Comprehensive Analysis of Myocardial Layer Specific Systolic and Diastolic Function in Patients With Coronary Artery Disease Undergoing Percutaneous Coronary Intervention

PART 1: ANALYSIS OF LAYER SPECIFIC SYSTOLIC AND DIASTOLIC FUNCTION DURING ACUTE ISCHEMIA INDUCED BY PERCUTANEOUS CORONARY INTERVENTION 35 patients with normal systolic left ventricular function at baseline with indication for elective percutaneous coronary angioplasty will be included in the study. In these patients acute ischemia will be induced by elective percutaneous coronary angioplasty with balloon inflation and thus vessel occlusion for 60 sec. During these 60 seconds ischemia will develop throughout all layers of the myocardium affecting diastolic systolic and diastolic function. During the subsequent reperfusion period signs of ischemia with systolic and diastolic dysfunction of all layers will subside. Echocardiographic imaging at short intervals of 10 sec during ischemia and at intervals of 20 sec during reperfusion up to 10 min after reopening of the vessel as well as 1 hour and 24 hours later will allow serial comparison of strain curves and thereby allow definition of the time sequence systolic and diastolic function abnormalities occur in three myocardial layers as well as the resolution of abnormalities during reperfusion. The analysis of circumferential as well as radial strain will allow definition of differences between radial and circumferential strain during ischemia induction and resolution.

PART 2: ANALYSIS OF LOCAL WORK INDEX DURING ACUTE ISCHEMIA INDUCED BY PERCUTANEOUS CORONARY INTERVENTION.

In the same 35 patients as in Clinical step 1 the local work index of the ischemic area as well as the contralateral non-ischemic areas will be determined in serial studies to determine the onset of abnormality, the amount of abnormality and the resolution of abnormality. Changes in local work index in the ischemic area will be related to changes in peak systolic strain and strain imaging diastolic index.