Diastolic Dysfunction of Left Ventricle during Transient Myocardial Ischemia : Usefulness of Color M-mode Doppler Echocardiography

ABSTRACT

BACKGROUND: Left ventricular diastolic dysfunction may precede systolic dysfunction and play a major role in producing the signs and symptoms of congestive heart failure. Ischemic heart disease can cause impairment of left ventricular filling without any alteration in systolic function so it is very important to evaluate relationship of left ventricular diastolic dysfunction and ischemic heart disease. The purpose of this study is to investigate left ventricular diastolic dysfunction during transient myocardial ischemia caused by balloon occlusion. METHODS: We prospectively studied 20 patients(11 males and 9 females, mean age 58.5+/-5.9 years) who had been undergone coronary angiography and confirmed significant luminal stenosis(> or =75%)in proximal or middle portion of left anterior descending artery. After coronary angiography, percutaneous transluminal coronary angioplasty were performed all patients. We measured early propagation slope of left ventricular inflow, time difference(TD) between occurrence of peak velocity in the apical region and at the mitral tip and normalized TD(nTD) which dividing TD by the distance of mitral opening to apical region using color M-mode Doppler echocardiography, peak earaly diastolic transmitral inflow velocity(E), peak velocity during atrial contraction(A), E to A ratio, acceleration time of E wave and deceleration time of E wave using pulsed wave Doppler echocardiography, left ventricular end diastolic pressure using left heart catheterization. A color M-mode Doppler echocardiography, pulsed wave Doppler echocardiography and left ventricular end diastolic pressure were recorded before, during 30sec, 60sec & 90sec and after 60sec & 180sec balloon occlusion. RESULTS: Early propagation slope of left ventricular inflow was significantly decreased during 30sec & 60sec balloon occlusion and significantly increased after 60sec & 180sec balloon occlusion, respectively (64.45+/-28.23cm/sec, 39.37+/-11.77cm/sec, 32.78+/-11.77cm/sec, 51.86+/-19.78cm/sec, 65.05+/-29.99cm/sec, p0.05). CONCLUSIONS: These data suggest that transient myocardial ischemia can cause left ventricular diastolic dysfunction and color M-mode Doppler echocardiography is very sensitive diagnostic method to detect early diastolic dysfunction compare to other echocardiographic diastolic indices.