Objective: The objective of this study was to correlate histologic changes in hibernating myocardium with dobutamine stress echocardiography (DSE).
Methods: Patients (n = 8) with anterior regional wall motion abnormalities in the seven echocardiographic segments representing the territory supplied by a significantly stenosed left anterior descending coronary artery had preoperative DSE performed (yielding 56 segments for analysis). Two transmural biopsy specimens were taken from the anterior wall of the left ventricle during coronary artery bypass grafting.
Results: Morphometric histologic analysis of biopsy specimens showed significantly less fibrosis in segments demonstrating inotropic reserve (p < 0.05) and significantly less fibrosis in segments demonstrating improvement in wall motion on echocardiography 3 months after revascularization (p < 0.05). DSE had a sensitivity of 100% and a specificity of 62% for detection of hibernating myocardial segments. Percent fibrosis was inversely correlated with percent nucleated cells (r = 0.66, p < 0.01) and directly correlated with cytoplasmic clearance (r = 0.76, p < 0.01).
Conclusion: Inotropic response during DSE correlates with histologic evidence of hibernating myocardium.