Dietrich Kalusche

Small or Large Isolation Areas Around the Pulmonary Veins for the Treatment of Atrial Fibrillation? Results From a Prospective Randomized Study

Background— Pulmonary vein (PV) isolation is a promising new treatment for atrial fibrillation (AF). We hypothesized that isolation of large areas around both ipsilateral PVs with verification of conduction block is more effective than the isolation of each individual PV. Methods and Results— A total of 110 patients, 67 with paroxysmal AF and 43 with persistent AF, were randomly assigned to undergo either isolation of each individual PV or isolation of large areas around both ipsilateral PVs. The isolation of each individual PV was an electrophysiologically guided, ostial segmental ablation with a 64-pole basket catheter or a 20-pole circular mapping catheter (group I). Isolation of large areas was performed around the 2 ipsilateral veins with a nonfluoroscopic navigation system and a circular 20-pole mapping catheter for verification of conduction block (group II). In both groups, an irrigated-tip ablation catheter (25 to 35 W) was used to achieve complete isolation. Procedure and ablation times were longer in group II, whereas fluoroscopic time was significantly shorter (P≤0.001). After a follow-up period of 15±4 months, 27 patients in group I (49%) and 37 patients in group II (67%) remained free of symptoms of AF and had no AF or atrial flutter during repetitive Holter monitoring without antiarrhythmic drug treatment after a single procedure (P≤0.05). Conclusions— The rate of success was significantly higher and fluoroscopy times were significantly lower in the group with large isolation areas around both ipsilateral PVs than in those who underwent individual PV isolation.

Incidence of pulmonary vein stenosis 2 years after radiofrequency catheter ablation of refractory atrial fibrillation

AIMS Pulmonary vein ablation offers the potential to cure patients with atrial fibrillation. In this study, we investigated the incidence of pulmonary vein stenosis after radiofrequency catheter ablation of refractory atrial fibrillation by systematic long-term follow-up. METHODS AND RESULTS Forty-seven patients with refractory and highly symptomatic atrial fibrillation underwent radiofrequency catheter ablation of arrhythmogenic triggers inside the pulmonary veins and/or ostial pulmonary vein isolation with conventional mapping and ablation technology. These patients had follow-up examinations at 2 years with transoesophageal doppler-echo and/or angio magnetic resonance imaging for the evaluation of the pulmonary veins. Seventy-seven percent of the patients were free from atrial fibrillation, 51% were without antiarrhythmic drugs, and 26% were on previously ineffective antiarrhythmic drug therapy. However, 13 of the 47 patients showed significant pulmonary vein stenosis or occlusion. Only three of these 13 patients complained of dyspnoea. Distal ablations inside the pulmonary vein were associated with a 5.6-fold higher risk of stenosis than ostial ablations. CONCLUSIONS At 2-year follow-up, the risk of significant pulmonary vein stenosis/occlusion after radiofrequency catheter ablation of refractory atrial fibrillation with conventional mapping and ablation technology was 28%. Distal ablations inside smaller pulmonary veins should be avoided because of the higher risk of stenosis than ablation at the ostium.

Feasibility and Safety of Pulmonary Vein Isolation Using a New Mapping and Navigation System in Patients With Refractory Atrial Fibrillation

Background—Ostial pulmonary vein (PV) isolation by radiofrequency (RF) catheter ablation can cure patients with atrial fibrillation (AF); however, this procedure carries the risk of PV stenosis. The aim of this study was to assess the feasibility of a new mapping and navigation technique using a multipolar basket catheter (BC) for PV isolation in patients with refractory AF and to analyze its safety with regard to PV stenosis at long-term follow-up. Methods and Results—We studied 55 patients (mean age, 53±11 years; 40 male) with drug-refractory AF (paroxysmal, n=37; persistent, n=18). A 64-pole BC was placed transseptally into each of the accessible PVs. By use of a nonfluoroscopic navigation system, the ablation catheter was guided to the BC electrodes at the PV ostium, with earliest activation during sinus rhythm. RF was delivered by use of maximum settings of temperature at 50°C and power at 30 W. The end point of the procedure was the complete elimination of all distal and fragmented ostial PV potentials. Of 165 targeted veins, 163 were successfully isolated with a mean RF duration of 720±301 seconds per vein. At 1-year follow-up, 62% of the patients were in sinus rhythm without antiarrhythmic drugs. Contrast-enhanced magnetic resonance angiography revealed 2 PV stenoses of >25% out of 165 treated vessels. Conclusions—The use of a multipolar BC allowed effective and safe PV isolation by combining 3D mapping and navigation. At 1-year follow-up, 62% of the patients were in sinus rhythm without antiarrhythmic drugs, and the incidence of relevant diameter reduction of the treated PVs was 1.2%.

