| Background:Acute coronary syndrome (ACS) is a high-risk population of sudden cardiac death (SCD). To risk stratification for such people and prevent the occurrence of sudden cardiac death, so as to further improve the clinical prognosis is the hot issue in recent years. Studies have shown that about3/4of ischemic heart disease accompanied by autonomic nervous system (autonomic nervous system, ANS) function disorder, is characterized by enhanced vagal tone decreases sharply and sympathetic nerve activity. This imbalance of ANS, increase the risk of fatal arrhythmia. Recently, marker of ANS balance is heart rate turbulence (HRT), which is a physiological phenomenon of sinus rhythm including the early acceleration and subsequent deceleration after a ventricular premature complex (VPC). Multiple clinical trials have defined the HRT mainly occurred in patients at high risk for sudden death after myocardial infarction and it had independent predictive value for prognosis of st-elevation myocardial infarction (STEMI) patients. Despite the ACS is roughly the same physiopathological mechanism, the role of HRT for risk stratification in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) has not been determined.Objective:To study the relationship of HRT with GRACE score and severity of coronary artery disease in patients with NSTE-ACS and the effect of PCI on HRT.Methods:We selected64NSTE-ACS patients who were underwent coronary angiography in our hospital. At the same time,71healthy cases were confirmed by coronary angiography to exclude coronary heart disease as control group. According to the degree of coronary artery lesions, the NSTE-ACS group was divided to left main lesion group (n=7), single-lesion group (n=26), bi-lesion group (n=21) and poly-lesion group (n=10). In addition, according to the GRACE scoring system, they were divided into very high risk group (24cases), high risk group (21cases) and low risk group (19cases). The results of coronary angiography by SYNTAX score, divided into high product group (9cases), group product group (25cases), low product group (30cases). Among these,39patients were underwent Percutaneous Coronary Intervention (PCI). All cases were performed24-hour Holter. Then turbulence onset (TO) and turbulence slope (TS) were calculated.Results:1. The NSTE-ACS group TO values were higher than those of the controls. TS values were significantly lower than those of the controls. The difference between the two groups was statistically significant (P<0.01).2. TO values were higher and TS were lower in the very high risk group compared to those in high risk group and low risk group (P<0.01).3. TO values have no difference among single-lesion group, bi-lesion group and the left main lesion group, but significantly increased in poly-lesion group (P<0.05). TS values were statistically significant (P<0.05) in each group.4. TO values rised and TS reduced successively among high product group, product group and low product group.5. In NSTE-ACS group, HRT value improved significantly one month after PCI compared with that before surgery (P<0.01).Conclusion:Heart rate turbulence is attenuated in patients with NSTE-ACS. The more serious the coronary artery lesion or the higher the GRACE or the more the SYNTAX, the weaken the HRT. The HRT parameters may be improved by PCI to a certain extent. |
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