RESUMEN
OBJECTIVE: To analyze the clinical features idiopathic ventricular tachycardia (IVT) and evaluate the effect of radiofrequency ablation therapy for their management. METHODS: An retrospective analysis was conducted in 165 IVT patients who received radiofrequency ablation therapy. IVT was classified into 3 types according to the site of origin, namely the right ventricular outflow tract (RVOT-IVT, 86 cases), left ventricular septum (LV-IVT, 75 cases), and left Valsalva sinus (4 cases). RESULTS AND CONCLUSION: RVOT-IVT was more frequent in female patients than in male patients (60 vs 26, M/F ratio of 0.43). In LV-IVT, male patients prevailed (54 vs 21, M/F ratio of 2.57), suggesting a gender difference in the incidence of IVT. IVT occurred mainly in young and middle-age patients. Most RVOT-IVT occurred in the third to fourth decade of life (mean 36-/+12 years), and LV-IVT occurred at a younger age than did RVOT-IVT (mean 26-/+15 years, P<0.01). Twelve-lead ECGs revealed left bundle branch block morphology in RVOT-IVT, and most of them presented with frequent premature ventricular contraction and/or non-sustained ventricular tachycardia. All the RVOT-IVT patients were successfully ablated by radiofrequency energy in pace mapping. LV-IVT patients with right bundle branch block morphology presented sustained ventricular tachycardia for most of the time, and 97% of the patients were successfully managed with radiofrequency ablation in activation mapping. Four IVT patients were characterized by atypical bundle branch block, an inferior axis, and an R/S ratio >1 in lead V3 or V2, and their tachycardia was ablated successfully in the left sinus of Valsalva using pace mapping. Radiofrequency ablation is currently an effective procedure for IVT management.
Asunto(s)
Ablación por Catéter/métodos , Taquicardia Ventricular/terapia , Adulto , Anciano , Angioplastia por Láser/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Taquicardia Ventricular/patología , Resultado del TratamientoRESUMEN
OBJECTIVE: To evaluate the protective effect of losartan, an angiotensin II type 1 (AT1) receptor antagonist, against myocardial ischemic reperfusion in intact canine. METHODS: Sixteen dogs were divided into model group(n=8) with left anterior descending coronary artery occlusion for 30 min followed by reperfusion for 30 min and losartan group (n=8) with 5 mg/(kg x d) intragastric losartan administration for 2 weeks before the ischemic-reperfusion model establishment. Monophasic action potential recording technique was employed to observe the incidence of early after depolarization (EAD) and reperfusion arrhythmias. RESULTS: In the model group, 5 dogs (62.5%) developed EAD and reperfusion arrhythmia while 3 (37.5%) developed the symptoms in losartan group, showing significant difference between the two groups (P<0.05). No ventricular tachycardia or ventricular fibrillation was observed in losartan group (P<0.01). CONCLUSION: Losartan can suppress the occurrence of EAD during reperfusion following myocardial ischemia to reduce the incidence of reperfusion arrhythmias, suggesting its protective effect against myocardial ischemic injury.