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L Mont

Publications and source records attributed to L Mont.

At least 19 recordsLinked to original sources
PubMed2003

Diagnostic value of onset-recordings and marker annotations in dual chamber pacemaker stored electrograms.

AIMS: Stored electrograms (EGM) have recently been introduced into pacemaker therapy. New generation devices offer the possibility to store the onset of the EGM (several seconds preceding storage trigger) and marker annotations. The aim of the study was to evaluate whether the diagnostic capabilities of EGMs are improved by these new features. METHODS: We studied 65 patients (age 68+/-12 years, 41 male) implanted with a DDDR-system (PulsarMax II 1280; Guidant). During a 1-month period 319 EGMs have been recorded. EGM triggers were: Ventricular Tachycardia (VT), Non-Sustained VT (NSVT), Atrial Tachycardia Response (ATR), Pacemaker Mediated Tachycardia (PMT) and Sudden Bradycardia Response (SBR). First, each EGM was analysed with onset and markers blinded. EGMs were classified with respect to their trigger as confirmed, not-confirmed or false-positive. Analysis was then repeated with markers visible but without onset, and thereafter vice versa. Finally, EGMs were analysed with both features. It was noted whether the presence of marker annotations and/or onset-recording changed the initial classification of the stored EGMs. RESULTS: 169 EGMs were triggered by SBR, which can only be confirmed with onset recording. False positive EGMs (atrial undersensing) occurred in 12%. The remaining 150 EGMs were triggered by ATR (80%), NSVT (11%), VT (6%) and by PMT (3%). Without onset/markers 37 of these 150 EGMs (25%) could not be confirmed. With markers and onset 33/37 (89%) of these EGMs could now be classified as confirmed or false positive. These EGMs became diagnostic with onset alone in 24%, with markers alone in 24%, and with the combination of both in 41%. In 4 EGMs no definite diagnosis could be established. CONCLUSION: Stored electrograms provide direct insights into device function, thereby providing a validation of diagnostic data. The expanded recording of onset and markers results in markedly improved diagnostic capabilities - compared with conventional EGMs. These new features were necessary to interpret correctly 61% of all stored electrograms, without which a diagnosis would not have been possible. Both onset-recording and marker annotation are necessary for optimal analysis.

Aged↗
PubMed2002

Long-lasting sport practice and lone atrial fibrillation.

AIMS: To analyse whether the proportion of patients with lone atrial fibrillation engaged in chronic sport practice was higher than that observed in the general population. METHODS AND RESULTS: The records of 1160 patients, seen at the arrhythmia outpatient clinic, were reviewed. A total of 70 patients (6%) suffered lone atrial fibrillation and were younger than 65 years. Thirty two of them had been engaged in long-term sport practice. All patients in the sport group were men as compared to only 50% in the sedentary group (P<0 x 0001). To avoid the confounding effect of sex distribution, women were excluded. Sportsmen started their episodes of atrial fibrillation at a younger age, they had a lower incidence of mild hypertension and their episodes of atrial fibrillation were predominantly vagal in contrast to the sedentary patients. The echocardiographic parameters were similar to those observed in the sedentary patients, but when compared with 20 healthy controls, they showed greater atrial and ventricular dimensions and a higher ventricular mass. The proportion of sportsmen among patients with lone atrial fibrillation is much higher than that reported in the general population of Catalonia: 63% vs 15% (P<0 x 05). CONCLUSION: Long-term vigorous exercise may predispose to atrial fibrillation.

Adolescent↗
PubMed2002

Low recurrence of syncope in patients with inducible sustained ventricular tachyarrhythmias treated with an implantable cardioverter-defibrillator.

