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We present a case study article demonstrating successful implementation of ultrasound guided extra cardiac vagus nerve stimulation during cardioneuroablation. To our knowledge it is first published description of this technique, as most ECVS are done in the internal jugular vein bulb area. This method allows for reduction of fluoroscopy time, and most importantly reproducible vagus nerve capture especially after full bi-nodal (sinus and atrioventricular) cardioneuroablation when stimulation of vagus nerve may not give any effect in the heart. This article includes a case study with “dual component” atrioventricular block, where functional component is cured with cardioneuroablation, but structural (PR elongation) remains after procedure.

Background: Predictors of long‑term outcomes and an optimal catheter set for ablation of the cavotricuspid isthmus in patients with atrial flutter (AFL) are not well known. Aims: This study aimed to identify predictors of clinical events following ablation. Methods: We studied 741 patients (mean [SD] age, 62.2 [10.8] years; 248 women) who were followed for a mean (SD) time of 4.4 (2.7) years. The 2- versus 3‑electrode approach and clinical predictors ofclinical events during follow‑up were analyzed. Results: The 2‑electrode approach was faster (mean [SD] time, 62.5 [30.3] vs 101.4 [51] min; P < 0.001), associated with shorter fluoroscopy time (13.1 [9.3] vs 20.3 [12.4] min; P < 0.001), cost‑effective (8.29 [2.82] vs 11.89 [2.51] units; P < 0.001), and more effective (92.1% vs 86.1%; P = 0.012). The independent predictors of AFL recurrence were: calcium blocker use (hazard ratio [HR], 3.24; 95% CI, 1.64–6.4), mitral valve disease (HR, 1.82; 95% CI, 1.12–2.95), previous stroke and/ or TIA (HR, 2.38; 95% CI, 1.21–4.65), pulmonary artery dilatation (HR, 3.94; 95% CI, 1.22–12.73), and previous pulmonary embolism (HR, 3.77; 95% CI, 1.14–12.43); of atrial fibrillation (AF): previous AF (HR, 6.054; 95% CI, 4.58–8), left atrial enlargement (HR, 1.43; 95% CI, 1.12–1.81), number of antiarrhythmic drugs used (HR, 1.16; 95% CI, 1.05–1.28), and mitral valve disease (HR, 1.28; 95% CI, 1.04–1.58); of pacemaker implantation: tachycardia‑bradycardia syndrome (HR, 6.17; 95% CI, 3.16–12.05), previous second-/third‑degree atrioventricular block (HR, 29.4; 95% CI, 7.37–117.28), centrally acting hypotensive drugs (HR, 29.55; 95% CI, 6.14–142.25), aortic dilatation or aneurysm (HR, 2.58; 95% CI, 1.06–6.3), a labile international normalized ratio (HR, 3.45; 95% CI, 1.72–6.93), left bundle branch block (HR, 4.7; 95% CI, 1.49–14.82), the shortest R‑R interval during AFL (HR, 1.003; 95% CI, 1.001–1.005), previous cardiac surgery (HR, 2.69; 95% CI, 1.27–5.7), and aortic valve disease (HR, 2.22; 95% CI, 1.08–4.59). Conclusion: Ablation of cavotricuspid isthmus with a minimal number of electrodes is safe and effective. Specific predictors of clinical events during long‑term follow-up can be determined.

Introduction: Atrioventricular nodal reentrant tachycardia (AVNRT) is one of the most common regular supraventricular arrhythmias referred for catheter ablation (CA). In Poland, several families with familial AVNRT (FAVNRT) were reported in Podkarpacie Province (PP). Objectives: We aimed to determine the frequency of FAVNRT in PP compared with other south-eastern provinces of Poland. Patients and methods: Clinical data of 1544 patients with AVNRT diagnosed by invasive electrophysiological study between 2010 and 2019 were screened for FAVNRT. From January 2017 to June 2019, patients were asked to provide details on family history and origin to obtain 3-generation pedigrees. Families with at least 2 members with previous CA of AVNRT were divided into those from south-eastern provinces (SEPs; including PP and bordering provinces [BPs]) and the remaining parts of Poland (RPP). Results: There were 932 patients from SEPs and 612 from RPP. FAVNRT was reported in 45 patients (2.91%) from 27 families, with a higher frequency in SEPs than RPP (4.02% vs 1.17%; P = 0.002) and the highest frequency in PP (6.33% vs 2.47% in BPs; P = 0.004). The risk of FAVNRT was higher in PP compared with BPs (odds ratio, 2.67; 95% CI, 1.36–5.23; P = 0.004) and similar in BPs compared with RPP (odds ratio, 2.14; 95% CI, 0.86–5.34; P = 0.1). Conclusions: A relationship exists between the geographic region and frequency of FAVNRT. A greater distance from PP was associated with less frequent FAVNRT. International cooperation and genetic testing are needed to confirm the genetic impact of FAVNRT in this part of Central Europe.

Funding Acknowledgements Type of funding sources: None. OnBehalf Rare-A-Care registry Background Extracardiac vagal nerve stimulation (ECANS) and cardioneuroablation (CNA) are promising methods to cure vagally mediated bradycardia and validate indications for permanent pacing for sinus node dysfunction (SND), atrioventricular blocks (AVB), tachycardia-bradycardia syndrome (TBS) and cardio-inhibitory or mixed reflex syncope (VVS). There are limited information on clinical utility of those procedures in validation of indication for continuation of permanent pacing (PM) and transcutaneous lead extraction (TLE). Methods Data were collected from prospective multicentre registry of CNA facilitated by interdisciplinary consultations, state-of-art autonomic tests, atropine/propranolol tests, electrophysiologic study as well as ECANS. Share-decision making were used by EP-HEART-TEAM to developed patient-oriented therapy. Results Between June 2018-Jan 2021 the first 102 consecutive patients underwent interdisciplinary approach before invasive EPS and/or invasive ECANS, to consider biatrial, binodal CNA, if possible to cure functional bradycardia. Eleven (10%) patients had implanted permanent PM"s due to SND/AVB/TBS/CI-VVS and were considered for TLE. In 2 out of 11 cases CNA was not performed due to: 1) structural advanced 2nd and 3rd degree AVB with indication for TLE and permanent HBP (no.1), 2) incidental severely symptomatic persistent 3rd degree AVB more than 15 year ago without any further bradycardia episodes (only TLE, no.2). In further 9 of 11 cases with PM CNA was performed, however TLE was not attempted in 2 patients [(SND + PVC ablation + indication for beta-blocker therapy due to IHD in older male. TLE had not yet been attempted to confirm long-term success therapy by patient and/or physician (no.3); two periprocedural successful CNA resulted in disappearance of CI reflex however despite pacing syncopal events persist due to mixed etiology (no.4)]. In further 7/11 cases TLE-s were performed. Three cases had TLE prior to CNA [VVS-CI + advanced functional AVB - prior 3 pacemaker reimplantations and further "rescue" CNA, (no.5); CI-VVS + pacemaker infection (no.6); TLE of PM + TBS no.7]. Finally, in 4 cases TLE was recommended after CNA [CI-VVS (no.8, no.9 and no.10); mixed etiology: TBS + VVS-CI + intermittent, recurrent pericardial efffusion due to lead perforation, PM syndrome, (no. 11)]. Conclusions Interdisciplinary and comprehensive autonomic approach with ECANS and CNA enable EP-HEART-TEAM to offer patient-oriented therapy with a complex clinical scenarios before final decision about TLE and discontinuation of permanent pacing therapy.

