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Dislocation of the transvenous left ventricular lead has been reported in a substantial number of patients selected for cardiac resynchronization therapy. We describe a novel technique using a retained guidewire in patients with repetitive intraoperative dislocation to stabilize the lead in its final position. Pacing and sensing parameters between patients in whom the retained guidewire technique was used (n = 6) were not significantly different as compared to the group of patients (n = 67) without this technique during a 6-month follow-up. No dislocations were observed in the group of patients with the retained guidewire technique and fluoroscopic evaluation did not reveal (minor) dislocation. This technique might be considered for patients with repetitive intraoperative left ventricular lead dislocation. [ABSTRACT FROM AUTHOR]

INTRODUCTION Cardiac resynchronization therapy (CRT) can be applied in patients with impaired left ventricular (LV) function and advanced heart failure if a reversible cause of a depressed LV function is excluded. We studied 23 patients with an ischemic cardiomyopathy and heart failure class III-IV NYHA and QRS duration > 120 msec who were rejected for surgical and percutaneous interventions. In 14 patients revascularisation was not amenable for technical reasons, 7 had extensive co-morbidity and 2 refused a (repeated) surgical intervention. All had documented myocardial ischemia on nuclear or echocardiographic stress studies. In all successful implantation was performed and follow-up was 13±1.9 months. RESULTS Nine patients had two-vessel disease and 14 patients had three-vessel disease on coronary angiography. Seven patients had previous myocardial infarction. Mean LV ejection fraction was 23±4 %. During follow-up 4 patients died: 3 patients had sudden death while 1 patient died 2 days after (recurrent) myocardial infarction. In the remaining group functional class improved from 3.2±1.4 to 2.0±1.0, p< 0.01. Quality-of-life assessed by the Minnesota Living with Heart Failure questionnaire improved from 39±15 to 28±13, p< 0.01. The 6-minutes walking test increased from 264±104 to 385±121(m), p<0.01). Despite an improvement in exercise capacity anginal attacks/week remained the same (2.3±0.7 to 2.2±0.6, p=ns). CONCLUSION In patients with advanced heart failure, stable angina and documented myocardial ischemia CRT can be performed safely with good long term follow-up. [ABSTRACT FROM PUBLISHER]

Aims: To assess safety, feasibility and short term outcome of pulmonary vein (PV) isolation in paroxysmal atrial fibrillation (AF) with a cryoballoon., Methods: We consecutively treated 57 patients with a double lumen 23 or 28 mm cryoballoon. The acute results, complications and follow-up over the first three months were analysed, using a comprehensive and intensive follow-up period., Results: During 57 procedures, 185 of 220 targeted PV's were successfully isolated using the cryoballoon (84%) (balloon group, 33 patients). In 33 veins (15%) an additional segmental isolation (hybrid group, 24 patients) was necessary with a standard cryocatheter to achieve isolation. The average procedure times were respectively 211 +/- 108 and 261 +/- 83 minutes (NS), the average fluoroscopy times 52 +/- 36 and 66 +/- 33 minutes (NS). The number of balloon applications did not differ between both groups: respectively a median 9 (4-18) and 10 (5-17) (NS). We observed four phrenic nerve paralysis after ablation of the right superior PV: two resolved immediately after cessation of the cryoenergy, one recovered after 3 months, one persisted up to 6 months. A daily transtelephonic rhythm recording showed a significant drop in mean AF burden from 24% to 10%, 8% and 5% during the three consecutive months of follow-up (p < 0.01 versus baseline). No differences were observed between the treatment groups. 34 patients (60%) were completely free from AF after a single procedure., Conclusions: Balloon cryoablation of the pulmonary veins with additional segmental isolation if necessary, is a good approach for patients presenting with paroxysmal AF, showing a significant reduction in AF burden after a single procedure. The major complication seems to be phrenic nerve paralysis after ablation of the right superior PV, but this is potentially reversible over several months.