AIMS: To determine the effectiveness of the implantable cardioverter defibrillator (ICD) in preventing recurrence of syncope in patients with structural heart disease, previously unexplained syncope and inducible ventricular arrhythmias. METHODS: Thirty-eight patients with syncope, structural heart disease and inducible arrhythmias had an ICD implanted. All ICDs delivered antitachycardia pacing and shocks of adjusted energy. Detection and therapy were programmed according to uniform criteria. RESULTS: The mean age of the patients was 63+/-11 years and most of them were male (36/38). After a mean follow-up of 28+/-15 (4-61) months, six patients died and one underwent heart transplantation. Syncope recurred in three patients, but in none of them was it caused by an arrhythmic event. In 18 patients, 113 episodes of ventricular tachycardia/ventricular fibrillation were detected and appropriately treated by the ICD. The mean time from implant until first appropriate therapy was 18+/-14 months. The actuarial probability of receiving appropriate therapy was 20% and 42% at 12 and 24 months, respectively. CONCLUSIONS: In patients with unexplained syncope, structural heart disease and inducible arrhythmias, ICD prevents syncope associated with arrhythmic events. Frequent effective use of antitachycardia pacing and shocks of adjusted energy seem essential to this aim.

Anti-Arrhythmia Agents↗
PubMed2001

Mechanism of syncope in patients with bundle branch block and negative electrophysiological test.

BACKGROUND: In patients with syncope and bundle branch block (BBB), syncope is suspected to be attributable to a paroxysmal atrioventricular (AV) block, but little is known of its mechanism when electrophysiological study is negative. METHODS AND RESULTS: We applied an implantable loop recorder in 52 patients with BBB and negative conventional workup. During a follow-up of 3 to 15 months, syncope recurred in 22 patients (42%), the event being documented in 19 patients after a median of 48 days. The most frequent finding, recorded in 17 patients, was one or more prolonged asystolic pause mainly attributable to AV block; the remaining 2 patients had normal sinus rhythm or sinus tachycardia. The onset of the bradycardic episodes was always sudden but was sometimes preceded by ventricular premature beats. The median duration of the arrhythmic event was 47 seconds. An additional 3 patients developed nonsyncopal persistent III-degree AV block, and 2 patients had presyncope attributable to AV block with asystole. No patients suffered injury attributable to syncopal relapse. CONCLUSIONS: In patients with BBB and negative electrophysiological study, most syncopal recurrences have a homogeneous mechanism that is characterized by prolonged asystolic pauses, mainly attributable to sudden-onset paroxysmal AV block.

Aged↗
PubMed2001

Mechanism of syncope in patients with isolated syncope and in patients with tilt-positive syncope.

BACKGROUND: Because of its episodic behavior, the correlation of spontaneous syncope with an abnormal finding can be considered a reference standard. METHODS AND RESULTS: We inserted an implantable loop recorder in 111 patients with syncope, absence of significant structural heart disease, and a normal ECG; tilt-testing was negative in 82 (isolated syncope) and positive in 29 (tilt-positive). The patients had had >/=3 episodes of syncope in the previous 2 years and were followed up for 3 to 15 months. Results were similar in the isolated syncope group and the tilt-positive group: syncope recurred in 28 (34%) and 10 patients (34%), respectively, and electrocardiographic correlation was found in 24 (23%) and 8 (28%) patients, respectively. The most frequent finding, which was recorded in 46% and 62% of patients, respectively, was one or more prolonged asystolic pauses, mainly due to sinus arrest, preceded for a few minutes by progressive bradycardia or progressive tachycardia-bradycardia. Bradycardia without pauses was observed in 8% and 12% of cases, respectively. The remaining patients had normal sinus rhythm or sinus tachycardia, except for one, who had ectopic atrial tachycardia. In the tilt-positive group, an asystolic syncope was also recorded when the type of response to tilt-testing was vasodepressor or mixed. Presyncopal episodes were never characterized by asystolic pauses; normal sinus rhythm was the most frequent finding. CONCLUSIONS: Homogeneous findings were observed during syncope. In most patients, the likely cause was neurally-mediated, and the most frequent mechanism was a bradycardic reflex. In the other cases, a normal sinus rhythm was frequently recorded. Presyncope was not an accurate surrogate for syncope in establishing a diagnosis.