Complete elimination of fluoroscopy during radiofrequency ablation (RFA) of idiopathic ventricular arrhythmias (IVAs) originating from the aortic sinus cusp (ASC) is challenging. The aim was to assess the feasibility, safety and a learning curve for a zero-fluoroscopy (ZF) approach in centers using near-zero fluoroscopy (NOX) approach in IVA-ASC. Between 2012 and 2018, we retrospectively enrolled 104 IVA-ASC patients referred for ZF RFA or NOX using a 3-dimensional electroanatomic (3D-EAM) system (Ensite, Velocity, Abbott, USA). Acute, short and long-term outcomes and learning curve for the ZF were evaluated. ZF was completed in 62 of 75 cases (83%) and NOX in 32 of 32 cases (100%). In 13 cases ZF was changed to NOX. No significant differences were found in success rates between ZF and NOX, no major complications were noted. The median procedure and fluoroscopy times were 65.0 [45–81] and 0.0 [0–5] min respectively, being shorter for ZF than for NOX. With growing experience, the preference for ZF significantly increased—43% (23/54) in 2012–2016 vs 98% (52/53) in 2017–2018, with a simultaneous reduction in the procedure time. ZF ablation can be completed in almost all patients with IVA-ASC by operators with previous experience in the NOX approach, and after appropriate training, it was a preferred ablation technique. The ZF approach for IVA-ASC guided by 3D-EAM has a similar feasibility, safety, and effectiveness to the NOX approach.

Background: Implantable cardioverter-defibrillator (ICD) therapy has been proven effective in the prevention of sudden cardiac death, but data on outcomes of ICD therapy in the young and otherwise healthy patients with long QT syndrome (LQTS) are limited. Aim: We sought to collect data on appropriate and inappropriate ICD discharges, risk factors, and ICD-related complications. Methods: All LQTS patients implanted with an ICD in 14 centres were investigated. Demographic, clinical, and ICD therapy data were collected. Results: The study included 67 patients (88% female). Median age at ICD implantation was 31 years (12–77 years). ICD indication was based on resuscitated cardiac arrest in 46 patients, syncope in 18 patients, and malignant family history in three patients. During a median follow-up of 48 months, 39 (58%) patients received one or more ICD therapies. Time to first appropriate discharge was up to 55 months. Inappropriate therapies were triggered by fast sinus rhythm, atrial fibrillation, and T-wave oversensing. No predictors of inappropriate shocks were identified. Risk factors for appropriate ICD therapy were: (1) recurrent syncope despite b-blocker treatment before ICD implantation, (2) pacemaker therapy before ICD implantation, (3) single-chamber ICD, and (4) noncompliance to b-blockers. In 38 (57%) patients, at least one complication occurred. Conclusions: ICD therapy is effective in nearly half the patient population; however, the rates of early and late complica­tions are high. Although the number of unnecessary ICD shocks and reimplantation procedures may be lowered by modern programming and increased longevity of newer ICD generators, other adverse events are less likely to be reduced.

AIM Left atrial (LA) fibrosis promotes atrial fibrillation (AF), may predict poor radiofrequency catheter ablation (RFCA) outcome, and may be assessed invasively using electroanatomical mapping (EAM). Speckle tracking echocardiography (STE) enables quantitative assessment of LA function. The aim was to assess the relationship between LA fibrosis derived from EAM and LA echocardiographic parameters as well as biomarkers of fibrosis in patients with AF. METHODS Sixty-six patients (64% males, mean age 56 ± 10) with nonvalvular AF treated with first RFCA were prospectively studied. Seventy-three percent of patients were in sinus rhythm at the time of examination. LA geometry, systolic, and diastolic function were assessed. In STE global, peak atrial longitudinal (PALS) and contractile (PACS) strain were calculated. LA stiffness index (LAs) - the ratio of E/e' to PALS - was assessed. The EAM of LA was build using Carto System before RFCA. Low amplitude potentials area (LAPA) was quantitatively analyzed and expressed as a percentage of LA surface using the cut-off

Patients with structural heart disease (SHD) are more difficult to ablate than those with a structurally healthy heart. The reason may be technical problems. We compared periprocedural data in unselected patients (including SHD group) recruited for zero-fluoroscopy catheter ablation (ZF-CA) of supraventricular arrhythmias (SVTs). Consecutive adult patients with atrioventricular nodal reentry tachycardia (AVNRT), accessory pathways (AP), atrial flutter (AFL), and atrial tachycardia (AT) were recruited. A 3-dimensional electroanatomical mapping system (Ensite Velocity, NavX, St Jude Medical, Lake Bluff, Illinois) was used to create electroanatomical maps and navigate catheters. Fluoroscopy was used on the decision of the first operator after 5 minutes of unresolved problems. Of the 1280 patients ablated with the intention to be treated with ZF approach, 174 (13.6%) patients with SHD (age: 58.2 ± 13.6; AVNRT: 23.9%; AP: 8.5%; AFL: 61.4%; and AT: 6.2%) were recruited. These patients were compared with the 1106 patients with nonstructural heart disease (NSHD) (age: 51.4 ± 16.4; AVNRT: 58.0%; AP: 17.6%; AFL: 20.7%; and AT: 3.7% P ≤ .001). Procedural time (49.9 ± 24.6 vs 49.1 ± 23.9 minutes, P = .55) and number of applications were similar between groups (P = 0.08). The rate of conversion from ZF-CA to fluoroscopy was slightly higher in SHD as compared to NSHD (13.2% vs 7.8%, P = .02) while the total time of fluoroscopy and radiation doses were comparable in the group of SHD and NSHD (P = .55; P = .48). ZF-CA is feasible and safe in majority of patients with SHD and should be incorporated into a standard approach for SHD; however, the procedure requires sufficient experience.

