ECG changes after rabbit coronavirus infection

This study examines the electrocardiographic (ECG) changes following rabbit coronavirus (RbCV) infection. We have shown that infection with RbCV resul ts in the development of myocarditis and congestive heart failure and that some survivors of RbCV infection So on to develop dilated cardiomyopathy in the chronic phase. Serial ECGs were recorded on 31 RbCv-infected rabbits. Measurements of heart rate; P-R interval; QRS duration; QTc interval; and P -, QRS-, and T-wave voltages were taken. The recordings were also examined for disturbances of conduction, rhythm, and repolarization. The acute and s ubacute phases were characterized by sinus tachycardia with depressed R- an d T-wave voltages as well as disturbances of conduction, rhythm, and repola rization. In most animals in the chronic phase, the sinus rate returned to near-baseline values with resolution of the QRS voltage changes. The ECG ch anges observed during RbCV infection are similar to the spectrum of interva l/segment abnormalities, rhythm disturbances, conduction defects, and myoca rdial pathology seen in human myocarditis, heart failure, and dilated cardi omyopathy. Because animals often died suddenly in the absence of severe cli nical signs of congestive heart failure during the acute phase, RbCV infect ion may increase ventricular vulnerability, resulting in sudden cardiac dea th. RbCV infection may provide a rare opportunity to study sudden cardiac d eath in an animal model in which the ventricle is capable of supporting ven tricular fibrillation, and invasive techniques monitoring cardiac function can be performed.