Very early stage detection of acute myocardial infarction by harmonic ultrasonic integrated backscatter.

To study the very early diagnosis of acute myocardial infarction (AMI) by harmonic imaging ultrasonic integrated backscatter (IBS). Thirty normal persons, 68 cases with AMI, of whom 28 cases were at the very early stage of acute myocardial infarction (in 2 h), and 40 cases with acute myocardial infarction (in 2 to 12 h) were examined by IBS and the cyclic variation of integrated backscatter (CVIB) with HP-5500 ultrasonic system in different segment (the segment of myocardial infarction and no myocardial infarction). In the segment of AMI of the very early stage (in 2 h) the IBS (dB) is much higher than that of the segment of no AMI (18.