Características clínicas y electrofisiológicas de pacientes fulgurados con radiofrecuencia por taquicardia por reentrada nodal típica / Clinical and electrophysiological characteristics of patients with atrioventricular nodal reentry tachycardia who underwent slow pathway ablation

AV nodal reentry tachycardia (AVNRT) is the most common cause of paroxysmal supraventricular tachycardia. Radiofrequency ablation is today the treatment of choice. Aim: To report our experience in patients who underwent slow pathway ablation. Patients and methods: Fifty six consecutive patients (68% female, mean age 43 years old) that underwent slow pathway ablation are reported. Results: Sixty four percent of patients had failed drug therapy. During electrophysiological study, AVNRT was induced in 55 patients. Isoproterenol was required for induction in 36%. Programmed atrial stimulation revealed dual AV nodal pathway in only 64% of the patients; 29% had AVNRT with single nodal curve and 7% only prolongation of AH interval. The slow pathway was ablated in 55 patients. One patient refused ablation because of risk of AV block. All patients had immediate success post ablation. Sixty four percent of patients persisted with partial evidence of dual curve manifested by sudden AH prolongation and single echoes. Conclusions: Isoproterenol is essential for ruling out AVNRT, since 29% of the patients had baseline single nodal curve and in only 64% was tachycardia induced without isoproterenol. Persistence of residual dual physiology does not rule out the success of ablation (Rev Méd Chile 2003; 131: 1237-42).

Ablación por radiofrecuencia de extrasistolía ventricular aislada sintomática en corazón sano / Radiofrequency catheter ablation in symptomatic premature ventricular depolarizations in patients without heart disease

Introduction: Premature ventricular depolarizations (PVDs) in patients without heart disease, are a frequent clinical problem that can cause important symptoms. Most commonly, this benign arrhythmia responds to treatment with antiarrhythmic drugs. However, occasionally PVDs are refractory to pharmacological treatment but they can be eliminated with radiofrecuency catheter ablation. Aim: To show our experience with four patients in whom we used this method. Material and method: We studied three men and a woman, twelve to forty six years old. All of them were symptomatic, their EKG and echocardiogram were normal and they had been treated with several drugs without response. In three of them the PVDs had left bundle-branch block morphology with inferior axis; the other patient had right bundle-branch block morphology with superior axis. The origin of the PVDs was determined using pace mapping. Results: Two of the patients had spontaneous PVDs; in the other two isoproterenol infusion was used to induce them. In three patients the origin of the PVDs was located in right ventricular outflow and in the other in the anterolateral region of the left ventricle. None had sustained atrial or ventricular arrhythmia. In all of them PVDs were eliminated. A patient presented a second morphology that could not be treated. None of the patients had complications and they were discharged within the next 24 hours. Three noted symptomatic improvement and after 18 months, only one had a probable recurrence of the arrhythmia. Conclusions: radiofrecuency catheter ablation can be successfully used to eliminate PVDs in severely symptomatic and drug-resistant patients