Infarct transmurality and adjacent segmental function as determinants of wall thickening in revascularized chronic ischemic heart disease

Abstract

There are many factors which influence regional left ventricular wall thickening (WT) in ischemic heart disease (IHD). We used magnetic resonance imaging (MRI) to explore, in patients with chronic ischemic heart disease (CIHD), how regional WT is affected by both infarct transmurality (IT) and the function of adjacent segments. We also compared these findings with a group of healthy volunteers (controls). Twenty patients (20 men, mean age 63, range 45-80 years) were imaged with cine MRI for function and delayed enhancement MRI for infarction 6 months after revascularization. Twenty age and sex matched controls underwent cine MRI. Short-axis images were analysed using a 12-segment per slice model in four midventricular slices per subject. WT and IT were inversely related (r(2) = 0.11, P<0.001). WT of non-infarcted segments in patients was lower than corresponding segments in controls (5.1 versus 4.6 mm, P<0.001). WT in patients decreased with an increasing number of dysfunctional adjacent segments (P<0.001) and increasing IT (P<0.001). WT was more strongly influenced by the number of dysfunctional adjacent segments (t = -22.93, P<0.001) than by IT (t = -4.50, P<0.001). The number of dysfunctional adjacent segments is a greater determinant than infarct transmurality on regional wall thickening.