Filippo Lamberti

Radiofrequency Catheter Ablation of Idiopathic Left Ventricular Outflow Tract Tachycardia: Utility of Intracardiac Echocardiography

Idiopathic LVOT Tachycardia. Introduction: The site of origin of idiopathic ventricular tachycardia (VT) arising from the left ventricular outflow tract (LVOT) may be closely related to the aortic valve leaflets, and radiofrequency (RF) delivery potentially can damage them. Intracardiac echocardiography (ICE) can identify accurately the ablation electrode and anatomic landmarks, and contact with the endocardium can be easily assessed. The aim of this study was to define the utility and the accuracy of ICE in guiding RF ablation of idiopathic VT of the LVOT.

Long-Term Follow-Up of Right Atrial Ablation in Patients with Atrial Fibrillation:

Introduction: The aim of this study was to evaluate the efficacy and the impact on quality of life of a new ablative approach to the right atrium in patients with atrial fibrillation (AF).

Postcardioversion atrial electrophysiologic changes induced by oral verapamil in patients with persistent atrial fibrillation

OBJECTIVES The aim of our study was to verify the effect of oral administration of verapamil on atrial electrophysiologic characteristics after cardioversion of persistent atrial fibrillation (AF) in humans. BACKGROUND Discordant findings have been reported regarding the efficacy of verapamil in preventing the electrical remodeling induced by AF. METHODS We determined the effective refractory periods (ERPs) at five pacing cycle lengths (300 to 700 ms) and in five right atrial sites after internal cardioversion of persistent AF (mean duration 238.1+/-305.9 days) in 19 patients. Nine patients received oral verapamil (240 mg/day) starting four weeks before the electrophysiologic study, whereas the other 10 patients were in pharmacologic washout. RESULTS The mean ERPs were 202.0+/-22.7 ms in the washout group and 189.3+/-18.5 ms in the verapamil group (p < 0.0001). The degree of adaptation of refractoriness to rate was similar in the two groups (mean slope value in the washout group and verapamil group: 0.07+/-0.03 and 0.08+/-0.05, respectively), showing a normal or nearly normal adaptation to rate in the majority of the paced sites in both groups. The mean ERP was slightly longer in the septum than in the lateral wall and in the roof, both in the washout and verapamil groups. CONCLUSIONS In patients with persistent AF, long-term administration of verapamil before internal cardioversion resulted in 1) shortening of atrial ERPs; 2) no change in refractoriness dispersion within the right atrium; and 3) no change in atrial ERP adaptation to rate.

Catheter ablation of idiopathic ventricular tachycardia without the use of fluoroscopy.

BACKGROUND Catheter ablation is the treatment of choice for many patients with idiopathic ventricular tachycardia (VT). Unfortunately, conventional catheter ablation is guided by fluoroscopy, which is associated with a small but definite radiation risk for patients and laboratory personnel. The aim of our study is to assess feasibility, success rate and safety of idiopathic VT ablation procedure performed without the use of fluoroscopy. METHODS Nineteen consecutive patients undergoing idiopathic VT ablation at our institution have been included. The ablation procedures were performed under the guidance of electroanatomical mapping (EAM) system and intracardiac echocardiography (ICE). RESULTS Nineteen patients (mean age 38.7 years) underwent ablation procedure for idiopathic VT. Twelve (63%) had outflow tract VT, 3 (18%) fascicular tachycardia, 2 (11%) peri-tricuspidal VT, 1 (5%) peri-mitral VT, and 1 (5%) lateral left free-wall VT. The mean procedural time was 170.2 ± 45.7 min. No fluoroscopy was used in any procedural phase. Acute success rate was 100%. No complication was documented in any patients. After a mean follow up of 18 ± 4 months, recurrences occurred in 2 patients. CONCLUSIONS In our preliminary experience idiopathic VT ablation without the use of fluoroscopy was feasible and safe, using a combination of EAM and ICE. Success rate was excellent with no complication.

Catheter Ablation in a Patient with a Congenital Giant Right Atrial Diverticulum Presented as Wolff‐Parkinson‐White Syndrome

A young woman symptomatic for tachycardia showed right ventricular preexcitation on the surface ECG with a pattern during induced atrial fibrillation suggestive of multiple APs. Noninvasive imaging techniques performed prior to catheter ablation demonstrated the presence of a giant right atrial diverticulum confirmed by hemodynamic procedure. This structure functioned as an enormous accessory AP. We performed catheter ablation of this pathway using a special 4‐mm multipolar catheter inside the diverticulum. This is the first case of such an anomaly being successfully treated with catheter ablation.

Effect of Percutaneous Closure of Patent Foramen Ovale on Post-Procedural Arrhythmias

To the Editor: Atrial arrhythmias after percutaneous patent foramen ovale (PFO) closure, including atrial fibrillation (AF), has been consistently reported in different series suggesting a causal link between mechanical closure of PFO and the new onset of post-procedural arrhythmias [(1–3)][1].

Transseptal activation during left atrial pacing in humans: electroanatomic mapping using a noncontact catheter and the intracardiac echocardiography.

AbstractBackground: A better understanding of transseptal activation may be important for the treatment of atrial fibrillation, but little is known about preferential routes of conduction from the left atrium (LA) to the right atrium (RA) in humans. Methods and Results: Twelve patients were studied. A noncontact mapping system was used to map the RA during pacing from several sites of LA at different cycle lengths. The location of the Bachmanns bundle (BB), the fossa ovalis (FO) and the coronary sinus (CS) ostium were determined using intracardiac echocardiography. The BB was the earliest area of right atrial activation during pacing from the atrial appendage, roof and postero-superior wall in 94% of cases. The FO was the area of earliest activation during pacing from the septum and the right superior pulmonary veins (PV) in 95% of cases. The CS ostium (alone or associated with the FO) was the region of transseptal breakthrough in all patients during pacing from the right inferior PV, postero-inferior wall and distal CS. Various patterns of activation with 2 or 3 distinct areas of transseptal breakthrough were observed during pacing from the lateral wall and the left superior PV. The pacing cycle length did not influence the modality of transseptal activation. Conclusions: Different patterns of transseptal activation were found during pacing from LA. The preferential routes of conduction from the LA to the RA were related to the sites of stimulation and were not influenced by the pacing cycle length.