79%) a complete heart block was induced requiring a pacemaker implantation. In group 1, 15 (2.95%) patients with a recurrence of AVNRT were readmitted for a repeat ablation procedure. No recurrences occurred in group 2. Conclusion: Despite a higher incidence of preexisting prolonged PR intervals slow-pathway ablation in elderly patients is both effective and safe and should be considered as the first line therapy also in this patient population.

Aims To collect information on the use of the Reveal implantable loop recorder (ILR) in the patient care pathway and to investigate its effectiveness in the diagnosis of unexplained recurrent syncope in everyday clinical practice. Methods and results Prospective, multicentre, observational study conducted in 2006–2009 in 10 European countries and Israel. Eligible patients had recurrent unexplained syncope or pre-syncope. Subjects received a Reveal Plus, DX or XT. Follow up was until the first recurrence of a syncopal event leading to a diagnosis or for ≥1 year. In the course of the study, patients were evaluated by an average of three different specialists for management of their syncope and underwent a median of 13 tests (range 9–20). Significant physical trauma had been experienced in association with a syncopal episode by 36% of patients. Average follow-up time after ILR implant was 10 ± 6 months. Follow-up visit data were available for 570 subjects. The percentages of patients with recurrence of syncope were 19, 26, and 36% after 3, 6, and 12 months, respectively. Of 218 events within the study, ILR-guided diagnosis was obtained in 170 cases (78%), of which 128 (75%) were cardiac. Conclusion A large number of diagnostic tests were undertaken in patients with unexplained syncope without providing conclusive data. In contrast, the ILR revealed or contributed to establishing the mechanism of syncope in the vast majority of patients. The findings support the recommendation in current guidelines that an ILR should be implanted early rather than late in the evaluation of unexplained syncope.

Discrimination of local and far field potentials during sinus rhythm and atrial fibrillation (AF) is essential for successful pulmonary vein (PV) isolation. We sought to introduce an expert system for the classification of electrophysiologic PV signals. For the expert system database, we analyzed ablation procedures of 50 patients with paroxysmal and persistent AF. Standard circumferential catheters and bipolar recordings were required. In a prospective trial, the expert system was compared with the performing electrophysiologists’ classifications of potentials during 15 procedures. A total of 1,343 recordings of local PV and far field signals were validated by the sudden disappearance of local potentials during ablation, the presence of dissociated PV activity, and pacing maneuvers. A fast Fourier transform was applied to the individual potentials. Analysis continued in the amplitude and phase representation. Four parameters significant (p

Post-MI Narrow QRS Dyssynchrony. Introduction: The mechanism of mechanical dyssynchrony in postinfarction patients with a narrow QRS complex is not defined but essential for cardiac resynchronization therapy (CRT). Methods and Results: Left ventricular electrical activation and subsequent wall motion were recorded for 16 patients with ischemic cardiomyopathy during intrinsic rhythm using a modified NOGA electromechanical mapping system. Ten patients presented mechanical dyssynchrony on tissue Doppler imaging, while 6 patients served as control subjects. The local activation time (LAT) was set by the maximum downslope of the unipolar electrogram. Local wall motion time (LMT) was defined as the time needed for the catheter tip to traverse half of its maximum inward deflection during systole. LAT and LMT were measured relative to the onset of the QRS complex. Electrical activation showed a septal-to-lateral pattern in all patients with a mean endocardial activation time of 65 ± 13 ms. Control subjects exhibited 97.5% of all LMTs 300 ms) showed no slowing of conduction. Wall motion time corrected for differences in electrical activation (LMT-LAT) was significantly longer in delayed (289 ± 34 ms) than in regular (204 ± 24 ms) motion areas (P = 0.002). Delayed motion segments were hypokinetic on echocardiography and presented a lower maximum inward motion (9.9 ± 1.1 mm) compared to regular segments (10.9 ± 1.2 mm) on electromechanical maps (P = 0.004). Viability, however, was preserved with unipolar and bipolar voltage amplitude >7 mV and >1.5 mV for 79% of all delayed motion areas. Conclusion: Dyssynchronous segments of an ischemic myocardium show unimpaired local activation but slow wall motion, thereby limiting the benefit of ventricular preexcitation via CRT. (J Cardiovasc Electrophysiol, Vol. 21, pp. 70–77, January 2010)

To evaluate the performance of velocity-encoded (VENC) magnetic resonance (MR) imaging, as compared with pulsed-wave echocardiography (PW-ECHO), in the quantification of interventricular mechanical dyssynchrony (IVMD) as a predictor of response to cardiac resynchronization therapy (CRT).The study was approved by the local ethics committee, and all patients provided written informed consent. The study involved the examination of 45 patients (nine women, 36 men; median age, 60 years; interquartile age range, 47-69 years) with New York Heart Association class 2.0-3.0 heart failure and a reduced left ventricular ejection fraction (median, 25%; interquartile range, 21%-32%), with (n = 25) or without (n = 20) left bundle branch block. Aortic and pulmonary flow curves were constructed by using VENC MR imaging and PW-ECHO. IVMD was defined as the difference between the onset of aortic flow and the onset of pulmonary flow. Intraclass correlation coefficient, Spearman correlation coefficient, Bland-Altman, and Cohen kappa analyses were used to assess agreement between observers and methods.Inter- and intraobserver agreement regarding VENC MR imaging IVMD measurements was very good (intraclass r = 0.96, P.001; mean bias, -3 msec +/- 11 [standard deviation] and 0 msec +/- 10, respectively). A strong correlation (Spearman r = 0.92, P.001) and strong agreement (mean difference, -6 msec +/- 16) were found between VENC MR imaging and PW-ECHO in the quantification of IVMD. Agreement between VENC MR imaging and PW-ECHO in the identification of potential responders to CRT was excellent (Cohen kappa = 0.94).VENC MR measurements of IVMD are equivalent to PW-ECHO measurements and can be used to identify potential responders to CRT.