Background Supraventricular tachycardias induced by dual antegrade conduction via the atrioventricular (AV) node are rare but often misdiagnosed with severe consequences for the affected patients. As long-term follow-up in these patients was not available so far, this study investigates outcomes in patients with dual antegrade conduction in the AV node. Methods and results In this multicentre observational study, patients from six European centres were studied. Catheter ablation was performed in 17 patients (52 ± 16 years) with dual antegrade conduction via both AV nodal pathways between 2012 and 2018. Patients with the final diagnosis of a manifest dual AV nodal non-re-entrant tachycardia had a mean delay of the correct diagnosis of over 1 year (range 2–31 months). Two patients received prescription of non-indicated oral anticoagulation, two further patients suffered from inappropriate shocks of an implantable cardioverter defibrillator. In 12 patients, a co-existence of dual antegrade and re-entry conduction in the AV node was present. Mean fast pathway conduction time was 138 ± 61 ms and mean slow pathway conduction time was 593 ± 134 ms. Successful radiofrequency catheter ablation was performed in all patients. Post-procedurally oral anticoagulation was discontinued, without detection of cerebrovascular events or atrial fibrillation during a long-term follow-up of median 17 months (range 6–72 months). Conclusion This first multicentre study investigating patients with supraventricular tachycardia and dual antegrade conduction in the AV node demonstrates that catheter ablation is safe and effective while long-term patient outcome is good. Autonomic tone dependent changes in ante- vs. retrograde conduction via slow and/or fast pathway can challenge the diagnosis and therapy in some patients. Graphic abstract

Introduction Radiofrequency ablation (RFA) of outflow tract ventricular arrhythmia (VA) that originates from the aortic cusps can be challenging. Data on long‑ term efficacy and safety as well as optimal technique after aortic cusp ablation have not previously been reported. Objectives This aim of the study was to determine the short- and long‑ term outcomes after RFA of aortic cusp VA, and to evaluate aortic valve injuries according to echocardiographic screening. Patients and methods This was a prospective multicenter registry (AVATAR, Aortic Cusp Ventricular Arrhythmias: Long Term Safety and Outcome from a Multicenter Prospective Ablation Registry) study. A total of 103 patients at a mean age of 56 years (34-64) from the "Electra" Registry (2005-2017) undergoing RFA of aortic cusps VA were enrolled. The following 3 ablation techniques were used: zero‑fluoroscopy (ZF; electroanatomical mapping [EAM] without fluoroscopy), EAM with fluoroscopy, and conventional fluoroscopy‑ based RFA. Data on clinical history, complications after RFA, echocardiography, and 24‑ hour Holter monitoring were collected. The follow up was 12 months or longer. Results There were no major acute cardiac complications after RFA. In one case, a vascular access complication required surgery. The median (interquartile range [IQR]) procedure time was 75 minutes (IQR, 58-95), median follow‑ up, 32 months (IQR, 12-70). Acute and long term procedural success rates were 93% and 86%, respectively. The long‑ term RFA outcomes were observed in ZF technique (88%), EAM with fluoroscopy (86%), and conventional RFA (82%), without differences. During long‑ term follow‑up, no abnormalities were found within the aortic root. Conclusions Ablation of VA within the aortic cusps is safe and effective in long‑ term follow up. The ZF approach is feasible, although it requires greater expertise and more imaging modalities.

Background Acquired long QT syndrome (a-LQTS) is associated with life-threatening ventricular arrhythmias, mainly torsades de pointes (TdP). ECG parameters predicting evolving into ventricular fibrillation (VF) are ill defined. Aims To determine ECG parameters preceding and during TdP associated with higher risk of developing VF. Methods We analyzed 151 episodes of TdP, recorded in 28 patients with a-LQTS (mean QTc 638 ms ± 57). Results All 28 patients had prolonged QT interval, (mean QTc 638 ms ± 57) ranging from 502 ms to 858 ms correcting by Bazett's formula. The mean TdP heart rate was 218 bpm ± 38 (mean cycle length of TdP 274 ± 47 ms). We classified TdPs episodes into “slower”-TdP (s-TdP) 1. Macro T wave alternans was observed in 4 patients. The QT interval was not different in patients with VF(+) and VF(−) episodes, 633 ± 60 and 639 ± 57, respectively. Conclusions Some electrocardiographic parameters can be helpful in determining the risk of TdP evolving into VF. The slower ventricular rate ( 30 ms) and the short episodes < 20 beats could predict benign evolution.

We present the case of a young patient with dilated cardiomyopathy (DCM) and concomitant pulmonary tuberculosis (TB), emphasising the need for an interdisciplinary approach when considering underlying aetiology. A 36‐year‐old male was admitted to the hospital due to signs of acute heart failure (HF). After diagnostic work‐up, which included laboratory examination, echocardiography, and coronary angiography, a diagnosis of DCM was established and therapy was initiated. Despite optimal medical therapy for HF, the patient’s condition did not improve. During further diagnostic workup, pulmonary tuberculosis was identified. A significant reduction in HF signs and symptoms and improvement in left ventricular ejection fraction occurred only after TB was treated with 6 months of therapy. The presented case study illustrates the necessity to perform a complete diagnostic workup to identify reversible causes of DCM. JRCD 2019; 4 (2): 56-58.

The cardiac autonomic nervous system plays an important role in the genesis and maintenance of atrial fibrillation. Although, pulmonary vein isolation is the cornerstone in today’s approach to atrial fibrillation ablation, a considerable proportion of patients will recur with atrial arrhythmias following this procedure, especially in the non-paroxysmal forms. The pulmonary vein isolation indirectly targets and ablate the ganglionated plexi. This might ultimately enhance the efficacy of the procedure, but an optimal ablation strategy and a reliable method to confirm and quantify the efficacy of vagal denervation following the procedure might be necessary, thus leading to significantly better results.

