Heart rate variability as a marker of myocardial perfusion

RR variability (HRV), an independent predictor of death following myocardia l infarction, may also be related to other features of coronary artery dise ase. We evaluated its ability to differentiate among sedentary patients wit h chest pain greater than or equal to 45 years of age demonstrating either normal or abnormal myocardial perfusion with rest and exercise thallium-210 tomographic imaging. The major HRV difference between 48 men and 50 women with normal perfusion was a significantly higher high frequency power in wo men. No significant differences in mean HRV values were found between the 5 7 men with abnormal perfusion scans and the 48 men with normal perfusion. I n both men and women with normal perfusion scans, duration of exercise was significantly related to age. In men with abnormal scans, impaired myocardi al perfusion alters the relationship between exercise duration and age, and a group of individuals with diminished HRV and low levels of physical fitn ess, regardless of age, can be identified. Despite these latter selective f indings, we conclude that HRV is not a sensitive indicator to differentiate patients with normal and abnormal myocardial perfusion.