Showing papers by "Marc A. Pfeffer published in 1989"
TL;DR: Captopril-treated patients with the same baseline distortion of LV shape did not manifest these shape-dependent objective and subjective measures of reduced functional capacity, and sphericity index was the only independent predictor of average exercise duration in the placebo group.
Abstract: The importance of left ventricular (LV) shape in determining exercise capacity was assessed in 40 male patients with LV dysfunction after anterior acute myocardial infarction (AMI). Because captopril therapy is known to improve exercise capacity in this patient population, the potential interaction between LV shape and captopril therapy was also evaluated. Patients underwent cardiac catheterization 2 to 4 weeks after AMI followed by randomization to receive placebo or captopril. LV shape was defined from biplane ventriculography by a sphericity index (volume observed/volume of sphere using long axis as diameter). Quarterly clinical assessments and maximal exercise testing were performed. A cumulative heart failure score, specific activity scale and average exercise time for the year were calculated. A greater shape distortion (increasing sphericity index) was associated with increased LV volumes, decreased ejection fraction and a larger abnormally contracting segment. Sphericity index was the only independent predictor of average exercise duration in the placebo group. Placebo-treated patients in the tercile with the most spherical ventricles had not only the lowest exercise capacity (p less than 0.01), but also accumulated the highest heart failure (p less than 0.05) and specific activity scale (p less than 0.05) scores. Captopril-treated patients with the same baseline distortion of LV shape did not manifest these shape-dependent objective and subjective measures of reduced functional capacity.
177 citations
01 Jan 1989
TL;DR: A close association has been demonstrated across many animal species between the mass of the heart and external work of the ventricle as mentioned in this paper, which is the source for the augmented energy needed to overcome the chronic burden of the pressure overload.
Abstract: A close association has been demonstrated across many animal species between the mass of the heart and external work of the ventricle [1]. Thus, within any single species of animals, any prolonged augmentation in the hemodynamic overload imposed on the ventricle will result in hypertrophy of that chamber sustaining that load. Systemic arterial hypertension is the most common condition leading to left ventricular hypertrophy since it is this chamber which is the source for the augmented energy needed to overcome the chronic burden of the pressure overload.
1 citations