Heart rate turbulence in patients with stable coronary artery disease and its relationship with the severity of the disease

OBJECTIVE
Heart rate turbulence (HRT) indicates the impairment of cardiac autonomic function. With the literature containing insufficient information on HRT in stable coronary artery disease (CAD), this study aimed to investigate the role of HRT in patients with stable CAD.

METHODS
The study included 58 patients (mean age: 58.9±10.0 years; 25 male) with documented CAD and demonstrating ventricular premature complexes on Holter monitoring, and a control group of 52 patients (mean age: 55.9±9.3 years; 36 male) with no history of CAD and demonstrating ventricular premature complexes. HRT parameters such as turbulence onset (TO) and slope (TS) were analyzed. Angiographic Gensini score were used to evaluate CAD severity.

RESULTS
There was a significant difference in HRT parameters between the 2 groups. TO: 0.47±1.52% vs. -1.61±2.0% (p=0.001) and TS: 4.7±3.0 vs. 6.4±3.7 ms/RR (p=0.009) in patients with CAD and control group respectively. Given also that TO ≥0% and TS ≤2.5 ms/ RR values are considered abnormal, there was significant difference between the two groups; TO abnormal: 27 patients (46.6%) vs. 7 patients (13.5%), p=0.001, and TS abnormal: 15 patients (25.9%) vs. 4 patients (7.7%), (p=0.004) in CAD patients and control group respectively. A positive correlation was detected between TO and Gensini score (r=0.282, p=0.001) and a negative correlation detected between TS and Gensini score (r=-0.287, p=0.001).

CONCLUSION
The study demonstrated that HRT variables are impaired in patients with stable CAD when compared to those in the control group, and that these variables also correlate with severity of CAD.