This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Laitio, T. T. Articles by Scheinin, H. Search for Related Content PubMed PubMed Citation Articles by Laitio, T. T. Articles by Scheinin, H. Related Collections Cardiovascular Economics and Health Care Research

---

CARDIOVASCULAR ANESTHESIA

Long-Term Alterations of Heart Rate Dynamics After Coronary Artery Bypass Graft Surgery

Timo T. Laitio, MD^*, Heikki V. Huikuri, MD, Juha Koskenvuo, MD, Jouko Jalonen, MD^*, Timo H. Mäkikallio, MD, Hans Helenius, MSc, Erkki S.H. Kentala, MD^*, Jaakko Hartiala, MD, and Harry Scheinin, MD^¶

Departments of *Anesthesiology and Intensive Care and Clinical Physiology, Turku University Hospital; Departments of Biostatistics and ¶Pharmacology and Clinical Pharmacology, Turku PET Centre, University of Turku; and Division of Cardiology, Department of Medicine, Oulu University Hospital, Finland

Address correspondence and reprint requests to Timo Laitio, MD, Department of Anesthesiology and Intensive Care, Turku University Hospital, P.O.B. 52, FIN-20521 Turku, Finland. Address e-mail to timo.laitio{at}tyks.fi.

We tested the hypothesis that there may be long-term alterations in overall heart rate (HR) variability and in fractal HR behavior after coronary artery bypass graft (CABG) surgery. Reduced HR variability predicts morbidity in various patient populations. Continuous 24-h electrocardiograph recordings were performed in 25 elective CABG surgery patients 1 wk before the operation and 6 wk and 6 mo after. Seventeen of the patients also had recordings 12 mo after CABG. Time and frequency domain measures of HR variability were assessed, along with measurement of short-term fractal scaling exponent (₁), approximate entropy, and power-law relationship of relative risk interval variability (ß-slope). The high, low, very low, and ultra low frequency powers decreased significantly after the operation and remained at a significantly decreased level 6 wk and 6 and 12 mo after the operation than before (P = 0.01, P < 0.001, P < 0.001, and P < 0.001 for overall difference between the time points, respectively). The fractal scaling exponent ₁ was at significantly more decreased 6 wk after (P < 0.05) CABG than before surgery but recovered to the preoperative level 6 mo after the operation. Long-term fractal organization (ß-slope) remained stable, but the overall complexity (approximate entropy) decreased toward more predictable HR dynamics during the study period (P < 0.01 after 1 yr). The predictive value of temporary and persistent long-term changes of the HR dynamics after CABG surgery for long-term outcome is not clear.

This article has been cited by other articles:

				C. Taneyama and H. Goto Fractal Cardiovascular Dynamics and Baroreflex Sensitivity After Stellate Ganglion Block Anesth. Analg., October 1, 2009; 109(4): 1335 - 1340. [Abstract] [Full Text] [PDF]

				K. S. Heffernan, J. J. Sosnoff, C. A. Fahs, K. K. Shinsako, S. Y. Jae, and B. Fernhall Fractal scaling properties of heart rate dynamics following resistance exercise training J Appl Physiol, July 1, 2008; 105(1): 109 - 113. [Abstract] [Full Text] [PDF]

				T. Laitio, J. Jalonen, T. Kuusela, and H. Scheinin The Role of Heart Rate Variability in Risk Stratification for Adverse Postoperative Cardiac Events Anesth. Analg., December 1, 2007; 105(6): 1548 - 1560. [Abstract] [Full Text] [PDF]