Background Recent studies have shown that cryoablation and radiofrequency (RF) ablation are comparable with regard to success rates and safety in the treatment of common atrial flutter (AFL). Long-term success requires persistence of bidirectional conduction block (BCB) in the inferior cavotricuspid isthmus (CTI). Objective The purpose of this study was to determine the persistence of BCB in a prospective randomized multicenter trial of the two ablation techniques. Methods A total of 191 patients were randomized to RF ablation or cryoablation of the CTI using an 8-mm-tip catheter. In all patients, BCB was defined as the ablation end-point. Primary end-point of the study was nonpersistence of achieved BCB and/or ECG-documented relapse of common AFL within 3-month follow-up. Results Acute success rates were 91% (83/91) in the RF group and 89% (80/90) in the cryoablation group (P = NS). Invasive follow-up after 3 months with repeated electrophysiologic study was available for 60 patients in the RF group and 64 patients in the cryoablation group. Persistent BCB could be confirmed in 85% of the RF group versus 65.6% of the cryoablation group. The primary end-point was achieved in 15% of the RF group and 34.4% of the cryoablation group (P = .014). As a secondary end-point, pain perception during ablation was significant lower in the cryoablation group (P Conclusion Persistence of BCB in patients treated with cryoablation reinvestigated after 3 months is inferior to that patients treated with RF ablation, as evidenced by the higher recurrence rate of common AFL seen in this study.

External cardioversion is an established and very important tool to terminate symptomatic atrial flutter. The superiority of the biphasic waveform has been demonstrated for atrial flutter, but whether electrode position affects the efficacy of cardioversion in this population is not known. The aim of this trial was to evaluate whether anterior-lateral (A-L) compared with anterior-posterior (A-P) electrode position improves cardioversion results. Of 130 screened patients, 96 (72 men, mean age 62 +/- 12 years) were included and randomly assigned to a cardioversion protocol with either A-L or A-P electrode position. In each group, 48 patients received sequential biphasic waveform shocks using a step-up protocol consisting of 50, 75, 100, 150, or 200 J. The mean energy (65 +/- 13 J for A-L vs 77 +/- 13 J for A-P, p = 0.001) and mean number of shocks (1.48 +/- 1.01 for A-L vs 1.96 +/- 1.00 for A-P, p = 0.001) required for successful cardioversion were significantly lower in the A-L group. The efficacy of the first shock with 50 J in the A-L electrode position (35 of 48 patients [73%]) was also highly significantly greater than the first shock with 50 J in the A-P electrode position (18 of 48 patients [36%]) (p = 0.001). In conclusion, the A-L electrode position increases efficacy and requires fewer energy and shocks in external electrical cardioversion of common atrial flutter. Therefore, A-L electrode positioning should be recommended for the external cardioversion of common atrial flutter.

Background: Predictors for recurrence of syncope are lacking in patients with vasovagal syncope. The aim of this study was to identify risk factors for recurrence of syncope and develop a simple prognostic risk score of clinical value. Methods: Two hundred seventy-six patients with a history of vasovagal syncope were prospectively followed for 2 years. Diagnosis of vasovagal syncope was based on clinical history and negative standard work-up. Inclusion in the study was independent from the result of the head-up tilt test, which was performed in all cases. Risk factors for syncope recurrence were evaluated by the Cox proportional hazards regression model and implemented in a risk score, which was validated with the log-rank test and an internal cross-validation. Results: The Cox-regression analysis identified the number of previous syncopal events, history of bronchial asthma, and female gender as predictors for syncope recurrence (all P < 0.05). In contrast, head-up tilt test response had no predictive value (P = 0.881). Developing a risk score, study patients were identified as having high (recurrence rate during 2 years of follow-up: 37.2%), intermediate (24.8%), and low (6.5%) risk for syncope recurrence (receiver operating characteristic [ROC] of score 0.83, P < 0.01; Log-rank test for event-free survival, P < 0.005). Conclusions: In patients with vasovagal syncope, risk of recurrence can be stratified and is predictable based on a simple risk score.

