Characterization of a stepwise approach in cavotricuspid isthmus ablation for typical atrial flutter: A randomized study comparing three catheters.

INTRODUCTION: Our aim was to characterize a stepwise approach in cavotricuspid isthmus ablation for typical atrial flutter in a prospective, noncrossover randomized study. METHODS: One hundred and fifty patients referred for cavotricuspid isthmus (CTI)-dependent atrial flutter ablation were randomized to undergo an ablation with an 8-mm-tip catheter (group 1), a 3.5-mm open irrigation-tip catheter (group 2), and a 3.5-mm open irrigation porous-tip catheter (group 3). A stepwise approach was performed, changing the ablation site from medial to septal aspects of the CTI, in case it was not effective without crossover between catheters. RESULTS: CTI block was achieved in all the patients using only one catheter. There was a 68% efficacy in group 1, 40% in group 2, and 28% in group 3 to achieve CTI block within 10 minutes (P  =  0.001) and 96%, 70%, and 70% in groups 1, 2, and 3, respectively, within 20 minutes (P  =  0.002) of radiofrequency ablation. The 8-mm catheter was also faster in fluoroscopy time and CTI block time. There were no differences in efficiency in the both irrigated catheters. There were no significant differences in complications among three catheters. CONCLUSIONS: With this stepwise approach, it is possible to achieve CTI block in all cases, using a single catheter without crossover, with good times of procedure and with a low complication rate. The 8-mm solid catheter is faster than the other irrigated-tip catheters. The 3.5-mm open irrigation porous-tip catheter is as effective and safe as the conventional irrigated-tip catheter.

Long-term arrhythmia follow-up of patients with myotonic dystrophy.

BACKGROUND: Myotonic dystrophy (MD) is the most common muscular dystrophy in adults and is associated with sudden death. Reported predictors of sudden death in this population include atrial tachyarrhythmias, a PR interval greater than 240 milliseconds, aberrant QRS conduction, and any degree of AV block. OBJECTIVE: We sought to report on the arrhythmic outcome of a cohort of patients with a new diagnosis of genetically proven MD. METHODS: We performed a retrospective review of 37 patients with genetically confirmed MD referred to our electrophysiology clinic for primary cardiac screening. RESULTS: There were 25 patients with MD type 1 (MD1) and 12 patients with MD type 2 (MD2). Eight patients with MD1 (32%) had atrial fibrillation, compared to only one patient with MD2 (8.3%). Patients with MD1 were more likely to have evidence of conduction disease abnormalities (40% vs. 8.3%, P = ns) and had a higher all-cause mortality (16% vs. 0%) than those with MD2. Criteria for recommending ICD implantation were based on sudden death risk factors suggested by published literature. Eleven patients were offered an ICD, 2 refused and died within the next year. Of the 9 patients who received an ICD, 8 had MD1. Three patients received appropriate shocks, 2 for monomorphic VT, and one for polymorphic VT. CONCLUSION: The presence of AV conduction disturbance in MD patients is associated with a greater risk for ventricular arrhythmias. MD1 was more likely to be associated with cardiac arrhythmias than MD2. The incidence of ventricular arrhythmias among those who received a primary prevention ICD was 33% over 22 months, with 2 patients experiencing monomorphic VT and one experiencing polymorphic VT.

Long-term follow-up of early repolarization pattern in elite athletes.

