Assessment of QT interval duration and dispersion in dogs with pyometra

• Grant number: 12/24841-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2013
• End date: December 31, 2013
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Clinics and Surgery
• Principal Investigator: Denise Saretta Schwartz
• Grantee: Thais Andrea Pereira
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The electrocardiogram (ECG) is a fast and non-invasive method to measure the electrical activity of the heart. The QT interval corresponds to the duration of ventricular depolarization and repolarization period, representing the duration of ventricular action potential. The prolongation of QT interval may predispose to arrhythmias. Pyometra is a reproductive tract disease, seen mainly in the canine specie, very common in small animal medicine. It is characterized as an emergency, due to the systemic compromise and rapid progression to endotoxemia and possibly septicemia. The toxemic state, acidosis and electrolytic disturbance may favor arrhythmia occurrence. The main treatment recommendation is ovarioshysterectomy, a surgical procedure that requires anesthesia. The imminent risk of arrhythmia secondary to endotoxemia/septicemia, may be considered a limiting factor for anesthesia and surgery. Therefore, the measurement of QT interval and its dispersion may be useful to predict arrhythmia occurrence and to allow the anesthesiologist to plan the anesthesia protocol and to insure the presurgergical therapy. This study aims to measure QT interval and to calculate QTc using Bazett´s and Fridericia´s formulas, and QT dispersion among 10 electrocardiographic leads, in 20 bitches with pyometra and compare to 20 healthy bitches of similar breed or size and approximated age, as there is no reference to this issue in the literature.(AU)