Aims Beneficial effects of atrial fibrillation (AF) ablation have been demonstrated in patients with congestive heart failure (CHF) and significantly impaired left ventricular ejection fraction (LVEF). However, the impact of pulmonary vein isolation (PVI) on cardiac function in patients with paroxysmal AF and impaired LVEF remains under discussion. This study aimed to evaluate the impact of PVI for paroxysmal AF on cardiac function in patients with impaired LVEF using cardiac magnetic resonance imaging (CMRI). Methods and results A total number of 70 patients with paroxysmal AF and episodes � 24 h were scanned on a 1.5-T-CMRI before and 6 months after PVI during sinus rhythm. End-diastolic volume, end-systolic volume, and LVEF were determined by epicardial and endocardial measurements. Patients were categorized into two groups regarding cardiac function as assessed by CMRI: group 1 patients (n ¼ 18) with an LVEF , 50% and patients with an LVEF . 50% (group 2, n ¼ 52). Group 1 patients demonstrated a significant lower success rate than patients of group 2 after a follow-up of 152+ 40 days (50 vs. 73%, P , 0.05). Cardiac magnetic resonance imaging in group 1 patients demonstrated a significant improvement in cardiac function after AF ablation (41+ 6v s. 51+ 12%, P ¼ 0.004), whereas group 2 patients did not show significant differences (60+ 6v s. 59+ 9%, P ¼ 0.22) after a 6 months follow-up. Conclusion Pulmonary vein isolation improves cardiac function in patients with paroxysmal AF and impaired LVEF. These data suggest that an impaired LV function can be partially attributed to AF with short-lasting paroxysms.

Aims Rhythm follow-up after catheter ablation of atrial fibrillation (AF ablation) is mainly based on Holter electrocardiogramm (ECG), tele-ECG or on patients symptoms. However, studies using 7-day Holter or tele-ECG follow-up revealed a significant number of asymptomatic recurrences. Thus, the aim of this study was to analyse continuous atrial recordings in pacemaker patients with an incorporated Holter function before and after AF ablation in order to determine all AF recurrences and thereby the ‘real’ success rates. Methods and results The study comprised 37 patients (64.6 ± 10 years) with prior pacemaker/implantable cardioverter defibrillator (ICD) implantation including an atrial Holter function referred for AF ablation. Holter data were obtained and correlated to patients’ symptoms before and every 3-month after AF ablation. AF recurrence was defined as an atrial high frequency episode of less than 330 ms (180 b.p.m.) lasting longer than 30 s. The ablation procedure consisted of pulmonary vein isolation (PVI) in patients with paroxysmal atrial fibrillation (PAF, n = 20) and additional substrate modification aiming arrhythmia termination in patients with persistent or inducible AF after PVI as well as in patients with a history of long-lasting persistent AF (PersAF, n = 17). The mean atrial Holter monitoring period was 7.4 ± 3.3 months before and 13.5 ± 4.2 months after ablation with an overall AF burden of 33.7% prior to ablation. During follow-up, AF burden decreased from 17.3–0.65% ( P = 0.001) in PAF patients and from 57.4 to 13.9% ( P = 0.024) in patients with PersAF. Complete AF freedom was observed in 85% (17 patients) of PAF patients and 59% (10 patients) in patients with PersAF. The absence of symptoms correlated well with documented freedom of AF. Conclusion In the present study we could show, that freedom from AF can be achieved by catheter ablation in a high percentage of patients even with PersAF. Continuous atrial monitoring reveals AF ablation success rates comparable with those assessed by clinical evaluation. Symptomatic freedom of AF correlated well with the actual freedom of AF at least in this highly symptomatic patient cohort.

AP localization can be predicted by analyzing the polarity of the delta wave, QRS polarity, and R/S ratio in patients with Wolff-Parkinson-White syndrome. However, the estimation of AP location is limited in patients with concealed pathways during atrioventricular reentrant tachycardias (AVRT). Thus, we analyzed retrograde P-wave polarity during orthodromic AVRT and developed an algorithm to predict the localization of concealed accessory pathways (AP).A total number of 131 patients with a single AP and inducible orthodromic AVRT were included. The initial 61 patients were analyzed retrospectively for algorithm development, whereas 70 patients were evaluated prospectively. The retrograde P-wave polarity was analyzed by subtracting the superimposing T-wave during orthodromic AVRT using custom-designed software. Four leads of the surface electrocardiogram (ECG) were identified to accurately distinguish AP locations assigned to four different regions around each AV annulus: I, aVR, aVL, and V(1). Lead V(1) was used to differentiate right (negative or isoelectric) from left (solely positive) APs. Retrograde P-wave in lead I was negative in left posterior APs exclusively and became more positive with an AP location shifting towards right anterior. P-wave polarity in lead aVR demonstrated a shift from a positive polarity from left APs to isoelectric in right APs. The opposite direction (shift from positive to isoelectric) was observed for lead aVL. The subsequently developed algorithm for concealed AP localization using these surface ECG leads demonstrated a high sensitivity, specificity, and positive predictive value particularly for common AP localizations (left posterior and inferior, and right septal) when applied in a prospective fashion.Concealed AP localization can be accurately predicted by the analysis of retrograde P-wave polarity during orthodromic AVRT using the algorithm derived from the presented study.

