Effect of Decrease in Heart Rate Variability on the Diagnostic Accuracy of 64-MDCT Coronary Angiography

Abstract

OBJECTIVE. The purpose of this study was to evaluate the effect of average heart rate and heart rate variability on the diagnostic accuracy of 64-MDCT in the assessment of coronary artery stenosis.SUBJECTS AND METHODS. CT and invasive coronary angiography were performed on 114 patients (mean age, 62 years) referred for known coronary artery disease (n = 26), atypical chest pain (n = 58), and presurgical exclusion of coronary artery disease before abdominal aortic (n = 14) or cardiac valve (n = 16) surgery. The population was divided into two groups depending on median average heart rate (60.0 beats/min) and median heart rate variability (2.7 beats/min) during scanning. Heart rate variability was calculated as SD from the mean heart rate. Two blinded observers using a 4-point scale independently assessed the quality of images of each coronary artery segment and classified each segment as being stenosed (luminal diameter narrowing > 50%) or not. Invasive coronary angiography was used as the reference standa...