Abstract
Simultaneous hemodynamic and radiocardiographic measurements were performed on 10 patients with mitral stenosis and pulmonary congestion for evaluating the acute effects of dobutamine (DB, 5 μg/kg/min), isosorbide dinitrate (ISD, 10 mg sublingually) or a combination of the two. DB alone produced a significant increase of the cardiac index (CI) from 2.9 ±0.1 to 3.7 ± 0.2 L/min/m2 (p <0.01), but a modest increase in pulmonary artery diastolic pressure (PADP) and in pulmonary blood volume by approximately 15%, respectively. ISD alone caused a decline in PADP from 26 ± 2 to 18 ± 1 mmHg (p < 0.001), in right heart volume from 300 ± 36 to 215 ±18 ml/m2 (p < 0.05) and in left heart volume from 321 ± 28 to 248 ± 20 ml/m2 (p<0.05), but no change in the CI. Combined administration of the two agents resulted in favorable alterations in both hemodynamic variables : PADP decreased from 26 ± 2 to 20 ±1 mmHg (p < 0.01) and the CI increased from 2.9 ± 0.1 to 3.3 ± 0.1 L/min/m2 (p < 0.05). Thus, DB alone had a tendensy to aggravate pulmonary venous congestion in our patients, while ISD is effective in reducing the congestive manifestations of heart failure due to its venodilating effects but less beneficial in increasing the CI. The combined therapy of DB and ISD appears to be extremely effective in restoring an adequate cardiac output and in relieving the symptoms of pulmonary vascular congestion in the presence of mitral stenosis.