Our purpose was to investigate the impact of short-lasting atrial fibrillation (AF) on the electrophysiological properties of the atria and pulmonary veins (PVs) in patients devoid of AF.The presence of AF is associated with electrical remodeling processes that promote a substrate for arrhythmia maintenance in the atria, which has been termed "AF begets AF." However, it is unclear whether those electrical alterations also occur in the PVs.Thirty-five patients with a left-sided accessory pathway and without a prior history of AF were included. After successful ablation, the effective refractory periods (ERPs) and conduction times of the right atrium (RA), left atrium (LA), and the PVs were determined. Afterwards, AF was induced and maintained for a period of 15 min. Thereafter, the stimulation protocol was repeated.At baseline, the PVs had significantly longer ERPs than the atria. After exposure to AF, the ERPs of both the atria and the PVs decreased significantly. The ERPs of the PVs, however, decreased by a significantly greater extent than the ERPs of the atria (PVs: 248 +/- 27 ms vs. 211 +/- 40 ms, p0.001; LA: 233 +/- 23 ms vs. 214 +/- 20 ms, p = 0.004; RA: 226 +/- 29 ms vs. 188 +/- 20 ms; p = 0.003). After AF exposure, the PVs demonstrated a significant conduction slowing whereas the atria did not (PVs: 125 +/- 33 ms vs. 159 +/- 37 ms, p0.001; LA: 129 +/- 26 ms vs. 130 +/- 24 ms, p = NS; RA: 192 +/- 36 ms vs. 196 +/- 32 ms, p = NS). Finally, AF was more frequently induced after the presence of AF, particularly by pacing in the PVs (14% vs. 49%, p = 0.001).New-onset, short-lasting AF creates electrical characteristics similar to those of patients with AF. However, these alterations are pronounced in the PVs compared with the atria, indicating that "AF begets AF in the PVs" (Electrophysiological Properties of the Pulmonary Veins; NCT00530608).

External cardioversion is effective to terminate persistent atrial flutter. Biphasic shocks have been shown to be superior to monophasic shocks for ventricular defibrillation and atrial fibrillation cardioversion. The purpose of this trial was to compare the efficacy of rectilinear biphasic versus standard damped sine wave monophasic shocks in symptomatic patients with typical atrial flutter.135 consecutive patients were screened, 95 (70 males, mean age 62 +/- 13 years) were included. Patients were randomly assigned to a monophasic or biphasic cardioversion protocol. Forty-seven patients randomized to the monophasic protocol received sequential shocks of 100, 150, 200, 300 and 360 J. Forty-eight patients with the biphasic protocol received 50, 75, 100, 150 or 200 J.First-shock efficacy with 50-Joule, biphasic shocks (23/48 patients, 48%) was significantly greater than with the 100-Joule, monophasic waveform (13/47 patients, 28%, p = 0.04). The cumulative second-shock efficacy with the 50- and 75-Joule, biphasic waveform (39/48 patients, 81%) was significantly greater than with the 100- and 150-Joule, monophasic waveform (25/47 patients, 53%, p0.05). The cumulative efficacy for the higher energy levels showed naturally no significant difference between the two groups. The amount of the mean delivered energy was significantly lower in the biphasic group (76 +/- 39 J) compared to the monophasic one (177 +/- 78 J, p0.05).For transthoracic cardioversion of typical atrial flutter, biphasic shocks have greater efficacy and the mean delivered current is lower than for monophasic shocks. Therefore, biphasic cardioversion with lower starting energies should be recommended.

Aims In the setting of right ventricular outflow tract-tachycardia (RVOT-T), data about long-term follow-up (FU) with respect to the therapeutic strategies are missing. All patients (pts) referred to our institution during the last 20 years for the treatment of RVOT-T were studied in a retrospective analysis to assess mortality and efficacy of treatment. Methods and results One hundred and thirty-three patients (77 female; 39 ± 13 years) with sustained RVOT-T were included in this study. At the time of first presentation, diagnosis of RVOT-T was made by complete invasive and non-invasive diagnostic assessment, including electrophysiology study and two-dimensional echocardiography. After 135 ± 68 months (median 136, range 29–248), patients were invited to undergo clinical assessment. Of the 133 pts, 127 (95%) survived and six (5%) died from non-cardiac disease. Anti-arrhythmic (AA) drugs were given to 62 of the 133 pts (47%); of them 32 (52%) had recurrences during follow-up. The mean time to recurrence was 10.02 years (95% CI 7.46–12.59). The other 71 study patients (53%) underwent catheter ablation. The procedure was successful in 58 pts (82%). During follow-up, 30 (52%) of the 58 successfully treated patients had recurrences of RVOT-T. The mean time to recurrence was 6.28 years (95% CI 4.96–7.6). RVOT-T recurrences were similar in morphology to those treated previously in 33% and different in 67% of cases. Conclusions Long-term follow-up in patients with RVOT-T is favourable. Catheter ablation is effective in this setting. However, late recurrences with similar or different morphology may arise in half of the patients after initially successful treatment. AA drug therapy is a valid initial therapeutic option, since it is effective in about half of the patients.

