Improved Detection Of Viable Myocardium By A Novel Strain Doppler Measure In Patients With Acute Myocardial Infarction

BACKGROUND: Detection of viable myocardium is vital for treatment strategy during acute myocardial infarction (AMI). The aim was to study if strain Doppler echocardiography (SDE) prior to reperfusion therapy could predict viable myocardium in AMI as determined by cardiac magnetic resonance imaging (CMR). METHODS: Twenty-five patients (58 ± 12 years, 7 women) with AMI who underwent percutaneous coronary intervention (PCI) were examined by SDE immediately prior to PCI. End-systolic longitudinal strain and duration of systolic lengthening was analyzed in 16 left ventricular segments. CMR was performed 11 ± 4 months after reperfusion therapy. Scars exceeding 50% of the segment was considered non-viable. RESULTS: Duration of systolic lengthening in non-viable myocardial segments was 249 ± 135 ms compared to 39 ± 86 ms in viable segments (p<0.0001), with a direct relationship to scar transmurality (r=0.89, p<0.0001). A duration of systolic lengthening longer than 67.3% (~2/3) of systole (Figure ) detected non-viable myocardium by a sensitivity of 90% and a specificity of 93%. Strain demonstrated end-systolic shortening (−15 ± 6%) in viable segments in contrast to lengthening in non-viable segments (3 ± 4%, p<0.0001). End-systolic strain correlated also with the scar transmurality (r=0.71, p<0.0001). CONCLUSION: SDE performed before reperfusion therapy in AMI can identify viable myocardium. Duration of systolic lengthening which is a novel parameter might prove to be a superior measure for predicting recovery of myocardial function.