Medizinische Universität Graz - Research portal
Selected Publication:
SHR Neuro Cancer Cardio Lipid Metab Microb
Floré, V; Claus, P; Antoons, G; Oosterhoff, P; Holemans, P; Vos, MA; Sipido, KR; Willems, R.
Microvolt T-wave alternans and beat-to-beat variability of repolarization during early postischemic remodeling in a pig heart.
Heart Rhythm. 2011; 8(7):1050-1057
Doi: 10.1016/j.hrthm.2011.02.015
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- Co-authors Med Uni Graz
- Antoons Gudrun
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- Abstract:
- BACKGROUND Repolarization variability is considered to predict sudden cardiac death. T-wave alternans (TWA) has been the subject of exhaustive research, whereas beat-to-beat variability of repolarization (BVR) is a new parameter that possibly predicts proarrhythmia. How these parameters interact has not been tested. OBJECTIVE The purpose of this study was to compare TWA and BVR as predictors of proarrhythmic substrate early after myocardial infarction (MI). METHODS In nine pigs, MI was induced by 1-hour occlusion of the left anterior descending coronary artery. Cardiac magnetic resonance imaging was performed at day 21. Six sham pigs served as control. Spectral TWA was tested during right atrial pacing before induction of MI and after 21 days. BVR was calculated from 60 consecutive QT intervals. RESULTS Magnetic resonance imaging showed transmural MI. TWA was negative in all pigs at clinical threshold rate and equally present in MI versus sham pigs at higher rates (170 bpm: 55% vs 50% positive TWA). In MI pigs, BVR of QT intervals increased significantly during acute ischemia (2.44 +/- 0.43 ms vs 3.55 +/- 0.41 ms, P < .01) and even more on day 21 (5.80 +/- 1.12 ms), but it differed significantly from sham (2.14 +/- 0.54 ms, P < .01). A clinical ventricular tachycardia induction protocol was positive in 2 of 8 MI pigs and in none of 6 shams. CONCLUSION In early remodeling after MI, BVR at intrinsic heart rate was a consistent phenomenon, whereas TWA during atrial pacing or baseline QT-interval changes were not. TWA and BVR could reflect different post-MI remodeling processes. BVR may be a new technique for predicting a potentially proarrhythmic substrate in the early postinfarction period.
- Find related publications in this database (using NLM MeSH Indexing)
- Animals -
- Cardiac Resynchronization Therapy - methods
- Death, Sudden, Cardiac - etiology
- Disease Models, Animal -
- Electrocardiography -
- Follow-Up Studies -
- Heart Conduction System - physiopathology
- Heart Rate - physiology
- Magnetic Resonance Imaging, Cine -
- Myocardial Ischemia - complications
- Swine -
- Tachycardia, Ventricular - complications
- Time Factors -
- Ventricular Remodeling -
- Find related publications in this database (Keywords)
- Beat-to-beat variability of repolarization
- Ischemic cardiomyopathy
- Noninvasive risk stratification
- Sudden cardiac death
- T-wave alternans