Background: Radiofrequency (RF) catheter ablation is highly effective with a low complication rate. However, lesions created by RF energy are irreversible, inhomogeneous, and therefore potentially proarrhythmic., Objectives: The aim of this study was to examine the magnitude and importance of long-term proarrhythmic effects of RF energy., Methods and Results: Between 1991 and 1995, 120 patients underwent RF ablation for atrioventricular nodal reentrant tachycardia (AVNRT). Patient data were collected by contacting patients and/or filling out a questionnaire, and medical files were screened for recurrent, documented arrhythmias, pharmacological treatment, and repeated EP study. Referring cardiologists were asked about recurrences of tachyarrhythmias. Fourteen patients (11%) were lost to follow-up. During a mean follow-up of 10 years, six patients died. Recurrences of AVNRT were not any more observed after 3 years after ablation. A total of 29 patients (24%) suffered from new arrhythmias, 6 from type 1 atrial flutter, 6 from atrial tachycardia, 9 from atrial fibrillation, and finally 16 from symptomatic premature atrial contractions (PACs), needing medical treatment or a combination of these arrhythmias. Nine patients underwent pacemaker implantation, 4 after developing procedural atrioventricular (AV) conduction disturbances, 2 after His ablation for permanent atrial fibrillation, 1 patient for sick sinus syndrome, and another 2 patients after developing late AV block, respectively, 7 and 9 years after ablation., Conclusion: During long-term follow-up after RF ablation for AVNRT, no AVNRT recurrences were observed, but 29 patients (24%) suffered from new arrhythmias or late AV block. This potential proarrhythmic effect of RF energy promotes the application of alternative energy sources for ablative therapies for cardiac arrhythmias.

Sarcoidosis is a multisystem granulomatous disorder characterised pathologically by the presence of noncaseating granulomas in the organs involved. Cardiac involvement, although well known, is rare. We describe a 72-year-old patient who was admitted to the intensive care unit after coronary artery bypass grafting. She developed refractory right and left ventricular failure complicated by multiple organ failure and died three days later. Postmortem examination revealed extensive sarcoidosis. On hindsight, preoperative ventricular tachycardia and an abnormal perfusion-ventilation scintigraphy of the lungs were manifestations of an underlying sarcoidosis.

Studies in patients without coronary artery disease have shown the restoration of glucose metabolism by cardiac resynchronization therapy (CRT) without changes in myocardial perfusion. We report on the long-term outcome of CRT in 24 patients with severe heart failure (HF) and advanced coronary artery disease not amenable for revascularization. All patients had documented myocardial ischemia on stress (99)Tc-sestamibi single-photon emission computed tomography, and all underwent successful implantations of CRT systems. The mean left ventricular ejection fraction was 21%+/- 4%, 19 patients (79%) had anginal complaints and 20 (83%) had diffuse three-vessel disease. During a follow-up of 13 +/- 0.7 months, two patients died suddenly and one died of progressive HF. Among survivors, functional capacity decreased from New York Heart Association class 3.2 +/- 1.4 to 2.1 +/- 1.0 (P < 0.01), and the Minnesota questionnaire quality-of-life scores decreased from 43 +/- 15 to 28 +/- 13 (P < 0.01). Despite an increase from 264 +/- 104 to 385 +/- 121 m in distance walked in 6 minutes (P < 0.01), the number of anginal attacks/week remained unchanged (4.7 +/- 0.7 to 4.5 +/- 0.6). Patients with advanced HF, stable angina, and documented myocardial ischemia may undergo safe and successful implantations of CRT systems.

Aim: Mitral valve surgery seldom suppresses atrial fibrillation (AF), present prior to surgery. Maze III surgery eliminates AF in >80% of cases, the reason why combining this procedure with mitral valve surgery in patients with AF seems worthwhile. We prospectively studied the outcome of combining the Maze III procedure with mitral valve surgery., Methods: Thirty-five patients with AF and a mean age of 64 years undergoing mitral valve surgery were prospectively randomized according to a 2.5:1 ratio to surgery with (n=25), or without (n=10) maze III and followed for at least 1 year., Results: At discharge and after 12 months freedom from AF was 56% and 92%, respectively, in the maze group, and 0% and 20%, respectively, in patients without maze (group differences at discharge p=0.002, after 12 months p=0.0007). Sinus node incompetence was seen in 1 of 25 maze patients requiring pacing. No in-hospital or late death occurred; stroke was observed in 1 patient (without maze). Quality of life markedly improved after surgery, but did not differ between patients with or without maze surgery., Conclusions: This first prospective randomized study shows that combining maze III with mitral valve surgery resulted in a significantly better elimination of preoperative AF than mitral valve surgery alone. As the quality of life did not differ between patients with, or without maze surgery, additional maze surgery is primarily recommended in patients in whom anticoagulation therapy can be avoided after surgery, specifically in patients with scheduled mitral valve plasty.

