Left ventricular shape, afterload and survival in idiopathic dilated cardiomyopathy

Abstract

Because idiopathic dilated cardiomyopathy is characterized by elevated wall stress and a more spherical left ventricle, the relations among shape, afterload and survival were examined. Thirty-six patients with cardiomyopathy were prospectively studied by two-dimensional echocardiography. Data included echocardiographic short- and long-axis cavity dimensions, their ratio and, with cuff systolic blood pressure, meridional and circumferential end-systolic stress and their ratios. Survivors (n = 16) were followed up for 52 months (range 40 to 76); nonsurvivors (n = 20) died an average of 11 months after study. Survivors had a smaller left ventricular end-diastolic short-axis dimension (6.4 versus 7.1 cm, p less than 0.03) but a similar long-axis length (8.6 versus 8.3 cm). However, overall cavity shape or the ratio of short- to long-axis end-diastolic dimensions was more spherical in those with poorer survival (ratio 0.76 versus 0.68, p less than 0.02). Meridional and circumferential end-systolic stresses were similar in the two groups, but stress was more evenly distributed in the long- and short-axis planes in nonsurvivors (meridional/circumferential stress ratio 0.57 versus 0.52 in survivors, p less than 0.05). Improved survival was associated with an end-diastolic short-axis dimension less than 7.63 cm, a short- to long-axis ratio less than 0.76 and a meridional to circumferential stress ratio less than 0.54. Life table analysis revealed a 28% mortality rate in patients with all three of these characteristics compared with 100% in patients with none. Survivors and nonsurvivors did not differ in systolic cavity dimension, wall thickness, relative wall thickness, cavity volume, percent posterior wall thickening or fractional shortening.(ABSTRACT TRUNCATED AT 250 WORDS)

Mechanisms and Models in Heart Failure

“…[52][53][54] Although some investigators currently view LV remodeling simply as the end-organ response that occurs after years of exposure to the deleterious effects of long-term neurohormonal stimulation, others have suggested that LV remodeling may contribute independently to the progression of heart failure. 52,55 Although a complete discussion of the complex changes that occur in the heart during LV remodeling is well beyond the intended scope of this brief review, it is worth emphasizing that the process of LV remodeling extends to and affects importantly the biology of the cardiac myocyte, the volume of myocyte and nonmyocyte components of the myocardium, and the geometry and architecture of the LV chamber (Table 3).…”

Mechanisms and Models in Heart Failure

“…[23][24][25] Although some investigators currently view LV remodeling simply as the end-organ response that occurs following years of exposure to the toxic effects of long-term neurohormonal stimulation, others have suggested that LV remodeling may contribute independently to the progression of heart failure. 23 Given the potential central importance of LV remodeling in the progression of heart failure, the following section will focus on the basic cellular and molecular mechanisms responsible for this process.…”

Left ventricular geometry and operative mortality in patients undergoing mitral valve replacement

“…In dilated cardiomyopathy, those patients with the most spherical ventricles demonstrate decreased survival. 6 Lamas er al. analyzed LV shape in 699 patients following MI, and noted that systolic sphericity index predicted mortality independent of ejection fraction.?'…”