Navegando por Palavras-chave "ventricular tachycardia"
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- ItemAcesso aberto (Open Access)Anatomia angiográfica do sistema venoso coronário. Aplicações em eletrofisiologia clínica(Sociedade Brasileira de Cardiologia - SBC, 1998-06-01) Melo, Wesley Duílio S. [UNIFESP]; Prudencio, Luis A. Renjel [UNIFESP]; Kusnir, Cássia E. [UNIFESP]; Pereira, Ana Lucia N. [UNIFESP]; Marques, Vera [UNIFESP]; Vieira, Magno César [UNIFESP]; De Paola, Angelo Amato Vincenzo [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)PURPOSE: To study the angiographic anatomy of human coronary veins and the possibility of epicardial venous mapping through microelectrode catheters. METHODS: We evaluated 30 patients with sustained ventricular tachycardia using a catheter which provided occlusion of the coronary sinus ostium during venous angiography. They were 25 males, 5 females, ages ranging from 24 to 76 years (mean=52.7). The veins were studied according to their number, caliber and distribution in the anterior and posterior wall of the left ventricle. RESULTS: Coronary sinus was catheterized in all patients. No discomfort or complications were observed. The number of veins from posterior wall of the left ventricle was 3.1 and anterior wall, 1.9, p<0.05. The caliber of the coronary veins were: anterior interventricular vein (distal segment = 1.19±0.22mm, midle segment = 1.65±0.35mm), posterior interventricular vein (distal segment = 1.83±0.47mm, midle segment = 2.00±0.52mm), left posterior vein (distal segment = 1.45±0.25mm, midle segment = 2.49±0.92mm); p<0.05. CONCLUSION: The balloon occlusion technique for coronary venous angiography is feasible and safe. The number and the caliber (distal and midle) of the veins from the posterior wall of the left ventricle were significantly greater than those from the anterior wall. Anatomic conditions for venous epicardial mapping are more adequate in the posterior wall of the left ventricle.
- ItemSomente MetadadadosAngiographic and electrophysiological substrates for ventricular tachycardia mapping through the coronary veins(British Med Journal Publ Group, 1998-01-01) De Paola, Angelo Amato Vincenzo [UNIFESP]; Melo, Wesley Duilio Severino de [UNIFESP]; Tavora, Maria Zildany Pinheiro [UNIFESP]; Martinez, E. E. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Objective-To study the value of epicardial mapping through the coronary venous system in patients with sustained ventricular tachycardia.Design-20 consecutive patients with sustained ventricular tachycardia who were candidates for radiofrequency ablation.Setting-Electrophysiological laboratory.Interventions-Coronary venous angiography was performed with a catheter, which provided coronary sinus occlusion during injection of contrast media. Multipolar microelectrode catheters were then manoeuvred into the tributaries of coronary sinus, using an over-wire system or an on-wire system. An endocardial ablation catheter was positioned in the left ventricle. Conventional programmed ventricular stimulation was performed for sustained ventricular tachycardia induction. Endocardial radiofrequency ablation was performed using impedance or temperature monitoring.Results-Coronary veins were catheterised in all patients; 20 had induction of sustained ventricular tachycardia, 14 were stable. Presystolic epicardial electrograms were recorded in six patients and concealed entrainment in two, helping as a landmark for endocardial ablation. After simultaneous epicardial and endocardial mapping, successful endocardial radiofrequency ablation was achieved in nine of 14 patients with stable ventricular tachycardia (64%).Conclusions-Epicardial mapping through the coronary veins in patients with ventricular tachycardia is feasible, safe, and can be a useful landmark for endocardial catheter mapping and ablation.
