[Recovery process from myocardial stunning after transient ischemia: assessment with pulsed wave Doppler transmitral...

Sustained left ventricular systolic dysfunction after transient myocardial ischemia is well known as "myocardial stunning", but little is known about the recovery in left ventricular diastolic function. Changes in left ventricular systolic and diastolic performance following dobutamine-induced ischemia were investigated in 13 patients with chest pain syndrome and normal coronary arteries (control) and 34 patients with coronary artery disease. Two-dimensional echocardiography and pulsed wave Doppler transmitral flow velocity curves were recorded at baseline, after infusion of a peak dose of dobutamine and at 20 min and 2 hours after dobutamine infusion. In control subjects, left ventricular ejection fraction and the peak early diastolic filling velocity increased at the peak dose of dobutamine. At 20 min after the cessation of dobutamine infusion, these values were restored to the baseline levels. In patients with coronary artery disease, ejection fraction and peak velocity increased at the peak dose of dobutamine but decreased at 20 min after infusion compared with baseline values despite the restoration of heart rate and blood pressure. Although ejection fraction increased at 2 hours compared with 20 min after infusion, peak velocity did not increase. Left ventricular diastolic dysfunction may be sustained longer than systolic dysfunction after transient myocardial ischemia.