Pathophysiology and Natural History Right Ventricular Ischemia

This study describes the clinical experience with four patients with variant angina caused by spasm of the right coronary artery who were assessed for evidence of right ventricular involvement. The patients were suspected of having predominant right ventricular ischemia on the basis of normal thallium-201 scans, left ventricular ejection fraction, regional wall motion assessed by equilibrium radionuclide angiography (RNA), two-dimensional echocardiographic findings, and left ventricular hemodynamics; all procedures were performed during transient ST segment elevation in the inferior leads. Right ventricular ischemia was documented in four patients by first-pass radionuclide studies and phase analysis of RNA, and in three patients by simultaneous right and left hemodynamic monitoring. The clinical findings from these four patients are compared with those from four other patients with similar electrocardiographic changes, coronary anatomic distribution, and documented right coronary spasm but with evidence of left ventricular involvement as documented by abnormal thallium-201 scintigraphy, RNA, two-dimensional echocardiography, and left hemodynamics during ischemic episodes. Although preliminary, these data indicate the existence of prevalent right ventricular ischemia during variant angina caused by right coronary vasospasm. This condition should be suspected whenever typical anginal symptoms and/or ischemic electrocardiographic changes are accompanied by normal thallium-201 scintigraphic findings and/or normal left ventricular function as assessed by RNA, echocardiography, and left hemodynamic monitoring. Among noninvasive procedures, first-pass radionuclide study and phase analysis of RNA represent suitable techniques for detecting transient right ventricular dysfunction. Circulation 70, No. 2, 170-177, 1984. CORONARY VASOSPASM is a well-recognized cause of transient ischemia at rest.1'' Correlation among clinical, electrocardiographic, and angiographic findings has demonstrated that the clinical spectrum of this syndrome is polymorphic and widely variable.2 Radioisotopic,3`' echocardiographic,6 7 and hemodynamicl 9 studies have characterized the patterns of left ventricular perfusion and wall motion abnormalities during resting angina. At present, few data on right ventricular involvement during vasospastic angina are available and are strictly confined to hemodynamic monitoring performed in patients with frequent ischemic attacks at rest.8 In the past few years, great interest has arisen about right ventricular involvement in the course of acute inferior myocardial infarction, and several authors From C. N. R. Institute of Clinical Physiology and Istituto di Patologia Medica I, University of Pisa, Italy. This study was supported in part by contract 82.02168.04 from the Cardiac Respiratory Project Grant and by contract 81-00408-83 from the Preventive Medicine Project of National Research Council. Address for correspondence: Oberdan Parodi, M.D., C.N.R. Institute of Clinical Physiology, Via Savi 8, 56100-Pisa, Italy. Received May 6, 1983; revision accepted March 29, 1984. have demonstrated the existence of predominant right ventricular infarction. 10-20 We describe the clinical features of four patients with Prinzmetal's angina characterized by ST segment elevation in the inferior leads caused by spasm of the right coronary artery (RCA) and evidence of predominant right ventricular impairment.