The Emergency Treatment of the Complications of Acute Coronary Artery Occlusion

¹ New York, New York

During recent years, the diagnosis of acute coronary occlusion has been greatly facilitated, for example, by the widespread use of serum and urine enzyme determinations. More definite means of direct and differential diagnosis makes for early recognition of complications and for the avoidance of therapy that may be contraindicated.

Serious complications of acute coronary occlusion include shock, very slow or very fast ventricular rates, advanced heart failure, embolic events, the postmyocardial infarction syndrome and rupture of either the ventricular wall, interventricular septum, chordae tendinae, or papillary muscles.

Correction of severe hypotension in shock may be accomplished either by increasing the peripheral vascular resistance or by increasing cardiac output. The sympathomimetic drugs commonly employed increase peripheral vascular resistance. Newer experimental approaches include the use of hypothermia, extracorporeal circulation, or mechanical augmentation of the diastolic pressure.

If arrhythmias do not remit or if shock or failure is present, sedatives, digitalis, quinidine, procaine amide, sympathomimetic drugs, isoproterenol, thiazides, atropine, ACTH, corticosteroids, the electrical defibrillator and pacemaker, implanted myocardial electrodes, closed and openchest methods of cardiac resuscitation have proved useful.

The treatment of heart failure is essentially the same as if coronary occlusion were not present except that one is more careful to avoid digitalis intoxication. Over-digitalization with resultant arrhythmias must be treated promptly by digitalis withdrawal, potassium administration and occasionally the use of chelating agents.

The present-day armamentarium used to treat failure includes morphine, theophylline, ethylenediamine, oxygen, tourniquets, phlebotomy, diuretics such as the organomercuriais, thiazides, spirolactones, sulfonureas, corticosteroids, acidifying agents including lysine and arginine hydrochloride and the low salt diet.

Prevention of embolic phenomena is the prime purpose of anticoagulants. There is no conclusive evidence that they can prevent impending attacks from materializing. In certain diseases simulating coronary occlusion, they are contraindicated. Longterm anticoagulant therapy is considered.

Bacterial and the newer fungal fibrinolytic agents have proved capable of lysing thrombi. Wider clinical application in acute coronary occlusion may occur in the near future.

The prognosis in coronary occlusion has greatly improved during the past 30 years. In private practice, the mortality rate during the first attack is now 5 per cent or less. Most patients can be rehabilitated within two or three months. The vast majority make a fair or better recovery. More than half make an excellent recovery. Four or five return to work.

The employment of the therapy reviewed in this paper will improve the ourlook of those sustaining a coronary occlusion. With the present concerted investigative attack on the problem, the future is encouraging for even greater therapeutic effectiveness.