SUPINE BICYCLE STRESS ECHOCARDIOGRAPHY IN HYPERTROPHIC CARDIOMYOPATHY

Haemodynamic changes during exercise may have important clinical and prognostic correlations in patients with hypertrophic cardiomyopathy. Supine exercise steress echocardiography was performed in 34 patients with hypertrophic cardiomyopathy (19 males, average age: 45±12 years). During the test echocardiographic parameters, including left ventricular outflow tract gradient (LVOTG) was measured at three time points: at baseline, at peak exercise and at recovery phase. In twenty patients invasive  haemodynamic examination has been also done.
No major complication occured during the examinations. Exercise capacity of the patients was low (median: 90 W, 95% CI: 75-100 W). Resting LVOTG increased significantly during peak exercise (40±38 vs. 74±62 mmHg, p<0,0001), and increased further during the recovery phase (72±60 vs. 95±73 mmHg, p=0,0004). In patients with resting LVOTG <30 mmHg only the LVOTG at peak exercise increased significantly (10±9 vs. 29±28 mmHg, p=0,0035). In patients with resting LVOTG  >30 mmHg both the LVOTG at peak exercise (71±32 vs. 119±54 mmHg, p=0,0009), and during recovery was increased significantly (111±53 vs. 141±56 mmHg, p=0,0014).  At peak exercise both pulmonary systolic peak pressure (35±14 vs. 53±31 mmHg, p=0,0420), mitral insufficiency grade (p=0,0001), and tricuspid insufficiency grade (p=0,0002) was significantly increased. Measurements of the resting LVOTG by echocardiography or by invasive methods correlated well (r=0,6614, p=0,0015), and echocardiographic LVOTG measured during peak exercise or recovery phase correlated also well with post extrasystolic LVOTG measured during hemodinamic examination (r=0,6093, p=0,0043 ill. r=0,6631, p=0,0097). In conclusion, supine exercise stress echocardiography is a safe method and provides important hemodynamic information in patients with hypertrophic cardiomyopathy.