Adult↗
PubMed2001

Outcomes after radiofrequency catheter ablation of atrial tachycardia.

The purpose of this study was to evaluate the efficacy, safety, and clinical benefit of radiofrequency catheter ablation (RFCA) in a large series of patients with atrial tachycardia (AT). The determinants of success or failure of RFCA in AT remain unclear. We evaluated the results of radiofrequency ablation in 73 women and 32 men (mean age 48 +/- 19 years) with AT. Mapping techniques were based on identification of the earliest endocardial atrial electrogram recorded during AT. AT originated from the right atrium in 91 patients and from the left atrium in 14. The cardiac ventricles were dilated in 12 patients. AT ablation was successful in 80 patients (77%) regardless of the site of origin. Age, gender, rate of tachycardia, temperature achieved during application, or presence of tachycardiomyopathy were not significant determinants of acute success by univariate analysis. There was a significantly higher acute success rate of ablation in patients with paroxysmal (88%, 45 of 51) and permanent (71%, 30 of 42) forms than in patients with repetitive forms of AT (41%, 5 of 12) (p <0.005). The mean local endocardial electrogram time (relative-to-surface P-wave onset) was -47 +/- 17 ms at successful ablation sites and -29 +/- 21 ms at unsuccessful sites (p <0.03). Ablation was unsuccessful in 25 cases. Thus, RFCA of AT can be performed with a high acute success rate. Patients with repetitive forms and those with multifocal origin had a lower acute success rate. The highest incidence of recurrences was found in anterior right atrial foci.

Adolescent↗
PubMed2001

[Long-term efficacy of radiofrequency catheter ablation in atrial tachycardia].

INTRODUCTION AND OBJECTIVES: Radiofrequency ablation has shown to be an effective treatment for supraventricular tachycardias including flutter and atrial tachycardia, however the clinical information available on atrial tachycardia is limited. The aim of this study was to evaluate the immediate and long term effectiveness of radiofrequency ablation in patients with atrial tachycardia and to establish predictors of effectiveness and arrhythmia recurrence. METHODS: We analyzed a series of 126 procedures of atrial tachycardia ablation in 117 patients (69% women) with a mean age of 50 +/- 19 years. RESULTS: Ninety-one percent of the foci were located in the right atrium. A mean of 6 applications were necessary to achieve an efficacy of 74% during the first procedure with a total of 80%. The only predictor of ablation success was the number of foci being smaller in multifocal compared to unifocal (p < 0.01) whereas for recurrences a less premature electrogram at the application point (p = 0.02) was predictive of ablation success. Over a follow-up of 34 +/- 19 months 7.4% of patients had recurrent atrial tachycardia. The probability of recurrence at one year calculated by the Kaplan-Meier method was 12%. Seventy-one percent of the recurrences occurred during the first 3 months after ablation. CONCLUSIONS: Ablation is an effective, safe procedure for short and long term treatment of patients with atrial tachycardia. Effectiveness depends on the number of foci while the recurrence rate is related to the prematurity of atrial electrogram at the application point.

Adult↗
PubMed2001

Coronary artery revascularization in patients with sustained ventricular arrhythmias in the chronic phase of a myocardial infarction: effects on the electrophysiologic substrate and outcome.

