Beat-to-beat heart rate and QT interval variability in patients undergoing coronary artery bypass graft surgery

Author

Frljak, S. ; Avbelj, V. ; Trobec, R. ; Gersak, B.

Author_Institution

Dept. of Cardiovascular Surg., Univ. Med. Center, Ljubljana, Slovenia

fYear

2002

fDate

22-25 Sept. 2002

Firstpage

661

Lastpage

664

Abstract

Non-uniform recovery of myocardial excitability may be essential in triggering malignant ventricular tachycardia in patients after cardiac surgery. Beat-to-beat heart rate and QT interval variability was investigated in 27 patients scheduled for elective coronary artery bypass graft surgery (CABG) and 20 control subjects. 35 channel ECG was recorded for 6 minutes, followed by off line computer analysis. Heart rate interval duration, RR SD, QT SD and power spectra of RR variability were computed from 256-second stable heart rate and QT interval series using MECG software. Study showed that CABG caused increased QT interval variability in face of nearly constant or slowly changing heart rate, suggesting a loss of autonomic coupling between heart rate and ventricular repolarization for sympathovagal modulation.

Keywords

electrocardiography; medical signal processing; surgery; ECG; QT interval variability; beat-to-beat heart rate variability; elective coronary artery bypass graft surgery; heart rate; heart rate interval duration; malignant ventricular tachycardia; myocardial excitability; off line computer analysis; sympathovagal modulation; ventricular repolarization; Arteries; Cancer; Cardiology; Data acquisition; Electrocardiography; Heart rate; Heart rate interval; Medical treatment; Myocardium; Surgery;

fLanguage

English

Publisher

ieee

Conference_Titel

Computers in Cardiology, 2002

ISSN

0276-6547

Print_ISBN

0-7803-7735-4

Type

conf

DOI

10.1109/CIC.2002.1166859

Filename

1166859