Background: Unmodified maze III operations show long-term eradication of atrial fibrillation (AF) in more than 85% of patients with or without structural heart disease. The effect of this procedure on atrial volumes is not known., Methods: Two patient populations were studied: (1) patients undergoing unmodified maze III operations combined with surgical structural heart disease, mostly mitral valve operations (group A; n = 32); and (2) patients with only AF selected for unmodified maze III operations (group B; n = 32). In groups A and B, transthoracic Doppler echocardiographic studies were prospectively made preoperatively, and at 3 and 12 months postoperatively. Left and right atrial dimensions and volumes and atrial contractions were determined and compared with base line patient characteristics and 12 months arrhythmia outcomes., Results: One year postoperatively all patients were alive. In groups A and B, 92% were free of AF and other atrial arrhythmias. A significant reduction of left atrial volume at 1 year postoperatively was apparent in group A, whereas the left atrial volume did not change significantly in group B. The reduction observed in group A was not related to postoperative age, type or duration of AF, or late atrial arrhythmia outcome. In both groups the right atrial volume remained unchanged at 12 months postoperatively., Conclusions: The unmodified maze III operation does not affect atrial volume in patients without structural heart disease. In patients with structural heart disease, the mitral valve operation contributes to the reduction of left atrial volume and dimension by improving the hemodynamic condition.

Background: Tissue mass and structure are relevant for initiation and persistence of fibrillation. Modification of the right atrium during maze surgery may change the arrhythmogenic substrate of atrial fibrillation (AF)., Methods and Results: Epicardial mapping was performed in 9 patients undergoing unmodified maze III surgery for lone paroxysmal AF. Simultaneous recording of AF on the right and left atrium was carried out with two spoon-electrodes each harbouring 64 terminals. Activation maps of AF were made to study AF wavelet organization. The recording position on right and left atria was outside the surgical field and remained unchanged before and after surgery. Before surgery, mean right and left fibrillatory intervals were 174+/-23 ms, and 175+/-26 ms, respectively, and did not differ. After completed right atrial surgery, these fibrillary intervals remained unchanged. Mean right and left atrial dispersion of refractoriness (expressed as the coefficient of variation) were 4.2+/-0.8 and 5.2+/-3.8 ms. Only right atrial dispersion of refractoriness increased significantly after right-sided surgery. Prior to surgery, activation patterns of the left atrium were more complex than that of the right atrium. The left activation patterns became less complex afterwards; the right atrial activation patterns did not change., Conclusion: The right atrial modification of maze III surgery neither affects atrial refractoriness during human lone AF nor changes AF wavelet organization. Thus, right atrial surgery does not modify the arrhythmogenic substrate of AF. These findings may imply that maze surgery can be restricted to the left atrium., (Copyright 2003 The European Society of Cardiology.)

A 35-year-old female was referred to our hospital. For more than ten years, she had had complaints of two types of paroxysmal palpitations, both with a sudden onset. The first type was rapid and often accompanied by light-headedness; the second she described as much less rapid, better tolerated, and often terminated by the Valsalva manoeuvre. The incidence and duration of both types of paroxysms were increasing. In the emergency room of the referring hospital, the tachycardia was terminated with intravenous verapamil. The electrophysiological study revealed normal conduction parameters. Premature atrial beats (due to catheter manipulation) or delivered atrial extra stimuli over a wide range easily induced two types of tachycardia. AV node modification by radiofrequency ablation using the posterior approach was performed. With this approach, RF ablation of the caudal extension of the AV node is performed, which modifies the slow pathway, so that the reentrant circuit is interrupted. After this intervention, no tachycardia whatsoever could be induced and during followup (8 months), no recurrent arrhythmia of any kind occurred.