Introduction Atrial fibrillation (AF) increases the risk of thromboembolic events by promoting clot formation in the left atrial appendage (LAA). Transesophageal echocardiography (TEE) is routinely used to exclude the presence of an LAA thrombus before AF ablation. So far, it has not been established what is the optimal combination of noninvasive parameters for thromboembolic risk stratification in this setting and whether patients at very low risk require TEE. Objectives The aim of the study was to assess predisposing factors for an LAA thrombus in patients scheduled for AF ablation and to identify those patients in whom preprocedural TEE is not necessary. Patients and methods In consecutive 151 patients (107 men; mean age, 57 ±10 years) the type of AF and renal function were assessed in addition to the CHA2DS2VASc score to improve thromboembolic risk stratification. Results An LAA thrombus or dense echo contrast with a strong suspicion of a probable thrombus was detected in 15 patients (10%). Diabetes, age of 65 years or older, persistent AF, and estimated glomerular filtration rate (eGFR) of less than 60 ml/min/1.73 m2 were predictors of the LAA thrombus. A multivariate logistic regression analysis showed that only persistent AF and an eGFR of less than 60 ml/min/1.73 m2 were independent predictors of the LAA thrombus. The receiver operating characteristic curves showed that the greatest area under the curve (0.845) was achieved for the CHA2DS2VASc-AFR (CHA2DS2VASc plus the type of AF and renal function); the difference was not significant. A CHA2DS2VASc-AFR score of 2 or greater or a CHA2DS2VASc score of 1 or greater identified patients with the LAA thrombus with a sensitivity of 100% (and specificity of 54% and 36%, respectively). Conclusions In patients scheduled for AF ablation, an LAA thrombus or dense echo contrast is a relatively common finding despite routine anticoagulant treatment. The addition of AF type and renal function to the CHA2DS2VASc score slightly improves thromboembolic risk stratification and may help identify patients who do not need preprocedural TEE.

INTRODUCTION The current guidelines of the European Society of Cardiology outlined electrocardiographic (ECG) differentiation of the site of origin (SoO) in patients with idiopathic ventricular arrhythmias (IVAs). OBJECTIVES The aim of this study was to compare 3 ECG algorithms for differentiating the SoO and to determine their diagnostic value for the management of outflow tract IVA. PATIENTS AND METHODS We analyzed 202 patients (mean age [SD]: 45 [16.7] years; 133 women [66%]) with IVAs with the inferior axis (130 premature ventricular contractions or ventricular tachycardias from the right ventricular outflow tract [RVOT]; 72, from the left ventricular outflow tract [LVOT]), who underwent successful radiofrequency catheter ablation (RFCA) using the 3‑dimensional electroanatomical system. The ECGs before ablation were analyzed using custom‑developed software. Automated measurements were performed for the 3 algorithms: 1) novel transitional zone (TZ) index, 2) V2S/V3R, and 3) V2 transition ratio. The results were compared with the SoO of acutely successful RFCA. RESULTS The V2S/V3R algorithm predicted the left‑sided SoO with a sensitivity and specificity close to 90%. The TZ index showed higher sensitivity (93%) with lower specificity (85%). In the subgroup with the transition zone in lead V3 (n = 44, 15 from the LVOT) the sensitivity and specificity of the V2-transition‑ratio algorithm were 100% and 45%, respectively. The combined TZ index+V2S/V3R algorithm (LVOT was considered only when both algorithms suggested the LVOT SoO) can increase the specificity of the LVOT SoO prediction to 98% with a sensitivity of 88%. CONCLUSIONS The combined TZ‑index and V2S/V3R algorithm allowed an accurate and simple identification of the SoO of IVA. A prospective study is needed to determine the strategy for skipping the RVOT mapping in patients with LVOT arrhythmias indicated by the 2 combined algorithms.

During incremental atrial pacing in patients with atrioventricular nodal reentrant tachycardia, the PR interval often exceeds the RR interval (PR RR) during stable 1:1 AV conduction. However, the PR/RR ratio has never been evaluated in a large group of patients with pacing from the proximal coronary sinus and after isoproterenol challenge. Our study validates new site of pacing and easier method of identification of PR RR.A prospective protocol of incremental atrial pacing from the proximal coronary sinus was carried out in 398 patients (AVNRT-228 and control-170). The maximum stimulus to the Q wave interval (S-Q = PR), SS interval (S-S), and Q-Q (RR) interval were measured at baseline and 10 min after successful slow pathway ablation and after isoproterenol challenge (obligatory).The mean maximum PR/RR ratios at baseline were 1.17 ± 0.24 and 0.82 ± 0.13 (p 0.00001) in the AVNRT and controls respectively. There were no PR/RR ratios ≥1 at baseline and after isoproterenol challenge in 12.3% of the AVNRT group and in 95.9% of the control group (p 0.0001). PR/RR ratios ≥1 were absent in 98% of AVNRT cases after slow pathway ablation/modification in children and 99% of such cases in adults (P = NS). The diagnostic performance of PR/RR ratio evaluation before and after isoproterenol challenge had the highest diagnostic performance for AVNRT with PR/RR = 1 (sensitivity: 88%, specificity: 96%, PPV-97%, NPV-85%).The PR/RR ratio is a simple tool for slow pathway substrate and AVNRT evaluation. Eliminating PR/RR ratios ≥1 may serve as a surrogate endpoint for slow pathway ablation in children and adults with AVNRT.

Background: Patients with pre-excitation without arrhythmic symptoms are diagnosed as Wolff-Parkinson-White (WPW) pattern. Aim: To evaluate the efficacy of radiofrequency ablation (RFA) in patients with a WPW pattern and reported dyspnoea. Methods: Five patients (four adults and one adolescent, all female, age 33 ± 15 years) with a WPW pattern were referred due to dyspnoea and exercise intolerance. None had a history of paroxysmal syncope, pre-syncope, dizziness or palpitation. Before and after RFA, additional tests were used to exclude organic diseases of the pulmonary vessels, heart and lung, as well as bronchial hyperreactivity and metabolic diseases. Cardiopulmonary exercise test (CPET), echocardiography, time of forced expiration, baseline dyspnoea index (BDI), and transition dyspnoea index (TDI) were included into an objective evaluation of breath pattern. Results: In all investigated patients, no arrhythmia was inducible during the electrophysiology study. The time of forced expiration increased immediately after RFA from 15.8 ± 2.9 to 29.2 ± 4.4 s (p < 0.001). The BDI score before RFA was 6.7 ± 1.9 and the TDI score after RFA showed a significant improvement: 8.0 ± 1.2 (p < 0.05). CPET revealed significant improvement in cardiopulmonary capacity after RFA in all cases: peak oxygen consumption [mL/kg/min]: 31.1 ± 7 vs. 42.6 ± 9.6 (p = 0.014); peak exercise minute ventilation [L/min]: 60.0 ± 19.9 vs. 82.0 ± 27 (p = 0.006); peak exercise tidal volume [L]: 1.56 ± 0.25 vs. 2.04 ± 0.24 (p = 0.002); ratio dead space/tidal volume at the end of exercise: 28 ± 2.6 vs. 25 ± 2.3 (p = 0.005). Conclusions: Dyspnoea during sinus rhythm in women with pre-excitation may be considered to be an evaluation criterion before RFA.

