[Use of sodium nitroprusside in cardiology]

Sodium nitroprusside (SNP) is rarely used in cardiology. It is reserved traditionally for severe episodes of arterial hypertension. Certain states of refractory heart failure represent new indications for use, which implies a double haemodynamic monitoring system: continuous control of systemic blood pressure by intra-arterial catheterization; control of pulmonary pressure and repeated measurements of cardiac output. Prolonged treatment requires continuous biological monitoring of toxicity and careful control of kidney function. As a moderator of blood pressure, SNP is remarkably effective. The hypotensive effect is immediate, readily reversible and generally tachyphylaxis is not observed. The effect of SNP on cardiac work is one of double load reduction: mainly a reduction in afterload or pressure and systemic resistance and a reduction in preload or pressure of ventricular filling. In this respect, SNP can be used effectively for severe cases of heart failure intractable to traditional cardio-stimulatory and diuretic treatments and stemming from diverse causes: acute stage of myocardial infarction, ventricular dilatation, mitral papillary syndrome, heart failure, either subacute or chronic, of various causes. As a rule, the immediate results are positive. Taking the patient off the drug can be difficult and may cause a return to the previous haemodynamic situation.