Malignant Arrhythmia in Acute Conus Artery Occlusion

Abstract

We present the case of a 74 y.o. woman with multiple cardiovascular risk factors, admitted for worsening angina over the past three weeks. On admission she had no significant electrocardiographic and echocardiographic changes and a negative Troponin test.
Coronary angiography revealed single vessel disease: severe stenosis of the right coronary artery (RCA) ostium (difficult to assess visually), 50% mid-vessel and 60% distal segment. The left anterior descending artery and circumflex artery had non-significant stenoses. Fractional flow reserve technique (FFR) was used to evaluate the RCA ostial lesion which proved to be significant, therefore angioplasty with three drug-eluting stents was performed for all three lesions of the right coronary artery, starting from the ostium. Due to its location, minimal aortic protrusion of the first stent occluded a small ostial branch which proved to be the conus artery and the patient developed mild transient angina during the procedure, but with good outcome regarding the intracoronary flow. After the angioplasty the patient presented anterior leads ST-elevation and developed mild chest pain with an increase in cardiac enzymes (CK-MB peak 39 U/L).
Later on, she had two episodes of ventricular fibrillation with rapid defibrillation to sinus rhythm, with no further events or echocardiographic changes and no recurrent angina. The patient was started on amiodarone to prevent ventricular arrhythmias and continued double antiplatelet therapy with aspirin and clopidogrel. She was discharged six days later.
In conclusion, although the conus branch is a small artery, its acute occlusion can have significant life-threatening complications.