Studies on Heart Rate Variability in Patients with Acute Myocardial Infarction

Lee, Ho Soon; Choi, Yong Seok; Han, Seong Woo; Park, Woo Jung; Doo, Young Cheoul; Oh, Dong Jin; Ryu, Kyu Hyung; Lee, Yung

Abstract

BACKGROUND
Heart rate variability(HRV) represents one of the methods of examining the function of autonomic nervous system. Many patients with acute myocardial infarction show evidence of autonomic disturbance during the acute phase of the attack and reduced heart rate variability is a significant predictor of mortality in patients after acute myocardial infarction. METHOD: The study groups included 25 patients admitted to our hospital with acute myocardial infarction and 23 age matched control group. Heart rate variability(time domain measures : mean NN, SDNN, SDANN, SD, rMSSD, pNN50 and frequency domain measures : TF, LF, HF) was measured from 24 hour Holter recording and wall motion score index(WMSI)was calculated from echocardiography in both groups. Jeopardy score(JS) and ejection fraction(EF) were calculated from coronary angiogram and left ventricular cineangiogram. In patients, HRV, echocardiography and coronary angiography were taken at a mean of 9+/-4, 4.3+/-2.9, and 13+/-6 days after admission.
Results
1) HRV(time domain measures : SDNN, SDANN, SD, rMSSD, pNN50 and frequency domain measures : TF, LF, HF) except mean heart rate was significantly decreased in patients with acute myocardial infarction(AMI)(p<0.001). 2) The angiographic EF and echocardiographic WMSI showed significant negative correlation in patients with AMI(r=-0.49, p<0.05). 3) The EF was significantly related with mean heart rate(r=0.52, p<0.05), SD(r=0.45, p<0.05), TF(r=0.46, p<0.05) and LF(r=0.50, p<0.05) in patients with AMI. 4) There was no correlation among the JS, WMSI, and HRV in patients with AMI.
CONCLUSIONS
These findings support that the autonomic control of the heart was pathologically changed in patients with AMI and among the HRV measurements, mean NN, SD, TF and LF were closely related with left ventricular function.