Q. Reduction in left ventricular?
Vasodilators improve stroke volume, and reduce degree of regurgitation. This results from decrease in systemic vascular resistance and leads to reduction in left ventricular end diastolic volume, after load, wall stress and LV mass. They also preserve LV systolic function. Hydralazine and nefedipine when given at appropriate doses decrease left ventricular size and improve LV function. The dose should be titrated to bring down systolic blood pressure as much as possible without getting side effects. Less consistent results were obtained with ACE inhibitors and increased plasma renin activity is not an issue in these patients. Vasodilators may be given in any patient with severe AR with LV dysfunction and symptoms of heart failure when patient is a poor candidate for surgery. They may also be given to a patient with severe AR and LV dysfunction with or without symptoms to improve hemodynamic profile before surgery. They are also indicated in a patient with severe AR and normal LV function. Here they delay the onset of LV dysfunction, symptom onset and postpone the time for AVR and also improve operative outcomes. In this situation there is no proven role of any other medication. Vasodilators should not be used as a substitute for aortic valve replacement in a patient with severe AR who needs surgery either due to LV dysfunction or symptoms. They are also not indicated in patients with mild AR and normal sized left ventricle with good LV function. Following AVR, ACE inhibitors may be better choice in patients with persistent myocardial systolic dysfunction.