Background The accuracy of three-dimensional mapping systems is affected by cardiac contraction and respiration. Objective The study sought to determine relative motion of cardiac and thoracic structures to assess positional errors and guide the choice of an optimized spatial reference. Methods Motion of catheters placed at the coronary sinus (CS), pulmonary vein (PV) ostia, left atrial (LA) isthmus and roof, cavotricuspid isthmus (CTI), and right atrial appendage (RAA) were recorded for 30 patients using Ensite-NavX. The right subclavian vein, left brachiocephalic vein, azygos vein, pulmonary arteries, and a static reference were included. The displacement from a mean position was calculated for each pair of sites. Respiration effects were assessed by the shift of the motion curve during in- and expiration phases. Results The PVs showed a mean interpair displacement of 4.1 ± 0.2 mm and a shift of 5.0 ± 0.5 mm. Proximal CS references for all LA structures (4.0 ± 1.1 mm) were superior to the static reference (4.9 ± 0.7 mm; P = .01). In addition, the shift due to respiration was less pronounced at 3.5 ± 0.8 mm versus 4.9 ± 0.5 mm ( P = .004), respectively. Motion of extracardiac vessels was influenced by a mean shift of 6.8 ± 1 mm. The remote subclavian and brachiocephalic veins were more affected (7.6 ± 0.7 mm) than the pulmonary arteries (5.9 ± 0.4 mm; P = .002). For the CTI, a minimized mean displacement of less than 4.6 ± 2.0 mm relative to the proximal CS, RAA, and azygos vein was found. Conclusion Respiration is the major source of relative motion, which increases with distance from the heart. For LA procedures, a proximal CS reference position is superior to a static reference position.

Coronary artery disease (CAD) and erectile dysfunction (ED) of vascular origin are closely related and share common risk factors. The endogenous NO synthase inhibitor asymmetrical dimethylarginine (ADMA) has recently been identified as an independent risk marker for cardiovascular disease and it was the purpose of the present study to investigate the role ADMA in ED with and without underlying CAD.We determined plasma ADMA levels in 132 men with ED. Patients were divided into a group of 56 men with underlying CAD (ED-CAD) and a group of 76 men without clinical evidence for underlying CAD (ED-No-CAD). Diagnosis of ED was based on the International Index of Erectile Function Score (IIEF-5). Plasma ADMA concentrations in the ED-CAD group were elevated as compared to the ED-No-CAD group, median (IQR): 0.76 (0.65-0.91) micromol/l ADMA vs. 0.49 (0.36-0.71) micromol/l, p0.001. In a multiple logistic regression analysis adjusting for hypertension, hypercholesterolemia, low HDL cholesterol and diabetes or fasting glucoseor =6.1 mmol/l, ADMA remained a strong and independent predictor for presence of CAD. Odds ratios for second and third tertiles as compared to lowest tertile of plasma ADMA were 3.3 (95%CI, 1.1-10.3; p = 0.041) and 8.7 (95%CI, 2.8-27.2; p0.001), respectively.As elevation of ADMA has been found to be associated with many risk factors for both CAD and ED, our data provide further strong evidence for the close interrelation of CAD and ED. Determination of ADMA may help to identify underlying cardiovascular disease in men with ED.

Navigation System for Ablation of Typical AFL. Introduction: Ensite® NavX (NavX) is a novel mapping and navigation system that allows visualization of conventional catheters for diagnostic and ablative purposes and uses them to create a three-dimensional (3D) geometry of the heart. NavX is particularly suitable for ablation procedures utilizing an anatomic approach, as in the setting of common-type atrial flutter (AFL). The aim of this study was to compare NavX-guided and conventional ablation procedures for AFL. Methods and Results: Forty consecutive patients (32 male, 59 ′ 12 years) with documented AFL were randomized to undergo fluoroscopy-guided (group I, 20 patients) or NavX-guided (group II, 20 patients) ablation, including 3D isthmus reconstruction. The same catheter setup was used in both groups. The endpoint of bidirectional isthmus block was obtained in all patients. Compared to conventional approaches, NavX-guided procedures significantly reduced fluoroscopy time (5.1 ′ 1.4 min vs 20 ′ 11 min, P < 0.01) and total x-ray exposure (5.1 ′ 3.1 Gycm 2 vs 24.9 ′ 1.6 Gycm 2 , P < 0.01). Isthmus geometry reconstruction could be performed in all patients of group II. In 4 patients (20%) of group II, anatomic isthmus variations were detected by NavX. No significant differences in radiofrequency current applications and procedural times were found between the two groups. Conclusion: NavX technology allows geometry reconstruction of the cavotricuspid isthmus. NavX-guided ablation of AFL reduces total x-ray exposure compared to the fluoroscopy-guided approach but does not prolong procedure time.

