CURRENT THERAPY

The Treatment of Shock in Myocardial Infarction

¹ The Department of Medicine, University of California School of Medicine, and Mount Zion Hospital.

The hypotension complicating acute myocardial infarction presents a threat to life when it is manifested by a shocklike clinical pattern, especially if associated with severe oliguria. The critical level of hypotension is dependent on the pre-infarction blood pressure.

If the hypotension is very severe or persists over three hours the shock becomes irreversible and chances of successful therapy are greatly reduced. Definitive therapy should be instituted promptly and maintained until recovery is assured.

Transient benefits may be obtained by use of short-acting pressor amines and transfusions, but in general recovery is dependent on the use of the longer-acting pressor drugs, i-norepinephrine and metaraminol (Aramine). Constant monitoring of the patient's condition and of the therapy is necessary.

Since both myocardial failure²⁷ and peripheral vasomotor mechanisms are responsible for shock, additional measures are recommended, namely, oxygen inhalation, use of digitalis and heparin, adequate carbohydrate and fluid intake, and avoidance of sodium and water accumulation and acidosis. Adrenal corticoids may be helpful in potentiating the pressor amines, but clinically they have not proved consistently valuable.