Clinical observation of heart rate variability and the sites of acute myocardial infarction

Abstract:

Objective：To observe the relationship between heart rate variability（HRV） and the sites of acute myocardial infarction（A－MI），and to observe the relationship between HRV and malignant ventricular arrhythmia（MVA） following AMI. Methods：Totally 120 patients with AMI in our hospital were selected. According to the classification of ventricular arrhythmia，patients was divided into two groups：MVA groups and non MVA（NMVA） groups. According to the infarction parts，patients was also divided into two groups：ante－rior wall infarction and non anterior wall infarction groups. HRV were obtained by the 24h-Holter. Results：Standard deviation of the average NN intervals（SDANN），standard deviation of the average NN intervals（SDANN），SDNNI，square root of the mean squared differences of successive NN intervals（RMSSD），low-frequency（LF），high-frequency（HF） and LF/HF were lower in MVA group than in NMVA group and the P values were 0.000，0.004，0.001，0.000，0.000，0.001 and 0.017，respectively. But there was no difference between the two groups in very low-frequency（VLF） （P=0.714）. Values of SDNN（P=0.000），SDANN（P=0.000），SDNNI（P=0.000），LF（P=0.000），LF/HF（P=0.013） were lower in anterior wall infarction group than in non anterior wall infarction groups. RMSSD（P=0.000） and HF（P=0.000） values were higher in anterior wall infarction group than in non anterior wall infarction group. And there was no difference between the two groups in VLF（P=0.064）. Conclusion：HRV is correlated with MVA following AMI. HRV might correlate with the site of myocardial infarction. Anterior wall infarction may be led by the increased sympathetic nervous activity，while non anterior wall infarction may be led by the decreased vagal activity.