Relationship between RR and QT Intervals in Normal and Pacing-induced Heart Failure Dogs

Authors

Vudhiporn Limprasutr
Nakkawee Saengklub
Suwanakiet Sawangkoon
Chollada Buranakarl
Narongsak Chaiyabutr
Anusak Kijtawornrat

Abstract

This study was conducted to determine the effects of rapid ventricular pacing on cardiac function and hemodynamics, and to determine the most suitable QTc formula for the effects of alterations in the RR interval on the QT interval of conscious dog with heart failure (HF). Electrocardiograms were acquired from dogs (n=18) at baseline and after rapid ventricular pacing (6, 9, 12 weeks). RR and QT intervals were measured and QTc intervals were calculated using 3 common formulae (Bazett, Fridericia and Van de Water). HF was confirmed by reduced left ventricular fractional shortening (p<0.05), significantly faster heart rate (p<0.001) and significantly changed QT and QTc intervals (p<0.001) when compared to the baseline. This model also demonstrated decreased systolic arterial pressure (p<0.01) and increased BNP (p<0.05). The appropriate regression equations were QT = 152.4+0.08RR for normal dogs and QT = 32.3 (RR) 0.29 for HF dogs. In normal dogs, the Van de Water formula reveals the least dependency of QTc on RR interval. In HF dogs, the Fridericia formula appears to be the best equation to remove the influence of heart rate.

DOI

10.56808/2985-1130.2548

First Page

31

Last Page

39

Recommended Citation

Limprasutr, Vudhiporn; Saengklub, Nakkawee; Sawangkoon, Suwanakiet; Buranakarl, Chollada; Chaiyabutr, Narongsak; and Kijtawornrat, Anusak (2014) "Relationship between RR and QT Intervals in Normal and Pacing-induced Heart Failure Dogs," The Thai Journal of Veterinary Medicine: Vol. 44: Iss. 1, Article 15.
DOI: https://doi.org/10.56808/2985-1130.2548
Available at: https://digital.car.chula.ac.th/tjvm/vol44/iss1/15