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Changes in left ventricular electromechanical relations during targeted hypothermia

Authors :
Kristin Wisløff-Aase
Viesturs Kerans
Kristina Haugaa
Per Steinar Halvorsen
Helge Skulstad
Andreas Espinoza
Source :
Intensive Care Medicine Experimental, Vol 8, Iss 1, Pp 1-13 (2020)
Publication Year :
2020
Publisher :
SpringerOpen, 2020.

Abstract

Abstract Background Targeted hypothermia, as used after cardiac arrest, increases electrical and mechanical systolic duration. Differences in duration of electrical and mechanical systole are correlated to ventricular arrhythmias. The electromechanical window (EMW) becomes negative when the electrical systole outlasts the mechanical systole. Prolonged electrical systole corresponds to prolonged QT interval, and is associated with increased dispersion of repolarization and mechanical dispersion. These three factors predispose for arrhythmias. The electromechanical relations during targeted hypothermia are unknown. We wanted to explore the electromechanical relations during hypothermia at 33 °C. We hypothesized that targeted hypothermia would increase electrical and mechanical systolic duration without more profound EMW negativity, nor an increase in dispersion of repolarization and mechanical dispersion. Methods In a porcine model (n = 14), we registered electrocardiogram (ECG) and echocardiographic recordings during 38 °C and 33 °C, at spontaneous and atrial paced heart rate 100 beats/min. EMW was calculated by subtracting electrical systole; QT interval, from the corresponding mechanical systole; QRS onset to aortic valve closure. Dispersion of repolarization was measured as time from peak to end of the ECG T wave. Mechanical dispersion was calculated by strain echocardiography as standard deviation of time to peak strain. Results Electrical systole increased during hypothermia at spontaneous heart rate (p

Details

Language :
English
ISSN :
2197425X
Volume :
8
Issue :
1
Database :
Directory of Open Access Journals
Journal :
Intensive Care Medicine Experimental
Publication Type :
Academic Journal
Accession number :
edsdoj.6df1bc79bdc34c2d951cfc07af7dd2c9
Document Type :
article
Full Text :
https://doi.org/10.1186/s40635-020-00363-7