Changes in ventricular volume, wall thickness and wall stress during progression of left ventricular dysfunction

AbstractTo assess the long-term changes in cardiac function in asymptomatic patients with severe left ventricular dysfunction, left ventricular (cineangiography) and right ventricular (radionuclide angiography) function were assessed at baseline in 49 patients enrolled in the prevention arm of the Studies of Left Ventricular Dysfunction. After an average follow-up period of 12.4 months, 30 patients (11 randomized to the placebo group and 19 to the enalapril group) could be restudied to assess the progression of ventricular dysfunction. After 1 year of follow-up, the changes in heart rate, left ventricular end-diastolic and systolic pressure and right ventricular volumes were comparable in both groups. However, there were modest but opposite changes in left ventricular end-diastolic volume (+ 9 ml/m2with placebo vs. −10 ml/m2with enalapril, p < 0.05) and end-systolic volume (+ 5 ml/m2with placebo vs. −13 ml/m2with enalapril, p < 0.05). Mean systolic wall stress increased insignificantly in both groups, whereas ejection fraction increased from 29% to 31% in the placebo group and from 28% to 32% with enalapril (p = NS, placebo vs. enalapril).Even in asymptomatic patients with severe left ventricular dysfunction, there was a slow progression of left ventricular dilation. Enalapril administration appeared to slow this progression, but wall stress was not normalized by the treatment at the doses used in the study, indicating that at least one of the stimuli for further remodeling remained present