Maria Luisa Loricchio

Catheter Ablation of Paroxysmal Atrial Fibrillation Using a 3D Mapping System

BACKGROUND We treated paroxysmal recurrent atrial fibrillation (AF) with radiofrequency (RF) catheter ablation by creating long linear lesions in the atria. To achieve line continuity, a 3D electroanatomic nonfluoroscopic mapping system was used. METHODS AND RESULTS In 27 patients with recurrent AF, a catheter incorporating a passive magnetic field sensor was navigated in both atria to construct a 3D activation map. RF energy was delivered to create continuous linear lesions: 3 lines (intercaval, isthmic, and anteroseptal) in the right atrium and a long line encircling the pulmonary veins in the left atrium. After RF application, the atria were remapped to validate completeness of the block lines, demonstrated by late activation of the areas circumscribed by the lines. The mean procedure duration was 312+/-103 minutes (range, 187 to 495), with mean fluoroscopy time of 107+/-44 minutes (range, 32 to 185 minutes). No acute complications occurred, but 1 patient experienced early prolonged sinus pauses and received a pacemaker. During the first day, 17 patients (63%) had AF episodes, but at discharge, 25 patients were in sinus rhythm. After a follow-up of 6. 0 to 15.3 months (average, 10.5+/-3.0 months), 16 patients are asymptomatic, 3 have an almost complete disappearance of symptoms, 1 patient is improved, and 7 patients have their AF attacks unchanged. CONCLUSIONS Paroxysmal recurrent drug-refractory AF can be treated by RF catheter ablation. Creation of long continuous linear lesions necessary to compartmentalize the atria is facilitated by a nonfluoroscopic electroanatomic mapping system.

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.

C-reactive protein and left atrial appendage velocity are independent determinants of the risk of thrombogenesis in patients with atrial fibrillation

BACKGROUND The association between inflammatory status and thrombosis in patients with atrial fibrillation (AF) is unclear. We studied the correlation between inflammation and the risk of thrombogenesis in patients with AF and the relationship of inflammation with other factors associated with thrombotic risk. METHODS We studied 150 consecutive patients (69 men, age 65+/-12 years) with persistent non-valvular AF who had transesophageal echocardiography prior to cardioversion. Patients underwent also measurements of high-sensitivity C-reactive protein, fibrinogen, D-dimer, and hematocrit levels. RESULTS Patients were divided into two groups according to the presence (n=52) or absence (n=98) of dense spontaneous echo contrast (SEC) in left atrium or left atrial appendage. The two groups were similar for age, sex, and major clinical risk factors. Patients with dense SEC had significantly larger left atrium diameter (p=0.007), lower left atrial appendage mean velocity (p<0.0001), and higher levels of C-reactive protein (p=0.003), D-dimer (p=0.008), and fibrinogen (p=0.006). At multivariate analysis, only left atrial appendage velocity (odds ratio: 19.11; 95% confidence interval 4.2-80.9) and C-reactive protein (odds ratio: 3.41; 95% confidence interval 1.2-9.8) were significantly associated with thrombus and/or dense SEC. However, there was no relationship between C-reactive protein levels and left atrial appendage velocity (p=0.24, r=-0.09). CONCLUSIONS Our results show that left atrial appendage velocity and C-reactive protein are independently associated with the risk of thromboembolism in AF. Thus, blood stasis and inflammation appear to constitute two major distinct components of thrombogenesis.

Prevention of Syncope through Permanent Cardiac Pacing in Patients with Bifascicular Block and Syncope of Unexplained Origin: The PRESS Study

Background—Syncope in patients with bifascicular block (BFB) is a common event whose causes might be difficult to assess. Methods and Results—Prevention of syncope through permanent cardiac pacing in patients with bifascicular block (PRESS) is a multicenter, prospective, randomized, single-blinded study designed to demonstrate a reduction in symptomatic events in patients with bifascicular block and syncope of undetermined origin implanted with permanent pacemaker. Device programming mode (NASPE/BPEG code) at DDD with a lower rate of 60 ppm is compared with backup pacing at DDI with a lower rate of 30 ppm. The end point consisted of (1) syncope, (2) symptomatic presyncopal episodes associated with a device intervention (ventricular pacing), and (3) symptomatic episodes associated with intermittent or permanent atrioventricular block (any degree). One hundred one patients were enrolled and randomized. Primary end point events at 2 years were observed in 23 patients, with a significant lower incidence in the study group (hazard ratio, 0.32; 95% confidence interval [CI], 0.10–0.96; P=0.042). Reduction of any symptoms, associated or not with device intervention, was superior in DDD60 compared with DDI30 (hazard ratio, 0.4; 95% confidence interval, 0.25–0.78; P=0.0053). Fourteen patients developed other rhythm diseases and met class I indication for pacing. The annual incidence of rhythm disease development was 7.4%. Conclusions—In patients with bifascicular block and syncope of undetermined origin, the use of a dual chamber pacemaker programmed to DDD60 led to a significant reduction of syncope or symptomatic events associated with a cardioinhibitory origin, compared with DDI30 programming. Symptoms associated with a new onset of rhythm disease were found in 15% of the population at 2 years.

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).

Pacing failure due to microdislodgement of ventricular pacing lead detected by home monitoring technology.

A 68-year-old woman affected by sick sinus syndrome was implanted with a dual-chamber pacemaker provided by home monitoring technology. After discharge, an increase in ventricular threshold and a high variability of R wave measurements were detected early by the home monitoring system. Manual tests confirmed the presence of pacing and sensing failure and a normal ventricular impedance. The pacing lead integrity and a stable position of the lead tip in right ventricular apex were assessed by chest X-ray. A diagnosis of microdislodgement was made. After a second procedure for ventricular lead repositioning, no further malfunctions were detected.

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.

Role of electroanatomic mapping in assessing the extent of atrial standstill: diagnostic and therapeutic implications.

Atrial standstill is characterized by failure of atrial excitation, either spontaneous or induced by atrial electric stimulation. We report the case of a 38-year-old man with severe bradycardia and junctional escape rhythm associated with dilative cardiomyopathy. Electroanatomic mapping showed the absence of atrial viability in almost the entire right atrial endocardial surface and excluded the feasibility of atrial pacing.