OBJECTIVES: The objective of this study was to analyze the influence of coronary artery revascularization in patients with ventricular arrhythmias. BACKGROUND: Coronary artery revascularization is an effective treatment for myocardial ischemia; however, its effect on ventricular arrhythmias not related to an acute ischemic event has not been carefully studied. METHODS: Sixty-four patients (58 men, mean age 65 +/- 8 years old) with prior myocardial infarction, spontaneous ventricular arrhythmias not related to an acute ischemic event (55 ventricular tachycardia, 9 ventricular fibrillation) and coronary lesions requiring revascularization were studied prospectively. Electrophysiological study was performed before and after revascularization, and events during follow-up were analyzed. RESULTS: At initial study 61 patients were inducible into sustained ventricular arrhythmias. After revascularization, in 62 survivors, 52 out of 59 patients previously inducible were still inducible (group A), and 10 patients were noninducible (group B). No differences were found in clinical, hemodynamic, therapeutic and electrophysiological characteristics between both groups. During 32 +/- 26 months follow-up, 28/52 patients in group A (54%) and 4/10 patients in group B (40%) had arrhythmic events (p = 0.46). An ejection fraction <30% predicted recurrent arrhythmic events (p = 0.02), but not the presence of demonstrable ischemia before revascularization (p = 0.42), amiodarone (p = 0.69) or beta-adrenergic blocking agent therapy (p = 0.53). Total mortality was 10% in both groups. CONCLUSIONS: In patients with ventricular arrhythmias in the chronic phase of myocardial infarction, probability of recurrence is high despite coronary artery revascularization, but mortality is low if combined with appropriate antiarrhythmic therapy. Recurrences are related to the presence of a low ejection fraction but not to demonstrable ischemia before revascularization, amiodarone or beta-blocker therapy nor are they the results of electrophysiological testing after revascularization.

Aged↗
PubMed2001

Prognostic value of electrophysiologic investigations in Brugada syndrome.

INTRODUCTION: The prognostic value of electrophysiologic investigations in individuals with Brugada syndrome is unclear. Previous studies failed to determine its value because of a limited number of patients or lack of events during follow-up. We present data on the prognostic value of electrophysiologic studies in the largest cohort ever collected of patients with Brugada syndrome. METHODS AND RESULTS: Two hundred fifty-two individuals with an ECG diagnostic of Brugada syndrome were studied electrophysiologically. The diagnosis was made because of a classic ECG with a coved-type ST segment elevation in precordial leads V1 to V3. Of the 252 individuals, 116 had previously developed spontaneous symptoms (syncope or aborted sudden cardiac death) and 136 were asymptomatic at the time of diagnosis. A sustained ventricular arrhythmia was induced in 130 patients (51%). Symptomatic patients were more frequently inducible (73%) than asymptomatic individuals (33%) (P = 0.0001). Fifty-two individuals (21%) developed an arrhythmic event during a mean follow-up of 34 +/- 40 months. Inducibility was a powerful predictor of arrhythmic events during follow-up both in symptomatic and asymptomatic individuals. Overall accuracy of programmed ventricular stimulation to predict outcome was 67%. Overall accuracy in asymptomatic individuals was 70.5%, with a 99% negative predictive value. Overall accuracy in symptomatic patients was 62%, with only a 4.5% false-negative rate. No significant differences were found in the duration of the H-V interval during sinus rhythm between symptomatic or asymptomatic individuals. However, the H-V interval was significantly longer in the asymptomatic individuals who became symptomatic during follow-up compared with those who did not develop symptoms (59 +/- 8 msec vs 48 +/- 11 msec, respectively; P = 0.04). CONCLUSION: Inducibility of sustained ventricular arrhythmias is a good predictor of outcome in Brugada syndrome. In asymptomatic individuals, a prolonged H-V interval during sinus rhythm is associated with a higher risk of developing arrhythmic events during follow-up. Symptomatic patients require protective treatment even when they are not inducible. Asymptomatic patients can be reassured if they are noninducible.

Adolescent↗
PubMed2000

[Prospective and comparative study of pacemaker implants carried out at the electrophysiology laboratory and the operating room].

