Claudio Pratola

Catheter-tissue contact force for pulmonary veins isolation: a pilot multicentre study on effect on procedure and fluoroscopy time.

Aims Catheter–tissue contact is critical for effective lesion creation in radiofrequency catheter ablation (RFCA). In a multicentre prospective study, we assessed the effect of direct contact force (CF) measurement on acute procedural parameters during RFCA of atrial fibrillation (AF). Methods and results A new open-irrigated tip catheter with CF sensing (SmartTouch™, Biosense Webster Inc.) was used. All the patients underwent the first ablation procedure for paroxysmal AF with antral pulmonary vein (PV) isolation, aiming at entry and exit conduction block in all PVs. Ninety-five patients were enroled in nine centres and successfully underwent ablation. Overall procedure time, fluoroscopy time, and ablation time were 138.0 ± 67.0, 14.3 ± 11.2, and 33.8 ± 19.4 min, respectively. The mean CF value during ablation was 12.2 ± 3.9 g. Force time integral (FTI) analysis showed that patients achieving a value below the median of 543.0gs required longer procedural (158.0 ± 74.0 vs. 117.0 ± 52.0 min, P = 0.004) and fluoroscopy (17.5 ± 13.0 vs. 11.0 ± 7.7 min, P = 0.007) times as compared with those in whom FTI was above this value. Patients in whom the mean CF during ablation was >20 g required shorter procedural time (92.0 ± 23.0 vs. 160.0 ± 67.0 min, P = 0.01) as compared with patients in whom this value was <10 g. Four groin haematomas were the only complications observed. Conclusion Contact force during RFCA for PV isolation affects procedural parameters, in particular procedural and fluoroscopy times, without increasing complications.

Value of right ventricular–left ventricular interlead electrical delay to predict reverse remodelling in cardiac resynchronization therapy: the INTER-V pilot study

AIMS Few studies have systematically evaluated the value of intra-procedural parameters in predicting response to cardiac resynchronization therapy (CRT). We investigated whether intracardiac (electrogram) measurements of electrical delays between the positioned right ventricular (RV) and left ventricular (LV) leads at implantation could predict the mid-term CRT response. METHODS AND RESULTS Fifty-two patients underwent CRT implantation according to standard techniques and clinical indications. The RV-LV interlead electrical delay measured during spontaneous rhythm and the difference between the pacing-induced (Deltap) RV-LV interlead electrical delays measured during RV and LV pacing were defined intraoperatively using the electrical depolarizations registered at the ventricular leads on the device programmer. At 6 months, a reduction of LV end-systolic volume > or = 15% was used to define CRT responders. Responders (62%), when compared with non-responders, showed a higher proportion of ischaemic aetiology (P = 0.007) and a lower value of DeltapRV-LV interlead electrical delay (22.1 +/- 18.4 vs. 46.3 +/- 15.0 ms, P = 0.0001). At multivariate analysis, the DeltapRV-LV interlead electrical delay was the only independent predictor of response to CRT (P = 0.001). For such a parameter, the receiving operating characteristic curve analysis identified a cut-off value of 42 ms corresponding with the highest accuracy: sensitivity 90.6%; specificity 70%; positive and negative predictive value 83% and 82%, respectively. Conversely, no difference was ascertained between responders and non-responders when RV-LV interlead electrical delay was measured during spontaneous rhythm (76.1 +/- 28.5 vs. 89.6 +/- 21.2, P = 0.078). CONCLUSION Intraprocedural measuring of paced RV-LV interlead electrical delay obtained during RV and LV pacing predicts mid-term CRT response.

Atrial Fibrillation and Recurrent Ventricular Fibrillation During Hypokalemia in Brugada Syndrome

A 41‐year‐old man with Brugada syndrome (BS) and no previous episodes of aborted sudden death or syncope referred to local emergency room for an episode of symptomatic atrial fibrillation. Blood chemistry results showed hypokalemia (2.9 mEq/L). The other parameters were within the normal range. After few minutes, an episode of ventricular fibrillation treated with biphasic DC shock 150 J occurred. In successive 2 hours, the patient experienced recurrent episodes of ventricular tachycardia and fibrillation. Each biphasic DC shock 150 J was effective to restore sinus rhythm. No further episodes occurred after normalization of serum levels of potassium. Before discharge, an implantable cardioverter defibrillator was inserted to prevent sudden cardiac death. Hypokalemia increases the risk of arrhythmic events in BS.

Impact of remote monitoring on the management of arrhythmias in patients with implantable cardioverter-defibrillator.