Introduction: Body surface mapping (BSM) can be used to identify the site of earliest endocardial activation of ventricular tachycardias (VTs). The multielectrode QRS morphology during VT is determined by both the site of earliest activation and the subsequent spread of electrical activation through the ventricles. This study investigated the relationship between the site of earliest endocardial activation, endocardial spread of activation, and the morphology of the multielectrode surface map in patients with remote myocardial infarction., Methods and Results: In 14 patients with VT late (8.2+/-5.2 years) after myocardial infarction, BSM and simultaneous left ventricular 64-site basket endocardial mapping was performed during a total of 17 monomorphic VTs. In addition, multisite pacing by sequential use of the 64 basket electrodes was performed in 9 patients. BSM and basket mapping revealed the same endocardial breakthrough sites in 8 (47%) of 17 VTs and 189 (59%) of 322 pacing sites; adjacent sites were found in 2 (12%) of 17 VTs and 36 (11%) of 322 pacing sites. Large zones of conduction block explained the mismatch in localization in 2 (12%) of 17 VTs and 52 (16%) of 322 pacing sites. Regional differences in endocardial electrogram amplitudes were found as a cause for dissimilarity in 3 (18%) of 17 VTs and 73 (23%) of 322 pacing sites. Multiple endocardial breakthrough sites were found in 1 (6%) of 17 VTs and 8 (2%) of 322 pacing sites Finally, an epicardial exit site was suggested in 3 (18%) of 17 VTs as an explanation for mismatch, as no early endocardial activity could be recorded., Conclusion: Zones of conduction block, regional differences in signal amplitude, and multiple endocardial breakthrough sites are frequent causes for mismatch between BSM and basket catheter activation mapping.

Ventricular tachycardia occurs frequently in patients with mitral valve prolapse. If antiarrhythmic drug therapy fails or mitral valve surgery is indicated, concomitant arrhythmia surgery may be considered. This report describes the first clinical use of an atrial transseptally inserted multielectrode basket catheter, placed across the mitral valve, to guide intraoperative mapping and ablation of monomorphic sustained ventricular tachycardia in association with mitral valve prolapse. Endocardial covering and signal quality of this percutaneous mapping catheter were of good quality, allowing an accurate localization of the site of origin of the tachycardia.

Introduction: The exit site and central common pathway of slow conduction are preferred sites to guide radiofrequency ablation of postinfarction ventricular tachycardia (VT). Both require inducibility of VT. In addition, their low amplitude hampers direct recording of potentials generated by activation in pathways of slow conduction. We hypothesized that pace mapping during sinus rhythm would help to detect the VT exit site and potentials generated by activation in pathways of slow activation., Methods and Results: In 13 patients suffering from VT late after anterior (n = 10) or inferior (n = 3) myocardial infarction, stimulation was performed in scarred endocardium at 23.5 (range 13 to 36) sites per patient during arrhythmia surgery. Multielectrode recordings (64 sites) during stimulation at a fixed cycle length of 500 msec were obtained. Endocardial breakthrough sites distant (>2 cm) from the pacing site were found at 4.3 (range 3 to 19) pacing sites per patient. Low-amplitude discrete potentials (LADPs) could be detected between the pacing site and the breakthrough site in 2.3 (range 0 to 13) of 4.3 stimulation sequences. In these patients, 19 VTs were induced and the exit site determined. In 6 patients, the distant pacing breakthrough site was identical to the VT exit site; in 7 patients, no similar exit sites were found. LADPs during VT were found at a median 2.0 (range 0 to 14) sites per patient., Conclusion: Pace mapping of the postinfarction endocardial scar during sinus rhythm revealed 50% of the endocardial exit sites of VT and the same number of LADPs observed during VT.

A 56-year-old woman without structural heart disease had an ECG typical of Brugada syndrome. Syncope occurred due to monomorphic VT with left bundle branch block (LBBB) morphology. At electrophysiological study, VT with the same morphology was inducible.

