[Effect of nitrates on left ventricular function and exercise tolerance in patients with mild circulatory failure...

In 26 patients with ischaemic heart disease with symptoms of mild chronic circulatory failure (NYHA grade II) aged 56.2 +/- 14.4 years the left ventricular function was tested by two-dimensional echocardiography, the exercise tolerance was determined on cycle ergometer at submaximal workloads, the cardiothoracic index (CTI) and cardiac volume index (CVI) were calculated from chest radiograms. The tests were done before and after 2 and 6 weeks of treatment with isosorbide dinitrate in doses of 49.6 +/- 15.2 mg/day. Isosorbide was found to increase somewhat the ejection fraction (EF), and to raise statistically significantly (p less than 0.05) the velocity of shortening of the circumferential fibres in left ventricular myocardium (mVCF), and to reduce the internal dimensions of the left ventricle (LVIDd and LVIDs), without changing the values of the ejection index (SVI) and cardiac index (CI). Decreased transverse dimensions of the left ventricle was correlated with a significant decrease of the CVI index. No statistically significant effect of isosorbide was noted on the parameters characterizing exercise tolerance but the quotient of the exercise-induced heart rate by the workload (HR/Wat) and the index of myocardial oxygen requirement (HRx Ps) were decreased in a demonstrable way.