The effects of acute coronary occlusion on noninvasive echocardiographically derived systolic and diastolic myocardial strain rates.
To compare the magnitude and rates of change of peak systolic (epsilon(')(SYS)) and diastolic (epsilon(')(DIAS)) strain rates, as measured using tissue Doppler echocardiography, to pressure and volumes left-ventricular indices during acute coronary occlusion.Six closed-chest dogs had a combination high-fidelity conductance pressure transducer placed into the left ventricle for determination of end-diastolic and end-systolic pressures (EDP and ESP) and volumes (EDV, ESV, and ejection fraction [EF]). Other indices included the time constant of left-ventricular relaxation (tau), +dP/dt(max), -dP/dt(max), end-systolic pressure/volume index (ESPV). A coronary angioplasty catheter was positioned into the left-anterior descending coronary artery. During coronary occlusion, strain rates and hemodynamic parameters were recorded continuously for 2 minutes.During occlusion, significant decreases in strain rates occurred within 30 seconds. Systolic indices (ESPV and +dP/dt(max)) changed at rates similar to epsilon(')(SYS) (each p = NS). Diastolic indices (tau, EDP, EDV, -dp/dt(max)) also changed at rates similar to epsilon(')(DIAS) (each p = NS). However, EF decreased at a significantly slower rate than did strain rates (p < 0.05).CONCLUSIONS:Peak systolic and diastolic strain rates decrease with acute ischemia similar to corresponding indices of left-ventricular systolic and diastolic function. Strain rates may be used in the noninvasive assessment of ischemic-induced left-ventricular dysfunction.
Firstenberg
MS
The Cardiovascular Imaging Center, The Cleveland Clinic Foundation, Cleveland, Ohio, USA
Greenberg
NL
Smedira
NG
Castro
P
Thomas
JD
Garcia
MJ