The Changes And Clinical Significances Of Heart Rate Turbulence In Patients With Acute Coronary Syndrome

Objective: The objective of this study is to analyse the changes and clinical significances of heart rate turbulence in patients with acute coronary syndrome.Methods: Total 186 hospitalization patients in the heart medicine wards this hospital were chosen from Jan.2005 to Feb. 2007. Among them there are 129 patients of acute coronary syndrome and 57 control subjects without organic heart diseases.All subjects were performed 24-hour ambulatory electrocardiogram.The 24-hour Holter record of each subject was processed by Holter 12.0 TOP Version HRT analysis software. HRT are stated by two parameters which including HRT onset(TO),HRT slope(TS).The parameters of HRT and heart rate variability (HRV) were obtained by software directly . The patients of acute coronary syndrome were divided into unstable angina pectoris(n=46)and myocardial infraction(n=83) according to the syndrome,electrocardiographic and cardiac muscle enzyme. Three groups were obtained in the unstable angina pectoris group by the difference of the coronary arterial narrow level .Comparing the differences of HRT among them. Also patients of myocardial infraction were classified into①perfused group and nonperfused group according to whether they were received emergency percutaneous coronary intervention(PCI)or thrombolytic therapy.②anterior wall AMI group and inferior wall AMI group according to the locative site of infraction③high risk patients and low risk patients were divided according whether they suffered from sustained ventricular tachycardia or ventricular flutter,ventricular fribrillation,acute left heart failure,cardiac shock or death during hospitalization or follow-up.comparing the value of HRT between them. Also evaluate the previsional value of HRT in the patients of AMI. Results: 1.There was no difference in age and gender between the ACS group and the control group.Compared with the control group, the value of TO was signigicantly higher in ACS patients(-0.06±3.53%vs-3.58±5.09% p<0.001)while the value of TS was significantly lower in ACS patients(2.90±2.90ms/RRIvs8.80±5.80 ms/RRI p<0.05).2.ACS patients were divided into AMI group and UAP group. There were no difference in age,gender,whether takingβ-block or ACEI/ARB medicine and smoking between them. But the value of TO was signigicantly higher in AMI patients (0.59±3.00%vs-1.40±3.54% p<0.01)while the value of TS was significantly lower in AMI patients(2.80±2.70 ms/RRI vs3.50±3.40ms/RRI p<0.05).3.The subgroup analysis in the UAP stated with the narrow of the coronary artery become more serious ,the value of TO become higher especially between the serious narrow group and low-grade group.The difference between them has stastical significance(-0.29±3.50%vs-3.24±3.16% p<0.05).While the difference between the moderate narrow group and low-grade isn't obvious.The difference of the value of TS has stastical significance between the serious narrow group and moderate narrow group(2.40±1.83ms/RRIvs3.55±1.93ms/RRI p<0.05). The difference of the value of TS has stastical significance also existed between moderate narrow and low-grade narrow group(3.55±1.93ms/RRIvs5.80±8.35ms/RRI p<0.05).TO is positively correlated with the narrow level of the coronary artery (r=0.470,p<0.01)while TS is negatively correlated with the narrow level of the coronary artery(r=-0.611, p<0.01).4.The subgroup analysis in the AMI showed as follows. First, between the nonperfused group and the perfused group the HRT has obvious difference.The value of TS(1.85±2.73ms/RRIvs4.00±3.00ms/RRI p<0.05) is stastical lower in nonperfused group.Second, the value of TS(2.30±2.90ms/RRIvs3.40±2.90ms/RRI p<0.05) in anterior wall AMI group has stastical lower than inferior wall AMI group.Third, the value of TS(2.05±2.78ms/RRIvs3.20±2.02ms/RRI p<0.01) is stastical lower in high risk patients group than low risk patients group after AMI. Conlusion: 1.The HRT in patients of ACS is lessened which showed the patients of ACS cardiac autonomic nerve function and the baroreceptor sensitivity was injured especially the vagus function was impared.2. HRT are closely related to the degree of the narrow of the coronary artery in the UAP patients. HRT can be a useful marker to evaluate the severity of the narrow of the coronary artery in the UAP patients.3. HRT can be a useful referenced marker to evaluate the heart function of the ACS patients and to determine successful reperfusion in the AMI patients.4.HRT is a useful marker to find the high risk patients in AMI. Meanwhile HRT have good previsional value to patients of AMI.