Relation of heart rate dynamics to the occurrence of myocardial ischemia after coronary artery bypass grafting

• Published in: The American journal of cardiology 2002-05, Vol.89 (10), p.1176-1181
• Main Authors: Laitio, Timo T, Mäkikallio, Timo H, Huikuri, Heikki V, Kentala, Erkki S.H, Uotila, Pekka, Jalonen, Jouko R, Helenius, Hans, Hartiala, Jaakko, Yli-Mäyry, Sinikka, Scheinin, Harry
• Format: Article
• Language: English
• Subjects: Aged; Cardiology; Coronary Artery Bypass; Coronary vessels; Electrocardiography, Ambulatory; Female; Finland - epidemiology; Heart; Heart Rate - physiology; Humans; Length of Stay; Male; Middle Aged; Myocardial Ischemia - etiology; Myocardial Ischemia - physiopathology; Postoperative Complications - etiology; Postoperative Complications - physiopathology; Postoperative Period; Predictive Value of Tests; Sensitivity and Specificity; Surgery; Time Factors
• ISSN: 0002-9149; 1879-1913
• DOI: 10.1016/S0002-9149(02)02300-7

Postoperative myocardial ischemia is a common finding after coronary artery bypass grafting (CABG) and is associated with an adverse short-term clinical outcome. The reasons and pathophysiologic background for the occurrence of ischemia after CABG are not well established. We tested the hypothesis that altered heart rate (HR) behavior precedes the onset of myocardial ischemic episodes in patients after CABG. Time-domain HR variability measurements, along with analysis of Poincaré plots and fractal scaling analysis were assessed in 40 CABG patients from 48-hour postoperative Holter recordings. Twenty patients experienced 195 ischemic episodes during the postoperative course. In the univariate analysis of HR variability measurements of the first postoperative day (POD), the increased ratio between the short-term (SD1) and long-term (SD2) HR variability analyzed from the Poincaré plot and the decreased short- and intermediate-term fractal scaling exponents α 1 and α 2 were significantly associated with ischemia during the study period (p