Detection and assessment of severity of regional ischemic left ventricular dysfunction by digital fluoroscopy

Abstract

Digital intravenous ventriculography (DIV) was used to detect and assess the severity of regional and global left ventricular (LV) function in the presence of graded levels of coronary stenosis. DIV was performed on six anesthetized dogs with a coronary blood flow probe and micrometer controlled occluder on the circumflex coronary artery (CXA) and pairs of sonic dimension crystals in the posterointerior (ischemic area) and anterior (control area) walls of the LV in the control state, with subtotal occlusion of the CXA (STEN), and with CXA occlusion (OCL). Global analysis at each stage included area-length calculation of end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF). Regional analysis included calculation of area displaced by anterior wall (AA), and posteroinferior wall (IA), average amplitude of excursion of the anterior wall (AE), and posteroinferior wall (IE). STEN caused significant increase in AA (14.4 ± 2.2%) and decreases in EF (−19.7 ± 2.5%), IA (−36.6 ± 4.2%), and IE (−30.8 ± 5.3%) ( p < 0.05). With OCL, there were significant increases in EDV (78.7 ± 7.6%), ESV (225 ± 20.6%), AA (42.6 ± 10.3%), and AE (25.5 ± 4.3%); with further fall in EF (−42.4 ± 2.1%), IA (−94.3 ± 6.6%), and IE (−84.7 ± 9.4%) ( p < 0.01). Regional functional indices derived from DIV detected regional wall motion abnormalities, when these were shown to be present by sonocardiometer measurements of myocardial segment length and extent of shortening in the ischemic region of the LV. We conclude that DIV is a sensitive technique for the detection and assessment of severity of regional and global LV dysfunction in ischemic heart disease.