Abstract
The present study was made to investigate the effects of the initial stage of filariais on canine cardiac function. Controls (n=10, BW 7.9±0.4kg, mean±SEM) and dogs with heartworm (n=9, BW 8.8±0.3 kg) were used. Electrocardiographic examination detected that the amplitude (3.8±0.3 mV) and duration (3.9±0.2 msec) of the P wave were increased in dogs with heartworm. Catheteric examination of the heart revealed the cardiac index (5.1±0.21/min/m2) to be significantly decreased (p<0.005), and right and left ventricular end diastolic pressures (7.3±0.7 and 12.6±2.1 mmHg) were greatly increased (P<0.025), compared with the controls. These results might indicate the presence of cardiac dysfunction in the initial stage of filariasis. The detail mechanism in the development of cardiac dysfunction is still unknown.