Background and aim: To assess safety and efficacy of antazoline for termination of atrial fibrillation (AF) occurring during ablation of accessory pathways (AP). Methods: We analyzed electrophysiological mechanism of antazoline (changes in A-A interval) and the percentage of pre-excited QRS complexes before and after antazoline administration. The total dose administered and the time from the start of injection to sinus rhythm restoration were also measured. Results: Out of consecutive 290 patients with Wolff-Parkinson-White syndrome undergoing radiofrequency (RF) ablation, 12 (4.1%) (4 females, mean age 36 ± 20 years) developed sustained AF which did not stop spontaneously within 10 min, and antazoline in 100 mg repeated boluses was administered. In all 12 patients the drug restored sinus rhythm after a mean of 425 ± 365 s (range 43–1245 s) using a mean cumulative dose of 176 ± 114 mg (range 25–400 mg). The drug slightly prolonged R-R intervals during AF (from 383 ± 106 to 410 ± 70 ms) and reduced the percentage of fully pre-excited QRS complexes (from 35% to 26%). Intracardiac recordings showed gradual increase in A-A intervals, as well as regularization and decreasing fractionation of atrial activity following drug injection (mean A-A interval of 162 ± 30 ms at baseline vs. 226 ± 26 ms shortly before sinus rhythm restoration, p < 0.001). AP was not completely blocked in any patient which enabled continuation of ablation. Conclusions: Antazoline safely and rapidly converts AF into sinus rhythm during ablation of AP. The drug does not block AP completely, enabling continuation of ablation. The drug converting AF into more organized atrial activity (atrial flutter/tachycardia) before sinus rhythm resumption.

Simplified, No-X-Ray Catheter Ablation of SVT Introduction Although the “near-zero-X-Ray” or “No-X-Ray” catheter ablation (CA) approach has been reported for treatment of various arrhythmias, few prospective studies have strictly used “No-X-Ray,” simplified 2-catheter approaches for CA in patients with supraventricular tachycardia (SVT). We assessed the feasibility of a minimally invasive, nonfluoroscopic (MINI) CA approach in such patients. Methods Data were obtained from a prospective multicenter CA registry of patients with regular SVTs. After femoral access, 2 catheters were used to create simple, 3D electroanatomic maps and to perform electrophysiologic studies. Medical staff did not use lead aprons after the first 10 MINI CA cases. Results A total of 188 patients (age, 45 ± 21 years; 17% 0.05), major complications (0% vs. 0%, P > 0.05) and acute (98% vs. 98%, P > 0.05) and long-term (93% vs. 94%, P > 0.05) success rates were similar in the “No-X-Ray” and control groups. Conclusions Implementation of a strict “No-X-Ray, simplified 2-catheter” CA approach is safe and effective in majority of the patients with SVT. This modified approach for SVTs should be prospectively validated in a multicenter study.

Objectives: The purpose of this study was to prospectively evaluate the feasibility and diagnostic value of right ventricular overdrive pacing (RVOP) during supraventricular tachycardia (SVT) using a 2-catheter approach with automatic pacing from the right ventricular inflow (RVIT) and outflow tract (RVOT). Methods: One hundred and thirty-six consecutive patients (with 138 arrhythmias, mean age 36 ± 20 years, range 4-95) were enrolled in this study. Only coronary sinus and ablation catheters were used. RVOP was delivered from RVIT and then from RVOT. Each attempt consisted of 10 synchronized beats delivered at a cycle length of 10-40 ms longer than the tachycardia cycle length. Results: RVOP was sufficient to confirm the transition zone within the first 9 beats in the majority of SVTs. Atrial perturbation (acceleration, delayed) in the transition zone was detected in all patients with orthodromic atrioventricular (AV) reentry. Patients with typical AV nodal reentry, atypical AV nodal reentry and atrial tachycardia did not show atrial timing perturbation during fusion complexes of RVOP. Conclusions: Synchronized RVOP from RVIT or RVOT is an easy and accurate method for the quick and reliable differential diagnosis of SVT in various clinical settings, particularly when only a limited number of catheters are used.

Background— Transesophageal echocardiography (TEE) is the gold standard for the exclusion of thrombi in the left atrial appendage (LAA) before ablation for atrial fibrillation. Intracardiac echocardiography (ICE) is used to assist atrial fibrillation ablation; however, it can also be used for LAA imaging. The aim of our study was to determine whether ICE could replace TEE and to identify the optimal ICE placement for LAA visualization. Methods and Results— Seventy-six consecutive patients (56 men; mean age, 55±9.6 years) scheduled for atrial fibrillation ablation underwent TEE before the procedure and LAA assessment by ICE. An 8F AcuNav probe was introduced into right atrium, pulmonary artery, and coronary sinus. LAA structure was analyzed by the echocardiographer and electrophysiologist who were blinded to the results of TEE. ICE probe was positioned in the right atrium in all patients, in the pulmonary artery in 64 of 74 (86%) patients, and in the coronary sinus in 49 of 74 (66%) patients. The LAA was properly visualized in 56 of 64 (87.5%) patients from the pulmonary artery versus 13 of 49 (26%) patients from the coronary sinus ( P Conclusions— ICE can be used safely and effectively for the evaluation of LAA in patients undergoing atrial fibrillation ablation. ICE imaging from pulmonary artery is accurate for LAA visualization. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT01371279.

Atrioventricular nodal reentrant tachycardia (AVNRT) is the commonest regular supraventricular tachyarrhythmia. Ablation in the area of slow pathway (SP) has been successfully implemented in everyday clinical electrophysiological practice for more than 20 years. Although the procedure is generally regarded as effective and safe, data on long-term effects and predictors of success or failure are incomplete.To identify predictors of successful AVNRT ablation.The study group consisted of 359 patients (105 males, mean age 51.1 ± 16.7 years) who underwent AVNRT radiofrequency ablation using typical combined electrophysiological and anatomical approach.Acute success was achieved in 342 (95%) patients, including 187 (52%) with SP ablation and 155 (43%) with SP modification. Patients with SP modification were younger, had shorter AVNRT cycle length, less often had typical echo, and had more frequent isoproterenol usage after ablation. Long-term follow-up data was available for 308 patients (86% of the total study group). During the mean follow-up of 52.9 ± 27.3 months (median 48, range 12-130 months), 22 patients experienced AVNRT recurrences (long-term efficacy 93%). These patients had less often complete SP abolition than SP modification (27% vs. 56%, p0.001) and typical jump (vs. no jump or multiple jumps) at baseline (74% vs. 89%, p0.06) than patients without recurrences. Multivariate Cox regression analysis showed that typical jump was associated with a favourable outcome (HR 5.8, 95% CI 0.44-3.1, p = 0.0089). There were no significant differences in the use of 2 or2 electrode approaches between patients with or without AVNRT recurrences.Typical jump and complete SP elimination are associated with a better outcome. A 2-electrode approach is as effective as2 electrode approach. The electrophysiological profile of patients in whom complete SP elimination was achieved may differ from that of patients in whom only SP modification was possible.

