John D. Bonagura, DVM, MS, DACVIM

Cardiovascular (CV) diseases in cats include congenital malformations, acquired heart, and vascular disorders. Myocardial disorders or cardiomyopathies, the major cause of heart failure, thromboembolism, and persistent arrhythmias in cats, constitute the focus of this presentation.

Arrhythmias can be classified based on ECG analysis based on the heart rate (normal, bradyarrhythmias, tachyarrhythmias); anatomic origin of the rhythm disturbance (SA, atrial, atrioventricular, or ventricular); or electrophysiologic mechanism when evident.

Acquired heart diseases of dogs include chronic degenerative valvular diseases (endocardiosis), pericardial diseases, cardiac neoplasia, dilated cardiomyopathy (DCM), arrhythmogenic right ventricular cardiomyopathy (ARVC), pulmonary hypertension (PH), infective endocarditis, and heart rhythm disturbances, some of which represent primary electrical disorders and others that develop secondary to cardiac remodeling.

The technician should appreciate the definition and causes of CHF, as well as methods of evaluation. The drugs used to treat CHF should be understood, as well as related side-effects. This awareness improves both patient care and client communications.