Necessity for Surgical Revision of Defibrillator Leads Implanted Long-Term Causes and Management

Background— Defibrillator lead malfunction is a potential long-term complication in patients with an implantable cardioverter-defibrillator (ICD). The aim of this study was to determine the incidence and causes of lead malfunction necessitating surgical revision and to evaluate 2 approaches to treat lead malfunction. Methods and Results— We included 1317 consecutive patients with an ICD implanted at 3 European centers between 1993 and 2004. The types and causes of lead malfunction were recorded. If the integrity of the high-voltage part of the lead could be ascertained, an additional pace/sense lead was implanted. Otherwise, the patients received a new ICD lead. Of the 1317 patients, 38 experienced lead malfunction requiring surgical revision and 315 died during a median follow-up of 6.4 years. At 5 years, the cumulative incidence was 2.5% (95% confidence interval, 1.5 to 3.6). Lead malfunction resulted in inappropriate ICD therapies in 76% of the cases. Implantation of a pace/sense lead was feasible in 63%. Both lead revision strategies were similar with regard to lead malfunction recurrence (P=0.8). However, the cumulative incidence of recurrence was high (20% at 5 years; 95% confidence interval, 1.7 to 37.7). Conclusions— ICD lead malfunction necessitating surgical revision becomes a clinically relevant problem in 2.5% of ICD recipients within 5 years. In selected cases, simple implantation of an additional pace/sense lead is feasible. Regardless of the chosen approach, the incidence of recurrent ICD lead-related problems after lead revision is 8-fold higher in this population.

Pre-ablative predictors of atrial fibrillation recurrence following pulmonary vein isolation: the potential role of inflammation.

AIMS An increasing body of evidence has demonstrated the essential role of inflammation in the genesis and maintenance of atrial fibrillation (AF). The aim of the present study was to investigate whether success or failure of electrical pulmonary vein isolation (PVI) in patients with AF is related with the presence of a pre-ablative inflammatory state as determined by known clinical parameters and conventional markers of inflammation including high-sensitivity C-reactive protein, white blood cell (WBC) count, and fibrinogen. METHODS AND RESULTS Seventy-two patients with paroxysmal (64%) or persistent AF (36%) underwent successful electrical PVI. The mean duration of arrhythmia was 5.5 +/- 2.9 years. After a mean follow-up period of 12.5 +/- 5.7 months, 44 patients (61%) were in sinus rhythm. In univariate Cox proportional hazard regression analysis, hypertension, body mass index (BMI), left ventricular ejection fraction, left ventricular end-diastolic diameter, left atrial diameter (LAD), WBC count, and high-sensitivity C-reactive protein were significantly associated with AF recurrence (P < 0.05). In multivariate Cox proportional hazard regression analysis, hypertension [hazard ratio (HR) 3.127; 95% confidence interval (CI) 1.269-7.706, P = 0.013], LAD (HR 1.077; 95% CI 1.014-1.144, P = 0.015), and WBC count (HR 1.423; 95% CI 1.067-1.897, P = 0.016) were independent pre-ablative predictors of AF recurrence following PVI. CONCLUSION Conventional markers of the inflammatory cascade such as WBC count and high-sensitivity C-reactive protein as well as elements of the metabolic syndrome such as hypertension and increased BMI were significantly associated with AF recurrence. The impact of a pre-ablative inflammatory state in the overall success rate of PVI needs further elucidation.

Tpeak-Tend interval and Tpeak-Tend/QT ratio as markers of ventricular tachycardia inducibility in subjects with Brugada ECG phenotype.

AIMS The present study investigated whether several ECG markers of ventricular repolarization are associated with ventricular tachycardia/fibrillation (VT/VF) inducibility in subjects with type 1 ECG pattern of Brugada syndrome (BS). METHODS AND RESULTS The clinical data of 23 individuals (19 males, age 42.69 +/- 14.63) with spontaneous (n = 10) or drug-induced (n = 13) type 1 ECG pattern of BS who underwent programmed ventricular stimulation were analysed. Sustained VT/VF was induced in 17 subjects (74%) and was significantly associated with the presence of spontaneous type 1 ECG of BS (P = 0.012). Among the studied ECG repolarization markers, subjects with inducible VT/VF displayed an increased T(peak)-T(end) interval in leads V(2) (88.82 +/- 15.70 vs. 78.33 +/- 4.08 ms, P = 0.02) and V(6) (76.33 +/- 10.08 vs. 66.66 +/- 5.16 ms, P = 0.04) and a greater T(peak)-T(end)/QT ratio in lead V(6) (0.214 +/- 0.028 vs. 0.180 +/- 0.014, P = 0.009) compared with those without arrhythmias. Ventricular tachycardia/fibrillation inducibility was not associated with arrhythmic events during a mean follow-up period of 4.61 +/- 2.14 years (P = 0.739). CONCLUSION The T(peak)-T(end) interval and T(peak)-T(end)/QT ratio were associated with VT/VF inducibility in BS. The utility of T(peak)-T(end)/QT ratio as a new marker of arrhythmogenesis in BS requires further studies, including a large number of patients.

