Nghiên cứu đặc điểm điện tâm đồ bề mặt của ngoại tâm thu thất khởi phát vùng cao và vùng thấp đường ra thất phải

Objective: To compare the features of the surface ECG of PVC from the upper and lower RVOT side to determine the characteristics of electrocardiogram for localization the sides, facilitation of mapping and ablation by the RF. Methods: The prospective study in 50 patients with PVC from RVOT (25 cases from upper side and 25 cases from lower side) burned successfully by the RF. Radiograph the right ventricle to locate onset sides and then study the surface ECG. Results: No difference in the shape, axis and duration of QRS and R-wave duration in all leads between two study groups. PVC from upper RVOT side has R-wave amplitude lower than one of PVC from lower RVOT side. And the difference between R-wave and S-wave amplitude (R-S) on inferior leads (DIl, DIII, aVF) is also lower. PVC from upper side has Rwave amplitude 1.1 mV and R-S 0.9 mV while PVC from lower side has R-wave amplitude or = 1.1 mV and R-S or = 0.9 mY. The initial R-wave amplitude in Vl, 0.1 mV could suggest PVC raising at upper RVOT region. Conclusions: Rwave amplitude and R-S on inferior leads and initial r amplitude on Vl of surface ECG could be useful for determining the location upper and lower RVOT side of PVC.