Assessment of Left and Right Ventricular Mechanical Sequence by Dual Doppler Echocardiography in Normal Subjects / 中国循环杂志

ABSTRACT

Objective: To observe left and right ventricular mechanical sequence in systole and diastole by dual Doppler Echocardiography in healthy subjects. Methods: Dual Doppler echocardiography was performed in 100 normal subjects with dual-outflow-tract-view and apical four chamber view to simultaneously record the spectrum of left/right ventricular outlfow tract (LVOT)/(RVOT) and left/right ventricular inlfow tract (LVIT)/(RVIT) at the same cardiac cycle. The time cycles of blood lfow spectrum from the peak of QRS complex to aorta, pulmonary artery, mitral valve (MV) and tricuspid valve (TV) were measured, the starting time differences for blood lfow spectrum of aorta and pulmonary artery, MV and TV were calculated to assess the mechanical sequence of left and right ventricle in systole and diastole respectively. Results: There were 48/100 (48%) subjects having LV ejection preceded than RV (95% CI 0.38-0.58), 46 (46%) having RV ejection preceded than LV (95% CI 0.36-0.56) and 6 (6%) having LV, RV simultaneous ejection (95% CI 0.01-0.11). There were 96/100 (96%) subjects having RV iflling prior to LV (95% CI 0.90-0.99), 3 (3%) having LV iflling prior to RV (95% CI 0.01-0.08) and 1 (1%) having LV, RV simultaneous iflling (95% CI 0.00-0.05). Conclusion: There is a regular pattern for mechanical sequence of LV and RV in systole and diastole in healthy subject; in systole, the sequence of LV varies from person to person, while in diastole, RV is always preceded. Based on normal ventricular mechanical sequence, optimizing programming parameter of pace maker and choosing cardiac sequence in diastole might be the ifnal criteria for cardiac resynchronization therapy in the future.