- ItemAcesso aberto (Open Access)Characteristics and identification of sites of chagasic ventricular tachycardia by endocardial mapping(Sociedade Brasileira de Cardiologia - SBC, 1999-04-01) Távora, Maria Zildany P. [UNIFESP]; Mehta, Niraj [UNIFESP]; Silva, Rose M. F. L. [UNIFESP]; Gondim, Fernando A. A. [UNIFESP]; Hara, Vanderlei M. [UNIFESP]; De Paola, Angelo Amato Vincenzo [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)OBJECTIVE: To study electrophysiological characteristics that enable the identification and ablation of sites of chagasic tachycardia. METHODS: Thirty-one patients with chronic Chagas' heart disease and sustained ventricular tachycardia (SVT) underwent electrophysiological study to map and ablate that arrhythmia. Fifteen patients had hemodinamically stable SVT reproducible by programmed ventricular stimulation, 9 men and 6 women with ages ranging from 37 to 67 years and ejection fraction varying from 0.17 to 0.64. Endocardial mapping was performed during SVT in all patients. Radiofrequency (RF) current was applied to sites of presystolic activity of at least 30 ms. Entrainment was used to identify reentrant circuits. In both successful and unsuccessful sites of RF current application, electrogram and entrainment were analyzed. RESULTS: Entrainment was obtained during all mapped SVT. In 70.5% of the sites we observed concealed entrainment and ventricular tachycardia termination in the first 15 seconds of RF current application. In the unsuccessful sites, significantly earlier electrical activity was seen than in the successful ones. Concealed entrainment was significantly associated with ventricular tachycardia termination. Bystander areas were not observed. CONCLUSION: The reentrant mechanism was responsible for the genesis of all tachycardias. In 70.5% of the studied sites, the endocardial participation of the slow conducting zone of reentrant circuits was shown. Concealed entrainment was the main electrophysiological parameter associated with successful RF current application. There was no electrophysiological evidence of bystander regions in the mapped circuits of SVT.
- ItemSomente MetadadadosClinical usefulness of electrophysiologic testing in patients with ventricular tachycardia and chronic chagasic cardiomyopathy treated with amiodarone or sotalol(Blackwell Futura Publishing, Inc, 2003-06-01) Leite, L. R.; Fenelon, G.; Simoes, A.; Silva, G. G.; Friedman, P. A.; De Paola, AAV; Mayo Clin & Mayo Fdn; Universidade Federal de São Paulo (UNIFESP)Introduction: This study assessed the role of electrophysiologic testing to identify therapeutic strategies for the treatment of patients with sustained ventricular tachycardia (VT) and chronic chagasic cardiomyopathy treated with amiodarone or sotalol.Methods and Results: One hundred fifteen patients [69 men (60%); mean age 52 +/- 10 years] with chagasic cardiomyopathy presenting with symptomatic VT were studied after loading with Class III antiarrhythmic drugs; 78 had a history of sustained VT, and 37 with symptomatic nonsustained VT had sustained VT induced at baseline electrophysiologic study. All but 12 patients also underwent baseline electrophysiologic study. Mean left ventricular ejection fraction was 0.49 +/- 0.14. Based on results of electrophysiologic study after loading with Class III drugs, patients were divided into three groups: group 1 (n = 23) had no sustained VT induced; group 2 (n = 45) had only tolerated sustained VT induced; and group 3 (n = 47) had hemodynamically unstable sustained VT induced. After a mean follow-up of 52 32 months, total mortality rate was 39.1%; it was significantly higher in group 3 than in groups 2 and 1 [69%, 22.2%, and 26%, respectively, P < 0.0001, hazard ratio (HR) 10.4, 95% confidence interval (CI) 3.8, 21.8]. There was no significant difference in total mortality rate between groups 1 and 2 (P = 0.40, HR 1.5, 95% CI 0.75, 4.58). Cardiac mortality and sudden cardiac death rates also were higher in group 3 patients.Conclusion: in patients with chagasic cardiomyopathy and sustained VT, electrophysiologic testing can predict long-term efficacy of Class III antiarrhythmic drugs. This may help in the selection of patients for implantable cardioverter defibrillator therapy.