The most widely accepted criterion for successful radiofrequency catheter (RFC) ablation of typical atrial flutter is the development of bi-directional isthmus block. In a subset of patients, conventional RFC ablation fails to achieve this endpoint because deeper and wider lesions are required. We investigated the efficacy of a long 8-mm tip catheter in these cases. One hundred and seventy-four consecutive patients (137 male; 61 +/- 9 years) with recurrent typical atrial flutter underwent conventional RFC ablation first with a standard 4 mm tip catheter. In resistant cases (n = 52), ablation was continued using a large tip 8-mm catheter when the 4-mm tip catheter failed. Resistant atrial flutter was identified when 21 RFC pulses failed to reach the selected endpoint of bi-directional isthmus block or in cases of transient bi- directional block (at least 3 episodes). In 122 of the 174 patients (70%) conventional atrial flutter ablation was successfully performed with 13 +/- 5 RFC applications. In the remaining 52 subjects (30%), the ablation procedure was completed using the large tip electrode catheter. In 30 of these 52 patients (58%), the catheter was changed because of persistent intra-atrial conduction after 21 RFC pulses and in 22 (42%) because of intermittent conduction block after 11 +/- 5 applications. Using the large tip electrode catheter, the selected endpoint was achieved in all patients of both groups with 3 +/- 2 RFC pulses (power output of 50-60 W, pulse duration of 60 sec). No post-procedure complications were observed. After 15 +/- 5 months of follow-up, 16 patients (9%) had recurrence of atrial flutter. Five of the patients had been in the resistant group. In patients with atrial flutter resistant to conventional ablation therapy, the long tip (8-mm) catheter appears to be a safe and effective alternative to use of the conventional 4-mm tip catheter.

Syncope is a common clinical condition,1 which for obvious reasons constitutes a very drastic form of driving impairment. The legislative and expert panels in most countries have therefore issued laws or guidelines regarding driving and syncope.2–4 So far, however, little is known about the impact of driving recommendations on the behaviour of patients or the incidence of traffic crashes. All patients referred to us for investigation of syncope who hold a driving licence are routinely given verbal advice on driving by the physician doing the diagnostic work up. From February 1998 until June 2000 we conducted an anonymous survey among these patients. The survey was based on self reporting and consisted of two short structured interviews about history of syncope, driving, and crashes. We did the first interview on the day of head-up tilt table testing, and …

This study evaluated the incidence of atrial premature beats (APBs) and the impact of various provocative maneuvers in patients with focally initiated AF. Fifty patients (39 men, 57 +/- 0.4 years) with focally initiated, paroxysmal AF underwent Holter recording and a standardized protocol of provocative maneuvers: vagomechanical stimulation, adenosine 12 mg i.v., esmolol 500 ng/kg i.v., orciprenaline i.v. 5 mg/50 mL saline 0.9%, and atropine 0.01 mg/kg i.v. A surface ECG was recorded for 20 minutes at baseline and following each part of the protocol. High focal activity was defined asor = 1 APB/minute. During Holter ECG, 29 (58%) patients had an amount of200 APBs, 12 (24%) patients700or = 200, and 9 (18%) patientsor = 700 APBs. Less than 1 hour of high focal activity was observed in 34 (68%) of the 50 patients. Before starting provocative maneuvers 15 (30%) patients had high focal activity whereas 35 (70%) presented1 APB/minute. In 29 (58%) patients APBs increased byor = 1/min during provocative maneuvers: by vagomechanical stimulation in 11 patients, after adenosine in 15, esmolol in 12, orciprenaline in 15, and after atropine in 9 patients. In all patients withor = 1 APB/min at baseline, focal activity decreased or disappeared during some single provocative maneuvers. AF occurred in eight patients under provocative maneuvers. No predictive factors of a successful provocative maneuver were detected with regard to the baseline patients characteristics and Holter results. In conclusion, patients with focally initiated AF have a low incidence of spontaneous APBs. Various provocative maneuvers successfully increase APBs in more than half of the patients; orciprenaline had the highest efficacy. Some provocative maneuvers may suppress APBs in the setting of high focal activity at baseline.

Isolation of arrhythmogenic pulmonary veins (PVs) by radiofrequency current (RF) application has been introduced as a curative treatment for patients (pts) with paroxysmal atrial fibrillation (AF). The present study sought to investigate the feasibility and efficacy of this approach guided by conventional and electroanatomical mapping (CARTO).Twenty pts (13 male; 57 +/- 8 years) with recurrent documented focally triggered idiopathic AF refractory to multiple antiarrhythmic drugs were prospectively included. Atrial premature beats were present at baseline in 9 pts and could be provoked in further 8 pts. Empirical ablation of both superior PVs was performed in 3 pts with no focal activity. After transseptal puncture selective angiography of all PVs was obtained. Thirty-six PVs (left superior: n = 18, right superior: n = 10, left inferior: n = 8) were targeted for RF ablation. A complete left atrial CARTO-map including the left atrial (LA) to pulmonary vein (PV) junction was obtained during sinus rhythm and/or coronary sinus pacing. RF was initially applied at the PV-LA junction at areas with the shortest left atrial- to PV potential interval (target 50 degrees C, max. 30 W, duration 60 sec). Isolation was confirmed by the complete disappearance of specific PV potentials. RF lesions were analyzed with respect to the number of segment-quarters covering the PV ostium.Functional isolation could be achieved in 35 out of 36 PVs following 10 +/- 5 RF applications for each PV. RF applications covered 2 or less quarter segments of the overall PV circumference in 29 (80%) PVs. Total session duration was 6.5 +/- 1.6 h with a mean fluoro-time of 54 +/- 18 minutes. For CARTO mapping and ablation a mean fluoro time of 34 +/- 6 min was required. During a mean follow up period of 8.3 +/- 2.5 months AF relapsed in 9 pts (46%). A second approach was performed in 5 pts. and demonstrated either new foci (n = 2) or recurrence of previously isolated PV (n = 8). The second RF ablation procedure led to stable sinus rhythm in 3 out 5 pts. Thus, the overall success rate including the second procedure was 70%.CARTO guided functional isolation of presumed arrhythmogenic PVs by RF lesions covering 2 or less segments of the PV ostium in most patients is feasible. However, repeat procedures are often warranted to permanently treat paroxysmal atrial fibrillation.

