Electrocardiographic exam in female spotted pacas (Cuniculus paca)

Considering the limited physiological information available on neotropical rodents and the importance of this information for pathophysiological and conservation studies of the­se species, the aim of this study was to evaluate the cardiac electric physiology of healthy captivity spotted pacas (Cuniculus paca) under chemical restraint, due to wild nature of these animals. Eleven adult female pacas were evaluated by blood count and biochemical dosage to rule out any associate disease. Each animal was evaluated in three periods every 15 days. After chemical restraint with intramuscular midazolam 0.5mg/kg and ketamine 25mg/kg, animals were subjected to a computerized electrocardiogram, where bipolar (DI, DII and DIII) and augmented unipolar leads (aVR, aVL, aVF) were obtained. Descriptive sta­tistics were calculated for each parameter and built the confidence interval (CI) at signifi­cance level of 95%. The electrocardiographic examination was performed without difficult. ECG tracing in DII represents a QRS complex with positive polarity, preceded by a P wave of the same polarity and proceeded by T wave of variable polarity. Heart rate mean was 150±17 bpm, and cardiac electrical axis 33.4±21.9°. All animals showed sinusal rhythm. The ECG recording technique associated with chemical restraint was well tolerated, allo­wing quick acquisition of reliable ECG tracings with high repeatability, which produced sufficient results to determine the heart rhythm and suggest measures of ECG complexes duration and amplitude.