Atypical form of tako-tsubo cardiomyopathy (TTC) is associated with regional wall motion abnormalities in basal and/or middle segments or only middle segments with sparing of apical segments or apical and basal segments. We described a case of47-year-old female with atypical form of TTC due to fast atrial fibrillation that converted into ventricular fibrillation in WPW syndrome. The echocardiogram made after direct current cardioversion revealed decreased left ventricular ejection fraction (LVEF 35%) with akinesis of inferior and posterior walls and anterior part of interventricular septum in the middle and the basal segments with hyperkinesis of apical segments. The biochemistry blood samples revealed elevated both troponin T- 0.35 ng/mL and NT-proBNP - 3550 pg/mL plasma level. The ECG showed sinus rhythm 62 bpm, shortened PQ interval 100 ms, widened QRS duration - 115 ms with delta wave, prolonged QT interval - 520 ms, QS in leads: II, III, aVF. NegativeT waves in leads: I, aVL and positive, symmetrical T waves in leads V1-V6. The coronarography revealed normal coronaryarteries. The control echocardiography after 10 days showed normal LVEF 70%, without any wall motion abnormalities. TTC was recognised based on: history of sudden stress situation before, ischaemic ECG changes, positive markers of myocardial injury, transient segmental wall motion abnormalities and normal coronary arteries. The ablation of right postero-septal accessory pathway was successfully performed.

Aims Syncope is a common problem. Demographic and clinical characteristics of patients admitted to different types of centres may vary, physician's adherence to the guidelines has been examined only in a few studies, and the requirements for implantable loop recorders (ILR) have not been well defined. The aim of this study was to (i) compare demographic and clinical characteristics of patients with syncope diagnosed and treated in tertiary electrophysiology cardiac centres and those attending syncope units or general hospitals, (ii) assess how physicians adhere to the published guidelines, and (iii) calculate the requirement for ILR insertion. Methods and results In total, 669 consecutive patients with syncope, admitted to 18 electrophysiological cardiac tertiary centres over a mean of 3 months (range 1–10 months), entered a special Internet database called the PL-US (Polish patients with Unexplained Syncope) registry. Detailed demographic and clinical characteristics of the patients, including the results of all diagnostic tests performed, were analysed. Adherence to the guidelines was assessed, based on the published recommendations. The ILR implantation was indicated when (i) all other tests were inconclusive (unexplained syncope) and (ii) syncope associated with injury or presence of organic heart disease or past medical history and ECG suggesting arrhythmic syncope. Syncope of cardiac/arrhythmic origin was the most frequent diagnosis (53%), followed by reflex syncope (33%). Adherence to the guidelines was less than satisfactory—measurement of blood pressure in an upright position, carotid sinus massage, exercise testing, and electrophysiological study were underused, whereas prolonged ECG monitoring and neurological consultations were overused. Unexplained syncope had 58 (9%) patients, and 42 (72%) of them had indication for ILR which accounts for 6% of the whole study population. The calculated need for ILR was 222 implants/million inhabitants/year. Conclusion Patients with syncope admitted to the tertiary electrophysiology cardiac centres are a highly selected group of patients with syncope and differ in their characteristics as well as underlying diseases to those managed at general hospitals, outpatient clinics, or special syncope units. In Poland, the adherence to the published guidelines is far from satisfactory. At least 6% of all consecutive patients with syncope are candidates for ILR insertion.

Chronic cough frequently remains unexplained. Although various cardiac arrhythmias have already been reported as a cause of chronic cough, this phenomenon has not been evaluated prospectively. Therefore, we studied the incidence and management of cough associated with premature ventricular complexes (PVCs) in a population of patients with this condition.Patients without organic heart disease who had been referred for the management of symptomatic PVC were evaluated prospectively. PVC-associated cough was recognized if cough episodes occurred just after spontaneous or induced PVC or observed in an ECG or a multichannel recording system that included ECG. A differential diagnosis of cough was performed according to the guidelines on cough. Afterward, antiarrhythmic therapy was instituted to eliminate PVC and cough.Of the 120 patients who were referred for the management of PVC, 10 had a chronic cough. After extensive workup for the cause of chronic cough, the cough was thought to be solely due to PVC in one patient, partially due to PVC plus another cause in five patients, and not due to PVC but to nonasthmatic eosinophilic bronchitis, gastroesophageal reflux disease, and chronic sinusitis in four patients. Patients with PVC-associated cough reported more severe perception of symptoms associated with arrhythmia than patients without cough (mean [+/- SD] visual analog scale score, 8.2 +/- 0.5 vs 5.7 +/- 1.6, respectively; p0.01). PVC-associated cough disappeared after antiarrhythmic treatment (radiofrequency ablation [n = 4], oral antiarrhythmic agent [n = 1]), or after spontaneous remission of PVC (n = 1).PVC may be a cause of chronic cough. Interdisciplinary cooperation is warranted for the proper diagnosis and management of PVC-associated cough.

We report our observations in a 54-year-old woman with right midseptal AV accessory pathway (AP) and manifest ventricular preexcitation. Although the patient has a several-year history of paroxysmal palpitations, her major daily symptom was impaired exercise tolerance due to resting and exertional dyspnea. Organic diseases of the pulmonary vessels, lung, and heart were excluded by x-ray film and computed tomographic angiography. Cardiopulmonary exercise test prior to ablation showed objective evidence of exertional dyspnea. Stress echocardiography using tissue Doppler imaging revealed significant interventricular asynchrony. The patient underwent successful AP radiofrequency (RF) ablation, which resulted in immediate disappearance of her exertional dyspnea. Cardiopulmonary exercise test performed 1 week after ablation showed significant improvement in pulmonary and cardiac performance. However, within 2 weeks of the procedure, her symptoms of resting and exertional dyspnea recurred simultaneously with recurrence of ventricular preexcitation. Cardiopulmonary exercise capacity in cardiopulmonary exercise test deteriorated as well. After a second RF ablation, the patient's symptoms and preexcitation resolved, and tissue Doppler imaging was free of interventricular asynchrony. These findings suggest that in patients without organic heart and pulmonary diseases, ventricular preexcitation may lead to symptomatic exertional dyspnea in sinus rhythm and interventricular asynchrony that persists during exercise. RF ablation can reverse dyspnea associated with preexcitation. Therefore, in symptomatic patients, preexcitation-related exertional dyspnea during sinus rhythm can be diagnosed by cardiopulmonary exercise test and could be an additional indication for RF ablation in patients with Wolff-Parkinson-White pattern.

