Patterns of coronary compromise leading to bradyarrhythmias and hypotension in inferior myocardial infarction.
BACKGROUND
Occlusion and reperfusion of the acutely occluded right coronary artery may result in abrupt bradycardia and hypotension, attributed to Bezold-Jarisch cardio-inhibitory reflexes arising from the ischemic left ventricle. Given that right ventricular infarction, a result of proximal right coronary artery occlusion, predisposes to bradycardia and hypotension, we hypothesized that proximal right coronary occlusions would be more likely to result in bradycardia-hypotension compared to more distal occlusions.


METHODS
In 216 patients with acute inferior myocardial infarction undergoing primary angioplasty of the right coronary artery, we retrospectively analyzed the incidence of bradyarrhythmias and hypotension during occlusion and with reperfusion.


RESULTS
Occlusion proximal to the right ventricular branches was identified in 151 (70%) of cases, with occlusions distal but compromising the left ventricular and atrioventricular nodal branches in 65 (30%) others. During occlusion, those with proximal occlusions were more likely to suffer hypotension (41 versus 15%, P=0.0002), advanced atrioventricular block (21 versus 3%, P=0.0008) and hypotension with bradycardia (25 versus 9%, P=0.01). Similarly, reperfusion of proximal occlusions more frequently resulted in abrupt hypotension (42 versus 19%, P=0.002), bradycardia (34 versus 14%, P=0.004) and hypotension with bradycardia (27 versus 12%, P=0.02).


CONCLUSIONS
These data demonstrate that during right coronary artery occlusion and with reperfusion, bradycardia and hypotension develop more commonly in patients with proximal occlusions compared with those with distal occlusions. These findings suggest that reflexes arising from the ischemic right ventricle may play a role in bradyarrhythmias and hypotension.
Division of Cardiology, William Beaumont Hospital, Royal Oak, Michigan 48073, USA. jgoldstein@beaumont.edu
James A
JA
Goldstein
Daniel T
DT
Lee
Mark C
MC
Pica
Simon R
SR
Dixon
William W
WW
O'Neill
D001919:Bradycardia / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology; D017023:Coronary Angiography; D003326:Coronary Circulation; D004452:Echocardiography; D004562:Electrocardiography; D006801:Humans; D007022:Hypotension / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology; D009203:Myocardial Infarction / Q000150:complications / Q000473:pathology* / Q000503:physiopathology*; D015425:Myocardial Reperfusion / Q000009:adverse effects; D012189:Retrospective Studies; D012720:Severity of Illness Index; D018487:Ventricular Dysfunction, Left / Q000209:etiology / Q000503:physiopathology