INTRODUCTION AND OBJECTIVES: Permanent pacemaker implantation is done by different physicians with either a surgical or clinical training. Our objective was to evaluate if there were significant differences in the implantation parameters and in the complication rate among implantations performed by cardiologists in the electrophysiologic laboratory and cardiological surgeons in the operating room. MATERIAL AND METHODS: We prospectively collected those patients' data who received a first pacemaker implantation by cardiovascular surgeons and electrophysiologists during the year 1998. Data collected included demographic information, indication for pacing, surgical time, complications during procedure, stimulation and sensing thresholds as well as type of pacing. RESULTS: We first-implanted 216 pacemakers in a one year period, 101 by cardiovascular surgeons and 115 by electrophysiologists. 56% were male patients. Average age in the surgery group was 74.2 +/- 9 years and 72.09 +/- 12 in the electrophysiology group (p = NS). Main diagnoses were as follows: complete heart block in 32.9% patients, complete heart block 2. degrees 16.4%, sinus node dysfunction 12.2%, AV node ablation 12.2% and others. The complications rate for surgery group was 4% and 1.7% for electrophysiologists (p = NS). Electrophysiologists placed more bicameral devices. No clinically significant differences were found among other implant parameters. CONCLUSIONS: Pacemaker implant by cardiologists in an electrophysiologists laboratory is a safe procedure that does not have more complications when compared to the same procedure done in the operating room by surgeons. This allows hospital resource optimization and reduction of hospital stay length.

Aged↗
PubMed2000

[Familial sick sinus syndrome associated to strabismus and persistent left superior vena cava].

We report a family in which the mother and her three sons suffered sick sinus syndrome and strabismus. Two members had a persistent left superior vena cava with drainage into coronary sinus. The illness in all members of this family was oligosymptomatic, and well tolerated with mild symptoms like dizziness, fatigue and exercise dyspnea associated with nodal rhythm. Three of them, had episodes of paroxysmal atrial fibrillation. All patients remain asymptomatic after pacemaker implantation.

Adult↗
PubMed1999

[Analysis of local electrograms and characteristics of the ablation procedure in left-sided accessory pathways that required five or more pulses of radiofrequency].

INTRODUCTION AND OBJECTIVES: Radiofrequency ablation of left sided accessory pathways requires multiple pulses in some patients due to different factors such as inadequate mapping, inappropriate tissue electrode contact and particular anatomic factors. However these characteristics have not been specifically analyzed. METHODS: We have studied a prospective ablative series of 65 consecutive patients with left-sided pathways submitted to radiofrequency ablation by a simplified technique. In every application point, we analyzed the electrogram features, application point, impedance, potency and temperature. RESULTS: 52 patients (80%) required less than 5 radiofrequency pulses (group A) and 13 (20%) required > or = than 5 pulses (group B). The presence of a suggestive potential accessory pathway in local electrogram was similar in both groups and there were no differences in the local A-V or V-A intervals. However, in patients with pre-excitation the Delta-V interval was shorter in group A than in group B (8 ms vs 15 ms; p < 0.001). Furthermore, the impedance observed from the ablation point in group A was lower (108 +/- 12 vs 121 +/- 22 ohms; p < 0.001), and the maximum watts required to reach the predetermined temperature was higher in group A (42 +/- 16 vs 31 +/- 18 watts; p < 0.001). Final success of the procedure was 100%. CONCLUSIONS: Patients requiring more than 5 radiofrequency pulses had electrograms and tissue contact equal or better than those requiring less than 5 pulses. This suggests that difficulties encountered in some procedures can be due to anatomical factors rather than inaccurate mapping or insufficient tissue contact.

Adolescent↗
PubMed1999

Arrhythmia recurrence in patients with a healed myocardial infarction who received an implantable defibrillator: analysis according to the clinical presentation.