Aims To develop a simple point score system that can accurately predict the optimal energy of initial rectilinear biphasic (RLB) waveform shock for cardioversion (DC) of persistent atrial fibrillation (AF). Methods and results Data from 302 consecutive patients with AF who underwent a step-up protocol of sequential shocks of 50 J—from 1 up to 2 J/kg—200 J of RLB waveform DC were prospectively examined. Using a logistic regression model, three variables independently predicted the need for 2 J/kg shocks: AF duration>7 months, previous DC, and increased left atrial (LA) diameter>4.5 cm. A simplified point score system (REBICAF score) that spans from 0 to 4 was developed. The score gives two points for AF duration>7 months and one point for previous DC or LA diameter>4.5 cm. The area under the receiver operator curve (ROC) of the proposed score for predicting the need for 2 J/kg shock was 0.84. There was a progressive increase in the need for 1 J/kg, 2 J/kg, and 200 J as the point score increased ( P

Background: Classification of patients with unstable angina (UA) by Agency for Health Care Policy and Research (AHCPR) guidelines in the emergency department reliably stratifies risk of death or myocardial infarction (MI) for triage to outpatient evaluation (low-risk), hospitalization (high-risk), or additional testing (intermediate-risk). Cardiac troponin-I elevation may identify patients at higher risk, but the incremental value may vary with AHCPR clinical risk. Hypothesis: The objective of this study was to determine whether cardiac troponin-I had any additional value beyond triage based upon history, physical examination, and electrocardiogram, in the evaluation of patients with UA. Methods: In all, 212 consecutive patients with UA and normal serum creatine kinase (CK)-MB levels and elevated troponin-I were risk stratified by AHCPR guidelines to evaluate the incremental value of adding routine troponin-I measurements to our current model for risk stratification. Results: Primary events (death/nonfatal MI) occurred in 35% of high-risk, 15% of intermediate-risk, and 0% of low-risk patients (p < 0.001 by chisquare for trend). High troponin-I (≥ 2.0 ng/dl) occurred in 48% of high-risk, 21% of intermediate-risk, and 19% of low-risk patients. The remaining patients in each risk group had indeterminate troponin-I levels (≥0.4 < 2 ng/dl). Of those with high troponin-I, a primary event occurred in 36, 42, and 0% in the respective high-, intermediate-, and low-risk groups (p < 0.001). High troponin-I levels corresponded with a statistically significant increased rate of primary events only in patients at AHCPR intermediate risk: 42.4 vs. 7.3%, p < 0.001. Conclusion: The AHCPR guidelines risk stratify patients with UA. High troponin-I adds significant (p < 0.001) prognostic value in the patients at AHCPR intermediate risk and should be evaluated further in larger trials of such patients.

Background: The Tei index of myocardial performance (IMP), which combines parameters of both systolic and diastolic ventricular function, is a useful prognostic factor in many clinical settings. Hypothesis: This study assessed the long-term prognostic value of IMP in patients discharged from hospital after acute myocardial infarction (AMI). Methods: Doppler/echocardiographic studies were recorded in 90 consecutive patients on Day 14 ± 2 following an AMI. The IMP was calculated from the Doppler recordings, as a sum of isovolumetric contraction time and isovolumetric relaxation time, divided by the ejection time. Results: The patients were followed for an average (SD) of 57.8 (16.1) months. During this period there were 22 (24%) cardiac events, defined as cardiac deaths (10) or Nonfatal recurrent myocardial infarctions (12). After multivariate Cox analysis, Tei index > 0.55 (relative risk [RR] 4.45; 95% confidence interval [CI] 1.28-15.45; p = 0.019), LV end-systolic volume > 65 ml (RR 3.23; 95% CI 1.34-7.79; p = 0.009), and mitral E wave deceleration time ⩽ 0.145 s (RR 2.94; 95% CI 1.24-6.92; p = 0.014) were the only independent predictors of cardiac events during the follow-up period. In a subgroup of patients with preserved LV systolic function (ejection fraction > 0.40), IMP was the only predictor of cardiac events (RR 6.37; 95% CI 1.32-30.77, p = 0.02). Conclusions: The Tei index of myocardial performance, which is simple and easy to calculate, is a useful tool for risk assessment in patients following myocardial infarction, and in a subgroup of patients with Normal or only mildly impaired systolic function.

Radiofrequency catheter ablation (RFCA) is an established effective method for the treatment of typical cavo-tricuspid isthmus (CTI)-dependent atrial flutter (AFL). The introduction of 3-dimensional electro-anatomic systems enables RFCA without fluoroscopy (No-X-Ray [NXR]). The aim of this study was to evaluate the feasibility and effectiveness of CTI RFCA during implementation of the NXR approach and the maximum voltage-guided (MVG) technique for ablation of AFL. Data were obtained from prospective standardized multicenter ablation registry. Consecutive patients with the first RFCA for CTI-dependent AFL were recruited. Two navigation approaches (NXR and fluoroscopy based as low as reasonable achievable [ALARA]) and 2 mapping and ablation techniques (MVG and pull-back technique [PBT]) were assessed. NXR + MVG (n = 164; age: 63.7 ± 9.5; 30% women), NXR + PBT (n = 55; age: 63.9 ± 10.7; 39% women); ALARA + MVG (n = 36; age: 64.2 ± 9.6; 39% women); and ALARA + PBT (n = 205; age: 64.7 ± 9.1; 30% women) were compared, respectively. All groups were simplified with a 2-catheter femoral approach using 8-mm gold tip catheters (Osypka AG, Germany or Biotronik, Germany) with 15 min of observation. The MVG technique was performed using step-by-step application by mapping the largest atrial signals within the CTI. Bidirectional block in CTI was achieved in 99% of all patients (P = NS, between groups). In NXR + MVG and NXR + PBT groups, the procedure time decreased (45.4 ± 17.6 and 47.2 ± 15.7 min vs. 52.6 ± 23.7 and 59.8 ± 24.0 min, P

