Computerized electrocardiography in healthy conscious guinea pigs (Cavia porcellus)

Abstract

The purpose of this study is to evaluate healthy conscious guinea pigs as a model for electrophysiology assessment and to describe normal electrocardiographic patterns in controlled laboratory environment, establishing the best QT formula for this method. Electrocardiographic recordings of fifty adult conscious guinea pigs were obtained using a computerized electrocardiography. The electrocardiographic measurements of three different tracings were analyzed. The results obtained established normal mean and range values for the parameters: heart rate, waves and intervals of P-QRS-T deflections, as well as the mean cardiac axis. Groups were separated by body weight: group 1 gathered animals with 500-699g and group 2 with animals 700-900g. No differences were found when measurements were compared between groups, showing no significant difference between weight/ body sizes to the electrocardiographic parameters (P<0.05). The mean corrected QT values (QTc) obtained using diverse formulae were significantly different (P<0.05), were the most consistent was Van der Water (QTcV). QTcV values were strongly correlated (r=98) and 95% confidence interval 185.7 to 195.2ms.Considering its simplicity and reliability, the QTcV was deemed the most appropriate to be used for the correction of QT interval in conscious guinea pigs.The results of this study also suggest that the values found can be used as reference for the species.

Standard Strain and Strain Rate by Two-Dimensional Speckle Tracking in Agoutis (Dasyprocta prymnolopha) Anesthetized with Ketamine and Xylazine

“…The HR in this study was like the findings for agoutis anesthetized by the same protocol [42] and for pacas (Cuniculus paca), similar sized rodents, also chemically contained [48]. However, it was lower when compared to values obtained for non-anesthetized agoutis [14,15], New Zealand rabbits [41] and guinea pigs [8], smaller rodents. HR is inversely proportional to the size of the animal, being higher in smaller species [39].…”

“…The animals studied presented TDI values similar to healthy humans, with no evidence of contractility deficits [40]. Once the LA/AO ratio was observed within the normality patterns described for other rodents and experimental animal models [8,9,27,41], besides diastolic filling velocities (E wave velocity, A wave velocity and E/A relationship) within the limits of normality [33], diastolic function is presumed to be preserved in the animals studied.…”

Non-invasive ECG recording and QT interval correction assessment in anesthetized rats and mice

“…The present work aims to contribute to such studies using the most common species and lineages evaluated in cardiovascular research. The use of a non-invasive six-channel ECG (Botelho et al 2016) and isoflurane anesthesia is a well-known technique that provides harmless, safe and low-cost recording with high repeatability . Ten animals were evaluated considering the similarity amongst rodents as previous works evaluating ECG variations showed such number is sufficient to establish correlations of its parameters (Roussel et al 2016).…”

“…The animals were induced with 2.5% isoflurane and maintained with 1.5% (VetCase -Incotec, Serra/ES, Brazil). Rodents were placed in a dorsal recumbence position on a wooden table covered with plastic material; electrocardiographic gel was applied, and four alligator clip electrodes were attached to the skin in the forelimbs and hindlimbs (Botelho et al 2016). All procedures were performed in a quiet room to minimize stress.…”

A comparative review on heart ion channels, action potentials and electrocardiogram in rodents and human: extrapolation of experimental insights to clinic

“…Based on previous studies the approximate values of heart rate and some ECG parameters of human and other animals have been shown in Table 4 [ 57 – 65 ]. Also, the strips of Lead II ECG and the connection model of standard ECG leads in humans and rodents are demonstrated in Fig.…”