title: Isolated circumflex coronary artery obstruction.
abstract: Isolated obstruction of the circumflex branch of the left coronary artery was present in 10 of 1,000 patients undergoing selective coronary angiography for suspected coronary artery disease. The clinical syndrome consisted of typical angina pectoris (six patients), atypical chest pain (three patients) and episodes of myocardial infarction (three patients). Left ventricular damage was mild, never involving more than 20% of the left ventricular circumference as measured during angiography. Left axis deviation was very common on the ECG. In eight patients, the ECG showed a mean frontal QRS axis of 0 degrees or less and in two, an axis of less than -30 degrees. The circumflex lesion typically occurred toward the end of the proximal third of the artery, often immediately after its major anterolateral marginal branch. Two patients had complete obstruction and eight had subtotal circumflex narrowing: the clinical picture was not differnet in these two subgroups. Overall left ventricular function, as measured by ejection fraction and left ventricular diastolic pressure, was normal in most of the patients. End-diastolic pressure was slightly increased in five patients, two of whom also had systemic hypertension.
mesh_terms: D000787:Angina Pectoris / Q000175:diagnosis; D017023:Coronary Angiography; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D004562:Electrocardiography; D005069:Evaluation Studies as Topic; D006801:Humans; D009203:Myocardial Infarction / Q000175:diagnosis