Left ventricular volume overload in isolated rheumatic mitral stenosis.

Having shown the absence of chronic preload insufficiency as the mechanism of modestly depressed left ventricular ejection performance in patients with rheumatic mitral stenosis in our previous work, we sought to characterise a subset of patients with left ventricular volume overload. Echocardiographically determined ventricular load, ejection and contractile performance and left ventricular geometry were studied in 19 patients with mitral stenosis having left ventricular volume overload (end-diastolic volume > 90 ml/m2, Group I) and in 83 patients with normal volume (end-diastolic volume < 90 ml/m2, Group II). The two groups were well matched for age, gender, body size and mitral valve area. Left ventricular ejection fraction was similar in the two groups; however, the patients in Group I had higher end-diastolic volume (101 +/- 15 vs 58 +/- 18 ml/m2, p < 0.0001), end-systolic wall stress (81.7 +/- 17 vs 64 +/- 22 Kdynes/cm2, p < 0.0001), left ventricular mass (109 +/- 20 vs 82 +/- 19 gm/m2, p < 0.001) but lower relative wall thickness (26 +/- 6 vs 34 +/- 9%, p = 0.007), mass/volume ratio (1.1 +/- 0.23 vs 1.49 +/- 0.46 gm/ml, p < 0.001) and wall stress/end-systolic volume ratio (2.07 +/- 0.58 vs 2.65 +/- 0.92, p = 0.016). Of these 19 patients in Group I, seven had isolated volume overload while 12 had associated eccentric hypertrophy. Wall stress correlated well with fractional shortening in Group II (r = 0.75, p < 0.001) but not in Group I (r = 0.09).(ABSTRACT TRUNCATED AT 250 WORDS)