OBJECTIVES: The purpose of this study was to analyze the type of arrhythmia recurrence, based on stored electrograms, in patients with a healed myocardial infarction (MI) who received an implantable defibrillator. BACKGROUND: Previous studies suggest that patients presenting with cardiac arrest (CA) tend to recur as ventricular fibrillation (VF), whereas those suffering sustained monomorphic ventricular tachycardia (SMVT) tend to recur as SMVT. However, these data have not been confirmed in a homogeneous population of patients with MI. METHODS: A total of 88 patients was divided into three groups according to their clinical presentation: SMVT (n = 57), CA (n = 16) or syncope (n = 15). RESULTS: There were no significant differences in clinical characteristics among groups. In the electrophysiologic study SMVT was induced in 93%, 94% and 80% of patients, respectively (p = NS). During the follow-up period, 52% of patients presented a total of 671 episodes of ventricular arrhythmia treated by the defibrillator. All recurrences were as SMVT except for one VF. There were 610 episodes of SMVT treated with antitachycardia pacing, with an effectiveness of 96%. A total of 61 episodes was treated initially with cardioversion. No differences in the probability of recurrence were observed among groups, although the statistical power was low (50%). CONCLUSIONS: In patients with an old infarction and malignant ventricular arrhythmias, the majority of recurrences are due to SMVT independently of the clinical presentation (SMVT, CA or syncope) or the induced arrhythmia at the electrophysiologic study. The programming of an antitachycardia zone seems to be appropriate also for patients who present with CA or syncope.

Aged↗
PubMed1999

[Arrhythmia recurrence in patients with an old myocardial infarct treated by implantable defibrillator: an analysis according to the initial clinical presentation].

INTRODUCTION AND OBJECTIVES: The importance of the clinical presentation in the frequency and type of recurrences of ventricular arrhythmias in patients that received an automatic implantable defibrillator is not well known. The purpose of this study was to analyze the frequency and type of recurrences in patients with an old myocardial infarction that received an automatic implantable defibrillator with electrogram recording. METHODS AND RESULTS: We analyzed 100 patients classified in 3 groups according to their clinical presentation: Sustained Monomorphic Ventricular Tachycardia (VT Group n = 65), Cardiac Arrest (CA Group = 19), and Syncope (Syncope Group n = 16). There were no significant differences in the clinical variables among the different groups, nor in the inducibility of arrhythmia at the electrophysiologic study. In a follow-up 27 +/- 14 months, 54% of patients presented at last one episode of sustained ventricular arrhythmia. All recurrences except one were as sustained monomorphic ventricular tachycardia (776 episodes). 81% of episodes of sustained monomorphic ventricular tachycardia (630) were treated with antitachycardia pacing with an effectiveness of 89%. There were no differences in the probability of arrhythmic recurrence among groups but death probability was higher in the ventricular fibrillation group at 36 follow-up months (38% vs 7% and 12% in the sustained monomorphic ventricular tachycardia and syncope groups respectively, p = 0.0113). CONCLUSIONS: In the patients with an old myocardial infarction and malignant ventricular arrhythmias, most of recurrences are due to sustained monomorphic ventricular tachycardia independently of the clinical presentation. The antitachycardia pacing is not only effective in patients with documented sustained monomorphic ventricular tachycardia but also in those that are presented as cardiac arrest or syncope.

Aged↗
PubMed1998

[Long term follow-up in patients with the permanent form of junctional reciprocating tachycardia treated with radiofrequency ablation].

