The authors examined physiologic changes in myocardial infarction patients during a family visit in the cardiac intensive care unit (CICU) and the relationship of these changes to illness variables, patient preference for visits, and patients' perceptions of the supportiveness of the visit. Forty-eight patients were studied for changes in heart rate, blood pressure, ST segment, and oxygen saturation. Patients who had the greatest physiologic changes were among those who had had more severe infarcts. However, many patients in the severe category did not show such changes. Examination of the reactive group revealed that, in addition to having more severe infarcts, it included a greater percentage of smokers than did the nonreactive group. Visit preferences were relatively low, but as visit preferences increased, so did cardiovascular changes. Supportiveness scores were quite high, and these were positively correlated with cardiovascular changes. Clinical and research implications are discussed.