Postgraduate Medical Journal (January 1971) 47, 16-22. Pacing after acute myocardial infarction

Experience of endocardial pacing in eighty-two patients with atrioventricular block after myocardial infarction is described. A unipolar pacing wire was passed into an antecubital fossa vein and passed into the right atrium and wedged into the apex of the right ventricle under radiological control using an image intensifier. All patients were attached to an external demand unit set at 60/min which will pace if there is asystole longer than 1 sec. The disadvantages of pacing are discussed. A fall in mortality occurred from 71 % of unpaced patients to 38 % of thirty-seven patients where demand pacing was given. When suppressant drugs (lignocaine, procainamide and quinidine) were given in addition to pacing the mortality dropped to 11 % of twenty-seven patients. The disadvantages of pacing are few and it is considered that suppressant drugs are only used with safety when a pacing system has been installed. ACUTE myocardial infarction is complicated by complete heart block in 5-8 % of all patients (Brown, Hunt & Sloman, 1969) and when untreated carries a mortality rate ranging between 48-71% Transvenous endocardial pacing for the manage-ment of Adams-Stokes disease is now established as a satisfactory method of treatment. More recently temporary transvenous pacing has been successfully used for the treatment of the acute disturbances of atrio-ventricular conduction which may follow acute myocardial infarction (Epstein et al., 1966; Harris & Bluestone, 1966; Lassers & Julian, 1968). During the past 9 years we have treated ninety-five patients with second degree or complete atrioventricular block complicating acute myocardial infarction. The majority of these patients have been referred to our unit from other hospitals and hence there must be some element of selection which might have in-fluenced our results. Details of the first fifty-five patients and the technique used have been reporte