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Structural and Functional Basis for the Long QT Syndrome: Relevance to Veterinary Patients

2003; Wiley; Volume: 17; Issue: 4 Linguagem: Inglês

10.1111/j.1939-1676.2003.tb02468.x

1939-1676

Melissa Finley, James D. Lillich, Robert F. Gilmour, Lisa C. Freeman,

Cardiac pacing and defibrillation studies

Journal of Veterinary Internal MedicineVolume 17, Issue 4 p. 473-488 Open Access Structural and Functional Basis for the Long QT Syndrome: Relevance to Veterinary Patients Melissa R.1 Finley, Melissa R.1 Finley Departments of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS Salk Institute, La Jolla, CASearch for more papers by this authorJames D. Lillich, James D. Lillich Departments of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, KSSearch for more papers by this authorRobert F. Gilmour Jr, Robert F. Gilmour Jr Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NYSearch for more papers by this authorLisa C. Freeman, Lisa C. Freeman Departments of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS DVM, PhD, Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, 228 Coles Hall, Manhattan, KS 66506-5802; E-mail: freeman@vet.ksu.eduSearch for more papers by this author Melissa R.1 Finley, Melissa R.1 Finley Departments of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS Salk Institute, La Jolla, CASearch for more papers by this authorJames D. Lillich, James D. Lillich Departments of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, KSSearch for more papers by this authorRobert F. Gilmour Jr, Robert F. Gilmour Jr Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NYSearch for more papers by this authorLisa C. Freeman, Lisa C. Freeman Departments of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS DVM, PhD, Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, 228 Coles Hall, Manhattan, KS 66506-5802; E-mail: freeman@vet.ksu.eduSearch for more papers by this author First published: 28 June 2008 https://doi.org/10.1111/j.1939-1676.2003.tb02468.xCitations: 18 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Abstract Long QT syndrome (LQTS) is a condition characterized by prolongation of ventricular repolarization and is manifested clinically by lengthening of the QT interval on the surface ECG. Whereas inherited forms of LQTS associated with mutations in the genes that encode ion channel proteins are identified only in humans, the acquired form of LQTS occurs in humans and companion animal species. Often, acquired LQTS is associated with drug-induced block of the cardiac K+ current designated IKr. However, not all drugs that induce potentially fatal ventricular arrhythmias antagonize IKr, and not all drugs that block IKr are associated with ventricular arrhythmias. In clinical practice, the extent of QT interval prolongation and risk of ventricular arrhythmia associated with antagonism of IKr are modulated by pharmacokinetic and pharmacodynamic variables. Veterinarians can influence some of the potential risk factors (eg, drug dosage, route of drug administration, presence or absence of concurrent drug therapy, and patient electrolyte status) but not all (eg, patient gender/genetic background). Veterinarians need to be aware of the potential for acquired LQTS during therapy with drugs identified as blockers of HERG channels and IKr. References 1 Moss AJ, Schwartz PJ, Crampton RS, et al. The long QT syndrome. Prospective longitudinal study of 328 families. Circulation 1991; 84: 1136– 1144. 2 Reef VB, Reimer JM, Spencer PA. Treatment of atrial fibrillation in horses: New perspectives. J Vet Intern Med 1995; 9: 57– 67. 3 Dumaine R., Antzelevitch C. Molecular mechanisms underlying the long QT syndrome. Curr Opin Cardiol 2002; 17: 36– 42. 4 Towbin JA, Vatta M. Molecular biology and the prolonged QT syndromes. Am J Med 2001; 110: 385– 398. 5 Bennett PB. Long QT syndrome: Biophysical and pharmacologic mechanisms in LQT3. 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