The American journal of cardiology
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Randomized Controlled Trial Comparative Study Clinical Trial
Hemodynamic comparison of primary venous or arteriolar dilatation and the subsequent effect of furosemide in left ventricular failure after acute myocardial infarction.
The hemodynamic effect of venous dilatation (intravenous isosorbide dinitrate [ISDN]) and arteriolar dilatation (intravenous hydralazine), both as firstline treatment and then combined with intravenous furosemide, were evaluated in a randomized, between-group comparison in 20 men with severe acute left-sided cardiac failure after myocardial infarction (MI). Both ISDN (50 to 200 micrograms/kg/hour) (Group 1) and hydralazine (0.15 mg/kg) (Group 2) reduced systemic arterial pressure (p less than 0.05) and vascular resistance (p less than 0.05). Pulmonary artery occluded pressure was reduced (p less than 0.01) only by ISDN, whereas heart rate (p less than 0.01), cardiac output (p less than 0.01) and stroke volume (p less than 0.05) were increased only after hydralazine. ⋯ In conclusion, ISDN-induced venous dilatation is preferable to primary arteriolar dilatation by hydralazine as first-line treatment in acute left-sided cardiac failure. However, hydralazine and furosemide in combination were equally effective in reducing pulmonary artery occluded pressure and increasing cardiac output. The influences of each regimen on prognosis await further investigation.
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Amiodarone was administered to 154 patients who had sustained, symptomatic ventricular tachycardia (VT) (n = 118) or a cardiac arrest (n = 36) and who were refractory to conventional antiarrhythmic drugs. The loading dose was 800 mg/day for 6 weeks and the maintenance dose was 600 mg/day. Sixty-nine percent of patients continued treatment with amiodarone and had no recurrence of symptomatic VT or ventricular fibrillation (VF) over a follow-up of 6 to 52 months (mean +/- standard deviation 14.2 +/- 8.2). ⋯ The most common symptomatic adverse reactions were tremor or ataxia (35%), nausea and anorexia (8%), visual halos or blurring (6%), thyroid function abnormalities (6%) and pulmonary interstitial infiltrates (5%). Although large-dose amiodarone is highly effective in the long-term treatment of VT or VF refractory to conventional antiarrhythmic drugs, it causes significant toxicity in approximately 50% of patients. However, when the dose is adjusted based on clinical response or the development of adverse effects, 75% of patients with VT or VF can be successfully managed with amiodarone.