The Effect of Low-Dose β-Blocker on Heart Rate and Heart Rate Variability in Healthy Subjects with a Resting Heart Rate of Less than 65 Beats per Minute: Effect on the Image Quality of Prospective Electrocardiography-Gated Coronary CT Angiography

• Published in: Journal of the Korean Society of Radiology Vol. 72; no. 2; pp. 83 - 91
• Main Authors: Park, Chul Hwan, Lee, Sang Min, Hong, Yoo Jin, Kim, Tae Hoon
• Format: Journal Article
• Language: English
• Published: The Korean Society of Radiology 01.02.2015; 대한영상의학회
• Subjects: coronary ct angiography; heart rate; heart rate variability; image quality; β-blocker; 방사선과학
• ISSN: 1738-2637; 2288-2928; 2951-0805
• DOI: 10.3348/jksr.2015.72.2.83

Purpose We assessed the effect of a low-dose β-blocker on heart rate (HR), HR variability (HRV) and image quality of prospective electrocardiography-gated coronary CT angiography (CCTA) in healthy subjects with low HR. Materials and Methods CCTA was performed with a 64-slice CT in 75 subjects with a HR of less than 65 beats per minute (bpm). Subjects were divided into 2 groups: Group 1 (G1), 35 with a low dose β-blocker; and Group 2 (G2), 40 without pre-medication. The image quality (IQ) of the CCTA was assessed on a 4-point grading scale (1, poor; 4, excellent). Results Initial HR (bpm) was not different between the 2 groups. HR during CCTA was lower in G1 than G2 (50.3 ± 5.6 vs. 53.3 ± 4.8, p = 0.016). HRV was not different between the 2 groups. Per-segment analysis showed better IQ at the mid-segment of the right coronary artery (3.0 ± 0.9 vs. 2.5 ± 1.1, p = 0.039) and the first diagonal branch (3.4 ± 0.6 vs. 3.1 ± 0.7, p = 0.024), in the G1 than the G2 group, respectively. The IQ was negatively correlated with HR, but no correlation was found between HRV and IQ. The IQs in the per-vessel analysis were not different between the 2 groups. Conclusion Low-dose β-blocker reduced HR and improved the IQ of CCTA in a few segments, even at a HR of less than 65 bpm. However the effect was limited.