TRANSIENT HEMODYNAMIC DYSFUNCTION AFTER MYOCARDIAL REVASCULARIZATION - TEMPERATURE-DEPENDENCE

  • 1 January 1983
    • journal article
    • research article
    • Vol. 86  (2) , 226-234
Abstract
Hemodynamics and the effects of right atrial pacing (110 beats/min) were studied following complete myocardial revascularization and hypothermic multidose K crystalloid cardioplegia in 12 patients with a normal preoperative left ventricular ejection fraction (LVEF). Measurements were made immediately preoperatively, postoperatively at specified temperatures during the rewarming period (90.degree., 94.degree. and 98.degree. F), and at 24 h. No patient had perioperative myocardial infarction. At 90.degree. F, hemodynamics were characterized by significant decreases in cardiac index, stroke volume index and left ventricular stroke work index (LSVW) and an increase in systemic vascular resistance index (SVRI) compared to preoperative values (P < 0.05). Right atrial pacing significantly increased cardiac index preoperatively and 24 h postoperatively, but not during the rewarming period. Over the entire rewarming period (90.degree.-98.degree. F), each of the following variables correlated with temperature: cardiac index (r = 0.71 in sinus rhythm and r = 0.66 with right atrial pacing); stroke volume index (r = 0.33 and 0.66); SVRI (r= -O.80 and -O.64); LVSW (r = 0.37 and 0.73); and heart rate in sinus rhythm (r = 0.51). During the rewarming period, there was an inverse relationship between cardiac index and SVRI (r = -0.87). In conclusion, after myocardial revascularization: transient hemodynamic dysfunction occurs during the rewarming period (90.degree.-98.degree. F); this dysfunction is temperature-dependent; and right atrial pacing at 110 beats/min does not improve hemodynamic function during the rewarming period. Temperature must be considered in the evaluation of left ventricular and hemodynamic function following myocardial revascularization.