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Objective To investigate the changes of heart rate deceleration capacity(DC)in patients with unstable angina pectoris(UAP)and its correlation with the scope and severity of coronary artery disease. Methods From September 2016 to January 2017,one hundred and nine patients with UAP and 52 with non-coronary artery disease were diagnosed in the department of cardiology in the Third Affiliated Hospital of Anhui Medical University. They were all measured with 24h dynamic electrocardiogram and the corresponding analysis software was used to analyze the results,and the difference in deceleration capacity between the two groups was compared. The severity and the number of coronary artery lesions were compared with different deceleration capacity in UAP patients. The relationship between deceleration capacity and the number of coronary artery stenosis, the scope and severity of coronary artery lesions were then analyzed. Results The deceleration capacity value of UAP group was significantly lower than that of the control group((5.10 ± 1.34)vs.(6.03 ±1.40),t=-3.775,P<0.01). The number of coronary artery lesions and Gensini score in group deceleration capacity>4.5 ms were smaller than those in group deceleration capacity ≤4.5 ms((1.67± 0.77)branches vs. (26.76±25.31)branches;(21.27±5.541)points vs.(42.69±8.61)points)(t= -3.910,-2.277,P<0.05). The deceleration capacity value was negatively correlated with the number of coronary artery stenosis(r=-0.206,P<0.01)and the Gensini score(r=-0.358, P<0.01)in patients with UAP. Conclusion Deceleration capacity decreased in patients with UAP and it was closely associated with the severity and the scope of coronary artery lesions.
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Objective@#To investigate the determinants affecting the heart rate deceleration capacity (DC) in patients with dilated cardiomyopathy (DCM).@*Methods@#One hundred patients with DCM (DCM group) and 202 healthy subjects (control group) were respectively enrolled. Echocardiography and 24 hours electrocardiogram were performed in all subjects. DC value was compared between the two groups. Multiple regression analysis was made to evaluate the related determinants of DC ((age, sex, echocardiographic parameters including the left atrial diameter (LAD) and left ventricular ejection fraction (LVEF)).@*Results@#(1) DC value was significantly lower in DCM group than in control group( (4.40±2.03) ms vs. (7.30±1.81) ms, P<0.01), prevalence of DC value≤4.5 ms was significantly higher in DCM group than in control group (62% vs. 6%, P<0.01). (2) DC value in the DCM group decreased in proportion to increasing LAD dimension, DC value was (5.60±2.04) ms, (4.50±2.07) ms and (3.60±1.62) ms (P<0.05) in DCM patients with LAD≤40 mm, 40 mm<LAD≤50 mm and LAD>50 mm, respectively. (3) DC value in the DCM group was negatively related to the LAD (r=-0.366, P<0.01), positively related to the LVEF (r= 0.241, P<0.01), but not related with age and sex. Multiple factors regression analysis showed that increased LAD was related to the reduced DC values independtly.@*Conclusion@#DC value of the patients in the DCM group is decreased, which indicate the decrease of the vagus nerve tension, and increased LAD is related to the reduced DC value independtly in DCM patients.
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Objective:To investigate the effectiveness of heart rate deceleration capacity (DC) measurement in predicting the car-diotoxicity of malignant tumor patients treated with epirubicin-based chemotherapy. Methods:The clinical medical records, including CK-MB and cTnI levels and dynamic electrocardiogram (ECG) parameters before and after each chemotherapy cycle, of 140 patients treated with epirubicin-based chemotherapy were analyzed. Patients were divided into the DC>4.5 ms group and the DC≤4.5 ms group based on the calculated DC values. The CK-MB and cTnI levels and the dynamic ECG parameters of the two groups were compared af-ter two and four cycles of chemotherapy. Results:Patients in the two groups exhibited no statistically significant difference in their rele-vant clinical and pathological data before receiving chemotherapy (P>0.05). However, after four cycles of chemotherapy, the DC≤4.5 ms group showed a significantly greater increase in serum CK-MB and cTnI concentrations over the pre-chemotherapy levels compared with the DC>4.5 ms group. After two and four cycles of chemotherapy, the DC≤4.5 ms group also exhibited a significantly greater in-crease in mean heart rate (beats/min) and supraventricular and ventricular arrhythmia counts (times/24 h) over the pre-chemotherapy values compared with the DC>4.5 ms group (P0.05). However, the DC values of patients with elevated cTnI were significantly lower than those with normal cTnI level (P<0.05). Conclusion:The risk of epirubicin-induced cardiotoxicity increased with decrease in DC value. The DC test was shown to be an effective predictor of the risk of epirubicin-induced cardiotoxicity.
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Objective To investigate the influence of six-minute walking training on autonomic nerve function in patients having chronic heart failure.Methods Eighty chronic heart failure patients with heart function Ⅱ-Ⅲ grade were divided into training group (40 cases) and control group (40 cases) by random digits table method.Patients in two groups were treated with conventional anti heart failure drug.Patients in training group insisted six-minute walking training twice a day on the basis of the conventional treatment.Changes of the index of heart function,heart rate variability (HRV) and heart rate deceleration force (DC) before and after treatment were tested in two groups.Results After treatment,the cardiac function in training group and control group was significantly improved (P ＜ 0.05).The indexes of HRV and DC in two groups were significantly higher than those before treatment (P ＜ 0.05).After treatment,the indexes of HRV and DC in training group were significantly higher than those in control group (P ＜ 0.05).Conclusion Six-minute walking training in patients having chronic heart failure can significantly improve the autonomic nerve function,which is an effective and safe rehabilitation exercise for patients having chronic heart failure.