Echocardiographic Evaluation of Right Ventricular Functions in patients with right coronary artery chronic total occlusions

Abstract

The prevalence of chronic total occlusions (CTOs) has been reported up to 15% to 30% among patients with suspected or known coronary artery disease. Decision of revascularization mode (percutaneous coronary intervention (PCI) or coronary artery bypass grafting surgery) mainly depends on concomitant significant left main and/or multivessel coronary artery disease. The main treatment targets are relief of symptoms, improvement in left ventricular (LV) functions and survival. Some studies showed that opening of CTO is associated with significantly lower mortality than leaving CTO, though other reports did not confirm these observations. However, no data exist on regarding possible improvement will occur in right ventricular (RV) functions after successful recanalization of right coronary artery (RCA) CTOs. Novel echocardiographic approaches like tissue Doppler imaging (TDI) improved the assessment of myocardial functions in both LV and RV, and may identify subtle changes in response to revascularization procedures. This study was done aiming at assessment right ventricular functions in patients with right coronary artery chronic total occlusion. This study included 60 patients with dominant RCA CTO. All patients had stable angina pectoris and/or in some cases, myocardial perfusion scintigraphy. All patients had a proximal RCA occlusion compromising RV branch perfusion. The population in the study underwent detailed history taking, clinical examination and resting ECG, trans thoracic echocardiography for assessing left and right ventricular functions. Our study revealed positive correlation between RV functions and Rentrop class of right coronary artery choronic total occlusion, in addition with ECG evidence of old inferior myocardial infarction. Our study was the first study to echocardiographic assess right ventricular function in patients with right coronary artery choronic total occlusion according to Rentrop class of collaterals in addition according to ECG evidence of old inferior myocardial infarction. The main study findings were as follows:  Patients with right coronary artery chronic total occlusion showed impaired systolic functions of right ventricle as assessed by echocardiography.  The degree of right ventricular functions impairment depends on the degree of collateral filling (Rentrop class) and in addition with ECG evidence of old INF M.I. as patients with Rentrop class I showed more impairment of both systolic and diastolic functions in comparison to patients with class III. In addition patients with ECG evidence of old inferior myocardial infarction showed more impairment of both systolic and diastolic functions in comparison to patients without ECG evidence of old INF M.I. We recommend future studies with follow-up of patients after revascularization of right coronary artery choronic total occlusion to follow up their right ventricular functions should be performed.