Kontopoulos A G, Athyros V G, Didangelos T P, Papageorgiou A A, Avramidis M J, Mayroudi M C, Karamitsos D T
Division of Cardiology, Aristotelian University, Hippocration Hospital, Thessaloniki, Greece.
Diabetes Care. 1997 Mar;20(3):355-61. doi: 10.2337/diacare.20.3.355.
Heart rate variability (HRV) time and frequency domain indexes are strong predictors of malignant arrhythmias and sudden cardiac death. Patients with diabetic autonomic neuropathy (DAN) have an increased cardiovascular mortality rate compared with diabetic patients without DAN.
The present double-blind, randomized, and placebo-controlled study analyzed the effect of quinapril, an ACE inhibitor, on HRV time and frequency domain variables in patients with DAN. Forty patients (17 men and 23 women) of a mean age of 51 (range 19-68) years, free of coronary artery disease and arterial hypertension, were randomized into a quinapril or placebo group. HRV was recorded at months 0, 3, and 6. The parameters measured were 1) time domain indexes: SD of all 24-h R-R intervals (intervals between consecutive electrocardiogram R waves), or SDNN/24-h; mean of SD of R-R intervals of all 5-min segements (SDNN/5-min); root-mean-square of the differences of successive R-R intervals (RMSSD); and percentage of the R-R intervals differing more than 50 ms (pNN50); and 2) frequency domain indexes: total power (TP), high-frequency power (HFP), low-frequency power (LFP), and very-low-frequency power (VLFP). HRV level of the 40 patients were compared with one of 20 matched diabetic patients, of analogous glycemic control without DAN, and 20 healthy control subjects.
Quinapril, compared with placebo, increased total HRV: SDNN/24-h (P < 0.05), TP (P < 0.05), and HRV parameters related to parasympathetic activity: pNN50 (P < 0.01). RMSSD (P < 0.05), and HFP in absolute and normalized units (P < 0.01). LFP/HFP ratio was decreased (P < 0.01). Despite the beneficial effect of quinapril on parasympathetic variables of HRV these remained less than those of diabetic patients without DAN and healthy control subjects.
Our findings suggest that quinapril significantly increases parasympathetic activity in patients with DAN 3 months after treatment initiation and sustains this effect until the 6th month. This might contribute to the reduction of the risk for malignant ventricular arrhythmias in these patients.
心率变异性（HRV）时域和频域指标是恶性心律失常和心源性猝死的有力预测指标。与无糖尿病自主神经病变（DAN）的糖尿病患者相比，患有DAN的患者心血管死亡率更高。
本双盲、随机、安慰剂对照研究分析了血管紧张素转换酶抑制剂喹那普利对DAN患者HRV时域和频域变量的影响。40例平均年龄51岁（范围19 - 68岁）、无冠状动脉疾病和动脉高血压的患者（17例男性和23例女性）被随机分为喹那普利组或安慰剂组。在第0、3和6个月记录HRV。测量的参数有：1）时域指标：24小时所有R - R间期（连续心电图R波之间的间期）的标准差，即SDNN/24小时；所有5分钟节段R - R间期标准差的平均值（SDNN/5分钟）；连续R - R间期差值的均方根（RMSSD）；以及R - R间期差值超过50毫秒的百分比（pNN50）；2）频域指标：总功率（TP）、高频功率（HFP）、低频功率（LFP）和极低频功率（VLFP）。将40例患者的HRV水平与20例匹配的无DAN且血糖控制相似的糖尿病患者以及20例健康对照者进行比较。
与安慰剂相比，喹那普利可提高总体HRV：SDNN/24小时（P < 0.05）、TP（P < 0.05），以及与副交感神经活动相关的HRV参数：pNN50（P < 0.01）、RMSSD（P < 0.05），以及绝对值和标准化单位下的HFP（P < 0.01）。LFP/HFP比值降低（P < 0.01）。尽管喹那普利对HRV的副交感神经变量有有益作用，但这些变量仍低于无DAN的糖尿病患者和健康对照者。
我们的数据表明，喹那普利在治疗开始3个月后可显著提高DAN患者的副交感神经活动，并将这种作用维持到第6个月。这可能有助于降低这些患者发生恶性室性心律失常的风险。
