心率震荡在原发性高血压中的变化及临床意义

目的研究心率震荡(HRT)新测量指标——震荡斜率起始时间(TT)及经典测量指标——震荡初始(TO)、震荡斜率(TS)在原发性高血压中的变化规律及临床意义,并探讨各指标与年龄、平均心率、心率变异性(HRV)、时域指标(SDNN)、左室射血分数(LVEF)、左室舒张末期内径(LVED)之间的关系。方法73例原发性高血压患者和55名正常对照者均接受24h动态心电图(Holter)记录,利用MGY分析系统自动回放扫描并计算HRT和SDNN指标,比较两组之间各指标的差异。同时获取超声心动图检测的LVEF、LVED,并分析TT、TO、TS与年龄、平均心率、SDNN、LVEF、LVED之间的关系。结果原发性高血压患者的TO、TT值明显高于对照组(P值均<0.01),TS、SDNN值明显低于对照组(P值均<0.01)。TO与LVEF呈负相关(r=-0.362,P<0.05),与年龄呈正相关(r=0.249,P<0.05),TS与平均心率呈负相关(r=-0.216,P<0.05)。结论原发性高血压患者HRT现象减弱或消失,提示其自主神经功能明显受损;TT有望成为HRT的又一项新的高效检测指标。

Variations and clinical implications of heart rate turbulence parameters in hypertension

Objective To investigate the variations and clinical implications of heart rate turbulence (HRT) parameters, including the both recently developed (turbulence timing, TT) and classic ones (turbulence onset TO] and turbulence slope TS]), in hypertension and to identify their correlations with age, mean heart rate, standard deviation of normal-to-normal RR intervals (SDNN), left ventricular ejection fraction (LVEF) and left ventricular end diastolic diameter (LVED). Methods TT, TO, TS and SDNN were measured and compared in 73 patients with hypertension and 55 healthy controls by the MGY software using 24-hour dynamic electrocardiogram (Holter) records. Data on LVEF and LVED were obtained using echocardiography. Correlations of TT, TO and TS with age, mean heart rate, SDNN, LVEF and LVED were analyzed. Results Patients with hypertension showed significantly higher TO and TT (both P<0.01), lower TS and SDNN as compared with controls (both P<0.01). There were significant correlations between TO and LVEF (r=-0.362, P<0.05), TO and age (r=0.249, P<0.05), TS and mean heart rate (r=-0.261, P<0.05). Conclusion HRT appeared significantly blunted in patients with hypertension, suggesting evidenced damage to autonomic nerve function in this condition. TT may be promising as a new effective indicator of HRT.