Psychophysiological factors in ventricular arrhythmias and sudden cardiac death. 
Plasma catecholamine levels were measured preceding programmed electrophysiological studies of patients who had survived a ventricular tachyarrhythmia episode.  Psychological assessments of desire for control, locus of control and behavior pattern were obtained.  Psychophysiological variables were analysed with respect to the severity of arrhythmias induced by the electrophysiological procedure.  Analysis of data from 17 subjects showed desire for control was significantly higher in those with induced sustained arrhythmias than in those in which nonsustained arrhythmias were induced.  No relationship was found between behavior pattern and arrhythmia severity or plasma catecholamine levels.  There was a significant interaction between desire for control and behavior pattern with respect to epinephrine level.  The findings indicate that psychological factors such as desire for control may be associated with potentially lethal arrhythmias and implicated in sudden cardiac death.