Patients with uncomplicated coronary artery disease have reduced heart rate variability mainly affecting vagal tone

Abstract

Aim-To investigate whether uncomplicated chronic coronary artery disease causes changes in heart rate variability and if so, whether the heart rate variability pattern is diVerent from that described in patients with acute myocardial infarction. Methods-Heart rate variability was studied in 65 patients with angina who had no previous myocardial infarcts, no other diseases, and were on no drug that could influence the sinus node. Results were compared with 33 age matched healthy subjects. The diagnosis of coronary artery disease in angina patients was established by coronary angiography in 58, by thallium scintigraphy in six, and by exercise test only in one. Patients and controls were Holter monitored 24 hours outside hospital, and heart rate variability was calculated in the frequency domain as global power (GP: 0.01-1.00 Hz), low frequency peak (LF: 0.04-0.15 Hz), high frequency peak (HF: 0.15-0.40 Hz), LF/HF in ms 2 , and in the time domain as SDNN (SD of normal RR intervals), SDANN (SD of all five minute mean normal RR intervals), SD (mean of all five minute SDs of mean RR intervals), rMSSD (root mean square of diVerences of successive normal RR intervals) (all in ms), and pNN50 (proportion of adjacent normal RR intervals diVering more than 50 ms from the preceding RR interval) as per cent. Results-The mean age in patients and controls was 60.4 (range 32-81) and 59.1 (32-77) years, respectively (NS), the male/female ratio, 57/65 and 24/33 (NS), and the mean time of Holter monitoring, 23.0 (18-24) and 22.8 (18-24) hours (NS). Mortality in angina patients was 0% (0/65) at one year, 0% (0/56) at two years, and 3% (1/33) at three years. Compared with healthy subjects angina patients showed a reduction in GP (p = 0.007), HF (p = 0.02), LF (p = 0.02), SD (p = 0.02), rMSSD (p = 0.01), and pNN50 (p = 0.01). No significant diVerence was found in RR, LF/HF, SDNN, or SDANN. Conclusions-Uncomplicated coronary artery disease without previous acute myocardial infarction was associated with reduced high and low frequency heart rate variability, including vagal tone. SDANN and SDNN, expressing ultra low and very low frequencies which are known to reflect prognosis after acute myocardial infarction, were less aVected. This is in agreement with the good prognosis in uncomplicated angina in this study. (Heart 2000;83:290-294)

Does heart rate variability predict hypotension and bradycardia after induction of general anaesthesia in high risk cardiovascular patients?*

“…The activity of the autonomic nervous system is reflected in the heart rate variability (HRV) [6][7][8]. Several authors have demonstrated depressed long-term HRV in patients with underlying cardiovascular disease [9][10][11] and HRV has proved to be highly predictive for cardiovascular morbidity and mortality in these patients [12][13][14]. Recently, short-term HRV analysis (5 min) has been shown to be a reliable tool to predict hypotension after spinal anaesthesia [15,16].…”

Alteration of heart rate variability in patients with coronary artery disease

“…[11] B Wennerblom et al analyzed the HRV in patients with uncomplicated CAD and found a reduction of HRV in the higher spectrum of frequencies. [5] Kunz et al demonstrated that patients with CAD had a lower complexity of HRV, greater sympathetic modulation, and lower parasympathetic modulation. [12] A change in the balance between the sympathetic and the parasympathetic nervous system is associated with increased risk of arrhythmias such as ventricular fibrillation, resulting in sudden death of patients.…”

“…[4] It is reported that a major part of the government exchequer has to be spent on managing subjects with CAD and serious complications arising out of the disease. [5] The list of risk factors in the causation of the disease is long but still incomplete. One of the newly emerging risk factor is the alteration in the autonomic balance of the heart.…”

A novel robust index to assess beat-to-beat variability in heart rate time-series analysis

“…T IME-DOMAIN analysis of heart rate (RR) time series improves the diagnosis and prognosis of some cardiac and neural disorders [1], [2]. Indexes such as the standard deviation of normal-to-normal RR time series quantify heart rate variability (HRV) regardless of its rate of variation.…”