Background In the last decade, there has been an exponential increase in cardioverter-defibrillator (ICD) implants. Remote monitoring systems, allow daily follow-ups of patients with ICD. Objective To evaluate the impact of remote monitoring on the management of cardiovascular events associated with supraventricular and ventricular arrhythmias during long-term follow-up. Methods A total of 207 patients undergoing ICD implantation/replacement were enrolled: 79 patients received remote monitoring systems and were followed up every 12 months, and 128 patients were followed up conventionally every 6 months. All patients were followed up and monitored for the occurrence of supraventricular and ventricular arrhythmia-related cardiovascular events (ICD shocks and/or hospitalizations). Results During a median follow-up of 842 days (interquartile range 476–1288 days), 32 (15.5%) patients experienced supraventricular arrhythmia–related events and 51 (24.6%) patients experienced ventricular arrhythmia–related events. Remote monitoring had a significant role in the reduction of supraventricular arrhythmia–related events, but it had no effect on ventricular arrhythmia–related events. In multivariable analysis, remote monitoring remained as an independent protective factor, reducing the risk of supraventricular arrhythmia–related events of 67% [hazard ratio, 0.33; 95% confidence interval (CI), 0.13–0.82; P = 0.017]. Conclusion Remote monitoring systems improved outcomes in patients with supraventricular arrhythmias by reducing the risk of cardiovascular events, but no benefits were observed in patients with ventricular arrhythmias.

Documentation of pulmonary vein isolation improves long term efficacy of persistent atrial fibrillation catheter ablation

BACKGROUND The aim of this study was to investigate the efficacy of catheter ablation in the treatment of persistent atrial fibrillation (AF) and the predictors of arrhythmia recurrence. METHODS Absence of atrial tachyarrhythmia (AT) recurrence during a mid-term follow-up was correlated with several clinical and procedural characteristics in a population of 82 patients aged 20-70 years who had experienced at least one documented relapse of persistent AF during a single trial of antiarrhythmic drug therapy. Electrophysiological success of ablation was declared when all identified PVs were isolated (confirmation of entry and exit block). Patients were followed for a maximum of 24 months after the blanking period with outpatient visits, ECG recordings, 24-hour Holter monitoring, and weekly transtelephonic monitoring for 30s. RESULTS Electrophysiological success was documented in 38/82 (46.3%) patients. During a mean follow-up of 24.7 ± 4.2 months, 69/82 (84.1%) patients presented at least one episode of AT after the 2 month blanking period. According to univariate and multivariate logistic regression analyses, only an electrophysiologically successful ablation significantly correlated with the absence of documented AT relapse (OR 5.32, 95% CL 1.02-27.72; p=.0472). CONCLUSIONS Mid-term outcome of a single procedure of catheter ablation without the adjunction of antiarrhythmic drug therapy is poor in patients with persistent AF. Documented PV isolation is useful to increase the success rate of circumferential PV ablation even in persistent AF patients.

Radiofrequency atrial fibrillation ablation based on pathophysiology: a diversified protocol with long-term follow-up.

Background The optimal approach and long-term results of radiofrequency catheter ablation of atrial fibrillation (AF) are still unknown. We report our experience with respect to an ablation protocol diversified on a patients AF pathophysiology with long-term follow-up. Methods Seventy-two patients with paroxysmal/persistent drug-resistant AF were selected. Patients with apparently normal hearts (group 1, n = 20) underwent electrophysiological disconnection of pulmonary veins (PVs) presenting a clear PV potential, whereas those with even initial cardiopathy (group 2, n = 52), underwent PV encircling. Results Sinus rhythm was maintained at 6 months in 85% of group 1 and 71% of group 2 patients. After 42 months of follow-up, including 15.2% re-do procedures, 85% of group 1 and 77% of group 2 patients were in sinus rhythm, including patients with anti-arrhythmic drugs (AADs). The long-term success rate without AADs was 75% and 46% for each group, respectively. Age and the 6-month success of the procedure were predictive of sinus rhythm maintenance during follow-up. Conclusions An ablation protocol diversified on AF pathophysiology assured, at 3 years of follow-up, sinus rhythm maintenance in 85% of patients with a normal heart and in 77% of those with even initial cardiopathy. The 6-month result of the ablation procedure remained stable over time.

A migrant left ventricular lead

We report the case of 70-year-old woman with Reel syndrome and cardiac resynchronization therapy device who experienced severe device malfunction. Reel syndrome was misdiagnosed for several months and the patient manifested fatigue, discomfort and diaphragmatic stimulation.

Correspondence: left ventricular pacing rate lower than expected during manual pacing threshold test in a biventricular defibrillator.

We appreciate the description of the case report by De Maria et al .1 The authors reported an example of threshold test in VVI mode of the left ventricular (LV) lead. They described the discrepancy between programmed heart rate of threshold test in LV VVI mode and effective heart rate of the patient during the test …