Catheter ablation of right atrial ganglionated plexi in patients with vagal paroxysmal atrial fibrillation.

BACKGROUND: Catheter ablation of ganglionated plexi (GP) in the left atrium has been proposed in different subgroup of patients with atrial fibrillation (AF). Anatomic studies found a high prevalence of GP in the posterior surface of the right atrium (RA). Experimental data suggested the potential role of right atrial GP in the AF initiation and maintenance. The aim of our study was to assess the efficacy of GP ablation in RA in patients with vagal AF. METHODS AND RESULTS: Thirty-four patients without structural heart diseases were randomly assigned for a selective ablation procedure targeted on the elimination of vagal reflex evoked by high frequency stimulation or an extensive approach at anatomic sites of GP. All patients underwent Holter ECG and heart rate variability evaluation at baseline and at 3, 6, 12, and 18 months of follow-up. At a mean follow-up of 19.7±5.2 months, AF recurred in 5 of 17 patients with anatomic ablation and in 13 of 17 patients with a selective approach (P=0.01). No patient had major complications. After ablation, heart rate variability parameters showed a significant parasympathetic (and sympathetic) denervation in the first 6 months, which was more prominent in patients with anatomic GP ablation and in those without AF recurrence. CONCLUSIONS: This study demonstrates that in a selected population of vagal paroxysmal AF, the anatomic ablation of GPs in the RA is effective in about 70% of patients. These results confirm that atrial vagal denervation can abolish AF, as suggested by experimental and clinical data.

Early detection of adverse events with daily remote monitoring versus quarterly standard follow-up program in patients with CRT-D.

BACKGROUND: A relative high rate of clinical and device-related adverse events (AE) is generally reported in patients with implantable defibrillators for cardiac resynchronization therapy (CRT-D). Aim of this study was to compare a daily remote monitoring (RM) to a standard program of in-office visits. METHODS AND RESULTS: We retrospectively analyzed RM database and hospital files of 99 CRT-D consecutive patients who were visited in the out-patient clinic every 3-4 months; thirty-three patients were in addition controlled remotely with RM (RM group). Kaplan-Meier curves of clinical or device-related AE-free rates were obtained. During a median follow-up of 7 months, clinical AEs were: ventricular and atrial arrhythmias in 14 and 11 patients, low CRT pacing in nine, heart failure, strokes, or death in 15. Device-related AEs were: insufficient pacing/sensing performances in nine patients, lead dislodgement in five. As comparing the RM group with the remaining patients, Kaplan-Meier curves of clinical AEs diverged to significantly different rates: 23.8% (confidence interval [CI] 0.1%-47.5%) in the RM group and 48.7% (21.6-75.7%) in the remaining patients (P = 0.00002), with a hazard ratio of 0.14 (CI 0.06-0.37). Nondivergent Kaplan-Meier curves were obtained for device-related AE-free rates. CONCLUSION: CRT-D patients followed with quarterly in-office visits without a daily RM system had an 86% higher risk of delayed detection of clinical AEs, during a median follow-up of 7 months.

How many atrial fibrillation ablation candidates have an underlying supraventricular tachycardia previously unknown? Efficacy of isolated triggering arrhythmia ablation.

AIMS: Supraventricular tachycardia may trigger atrial fibrillation (AF). The aim of the study was to evaluate the prevalence of supraventricular tachycardia (SVT) inducibility in patients referred for AF ablation and to evaluate the effects of SVT ablation on AF recurrences. METHODS AND RESULTS: Two hundred and fifty-seven patients (185 males; mean age: 53.4 ± 14.6 years) referred for AF ablation were studied. In all patients only AF relapses had been documented in the clinical history. Twenty-six patients (10.1%; mean age: 43.4 ± 13.3 years; 17 males) had inducible SVT during electrophysiological study and underwent an ablation targeted only at SVT suppression. Ablation was successful in all 26 patients. The ablative procedures are: 12 slow-pathway ablations for atrioventricular nodal re-entrant tachycardia; 9 concealed accessory pathway ablations for atrioventricular re-entrant tachycardia; and 5 focal ectopic atrial tachycardia ablations. No recurrences of SVT were observed during the follow-up (21 ± 11 months). Two patients (7.7%) showed recurrence of at least one episode of AF. Patients with inducible SVT had less structural heart disease and were younger than those without inducible SVT (interventricular septum thickness: 8.4 ± 1.6 vs. 11.0 ± 1.4 mm, P < 0.01; left atrial diameter: 37.0 ± 3.0 vs. 44.0 ± 2.2 mm, P < 0.01; age: 43.4 ± 13.3 vs. 57.3 ± 11.2 years, P < 0.01). Prevalence of paroxysmal AF was higher in patients with inducible SVT when compared with those with only AF (84.6 vs. 24.6%, P < 0.01). CONCLUSION: A significant proportion of candidates to AF ablation are inducible for a SVT. SVT ablation showed a preventive effect on AF recurrences. Those patients should be selected for simpler ablation procedures tailored only on the triggering arrhythmia suppression.

Efficacy of ivabradine administration in patients affected by inappropriate sinus tachycardia.

BACKGROUND: Inappropriate sinus tachycardia (IST) is characterized by an elevated heart rate (HR) at rest and an exaggerated HR response to physical activity or emotional stress. Beta-blockers and calcium channel blockers are the first-line therapy but sometimes are poorly tolerated due to side effects. OBJECTIVE: The purpose of this study was to evaluate the efficacy and safety of ivabradine, a selective inhibitor of the I(f) current of the sinoatrial node, in patients affected by IST. METHODS: Eighteen consecutive symptomatic patients (2 men and 16 women; mean age 45 +/- 15 years) affected by IST were enrolled in the study. Every patient underwent resting ECG, 24-hour Holter ECG, and exercise ECG at baseline and at 3-month and 6-month follow-up. RESULTS: Sixteen patients (14 women; mean age 41 +/- 14 years) completed the study. Holter ECG assessment showed a significant reduction of medium HR (P <.001) and maximal HR (P <.001, basal vs 3-6 months; P = .02, 3 vs 6 months). Minimal HR slightly decreased at 3 months and then stabilized (P = .49, 3 vs 6 months) despite an increased drug dose. Stress test showed a significant decrease at rest (P <.001) and maximal HR (P <.05), suggesting an increased tolerance to physical stress, which was confirmed by a progressive increase of maximal load reached (>100 W) during stress test at 3 months (75%) and 6 months (85%). One patient was excluded because of phosphenes despite dose lowering, and another patient did not complete the protocol. CONCLUSION: Ivabradine could represent an effective and safe alternative to calcium channel blockers and beta-blockers for treatment of IST.