Aim: In patients with and without a permanent pacemaker His bundle ablation was performed for symptomatic drug-refractory atrial fibrillation. This study was performed to examine the complications of temporary pacing in patients without an already implanted pacemaker., Methods and Results: Between January 1996 and December 1998, 152 consecutive patients, both referred and our own (non-referred), underwent His bundle ablation for drug-refractory atrial fibrillation. Primary end-point complications were temporary lead dislodgement requiring immediate repositioning (1), severe arrhythmia (2), death (3) and persistent damage to an already implanted pacing system (4). Secondary end-points were malsensing and malpacing of the temporary lead, and blood vessel problems. Lead dislodgement of the temporary pacemaker occurred in three patients (2.9%), all of whom were in the referred group. Severe arrhythmia and death did not occur. Persistent damage of the already implanted pacing system was not observed. Secondary end-points occurred in 15.8%) of the patients and were successfully managed by a conservative approach., Conclusion: Permanent pacemaker implantation is recommended prior to His bundle ablation in order to avoid haemodynamic deterioration due to dislocation of the temporary pacemaker lead. RF current used for His bundle ablation caused no permanent damage to permanent pacing systems.

Objective: Atrial fibrillation (AF) persisting after mitral valve surgery reduces survival due to heart failure and thrombo-embolisms, and impairs quality of life. Arrhythmia surgery for AF shows today very satisfying results and therefore mitral valve surgery with AF surgery appears appealing. This study explores whether combined surgery in view of today's results of mitral valve surgery is indicated., Methods and Results: An outcome analysis of the arrhythmia outcome of patients undergoing exclusive mitral valve surgery with or without tricuspid repair was done. Preoperative baseline characteristics including arrhythmia pattern, surgical methods and follow-up findings were reviewed. Postoperative management of AF was not protocolized. Between 1990 and 1993, 162 consecutive patients underwent mitral valve surgery; follow-up was a mean of 3.3+/-1.9 years. In-hospital and late mortality were 1 and 9%, respectively. Sinus rhythm was preserved in 40 of 57 (70%) patients with preoperative sinus rhythm whereas AF persisted in 58 of 68 (85%) of patients with preoperative chronic AF (>1 year present). Sinus rhythm without AF was observed in 10 of 29 (34%) patients with preoperative paroxysmal AF. The 4-year Kaplan-Meier survival did not differ between patients with preoperative sinus rhythm (95.2%), paroxysmal AF (89.2%) and chronic AF (82.9%) but AF persisting after surgery tended to determine survival (P=0.05). Gender, age and right ventricular pressure and tricuspid valve repair were risk factors for postoperative recurrence of AF in patients with sinus rhythm at discharge, relative risk 0.35, 1.06, 1. 04 and 2.9, respectively., Conclusion: Current mitral valve surgery with or without tricuspid valve repair does not eliminate preoperative paroxysmal or chronic AF. Secondly, because preoperative AF did not determine survival after mitral valve surgery, whereas postoperatively persisting AF was weakly associated with survival, atrial arrhythmia surgery primarily aims to reduce morbidity due to AF. Some characteristics can identify patients with increased propensity for persisting AF after surgery. Randomized studies of AF surgery are needed to identify suitable candidates for combined surgery.

Adequate atrial lead performance consists of stable sensing and pacing properties. To evaluate whether the CPI 4269 bipolar lead, covered with mannitol (Sweet Tip), in the atrial position encounters these properties, we performed a prospective study of this lead. After complete dissolution of the mannitol helix, mapping of the atrium to obtain the highest electrogram and lowest threshold was followed by screw-in into the endocardium. Intraoperative measurements were performed and long-term follow-up was scheduled every 6 to 12 months to measure threshold and perform an intracardial electrogram. Between February 1993 and December 1996, a total number of 73 leads in the atrial position in a consecutive series of patients was implanted. Implantation was performed in 28 patients receiving an AAIR and 45 patients a DDDR pacemaker. Reason for pacemaker implantation was a third-degree AV block in 37% of patients, type II second-degree AV block in 25%, sick sinus syndrome in 35%, and drug refractory paroxysmal atrial fibrillation following His-bundle ablation in 3%. The intraoperative bipolar atrial electrogram had a mean voltage of 4.25 +/- 2.1 mV. The acute atrial bipolar threshold was 0.63 +/- 0.43 V, and current was 1.35 +/- 0.81 mA at a 1.0-ms pulse duration. The mean acute resistance of the lead was 572 +/- 86 Ohm. After a mean follow-up of 18.3 months, the bipolar intracardial electrogram was 3.37 +/- 2.00 mV, the mean atrial threshold measured at the last outpatient clinic visit was 0.99 +/- 0.74 V and the mean impedance was 640 +/- 127 Ohm. A sensing problem due to traction of the atrial lead occurred in only one patient. Acute and late dislodgement did not occur. The CPI 4269 (Sweet Tip) lead is manufactured with a dissolvable capsule covering the helix tip electrode, permitting a safe passage through the venous system. This interim analysis shows that this lead in the atrial position has favorable acute and chronic results.

