Haemodynamic effects of isosorbide dinitrate in patients with congestive cardiac failure at rest and during submaximal supine exercise.

Eight patients with chronic congestive cardiac failure secondary to ischaemic heart disease performed submaximal supine exercise before and after 5 mg sublingual isosorbide dinitrate (ISDN) at the time of cardiac catheterisation. Exercise before ISDN produced a poor response in left ventricular performance. After ISDN this response was significantly improved. Compared with the control exercise period cardiac index (CI) increased from mean 2.9 to 3.5 l/mn/m2 (p = less than 0.0025), stroke volume index (SVI) from mean 24 to 29 ml/m2 (p = less than 0.0005) and left ventricular stroke work index (LVSWI) from mean 22 to 28 g-m/m2 (p = less than 0.0025). Although ISDN reduced LVEDP significantly at rest, there were associated small but significant falls in CI, SVI and LVSWI. The improvement in exercise cardiac index was related to the ejection fraction, or the ejection fraction of the contractile section where a left ventricular aneurysm was present. ISDN may be effective in improving exercise tolerance in ambulant patients with chronic congestive cardiac failure.