OBJECTIVETo study change and the value of diagnosis of harmonic imaging ultrasonic integrated backscatter (IBS) on the very early diagnosis of acute myocardial infarction (AMI).

METHOD72 patients were divided 2 groups, A group 30 cases with AMI at the very early stage of acute myocardial infarction (in 2 hours), B group 42 cases with typical acute myocardial infarction (in 2 - 12 hours) were examined by IBS and the cyclic variation of integrated backscatter (CVIB) with HP-5500 ultrasonic system in the segment of myocardial infarction and no myocardial infarction.

RESULTSIn A group the IBS of the segment of AMI are very higher than that of the segment of no AMI [(18.8 +/- 3.4) dB vs (8.3 +/- 1.2) dB, P < 0.01], the CVIB are lower [(6.3 +/- 0.7) dB vs (7.6 +/- 1.1) dB, P < 0.01]. But in the meanwhile there are no obvious changes in ECG. In B group the IBS of the segment of AMI is obvious higher than the normal person and no infarction segment in the same heart [(22.2 +/- 4.1) dB vs (8.3 +/- 1.2) dB, (21.1 +/- 3.2) dB vs (8.7 +/- 0.9) dB, P < 0.05], but CVIB is obvious lower than the normal person and no infarction segment in the same heart [(5.6 +/- 0.8) dB vs (7.6 +/- 1.1) dB, P < 0.05; (5.8 +/- 0.7) dB vs (9.3 +/- 0.9) dB, P < 0.01], the changes of the ultrasonic is coincidence with ECG. The change of IBS are very obvious just as in ECG.

CONCLUSIONThe result demonstrate that ultrasonic tissue characterization with harmonic imaging integrated backscatter can be used for diagnosis the very early stage of AMI, and can judge the segment range of AMI and function of the whole heart.