Intravenous coronary angiography with synchrotron radiation is a novel and minimally invasive technique for coronary imaging. At the Hamburger Synchrotronstrahlungslabor HASYLAB at DESY, a dedicated angiography system has been developed, which has been shown to provide detailed images of coronary artery segments. For each scan, two monochromatic X-ray images below and above the K-edge of iodine were recorded simultaneously. The two images were subtracted logarithmically to produce a maximal contrast enhancement of the iodine. To date, the procedure has been carried out on 379 outpatients. No complications occurred during or after the angiographic procedure, and hospitalization was not required in any subject. The acceptance by patient is extremely high. Five outside reviewers, blinded as to the clinical data or prior angiographic interpretation, reviewed the images for the presence or absence of 70% or more occlusion of a vessel. They reached a sensitivity of 79% and a specificity of 99%. The study has demonstrated that the synchrotron method has satisfactory sensitivity and very high specificity for severe stenoses. The new method has several advantages over magnetic resonance imaging (MRI), electron beam computed tomography (EBCT), and multi-slice computed tomography (MSCT). Neither vascular calcification (CT) nor the presence of metal stents (MRI) impairs the evaluation of perfusion of segments of the coronary arteries. Furthermore, the spatial resolution is three or four times higher using synchrotron angiography, and problems due to respiratory motion are eliminated.

The aim of this study was to assess the efficacy of lipophilic beta-blockers in preventing recurrent neurocardiogenic syncope and the value of head-up tilt test (HUT) in predicting response to therapy. The efficacy of beta-blockers in recurrent syncope is controversial. The value of HUT in predicting efficacy of therapy has not been investigated. Fifty-six patients (44+/-18 years, 36 women) with recurrent syncope (> 1 event in the last 6 months) of suspected neurocardiogenic origin were included in the study. Independent of the response to HUT, patients were randomized to receive metoprolol or propanolol at the maximal tolerated dose (28 patients, group A, 86+/-23 vs 98+/-29 mg/d) or no pharmacological therapy (28 patients, group B). The primary endpoint was the first recurrence of syncope. During the 1-year of follow-up, 20 patients of group A and 8 of group B had no recurrence. In group A, of 20 patients without recurrences 12 had a positive and 8 a negative HUT result while of 8 patients with recurrences 5 had a positive and 3 a negative response to HUT. In the group B, of 20 patients with recurrences 10 had a positive and 10 a negative HUT result while of 8 patients without recurrences 4 had a positive and 4 a negative response to HUT. In a multivariate Cox-regression analysis, medical therapy was the only independent factor for predicting recurrence of syncope (P = 0.004); HUT had no influence in this regard (P = 0.773). In conclusion, lipophilic beta-blockers appear efficacious in preventing recurrent syncope of suspected neurocardiogenic origin. The efficacy of therapy seems to be not predicted by HUT.

Aims The relationship between syncope and psychiatric disorders is little investigated. This study evaluated the prevalence of psychiatric diseases and prognostic outcome in patients with recurrent unexplained syncope. Methods and Results After an inconclusive standard diagnostic work-up for syncope, including head-up tilt testing, a psychiatric evaluation was offered to 50 consecutive patients with recurrent syncope. The evaluation was accepted by 26 patients (77% females, 36±16 years) and refused by 24 (63% females, 50±19 years). A psychiatric disorder was diagnosed in 21 (81%) patients: 12 had depression, four panic attacks, two general anxiety, and three a somatization disorder. Only five patients showed normal psychosocial function. Of the patients with psychiatric disorders four accepted psychiatric care, such as psychotherapy and/or pharmacotherapy; 17 patients refused treatment. During 6 months of follow-up no patient under psychiatric care had syncope, while all patients without psycho- or pharmacotherapy had recurrent syncopal events. In these patients the median of syncopal episodes was three in a 6 months interval before and after clinical assessment. Patients who refused both psychiatric evaluation and therapy continued to experience syncope as before. Conclusions In patients with recurrent unexplained syncope psychiatric alteration is common. However, patients seldom accepted a psychiatric evaluation and treatment.