Aims: Although arrhythmia surgery and radiofrequency catheter ablation to cure atrioventricular nodal reentrant tachycardia differ in technical concept, the late results of both methods, in terms of elimination of the arrhythmogenic substrate and procedure-related new and different arrhythmias, have never been compared. This constituted the purpose of this prospective follow-up study., Methods and Results: Between 1988 and 1992, 26 patients were surgically treated using perinodal dissection or 'skeletonization', and from 1991 up to 1995, 120 patients underwent radiofrequency modification of the atrioventricular node for atrioventricular nodal reentrant tachycardia. The acute success rates of surgery and radiofrequency catheter ablation were 96% and 92%, respectively. Late recurrence, rate in the surgical and radiofrequency catheter ablation groups was 12% and 17%, respectively. Mean follow-up was 53 months in the surgical group and 28 months in the radiofrequency catheter ablation group. The final success rate after repeat intervention was 100% in the surgical group and 98% in the radiofrequency catheter ablation group. Comparison of the initial and recent series of radiofrequency catheter ablated patients showed an increased initial success rate with fewer applications. In the radiofrequency catheter ablation group, a second- or third-degree block developed in three patients (2%), requiring permanent pacing, whereas in the surgical group no complete atrioventricular block was observed. Inappropriate sinus tachycardia needing drug treatment was observed in 13 patients (11%), mostly after fast pathway ablation, but was never observed after surgery. New and different supraventricular tachyarrhythmias arose in 27% of the patients in the surgical group and in 11% of the radiofrequency catheter ablation group, but did not clearly differ., Conclusion: This one-institutional follow-up study demonstrated comparable initial and late success rates as well as incidence of new and different supraventricular arrhythmias following arrhythmia surgery and radiofrequency catheter ablation for atrioventricular nodal reentrant tachycardia. Today radiofrequency catheter ablation has replaced arrhythmia surgery for various reasons, but the late arrhythmic side-effects warrant refinement of technique.

Objective: To compare the long-term results of surgical modification and of radiofrequency (RF) catheter modification of the atrioventricular node (AV node), to combat recurrent atrioventricular nodal re-entrant tachycardia (AVNRT)., Design: Retrospective descriptive., Setting: St. Antonius Hospital, Nieuwegein, the Netherlands., Method: In the period 1988-1992, 26 patients underwent surgical modification and in 1991-1996, 120 patients were subjected to RF catheter modification of the AV node for recurrent AVNRT. The follow-up amounted to at least one year., Results: Surgery was immediately successful in 96%, and RF catheter ablation in 92%. A recurrence AVNRT was seen in 12 and 17% respectively, the ultimate success rates (after retreatment) were 100 and 98%. Three patients (3%) in the RF catheter ablation group developed a second or third-degree AV block necessitating pacemaker implantation. No third-degree AV block was seen in the surgical group. Mean follow-up was 53 months in the surgical group and 28 months in the RF catheter ablation group. Both procedures were accompanied by other supraventricular tachycardias, viz. in 27% of the surgical and in 11% of the RF catheterization ablation group., Conclusion: RF catheter ablation for the treatment of AVNRT had early and long-term results comparable with those of rhythm surgery. Since catheter treatment is far less taxing to the patient than rhythm surgery, RF catheter ablation now constitutes the most appropriate method for treatment of this arrhythmia.