Prevalence of early repolarization pattern in inferolateral leads in patients with Brugada syndrome

BACKGROUND Recent data have shown a high incidence of the early repolarization pattern confined in inferolateral leads in patients with idiopathic ventricular fibrillation. OBJECTIVES The purpose of the present study was to investigate the prevalence and the prognostic significance of the early repolarization pattern in inferolateral leads in patients with Brugada syndrome. METHODS Clinical, genetic, and electrophysiologic data from 290 individuals (223 males, mean age 48.3 +/- 14.2 years) with a spontaneous or drug-induced type 1 electrocardiogram (ECG) pattern of Brugada syndrome and structurally normal hearts were analyzed. Twelve-lead ECGs were evaluated for the presence of early repolarization pattern, which was defined as J-point elevation of at least 0.1 mV from baseline in at least two inferior or lateral leads. Follow-up data were obtained for all subjects. RESULTS An early repolarization pattern manifested as notched or slurred J-point elevation mainly in lateral leads was observed in 35 subjects (12%). The prevalence of the early repolarization pattern was significantly higher in male subjects (P = .004). During a mean follow-up period of 44.9 +/- 27.5 months, 22 subjects (8%) displayed an arrhythmic event including sudden cardiac death. There were no significant differences regarding spontaneous ECG type of Brugada syndrome, symptoms, family history of sudden cardiac death, and positive genetic test between subjects with and without the early repolarization pattern. The presence of early repolarization pattern was not associated with arrhythmic events during follow-up (Hazard ratio [HR] 1.090; 95% confidence interval 0.349-3.403; P = .882). CONCLUSION The early repolarization pattern in inferolateral leads is not an uncommon finding in Brugada syndrome. In our population, the early repolarization features were not associated with a worse outcome in subjects with Brugada syndrome.

Cellular damage, platelet activation, and inflammatory response after pulmonary vein isolation: a randomized study comparing radiofrequency ablation with cryoablation.

BACKGROUND Experimental data suggest that use of cryoablation in pulmonary vein isolation (PVI) is associated with less cell damage and less thrombus formation compared to radiofrequency (RF) energy. OBJECTIVE The purpose of this study was to test the hypothesis that cryoablation significantly reduces markers of cell damage, platelet activation, and inflammation in patients undergoing PVI for treatment of atrial fibrillation (AF). METHODS Sixty patients with symptomatic drug-resistant AF (age 56 ± 9 years, 48 males, 38 with paroxysmal AF) were randomly assigned to undergo PVI using either an open irrigated-tip RF catheter or a cryoballoon. Markers of cell damage (high-sensitive troponin T [hs-TnT], microparticles), platelet activation (platelet reactivity by aggregometry, expression of platelet surface proteins P-selectin and activated glycoprotein [GP] IIb/IIIa), and inflammatory response (high-sensitive C-reactive protein [hs-CRP]) were determined before and up to 48 hours after the procedure. RESULTS PVI resulted in a significant rise in hs-TnT, microparticles, markers of platelet activation, and hs-CRP over time, with distinct temporal patterns for each parameter. However, after Bonferroni correction for repeated measurements, no significant differences were noted in these parameters between patients treated with cryoablation or RF energy. Procedural time was significantly shorter in patients treated with cryoballoon (177 ± 30 minutes vs 200 ± 46 minutes, P = .03), with no differences in fluoroscopic time, periprocedural complications, or success rate. CONCLUSION Cryoablation and RF energy result in a comparable rise of markers of cell damage, platelet activation and inflammatory response. The data do not support the concept of an improved safety profile for cryoablation in PVI.

High-density mapping of spontaneous pulmonary vein activity initiating atrial fibrillation in humans.

Introduction: High‐density three‐dimensional (3D) mapping of the pulmonary vein (PV)‐left atrial (LA) junction was performed to characterize spontaneous PV activity in humans.

The impact of body mass index on the efficacy and safety of catheter ablation of atrial fibrillation.

BACKGROUND Obesity is a well established risk factor for atrial fibrillation (AF) development. Our purpose was to determine the impact of body mass index (BMI) on the safety and efficacy of radiofrequency catheter ablation of AF. METHODS Two hundred and twenty-six consecutive patients with symptomatic, drug-refractory paroxysmal (59.3%) and persistent (40.7%) AF underwent wide circumferential electrical pulmonary vein isolation. Patients were classified according to BMI as normal (<25kg/m(2)); overweight (25 to 29.9kg/m(2)); and obese (≥30kg/m(2)). RESULTS Patients with high BMI were younger and displayed a higher rate of hypertension, increased left atrial diameter, increased left ventricular end-diastolic and end-systolic diameters, and increased levels of several conventional markers of inflammation and oxidative stress including white blood cell count, fibrinogen, uric acid, alanine aminotransferase, and gamma-glutamyltransferase (p<0.05). After a mean follow-up period of 432.32±306.09days from the index procedure, AF recurrence rate was 34.9% for normal weight, 46.2% for overweight, and 46.2% for obese patients (p: 0.258). Subjects classified above the 50th percentile for BMI displayed a trend toward a higher AF recurrence rate (p: 0.08). In univariate Cox regression survival analysis, BMI was not predictive of AF recurrence. Radiation exposure was significantly higher in overweight and obese patients in relation to normal weight patients (p: 0.003). No significant differences regarding major complications were observed among BMI groups. CONCLUSIONS In this study population, BMI was not an independent predictor of AF recurrence following left atrial catheter ablation.