Evaluation of QT interval in dogs with renal insufficiency

• Grant number: 14/23712-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2015
• End date: December 31, 2015
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Clinics and Surgery
• Principal Investigator: Denise Saretta Schwartz
• Grantee: Amanda Rodrigues de Faria
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

This study aims to evaluate the corrected QT interval (QTc) and QT interval dispersion on the electrocardiogram of dogs with renal insufficiency, including chronic kidney disease (CKD) in stages 3 and 4 (ISIS classification), and acute renal failure (ARF), compared to clinically healthy dogs. The QT interval is measured from the beginning of the QRS complex to the end of the T wave of the electrocardiogram. It represents the sum of ventricular depolarization and repolarization, which is equivalent to the duration of the action potential and corresponds to ventricular systole. The QT interval dispersion is an indicative marker of risk of sudden death in humans, according to several studies. Its analysis has been used to stratify the risks and measure the effects of specific interventions on ventricular repolarization. The QT interval may be altered in many systemic diseases, including CKD and ARF, which affects several organs, causing metabolic derangements. Electrolyte disturbances may occur, such as hyperkalemia, which acts directly in the myocardium, interfering in action potential, and may contribute to the development of arrhythmias. Currently, there is no data on corrected QT and QT dispersion for dogs with CKD and ARF to anticipate the occurrence of arrhythmias or to describe the magnitude of variation inside the margin of measurement error.