His-bundle ablation followed by pacemaker implantation is today a widely accepted therapeutic choice when drug refractoriness of symptomatic AF is evident. The selection of pacing mode in patients suffering from paroxysmal AF is still controversial. Preservation of AV synchrony is an attractive option in patients with paroxysmal AF who undergo His-bundle ablation. The purpose of this study was to examine prospectively the contribution of VDDR pacing for preservation of AV synchrony. After His-bundle ablation a VDDR pacing system was implanted in 17 patients with paroxysmal AF, and all antiarrhythmic drugs were withdrawn. The endpoint of the study was defined as the onset of chronic AF. To document the onset of chronic AF 48-hour Holter recordings were made every 6-8 weeks. After a mean followup of 18.2 (range 14-21) months, VDDR pacing is still operative in 13 patients (77%). Four patients developed chronic AF after a mean follow-up of 6 months. Of several baseline characteristics, only the intraatrial P wave at implantation was significantly smaller in patients developing chronic AF than in patients in whom the VDDR mode is still operative. This pilot study suggests that VDDR pacing is an attractive pacing method for patients with paroxysmal AF after His-bundle ablation. A low intraatrial P wave electrogram at implant was associated with a higher risk for the development of chronic AF.

Background: The morphology and polarity of the P wave on 12-lead ECG are of limited clinical value in localizing ectopic atrial rhythms. It was the aim of this study to assess the spatial resolution of body surface P-wave integral mapping in identifying the site of origin of ectopic right atrial (RA) impulse formation in patients without structural atrial disease., Methods and Results: Sixty-two-lead ECG recordings were obtained during RA pacing at 86 distinct endocardial sites in nine patients with normal biatrial anatomy. After P-wave integral maps were generated for each paced activation sequence, 17 groups with nearly identical map features were visually selected, and a mean P-wave integral map was computed for each group. Supportive statistical analysis to corroborate qualitative group selection was performed by assessment of (1) intragroup pattern uniformity by use of jackknife correlation coefficient analysis of the integral maps contained in each group and (2) intergroup pattern variability by use of the calculation of cross correlations between the 17 mean integral maps. The spatial resolution of paced P-wave body surface mapping in the right atrium was obtained by estimating the area size of endocardial segments with nearly identical P-wave integral maps by use of a biplane fluoroscopic method to compute the three-dimensional position of each pacing site. The latter approach yielded a mean endocardial segment size of 3.5+/-2.9 cm2 (range, 0.79 to 10.75 cm2)., Conclusions: Use of the P-wave morphology on the 62-lead surface ECG in patients with normal biatrial anatomy allows separation of the origin of ectopic RA impulse formation into one of 17 different endocardial segments with an approximated area size of 3.5 cm2. This database of paced P-wave integral maps provides a versatile clinical tool to perform detailed noninvasive localization of right-sided atrial tachycardia before radiofrequency catheter ablation.

Rationale and Objectives: The authors developed an analytic software package for the objective and reproducible assessment of a single leg separation (SLS) in the outlet strut of Björk-Shiley convexoconcave (BSCC) prosthetic heart valves., Methods: The radiographic cinefilm recordings of 18 phantom valves (12 intact and 6 SLS) and of 43 patient valves were acquired. After digitization of regions of interest in a cineframe, several processing steps were carried out to obtain a one-dimensional corrected and averaged density profile along the central axis of each strut leg. To characterize the degree of possible separation, two quantitative measures were introduced: the normalized pit depth (NPD) and the depth-sigma ratio (DSR). The group of 43 patient studies was divided into a learning set (25 patients) and a test set (18 patients)., Results: All phantom valves with an SLS were detected (sensitivity, 100%) at a specificity of 100%. The threshold values for the NPD and the DSR to decide whether a fracture was present or not were 3.6 and 2.5, respectively. On the basis of the visual interpretations of the 25 patient studies (learning set) by an expert panel, it was concluded that none of the patients had an SLS. To achieve a 100% specificity by quantitative analysis, the threshold values for the NPD and the DSR were set at 5.8 and 2.5, respectively, for the patient data. Based on these threshold values, the analysis of patient data from the test set resulted in one false-negative detection and three false-positive detections., Conclusions: An analytic software package for the detection of an SLS was developed. Phantom data showed excellent sensitivity (100%) and specificity (100%). Further research and software development is needed to increase the sensitivity and specificity for patient data.