BACKGROUND: Early repolarization pattern (ERP) is considered a benign variant of the electrocardiogram (ECG), more frequent in athletes. However, prospective studies suggested that ERP is associated with an increased risk of sudden cardiac death (SCD). The purpose of this study is to determine the prevalence, clinical characteristics, and long-term outcome of ERP in elite athletes during professional activity and after retirement. METHODS AND RESULTS: A cohort of 299 white elite athletes recruited between 1960 and 1999 was retrospectively analyzed. Athletes were eligible if they had participated for at least 6 consecutive months in high competition and retired for a minimum of 5 years before inclusion. Clinical data and ECG were abstracted from the clinical records using a questionnaire, and outcomes after a mean follow-up of 24 years were registered. Among the 299 athletes, 66% were men with a mean age of 20 (SD 6.4) years. ERP was found in 31.4% of participants, and it was located in lateral ECG leads in 57.4% of cases, in inferior leads in 6.4%, and in both leads in the remaining 36.2%. After retirement, ERP still persisted in 53.4% of athletes. Predictive factors for the persistence were: left ventricular hypertrophy signs at the baseline ECG (odds ratio [OR] 4.35; 95% confidence interval [CI], 1.43-13.24; P = .010), sinus bradycardia after retirement (OR 2.56; 95% CI, 1.09-5.99; P = .031), and presence of ERP during the sportive career (OR 20.35; 95% CI, 8.54-48.51; P < .001). After a mean follow-up of 24 years, no episodes of SCD occurred. CONCLUSIONS: A third of elite athletes presented ERP, and this persisted in 53.4% of cases after retirement. After a long follow-up period, no difference in outcome of SCD was seen.

Idiopathic ventricular arrhythmias originating from the moderator band: Electrocardiographic characteristics and treatment by catheter ablation.

BACKGROUND: The moderator band (MB) can be a source of premature ventricular contractions (PVCs), monomorphic ventricular tachycardia (VT), and idiopathic ventricular fibrillation (IVF). OBJECTIVE: The purpose of this study was to define the electrocardiographic (ECG) characteristics and procedural techniques to successfully identify and ablate MB PVCs/VT. METHODS: In 10 patients with left bundle branch block morphology PVCs/VT, electroanatomic mapping in conjunction with intracardiac echocardiography (ICE) localized the site of origin of the PVCs to the MB. Clinical characteristics of the patients, ECG features, and procedural data were collected and analyzed. RESULTS: Seven patients presented with IVF and 3 presented with monomorphic VT. In all patients, the ventricular arrhythmias (VAs) had a left bundle branch block QRS with a late precordial transition (>V4), a rapid downstroke of the QRS in the precordial leads, and a left superior frontal plane axis. Mean QRS duration was 152.7 ± 15.2 ms. Six patients required a repeat procedure. After mean follow-up of 21.5 ± 11.6 months, all patients were free of sustained VAs, with only 1 patient requiring antiarrhythmic drug therapy and 1 patient having isolated PVCs no longer inducing VF. There were no procedural complications. CONCLUSION: VAs originating from the MB have a distinctive morphology and often are associated with PVC-induced ventricular fibrillation. Catheter ablation can be safely performed and is facilitated by ICE imaging.

Síndrome coronario agudo por embolismo distal de un trombo localizado en el tronco común / Acute coronary syndrome due to distal embolization of a thrombus located in the left main coronary artery

No disponible

Mechanical left ventricular dyssynchrony detection by endocardium displacement analysis with 3D speckle tracking technology.

Myocardium deformation and displacement analysis by echocardiography has proven useful to evaluate the synchrony of myocardial mechanics. The aim of our study was to evaluate the mean standard deviation of time to longitudinal peak displacement in 16 cardiac segments by 3D echo wall motion Speckle Tracking analysis. We studied 15 patients with ventricular dyssynchrony-defined by a QRS > 120 ms in the ECG. We obtained the differences between time peaks of endocardial longitudinal displacement for 16 segments of the heart by 3D echo Speckle Tracking. We compared the temporal dispersion of these peaks with results obtained in a control group of 13 healthy individuals without dyssynchrony. The results showed a significant difference (p < 0.001) between the dispersion of standard deviation in the 13 patients in the control group (34 ms ± 19) and the 15 patients in the dyssynchrony group (117 ms ± 57). We describe a new parameter obtained by 3D echo wall motion Speckle Tracking analysis for the detection of dyssynchrony. It can be useful to identify dyssynchrony of left ventricular myocardial mechanics, to indicate the resynchronization therapy, to optimize the parameters of the device and to achieve a less operator-dependent evaluation.