Influence of left ventricular hypertrophy on left ventricular function during dynamic exercise in the presence or absence of coronary artery disease

Objectives. We investigated the influence of left ventricular hypertrophy in the presence or absence of coronary artery disease on hemodynamic characteristics during exercise in subjects without previous myocardial infarction. Background. Left ventricular hypertrophy has been found to increase the vulnerability of the myocardium to the development of ischemia. However, the independent influences of left ventricular hypertrophy and coronary artery disease have not been assessed in humans. Methods. Symptom-limited supine leg exercise tests were performed by 78 patients. They were classified into the following subgroups: no coronary artery disease or left ventricular hypertrophy (group I, N = 30), left ventricular hypertrophy only (group II, N = 12), coronary artery disease only (group III, N = 20) and both left ventricular hypertrophy and coronary artery disease (group IV, N = 16). Mean left ventricular mass index was 105, 158, 109 and 159 g/m2 in groups I to IV, respectively. Results. Pulmonary artery wedge pressure increased from 6 ± 3 (mean ± SD) mm Hg at rest to 10 ± 5 mm Hg at peak exercise in group I, from 8 ± 2 to 18 ± 8 mm Hg in group II (p < 0.05 vs. group I), from 6 ± 3 to 23 ± 6 mm Hg in group III (p < 0.01 vs. group I) and from 8 ± 4 to 30 ± 7 mm Hg in group IV (p < 0.01 vs. group I; p < 0.01 vs. group II; p < 0.05 vs. group III). Multiple regression analysis showed that the number of diseased coronary vessels and left ventricular mass index were independent predictors of peak pulmonary artery wedge pressure (F = 59.2 and 19.1, respectively; multiple correlation coefficient R = 0.74, p < 0.0001). Conclusions. Left ventricular hypertrophy and coronary artery disease independently increased left ventricular filling pressure during supine leg exercise. Severe left ventricular dysfunction was induced by exercise when both conditions were present.