Noninvasive Coronary Angiography with 64-Section CT: Effect of Average Heart Rate and Heart Rate Variability on Image Quality

Abstract

Coronary angiography with 64-section CT provides diagnostic image quality within a wide range of heart rates. Reducing average heart rate and heart rate variability is beneficial for reducing artifacts.

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

“…Besides the heart rate decreasing effect of β-blockers, the major mechanism of β-blockers in improving the image quality of CT coronary angiography is considered its ability to reduce heart rate variability [14]. Consequently, administration of β-blockers can be recommended for imaging of patients with only slightly increased but highly irregular heart rates.…”

“…For calculation of heart rate variability, the length of each heartbeat during CT acquisition was measured for each patient. The variability of heart rate during scanning was calculated as the SD from the average heart rate from this set of measurements, as previously described [14].…”

“…An investigation of the influence of average heart rate and heart rate variability on image quality [14] showed that an average heart rate had no significant effect on image quality whereas a variable heart rate during scanning significantly degraded visualization of coronary arteries. In addition, there was only a minor difference in the number of nonevaluable segments between the groups with low and high heart rates.…”

Superior CT Coronary Angiography Image Quality at Lower Radiation Exposure with Second Generation 320-Detector-Row CT in Patients with Elevated Heart Rate – A Comparison with First Generation 320-Detector-Row CT

“…Superior CT coronary angiography image quality at lower radiation exposure with second generation 320-detector row CT in patients with elevated heart rate: a comparison with first generation 320-detector row CT quality (11). However, heart rate acceleration during image acquisition in response to intravenous contrast injection, anxiety and breath holding remains problematic (11)(12)(13).…”

“…However, heart rate acceleration during image acquisition in response to intravenous contrast injection, anxiety and breath holding remains problematic (11)(12)(13). The ability to scan patients at higher heart rate with lower radiation exposure will significantly improve CTCA safety, applicability and may improve clinical efficiency.…”