Petretta M, Marciano F, Migaux M L, Salemme L, Themistoclakis S, Esposito N, Carpinelli A, Apicella C, Piscione F, Bonaduce D
Istituto di Medicina Interna, Cardiologia e Chirurgia Cardiovascolare, Università Degli Studi di Napoli, Federico II.
G Ital Cardiol. 1994 Aug;24(8):973-84.
Heart period variability is frequently reduced in patients with coronary artery disease. Although the mechanism for this reduction is still unclear, it seems to reflect alterations in cardiac autonomic control. In this study we have evaluated the relation between reversible segmental left ventricular dysfunction and time and frequency domain measures of heart period variability in patients with coronary artery disease.
Echocardiographic segmental left ventricular wall motion and time and frequency domain measures of heart period variability were evaluated in 32 patients with one-vessel coronary artery disease before and 16-24 days after successful percutaneous transluminal coronary angioplasty (PTCA). At baseline examination 12 patients (Group A) had normal and 20 (Group B) abnormal regional wall motion. Prevalence of previous myocardial infarction was higher and mean angiographic ejection fraction lower in Group B than in Group A. At baseline, time domain measures were comparable between the 2 groups, while low frequency (LF) and high frequency (HF) power were lower in Group B than in Group A. After PTCA, in Group A regional wall motion and time and frequency domain measures of heart period variability were unchanged. In Group B summed segment score improved from 17.1 +/- 3.6 to 12.8 +/- 2.0 (p < 0.01) and a significant increase occurred in standard deviation of the average normal RR (NN) intervals for all 5-minute segments of a 24-hour recording (SDNN index), in root mean square successive difference (r-MSSD) and in the percentage of differences between adjacent NN intervals > 50 msec (pNN50). In this group also LF and HF power (logarithmic units) increased from 6.14 +/- 0.23 to 6.35 +/- 0.34 (p < 0.01) and from 5.43 +/- 0.32 to 5.68 +/- 0.52 (p < 0.01) respectively. There was no correlation between measures of heart period variability, summed segment score, and left ventricular ejection fraction.
This study demonstrates that segmental left ventricular dysfunction is involved in determining sympathovagal imbalance in patients with one-vessel coronary artery disease; the reversal of left ventricular dysfunction by successful PTCA improves heart period variability. These findings support the hypothesis that alterations in cardiac geometry may influence the discharge of afferent sympathetic mechanoreceptors, thus contributing to the derangement in autonomic control of heart rate.
冠心病患者的心率变异性常降低。尽管这种降低的机制尚不清楚，但似乎反映了心脏自主神经控制的改变。在本研究中，我们评估了冠心病患者可逆性节段性左心室功能障碍与心率变异性的时域和频域指标之间的关系。
对32例单支冠状动脉疾病患者在成功进行经皮腔内冠状动脉成形术（PTCA）前及术后16 - 24天进行超声心动图节段性左心室壁运动以及心率变异性的时域和频域指标评估。在基线检查时，12例患者（A组）区域壁运动正常，20例（B组）异常。B组既往心肌梗死的患病率较高，平均血管造影射血分数低于A组。基线时，两组的时域指标相当，而B组的低频（LF）和高频（HF）功率低于A组。PTCA术后，A组区域壁运动以及心率变异性的时域和频域指标未改变。在B组，节段总分从17.1±3.6改善至12.8±2.0（p<0.01），24小时记录中所有5分钟节段的平均正常RR（NN）间期标准差（SDNN指数）、均方根连续差值（r-MSSD）以及相邻NN间期差值>50毫秒的百分比（pNN50）均显著增加。在该组中，LF和HF功率（对数单位）也分别从6.14±0.23增加至6.35±0.34（p<0.01）和从5.43±0.32增加至5.68±0.52（p<0.01）。心率变异性指标、节段总分与左心室射血分数之间无相关性。
本研究表明，节段性左心室功能障碍参与了单支冠状动脉疾病患者交感迷走神经失衡的决定；成功的PTCA使左心室功能障碍逆转可改善心率变异性。这些发现支持了心脏几何形状改变可能影响传入交感机械感受器放电，从而导致心率自主控制紊乱的假说。