Introduction: Currently, surgery- and catheter-mediated ablation is applied when drug refractoriness of atrial fibrillation is evident, although little is known about the long-term incidence of new atrial arrhythmia and the preservation of sinus node function., Methods and Results: To address this issue, 30 patients with successful corridor surgery for lone paroxysmal atrial fibrillation and normal preoperative sinus node function were followed in a single outpatient department. Five years after surgery, the actuarial proportion of patients with recurrence of atrial fibrillation arising in the corridor was 8% +/- 5%, with new atrial arrhythmias consisting of atrial flutter and atrial tachycardia in the corridor 27% +/- 8%, and with incompetent sinus node requiring pacing therapy 13% +/- 6%. Right atrial transport was preserved in 69% of the patients without recurrence of atrial fibrillation and normal sinus node function. Stroke was documented in two patients., Conclusions: Corridor surgery for atrial fibrillation is a transient or palliative treatment instead of a definitive therapy for drug refractory atrial fibrillation. This observation strongly affects patient selection for this intervention and constitutes a word of caution for other, nonpharmacologic interventions for drug refractory atrial fibrillation.

Objective: To describe the results of treatment of patients with a life-threatening arrhythmia by implantation of an second generation implantable cardioverter defibrillator with transvenous electrodes., Design: Descriptive., Setting: St.-Antonius Hospital, Nieuwegein, the Netherlands., Method: In the period October 1991-February 1996 the ICD with transvenous electrodes was implanted in 44 patients. After a year the quality of life was assessed by written questionnaire., Results: The in-hospital mortality was 1/44 (2%), without peroperative death. During follow-up 4 patients died: 3 due to congestive heart failure and 1 due to sudden cardiac death. Within one year 50% of the patients had a therapeutical ICD discharge. In 30/44 (68%) patients antiarrhythmic drugs were prescribed to reduce the number of ICD discharges or because they were suffering from paroxysmal atrial fibrillation with high heart rates, which could result in an inappropriate ICD discharge. Quality of life analysis showed a good acceptance of the ICD, although 86% of the patients considered it a very serious limitation that they were not allowed to drive a motor vehicle anymore., Conclusion: The ICD constitutes a major step forward in the treatment of life-threatening ventricular arrhythmias because the implantation is easier and follow-up shows adequate antiarrhythmic effects and survival.

In a single-blind randomized study, the efficacy and safety of intravenous propafenone (2 mg/kg body weight per 10 min) versus flecainide (2 mg/kg per 10 min) were assessed in 50 patients with atrial fibrillation or flutter. Treatment was considered successful if sinus rhythm occurred within 1 h. Conversion to sinus was achieved in 11 (55%) of 20 patients with atrial fibrillation treated with propafenone and in 18 (90%) of 20 with atrial fibrillation treated with flecainide (p less than 0.02). If atrial fibrillation was present less than or equal to 24 h, conversion to sinus rhythm was achieved in 8 (57%) of 14 patients in the propafenone group and 13 (93%) of 14 in the flecainide group (p less than 0.05). Atrial flutter was converted in two (40%) of five patients treated with propafenone and in one (20%) of five with flecainide (p = NS). Mean time to conversion was 16 +/- 10 min in the propafenone group versus 18 +/- 13 min in the flecainide group (p = NS). QRS lengthening (83 +/- 15 to 99 +/- 20 ms) was observed only in the patients treated with flecainide (p less than 0.001). Patients successfully treated with propafenone showed significantly higher plasma levels than those whose arrhythmia did not convert to sinus rhythm. Transient adverse effects were more frequent in the flecainide group (40%) than in the propafenone group (8%) (p less than 0.01). In conclusion, at a dose of 2 mg/kg in 10 min, flecainide is more effective than propafenone for conversion of paroxysmal atrial fibrillation to sinus rhythm. However, considering the propafenone plasma levels and very few adverse effects, the dose or infusion rate, or both, used in the propafenone group may not have been sufficient to achieve an optimal effect. Neither drug seems very effective in patients with atrial flutter.