This review discusses the current evidence relating to the prevalence and significance of markers of electrical instability and of autonomic dysfunction in patients who have suffered acute myocardial infarction in light of recent studies performed in patients given thrombolytic therapy during the acute phase. Among markers of electrical instability, emphasis is placed upon the frequency of ventricular arrhythmias during Holter monitoring, the presence of late potentials at signal averaging and the inducibility of ventricular tachycardia during programmed electrical stimulation. Among indices of autonomic nervous system dysfunction, data relating to heart rate variability and baroreflex sensitivity are summarized and discussed.
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