RESUMEN
The haemodynamic effects of an intravenous amiodarone infusion (5 mg/kg for 10 minutes) were measured in ten patients with hypertrophic cardiomyopathy (two with a left ventricular outflow gradient at rest) five, 15, and 30 minutes after drug administration. Mean (SD) pulmonary capillary wedge pressure rose significantly at five and 15 minutes (from 12.3 (6.2) mm Hg to 17.6 (9.2) and to 16.2 (8.6] with a subsequent tendency to fall to control values at 30 minutes. Mean right atrial and right ventricular end diastolic pressures increased from 3.6 (1.8) mm Hg to 7.3 (3.1) and from 6.3 (2.4) to 9.8 (3.2) mm Hg respectively at 30 minutes. The increase in filling pressures was paralleled by a decrease of left ventricular max dP/dt from 1522 (414) to 1372 (327) to 1316 (338) and to 1326 (379) five, 15, and 30 minutes after infusion. Despite this slight negative inotropic effect, cardiac index and stroke volume index were unchanged or slightly increased, possibly because of the decrease in systemic vascular resistance (from 1326 (330) dyn s cm-5/m2 to 1152 (285]. In both patients with outflow gradient the pressure gradient at rest decreased (from 110 to 65 and from 85 to 65 mm Hg) through a reduction of left ventricular systolic pressure. Thus short term intravenous infusion of amiodarone is safe in patients with hypertrophic cardiomyopathy. The main changes were a mild depression of ventricular contractility, which was well tolerated and adequately compensated for by a decrease in afterload.
Asunto(s)
Amiodarona/farmacología , Cardiomiopatía Hipertrófica/tratamiento farmacológico , Hemodinámica/efectos de los fármacos , Adulto , Amiodarona/administración & dosificación , Amiodarona/uso terapéutico , Cardiomiopatía Hipertrófica/fisiopatología , Femenino , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana EdadRESUMEN
Prognosis of asymptomatic myocardial ischemia is largely unknown and the opportunity is still controversial of seeking for patients with silent ischemia. Aim of the present study is to evaluate the prognosis of painless myocardial ischemia documented by exercise test and myocardial scintigraphy. From June 1981 through November 1986, 206 patients without angina, history or ECG signs of old myocardial infarction, presenting a positive (decreases ST greater than or equal to 1.5 mm) exercise treadmill test, underwent exercise Thallium 201 myocardial imaging. Myocardial scintigraphy showed a normal scan in 85 cases and a reversible or fixed perfusion defect in 121. Patients with abnormal scan presenting ischemia at a low to moderate ergometric work-load were treated with betablockers or calcium-antagonist drugs. Out of patients with positive myocardial scintigraphy a sample of the first 100 consecutive subjects was considered. They were 87 men and 13 women aged 28-72 years (mean 54.8) observed during a mean follow up period of 33.1 +/- 1.6 months. Seven patients underwent coronary angiography which showed 3-vessel critical stenosis in 3 cases, 3-vessel lesions plus critical stenosis of the left main coronary-artery in 1 and 2-vessel lesions in 3. Two patients underwent coronary artery bypass surgery. A non fatal myocardial infarction occurred in 1 and 1 became symptomatic for angina, 11 and 20 months respectively after the diagnosis of ischemia. Three patients with ischemia at a low work-load and extensive scintigraphic perfusion defects died of sudden death and one of cancer.(ABSTRACT TRUNCATED AT 250 WORDS)