Coronary anatomy characteristics in patients with isolated right bundle branch block versus subjects with normal surface electrocardiogram

Abstract

a b s t r a c tIntroduction and objective: Isolated right bundle branch block is a common finding in the general population. It may be associated with variations in detailed coronary anatomy characteristics. The aim of this study was to investigate the coronary anatomy in patients with isolated right bundle branch block and to compare that with normal individuals. Method: In this caseecontrol study we investigated the coronary anatomy by reviewing angiographic films in two groups of normal coronary artery patients: patients with right bundle branch block (RBBB) (n ¼ 92) and those with normal electrocardiograms (n ¼ 184). Results: There was no significant difference between the two groups in terms of diminutive left anterior descending artery, dominancy, number of obtuse marginal artery, diagonal, acute marginal artery, the position of the first septal versus diagonal branch, presence of ramus artery, and size of left main artery. The number of septal branches was higher in the case group (p-value <0.001). Origination of the atrioventricular node artery from the right circulatory system was more common in both groups but cases showed more tendency to follow this pattern (p-value ¼ 0.021). The frequency of the normal conus branch was higher in the cases versus controls (p-value ¼ 0.009). Conclusions: Coronary anatomy characteristics are somewhat different in subjects with RBBB compared to normal individuals.

Clinical Impact of Newly Diagnosed Right Bundle Branch Block (RBBB) in ST Segment Elevation Myocardial Infarction (STEMI)

“…Decreased blood flow in the proximal RCA could result in right ventricle elongation and dilation, leading to the formation of new RBBB. Complete occlusion of the RCX may result in occlusion of the RV branch that originates from it (Pakbaz et al 2013). Large areas of RV myocardial ischemia can cause the maximal rate of phase 0 depolarization to go down due to the lack of RV branch vasculature.…”

“…As a consequence, the rate of conduction activation decelerates in the RV myocardium, resulting in asynchronous depolarization of the left and right ventricles, which might result in Major Adverse Cardiac Events (MACE) (Pakbaz et al 2013;Li et al 2018).…”

An Important Concern for the Analysis of Culprit Artery

“…These features suggest an acute extensive anterior wall myocardial infarction (MI). In patients with acute ischemic injury, the right bundle branch is mainly supplied by the left anterior descending coronary artery (LAD) or combined with atrioventricular node artery; therefore, we suspected that in the current patient, the RBBB was probably new. The presence of ST-segment elevation in leads I and aVL associated with new or presumed new RBBB usually indicates the occlusion of the LAD .…”

Clinical Significance of Coronary Arterial Dominance: A Review of the Literature

“… 57 , 65 , 66 Alternatively, the sinoatrial node is less frequently perfused by the dominant coronary artery compared to the atrioventricular node, 67 , 68 with some authors observing the sinoatrial nodal artery often branches from the nondominant artery. 7 , 69 In terms of more distal conduction system perfusion, the right bundle‐branch system is proximally supplied by both the LAD and atrioventricular nodal arteries and distally by only the LAD, 70 which may have clinical implications for conduction disease.…”

“…Similarly, atrioventricular node dysfunction in the setting of coronary disease appears to be dependent on dominance pattern. 87 Following perfusion patterns, right‐dominant systems with atrioventricular node arteries from the RCA appear to have an increased tendency to develop right bundle‐branch blocks, 70 although the overall dominance pattern was noted to be similar in patients with and without right bundle‐branch blocks. The left anterior fascicle, which generally receives its blood supply from the LAD, is observed to develop conduction blocks resulting in hemiblocks more frequently in left coronary dominance in the setting of LAD obstruction.…”