Ultrasound strain measurement, a type of Doppler echocardiography that can detect systolic regional myocardial dysfunction, may be useful in predicting wall motion recovery after PCI for acute myocardial infarction.

Ultrasound strain measurement, a type of Doppler echocardiography that can detect systolic regional myocardial dysfunction, may be useful in predicting wall motion recovery after percutaneous coronary intervention (PCI) for acute myocardial infarction, Japanese cardiologists report.

Dr. Yoshikazu Ohara and associates at Tokushima Red Cross Hospital analyzed ultrasound strain measurements in 43 patients following successful PCI of the left anterior descending (LAD) coronary artery.

Regional wall strain in the LAD artery territory in the long-axis view was measured 24 hours after PCI.

They also measured anterior wall motion score index (A-WMSI) at baseline and at four weeks. Viable myocardium was defined as an A-WMSI of 2.0 or less at four weeks. Based on that definition, there were 24 patients with viable myocardium and 19 without.

End-systolic strain was -4.8 per cent in those with viable myocardium compared with -9.9 per cent in those with nonviable myocardium. Corresponding peak strain measurements were -9.9 per cent vs. -13.5 per cent, the investigators report in the March 15th issue of the American Journal of Cardiology.

The corrected time to peak strain (cTPS) -- the time from end-diastolic to peak strain, divided by the RR interval -- was significantly longer in the nonviable group than the viable group. Dr. Ohara's team found a cTPS of less than 0.15 had a sensitivity of 95 per cent and a specificity of 85 per cent in predicting viable myocardium.

They conclude, "Strain, especially, cTPS, is useful for predicting recovery of regional left ventricular function in patients with AMI after percutaneous coronary intervention.