Significance of Cardiac Arrhythmias Preceding First Cardiac Arrest in Patients with Acute Myocardial Infarction

In 417 consecutive cases of acute myocardial infarction (AMI) within a minimum of 21 days' stay in the Coronary Care Unit (CCU), primary cardiac arrest occurred in 41 patients (9.9%), the first episode occurring during ECG monitoring in 24 patients. After cessation of ECG monitoring, and within 2-25 days after admission, it occurred in 17 patients. Cardiac arrhythmias before the first cardiac arrest were analysed in these two groups of patients, and compared with the occurrence of cardiac arrhythmias within the first 5 days in 100 consecutive patients with AMI without complicating cardiac arrest. No significant difference in the frequency of cardiac arrhythmias could be demonstrated between the two groups with cardiac arrest and the control series. Moreover, complete absence of rhythm disturbances right up to the beginning of cardiac arrest was as frequent in the patient groups as in the control series (around 20%). As there is not sufficient evidence that treatment with antiarrhythmic drugs can provide safe prophylaxis against the occurrence of cardiac arrest, it is concluded that all patients with AMI should be kept in the CCU and monitored, by cable or by telemetry, for the duration of their stay. To achieve this, the cost in financial terms, manpower and reorganization is not a deterrent. Furthermore, this study does not give any support to the usual practice of confining possible attempts of prophylactic antiarrhythmic treatment to patients with arrhythmias of certain frequencies and/or types.