Pharmaceutical preparations for the treatment of hypertension, isolated systolic hypertension, essential hypertension, hypertension with renal disease, primary pulmonary hypertension, hypertension encephalopathy, congestive heart failure, diastolic heart failure, peripheral vascular disease, left ventricular dysfunction following myocardial infarction, definite or suspected acute myocardial infarction, angina pectoris, chest pain, neuropathy in Type II diabetics, endothelial dysfunction, coronary artery disease, chronic ischemic disease, atrial fibrillation and flutter, coronary atherosclerosis, atherosclerotic renal arteries, diabetes with renal manifestations, mitral valve disorders, aortic valve disorders, tachycardia, cardiac dysrhythmias, primary cardiomyopathy, metabolic syndrome, pulmonary valve disorder, migraine, and for the prevention of migraine