Discordance in degree of right and left ventricular dilation in patients with dilated cardiomyopathy: recognition and clinical implications.

OBJECTIVES

The purpose of the present study was to assess the influence of variations in the relative degree of dilation of left and right ventricular chambers on the clinical outcome of patients with dilated cardiomyopathy.

BACKGROUND

Dilated cardiomyopathy, a primary myocardial disease characterized by ventricular dilation and systolic dysfunction, is generally associated with a poor prognosis. However, considerable variability has been observed in the clinical course and the morphologic and hemodynamic features in individual patients.

METHODS

We evaluated 67 consecutive patients with dilated cardiomyopathy and without evidence of ischemic or primary valvular heart disease. On the basis of diastolic ventricular chamber area measurements obtained by echocardiography, patients were classified into two groups: 38 patients with a relatively equal degree of left and right ventricular dilation (LV congruent to RV) and 29 patients with predominant and disproportionate dilation of the left ventricle (LV > RV).

RESULTS

The 67 patients ranged in age from 19 to 81 years (mean 56); 49 (73%) were male. The two subsets of patients with dilated cardiomyopathy did not differ with regard to age, left ventricular diastolic dimension, wall thickness and mass or ejection fraction. However, patients in the LV congruent to RV group showed more severe mitral and tricuspid regurgitation by Doppler echocardiography than did those in the LV > RV group (p = 0.01 for mitral and 0.004 for tricuspid regurgitation). Over the follow-up period of 2 to 60 months (mean 28), there were 19 deaths. Survival in the LV > RV group was significantly better than in the LV congruent to RV group (p = 0.03).

CONCLUSIONS

Patients with dilated cardiomyopathy represent a heterogeneous group with regard to both clinical outcome and the relative degree of left and right ventricular chamber dilation. Patients in the LV > RV subset appear to have better overall survival and less severe mitral and tricuspid regurgitation than do patients in the LV congruent to RV subset. Longitudinal studies are needed to determine whether these morphologic subsets in fact represent a continuum within the disease spectrum of dilated cardiomyopathy.