Author/Editor | Frljak, S; Avbelj, V; Trobec, R; Meglič, B; Ujiie, T; Geršak, B | |
Title | Beat-to-beat QT interval variability before and after cardiac surgery | |
Type | članek | |
Source | Comput Biol Med | |
Vol. and No. | Letnik 33, št. 3 | |
Publication year | 2003 | |
Volume | str. 267-76 | |
Language | eng | |
Abstract | Non-uniform recovery of excitability may be essential in triggering malignant ventricular tachycardia after cardiac surgery. Thirty-five channels ECG was recorded for 6 min in 27 patients before and after heart surgery and in 20 control subjects. Off-line analysis was performed. RR interval duration, RR SD, QT SD and power spectra of RR variability were computed from 256 s stable RR and QT interval series. When compared to controls, patients had decreased RR SD and increased QT SD before surgery (p < 0.002 and p < 0.0005, respectively); RR SD further decreased and QT SD increased after the surgery ( p < 0.0001 and p < 0.0002, respectively). Increase of QT variability and decrease of RR variability after cardiac surgery may reflect disrupted electrophysiological stability of the myocardium and thus electrophysiological substrate for triggering malignant arrhythmia. | |
Descriptors | HEART RATE ELECTROCARDIOGRAPHY CORONARY ARTERY BYPASS TACHYCARDIA, VENTRICULAR |