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Caffeine and dobutamine challenge induces bidirectional ventricular tachycardia in normal rats
- Source :
- Heart Rhythm O2, Vol 1, Iss 5, Pp 359-367 (2020), Heart Rhythm O2
- Publication Year :
- 2020
- Publisher :
- Elsevier, 2020.
-
Abstract
- Background: Bidirectional ventricular tachycardia (BD-VT) is an intriguing arrhythmia, characterized by a beat-to-beat alternation of the QRS polarity on electrocardiogram. Currently there is no simple BD-VT animal model. Objective: We report a simple animal model of BD-VT induced by caffeine and dobutamine (C+D) challenge in normal rats in which the arrhythmia can be attenuated by dantrolene (a ryanodine receptor stabilizer) treatment, but not by the pacemaker channel blocker ivabradine treatment. Methods: Adult (4–5 months old) Sprague-Dawley rats (both sexes) were randomized into C+D (n = 8, received caffeine 120 mg/kg intraperitoneally [IP] and dobutamine 60 μg/kg IP, sequentially) and control (n = 8) groups. In addition, a group of 7 rats were pretreated with dantrolene (10 mg/kg, IP) 30 minutes before the C+D challenge and another group of 8 rats were pretreated with ivabradine (5 mg/kg, IP) 30 minutes before the C+D challenge. Results: C+D challenge induced spontaneous premature ventricular contractions (PVCs) in 7 of 8 rats and BD-VT (lasted 4.3 ± 2.9 minutes, terminated spontaneously) in 6 of 8 (75%) rats. No ventricular arrhythmia was induced in the control group (P < .05 vs C+D group). Dantrolene treatment significantly decreased BD-VT (1 of 7 rats in the Dantrolene+C+D group vs 6 of 8 rats in C+D group, P < .05). Ivabradine treatment did not affect C+D-induced BD-VT (7 of 8 rats in the Ivabradine+C+D group vs 6 of 8 in the C+D group, P > .05). Conclusion: Caffeine and dobutamine challenge induces BD-VT in a majority of normal rats. Stabilizing cardiac ryanodine receptors with dantrolene treatment can significantly decrease the occurrence of BD-VT, but pacemaker channel blocker ivabradine treatment does not have effect in this animal model.
- Subjects :
- medicine.medical_specialty
Dantrolene
Experimental
chemistry.chemical_compound
QRS complex
Internal medicine
Caffeine
Dobutamine
medicine
Diseases of the circulatory (Cardiovascular) system
Channel blocker
business.industry
Ryanodine receptor
Bidirectional ventricular tachycardia
chemistry
RC666-701
cardiovascular system
Cardiology
Ventricular arrhythmia
business
Ivabradine
medicine.drug
Subjects
Details
- Language :
- English
- ISSN :
- 26665018
- Volume :
- 1
- Issue :
- 5
- Database :
- OpenAIRE
- Journal :
- Heart Rhythm O2
- Accession number :
- edsair.doi.dedup.....f7274b6d4c46e5b9d10d432c539e043f