OBJECTIVE: In recent years, the ventricular resynchronization has been proposed as an assisting therapy in congestive heart failure. This study objective is to compare the electrocardiographic changing and the acute hemodynamics effects of right ventricular (RVS) and biventricular stimulation (BVS), in post-operative of myocardial revascularization with cardiopulmonary bypass. MATERIAL AND METHODS: In a cross-over trial, thirteen patients with multiarterial coronary disease and ejection fraction lower than 50%, were submitted to right ventricular and biventricular epicardial temporary stimulation, in 5th post-operative day. The variables researched were lenght of time of the QRS complex, diameter of left atrium (LA) and left ventricle (LV), the LV shortening fraction and LV ejection fraction. The results from two groups were compared through the Student's t test for paired observations and the value p<0.05 was considered significant. RESULTS: The duration of QRS complex was 185±26 ms during RVS, and 126±37 ms with BVS (p<0.001). The left atrium diameter with RVS was 40±4 mm, and 35±4 mm during BVS (p<0.001). The end systolic and dyastolic LV diameters were respectivelly 49±13 mm and 59±11 mm during RVS, and 42±12 mm and 52±10 mm with BVS (p<0.001). The LV shortening fraction established by RVS was 18±7 %, and with BVS was 22±8 % (p=0.017). The LV ejection fraction during RVS was 33±14 %, and with BVS was 46±17 % (p<0.001). CONCLUSION: In the studied pattern, biventricular artificial stimulation determined a significant improvement of the hemodynamic performance in comparison to the right ventricular stimulation, and a QRS complex with duration close to the physiological.
Myocardial revascularization; Cardiac pacing, artificial; Pacemaker, artificial