OBJECTIVES: This study sought to determine the long-term follow-up, safety and efficacy of radiofrequency catheter ablation in patients with the permanent form of junctional reciprocating tachycardia. We assessed the reversibility of tachycardia-related left ventricular dysfunction and we detailed the location and electrophysiologic characteristics of these atrioventricular decremental pathways. BACKGROUND: Permanent junctional reciprocating tachycardia is an infrequent form on reciprocating tachycardia, commonly incessant and usually drug-refractory. The electrocardiographic hallmarks include an RP interval > PR with inverted P waves in leads II, III, aVF and V3-V6. During tachycardia, retrograde ventriculo-atrial conduction occurs over an accessory pathway with decremental conduction properties, located predominantly in the posteroseptal zone. It is known that long lasting and incessant tachycardia may result in tachycardia-related severe ventricular dysfunction, the so called tachycardiomyopathy. PATIENTS AND METHODS: We included 24 patients (9 males, 15 females; mean age 42 +/- 22 years) with the diagnosis of permanent junctional reciprocating tachycardia at electrophysiologic study. Six patients had tachycardia-related left ventricular dysfunction. Radiofrequency energy was delivered at the site of earliest retrograde atrial activation during reciprocating tachycardia (n = 22) or ventricular pacing (n = 2). All patients were followed at the outpatient clinic and serial echocardiograms were performed in those who presented depressed left ventricular function. RESULTS: Radiofrequency catheter ablation was performed in 24 decremental accessory pathways. Earliest retrograde atrial activation was right posteroseptal in 22 patients (92%), right midseptal in 1 (4%) and right posterolateral in 1 (4%). Twenty-three accessory pathways were successfully ablated with a mean of 5 +/- 3 (median, 4) radiofrequency applications of a mean duration of 48 +/- 13 s. Only the midseptal accessory pathway could not be ablated. After a mean follow-up of 21 +/- 16 months (median, 15; range 2 to 64) 22 patients remain asymptomatic. There were recurrences in 4 patients after the initial successful ablation (three during the first month and one during the second month after the procedure), two were ablated in a second ablation procedure, one patient required a third procedure and one required a fourth. All patients with left ventricular dysfunction experienced an improvement after ablation. Mean preablation left ventricular ejection fraction in patients with tachycardiomyopathy was 28 +/- 6% (median, 27) and raised to 51 +/- 16% (median, 47) after ablation (p < 0.02). CONCLUSIONS: Our study supports the concept that radiofrequency catheter ablation is a safe and useful treatment for patients with permanent junctional reciprocating tachycardia. Radiofrequency current should be the treatment of choice in these patients because this arrhythmia is usually drug-refractory. The majority of accessory pathways with decremental conduction properties are localized in the posteroseptal zone. Cessation of the arrhythmia after successful ablation results in recovery of left ventricular dysfunction.

Adolescent↗
PubMed1998

[Hemodynamic deterioration in patients submitted to ablation of the atrioventricular node].

INTRODUCTION: Radiofrequency ablation of the atrioventricular conduction system has become an established therapy for patients with drug-refractory atrial fibrillation. We observed 14 patients with hemodynamic deterioration related to worsening of mitral regurgitation after the procedure. PATIENTS AND METHODS: We retrospectively evaluated 256 consecutive patients with drug-refractory atrial fibrillation referred for radiofrequency ablation of the AV node and implantation of a pacemaker. Because we found hemodynamic deterioration related to worsening mitral regurgitation, we compared the clinical history, electrophysiologic and echocardiographic data from the patients with hemodynamic deterioration and worsening mitral regurgitation (group A) with those without hemodynamic deterioration (group B). RESULTS: Fourteen out of 256 patients (group A) undergoing ablation of the atrioventricular conduction system deteriorated with acute pulmonary edema (3 patients) or congestive heart failure (11 patients) at a mean of 6 weeks after the ablation procedure. Four of these patients were referred for mitral valve surgery. The length of the procedure and the number of applications during ablation were similar in both groups. Compared with group B patients, group A patients had significantly higher left ventricular end-diastolic diameters (64 +/- 6 mm vs 56 +/- 9 mm; p < 0.05) at baseline despite similar left ventricular end-systolic diameters, fractional shortening and grade of mitral regurgitation (1.15 +/- 1.05 vs 1.11 +/- 0.97). Moreover, whereas no change was observed in left ventricular end-diastolic diameter, left ventricular end-systolic diameter, fractional shortening and grade of mitral regurgitation in group B patients after ablation, group A patients experienced a significant increase in left ventricular end-diastolic diameter (64 +/- 6 mm vs 72 +/- 9 mm; p < 0.01) and grade of mitral regurgitation (1.15 +/- 1.05 vs 2.90 +/- 1.15; p < 0.01). In patients operated on no ablation related structural damage to the mitral valve apparatus could be detected. The worsening of the mitral regurgitation was related to dilation of the mitral valve annulus. CONCLUSIONS: Hemodynamic deterioration together with progression of mitral regurgitation is a potential complication of ablation of the atrioventricular conduction system.

Adult↗