Automatic threshold tracking in cardiac pacemakers allows ventricular capture verification and self-adaptive pacing output regulation. The Autocapture algorithm detects the evoked response (ER) signal immediately after the pacing pulse to verify the efficacy of ventricular pacing. Before hospital delivery, the ER sensitivity must be programmed individually so that the pacemaker detects the ER signal adequately without sensing lead polarization. The aims of the study were to assess the frequency of patients in whom Autocapture could be activated and whether the ER sensitivity had to be adjusted after hospital discharge. The study included 44 patients who received the VVIR pacemaker Regency SR+ (St. Jude Medical) connected to the model 1450 T pacing lead. ER signal, lead polarization, and ER sensitivity were evaluated before hospital discharge and 1, 3, and 6 months after implantation. The system recommended activating Autocapture in 42 of 44 patients. The mean ER signal was 8.4+/-1.2 mV at discharge, 9.0+/-3.9 mV at month 1, 8.9+/-4.9 mV at month 3, and 9.3+/-4.5 mV at month 6. Polarization was 1.0+/-0.1 mV at discharge, 1.1+/-0.5 mV at month 1, 1.1+/-0.2 mV at month 3, and 1.1+/-0.5 mV at month 6. Mean ER sensitivity was 3.7+/-1.8 mV at discharge, 4.0+/-1.8 mV after 1, 4.1+/-2.2 mV after 3, and 4.1+/-1.8 mV after 6 months. ER sensitivity could remain unadjusted in 14 patients. Programming to a less sensitive ER setting from 2.9+/-1.2 mV to 4.3+/-1.5 mV was possible in 21 patients. Programming to a more sensitive ER setting from 4.1+/-1.1 mV to 2.5+/-0.9 mV was required in nine patients because of the decrease of the ER signal. The automatic threshold tracking algorithm Autocapture could be activated in 95% of patients. Programming to more sensitive ER settings was recommended in 21% of the patients after hospital discharge. Therefore, ER signal and polarization must be checked at each follow-up, as a decrease in ER signal amplitude can make reprogramming of the ER sensitivity necessary. There is no risk for the patient if the ER is not sensed, as high voltage backup stimulation is present.

Electroanatomic vs Conventional Mapping for Atrial Flutter Ablation. Introduction: Three-dimensional electroanatomic (CARTO) activation mapping of the cavotricuspid isthmus can be helpful to guide atrial flutter ablation, but to date has not heen investigated in comparison to conventional strategies. The aim of the present study was to assess the efficacy of the CARTO navigation system, especially with respect to the fluoroscopy time required for successful atrial flutter ablation. Methods and Results: Eighty patients with recurrent common-type atrial flutter were randomly assigned to temperature-controlled radiofrequency (RF) catheter ablation, either guided by conventional criteria (group 1) or additionally oriented on electroanatomic mapping (group 2). In all patients, similar multipolar catheters were inserted into the coronary sinus and placed at the tricuspid annulus. respectively. In group 2, positioning of the mapping electrode and delivery of RF pulses within the cavotricuspid isthmus was mainly oriented on the CARTO map to achieve the most linear and continuous RF lesions. Abolition of intra-atrial conduction verified by conventional criteria (group 1) and electroanatomic mapping (group 2) could be verified in all patients. The overall number of RF pulses (group 1: 16.7 ± 6.5; group 2: 13.2 ± 5.3) and mean procedure duration (group 1: 172.5 ± 47.4 min; group 2: 169.3 ± 47.3 min) were not different between the two groups, but mean fluoroscopy time was significantly shorter when the CARTO tecbnology was used (group 1: 29.2 ± 9.4 min; group 2: 7.7 ± 2.8 min; F = 0.0001). Recurrence of atrial flutter was observed in 3 (9%) patients in each group after a mean follow-up of 8.5 ± 2.months. Conclusion: Atrial flutter can be abolished effectively using the conventional technique as well as oriented on electroanatomic mapping. However, overall X-ray exposure can he significantly reduced by the CARTO-guided approach without prolongation of procedure duration.

The Autocapture function controls and optimizes the output of the ventricular pulse amplitude automatically. For this reason an automatic test has to be performed during follow-up to measure the evoked response signal and lead polarization for the calculation of the appropriate evoked response sensitivity setting. The aim of the study was to assess whether body position and exercise influence the evoked response and polarization. Both parameters were determined in the supine and upright position and subsequently during supine and upright symptom-limited ergometry. The study included 14 patients with the VVIR pacemaker Regency SR+ who had received the ventricular pacing leads Membrane E 1450 T (n = 8), CapSure Z 5034 (n = 4), or SX 60 (n = 2). The evoked response signal was 7.4 +/- 3.3 mV during supine and increased to 9.7 +/- 5.6 mV (+35%) during upright position (P < 0.05). The exercise tests were terminated at 105 +/- 36 W (supine) and 110 +/- 34 W (upright). There was a gradual insignificant decrease of the evoked response during each exercise test with a mean decrease of -1.1 +/- 0.9 mV (-15%; supine) and -1.6 +/- 2.1 mV (-16%; upright). The evoked response increased within 5 minutes during recovery to the initial values. Polarization remained unchanged during both tests. The pacemaker did not recommend activating autocapture in four patients who all had received high-ohmic pacing leads. In conclusions, the measurement of the evoked response in supine position seems to represent the worst case. Physical activities did not effect autocapture function in patients with the recommended lead, but the pacemaker did not always recommend Autocapture activation in some patients with high-ohmic pacing leads.

Pulmonary vein (PV) isolation for the treatment of atrial fibrillation is limited by procedure related complications, such as PV stenosis and occlusions. We report about a PV isolation using a circumferential cryoablation catheter which applies the ablation energy simultaneously at the entire circumference by cooling down to a minimal temperature of −80°C. (PACE 2004; 27:1024–1025)