The Changes And Clinical Significance Of Heart Rate Turbulence In Patients With Unstable Angina

Objective The objective of the study is to discuss the changes and clinical significance of heart rate turbulence (HRT) in patients with unstable angina (UA).Methods 76 UA patients and 34 patients who coronary artery angiography (CAG) is normal in the heart medicine ward of Guangxi Medical University the first affiliated hospital were chosen as the UA group and the control group from January 2009 to November 2009. There was no difference in gender and age between the UA group and the control group.After being selected collects patients clinical data.The 24-hour ambulatory electrocardiograph (Holter) and ultrasonic cardiogram (UCG) were performed for all subjects to obtain turbulence onset (TO),turbulence slope (TS),standard deviation of average R-R interval (SDNN) and left ventricular ejection fraction (LVEF).Patients were divided into the UA non-merge heart failure group (NYHAⅠ) and the UA merge heart failure group (NYHAⅡ~Ⅳ) according to the NYHA classification.Then patients with UA were followed up.According to the outcome of following up,patients were divided into the UA non-event group and the UA event group.The value of above indexes were compared between the UA group and the control group,the UA non-merge heart failure group and the UA merge heart failure group, the UA non-event group and the UA event group.The high-risk factors were determined according to previous danger stratification and were analyzed through logistic regression analysis to assess the predictive value of these indexes for patients with subsequent heart incident.Results 1. There was no difference in gender,age,C-reactive protein (CRP),LVEF and SDNN between the UA group and the control group(p>0.05).The value of TO was significantly higher(﹣0.91±1.23% vs﹣1.65±1.37%,p<0.01)and TS was significantly lower (3.85±2.02ms/RRI vs 5.49±1.53ms/RRI,p<0.01)in the UA group than those of the control group.2.Patients with UA were divided into the UA non-merge heart failure group and the UA merge heart failure group.There was no difference in gender,age,TO,CRP,SDNN and LVEF between them(p>0.05).Compared with the UA non-merge heart failure group,CRP was significantly higher(4.50±4.45mg/L vs 9.00±23.80mg/L,p<0.01)and TS was significantly lower(4.10±2.02ms/RRI vs 2.38±1.37ms/RRI,p<0.01)in the UA merge heart failure group.3. There was not remarkable relevance between HRT indexes and age(p>0.05).TO and TS were independent of each other in the UA group. TO is positively correlated with CRP (r=0.250,p<0.05)while TS is negatively correlated with CRP(r=﹣0.306,p<0.01).TS is positively correlated with LVEF and SDNN (r=0.346,p<0.01 and r=0.266,p<0.05). Compared with the quartile 2,TO was higher in the quartile 4(﹣1.44±0.26% vs﹣0.28±0.23%,p<0.05).Compared with the quartile 1,TS was lower in the quartile 4(4.29±0.45ms/RRI vs 2.53±0.34 ms/RRI,p<0.05);Compared with the quartile 2,TS was significantly lower in the quartile 4(4.88±0.49ms/RRI vs 2.53± 0.34ms/RRI,p<0.01).4. During a mean following-up of 7.63±2.03 months,there were 10 patients who caught subsequent heart incident.There was no difference in gender, CRP,LVEF,SDNN,TO and myocardial revascularization proportion between the UA non-event group and the UA event group(p>0.05). Compared with the UA non-event group,age was higher (60.68±10.83 years vs 70.00±9.10 years,p<0.05),TS was significantly lower(4.13±2.02ms/RRI vs2.08±1.17ms/RRI,p<0.01).5. Logistic multivariate analysis presented that TS≤2.5ms/RRI(OR=6.533,95%CI 1.411~30.238,p=0.016) and age≥65year(OR=6.156, 95%CI 1.125~33.666, p=0.036)were independent risk predictors.TS≤2.5ms/RRI was the more power risk predictor.Conclusion 1. Myocardial ischemia and heart failure would lead to decreased or stunned hrt in patients with UA.2. HRT is related to the level of CRP.Impaired parasympathetic function and increased markers of inflammation affect the prognosis of patients with UA.3. TS has good previsional value to patients with UA.