Ablacja migotania przedsionkow (AF) jest uznaną metodą leczenia tej arytmii. Z powodu bliskości anatomicznej tylnej ściany lewego przedsionka i przelyku istnieje ryzyko jego uszkodzenia, wlącznie z wytworzeniem przetoki przedsionkowo-przelykowej. Znane są takze zaburzenia czynnościowe przelyku wystepujące po zabiegu ablacji. Na Oddzial Kardiologii przyjeto 60-letniego pacjenta z objawowym, opornym na farmakoterapie AF w klasie EHRA 3 w celu wykonania ablacji prądem o wysokiej czestotliwości (RF) — okreznej izolacji zyl plucnych z powodu AF. Zaplanowano diagnostyke zaburzen czynnościowych przelyku przed i po ablacji. Wykonano gastroskopie, impedancje przelykową i manometrie przelykową. Badania te przeprowadzono u pacjenta 3 dni przed zaplanowaną ablacją oraz 3 i 30 dni po zabiegu. W manometrii przelykowej stwierdzono w kolejnych badaniach zmniejszenie średniego ciśnienia spoczynkowego w dolnym zwieraczu przelyku z 38,9 mm Hg (przed ablacją) do 17,8 mm Hg (3 dni po zabiegu). Po miesiącu od ablacji stwierdzono ponowny wzrost wartości średniego ciśnienia spoczynkowego w dolnym zwieraczu przelyku do 28,1 mm Hg. Redukcji napiecia spoczynkowego dolnego zwieracza przelyku towarzyszyl spadek wartości wskaźnika IRP, opisującego relaksacje dolnego zwieracza przelyku po wykonanym przelknieciu. Wskaźnik ten obnizyl sie z początkowego 8,71 mm Hg do 2,915 mm Hg stwierdzonego 3 dni po ablacji, a nastepnie po miesiącu od zabiegu wzrosl do 6,59 mm Hg. U pacjenta początkowo, podczas manometrii przelykowej stwierdzono 100% przelkniec prawidlowych, perystaltycznych. Po ablacji nastąpilo pogorszenie fali perystaltycznej ściany przelyku i zmniejszenia odsetka przelkniec prawidlowych do 65%. Po miesiącu od zabiegu zaobserwowano stopniową poprawe motoryki ściany przelyku i 85% przelkniec perystaltycznych. Upośledzonej perystaltyce ściany przelyku towarzyszylo zmniejszenie średniej amplitudy skurczow ściany przelyku z 89,5 mm Hg do 63,9 mm Hg. stwierdzanej tuz po ablacji i do 64,0 mm Hg miesiąc po zabiegu (ryc. 1). W impedancji przelykowej początkowo obserwowano niskie wartości wskaźnika DeMeestera (1,4) opisującego nasilenie refluksu zolądkowo-przelykowego. Wspolczynnik ten stopniowo wzrastal — do 2,2 podczas badania po 3 dniach od ablacji oraz do 3,4 stwierdzanych po miesiącu od zabiegu. Zwiekszyla sie rowniez calkowita liczba refluksow zolądkowo-przelykowych z 25 (przed zabiegiem) do 47 (3 dni po ablacji). Po miesiącu calkowita liczba refluksow wynosila 10. Zanotowano rowniez wzrost liczby epizodow refluksow niekwaśnych z 18 do 35 stwierdzanych 3 dni po ablacji. Po miesiącu ich liczba wynosila juz tylko 7 (ryc. 2). W gastroskopii wykonanej przed zabiegiem zaobserwowano zapalenie blony śluzowej zolądka i przepukline rozworu przelykowego przepony. Podobny obraz gastroskopowy utrzymywal sie w badaniach wykonanych 3 dni oraz miesiąc po zabiegu. Nie stwierdzono nasilenia zmian zapalnych ani wystąpienia nowych zmian w przelyku po ablacji. Podsumowując, przejściowe zaburzenia czynności przelyku, stwierdzone u opisywanego chorego i wystepujące prawdopodobnie u wiekszości pacjentow poddawanych ablacji AF, dodatkowo wskazują na koniecznośc zachowania szczegolnej ostrozności podczas aplikacji RF w obrebie tylnej ściany lewego przedsionka.

Background Experimental studies suggest that the electrocardiographic Tpeak–Tend (TpTe) interval reflects transmural dispersion of repolarization (TDR). The genesis and role of the TpTe interval in a clinical setting have not been established. This study aimed to assess the clinical usefulness of the TpTe interval as an index of TDR and a pro-arrhythmic marker. Materials and methods Endocardial monophasic action potential (MAP) duration and electrocardiographic QTp, QTe and TpTe intervals were assessed in 13 patients undergoing an electrophysiological study. Surface electrocardiograms were recorded during right ventricular pacing (Basic Cycle Length = 600 ms) before and after single extrastimuli. Results Ventricular arrhythmia was induced in six patients. During ventricular pacing, MAP duration and QTp intervals shortened in response to extrastimuli applied at progressively shorter coupling intervals. In contrast, QTe intervals increased in response to premature stimulation and QTe dispersion increased at short coupling intervals. During sinus rhythm, the TpTe interval was greater in the inducible group in leads V3-V4. Premature stimulation increased the duration of TpTe intervals, suggesting an increase in TDR. The maximum TpTe interval was greater in the inducible than in the noninducible group, both during baseline ventricular drive pacing (163 ± 22 vs. 130 ± 27 ms, respectively, P

Background Syncope after acute myocardial infarction (AMI) is a common clinical problem. It may be hypothesised that remodelling and neurohormonal changes following AMI may predispose to neuromediated syncope. Design To address this issue we prospectively evaluated the incidence of positive results of head-up tilt-table testing in 40 patients following AMI and 40 age and sex matched controls without a history of syncope. The mechanisms of tilt-induced changes in autonomic tone were assessed using spectral analysis of heart rate variability. The patients were followed-up for one year. Results Positive results of tilt-test occurred in 4 (10%) controls and 13 (33%) AMI patients (P = 0.01). No significant differences in sympathovagal interaction (assessed by a low frequency/high frequency ratio) were detected between the groups before tilting (2.9 ± 1.9 vs. 3.1 ± 2.2; NS). However, dynamic changes of this parameter differed significantly during the first 5 symptomless minutes of the active phase of tilt-test. The ratio increased in the majority of controls (87%) and decreased in the majority of patients (62%) (P