Electrophysiological Effects of Selective Atrial Coronary Artery Occlusion in Humans

Abstract

Background-The arrhythmogenesis of ventricular myocardial ischemia has been extensively studied, but models of atrial ischemia in humans are lacking. This study aimed at describing the electrophysiological alterations induced by acute atrial ischemia secondary to atrial coronary branch occlusion during elective coronary angioplasty. Methods and Results-Clinical data, 12-lead ECG, 12-hour Holter recordings, coronary angiography, and serial plasma levels of high-sensitivity troponin T and midregional proatrial natriuretic peptide were prospectively analyzed in 109 patients undergoing elective angioplasty of right or circumflex coronary arteries. Atrial coronary branches were identified and after the procedure patients were allocated into two groups: atrial branch occlusion (ABO, n=17) and atrial branch patency (non-ABO, n=92). In comparison with the non-ABO, patients with ABO showed: (1) higher incidence of periprocedural myocardial infarction (20% versus 53%, P=0.01); (2) more frequent intra-atrial conduction delay (19% versus 46%, P=0.03); (3) more marked PR segment deviation in the Holter recordings; and (4) higher incidence of atrial tachycardia (15% versus 41%, P=0.02) and atrial fibrillation (0% versus 12%, P=0.03). After adjustment by a propensity score, ABO was an independent predictor of periprocedural infarction (odds ratio, 3.4; 95% confidence interval, 1.01-11.6, P<0.05) and atrial arrhythmias (odds ratio, 5.1; 95% confidence interval, 1.2-20.5, P=0.02). Conclusions-Selective atrial coronary artery occlusion during elective percutaneous transluminal coronary angioplasty is associated with myocardial ischemic damage, atrial arrhythmias, and intra-atrial conduction delay. Our data suggest that atrial ischemic episodes might be considered as a potential cause of atrial fibrillation in patients with chronic coronary artery disease.

Prognostic of Interatrial Block after an Acute ST-Segment Elevation Myocardial Infarction

“…Atrial coronary occlusion during right or circumflex coronary arteries angioplasty has been related to atrium conduction delay [23]. In our cohort, we did not find an association between infarct location and the presence of IAB, although we did find a trend towards a higher rate of right ventricle infarctions in patients with aIAB.…”

Side branches don't get respect

“…Occluding them can cause significant myocardial infarction and, in some patients, prolonged chest pain and anxiety. Prior studies have correlated atrial side branch occlusion with atrial arrhythmias . We suggest that if PCI leads to small side branch occlusion it is appropriate to give intracoronary nitroglycerine to relieve spasm.…”

“…Yet some might argue that side branches are important. Popma et al reported that small side branches were responsible for 30% of periprocedural myocardial infarctions and Alvarez‐Garcia et al found that atrial side branch occlusion increased the rate of periprocedural myocardial infarction by 2.5‐fold . Every interventionalist has had the experience of losing what was thought to be a trivial side branch during PCI, only to have the patient experience hours of chest pain and a significant rise in enzymes.…”

“…Side branches supplying key parts of the heart might be particularly important. For example, the electrical conduction system of the heart, which is supplied by small side branches averaging 1.2–1.4 mm, may be particularly susceptible to ischemia. Alvarez‐Garcia et al found that atrial fibrillation and atrial tachycardia occurred more frequently in patients with periprocedural atrial side branch occlusion compared to patients without PCI‐induced atrial side branch occlusion (41 vs. 15%, p = .02 and 12 vs. 0% p = .01, respectively) …”

Letter by Ng and Efimov Regarding Article, “Electrophysiological Effects of Selective Atrial Coronary Artery Occlusion in Humans”

“…1 The authors report an association between selective atrial coronary artery occlusion during elective percutaneous coronary intervention with increased atrial arrhythmias and intra-atrial conduction delay.…”