Pulsed Wave Doppler Echocardiographic Evaluation and Management of Atrial Fibrillation in Dogs with Dilated Cardiomyopathy

Atrial fibrillation is usually a chronic supraventricular arrhythmia most commonly associated with canine dilated cardiomyopathy (DCM) and degenerative mitral valve disease in dogs. The management of atrial fibrillation is quite challenging with the control of rate and rhythm being the main strategies. In the present study, a total of 150 dogs were subjected to detailed clinical examination, physical examination, electrocardiography and echocardiography. Among 150 dogs, DCM was diagnosed in 58 dogs (38.66%). Out of 58 DCM cases, 21 had atrial fibrillation. The predominant clinical signs noticed in DCM with atrial fibrillation were exercise intolerance, ascites, cardiac cachexia, coughing and syncope. The study of echocardiographic changes in dogs with atrial fibrillation may be helpful to predict the prognosis and survival time. All 21 dogs with DCM and atrial fibrillation were divided into two groups (Group I & II) based on mitral E wave deceleration time (Edt) on Pulsed Wave Doppler. The mean values of Edt were 74.82 ± 1.29 ms and 88.99 ± 1.31 ms in Group I and Group II dogs respectively. All the dogs were treated with Tab. Pimobendan (0.25mg/kg b.wt, bid, PO), Tab. Digoxin (0.005 mg/kg b.wt, bid, PO), Tab. Enalapril (0.5mg/kg b.wt, bid, PO) and Tab. Furosemide (2mg/kg b.wt, bid, PO). After 10 days of treatment, the echocardiography was repeated to measure the peak mitral E wave velocity and deceleration time. The study revealed a high degree of positive correlation between Edt and survival time, as indicated by the increase of survival time with every unit raise in Edt.

• Atrial fibrillation was the most common arrhythmia in dogs with DCM.

• Pimobendane with standard therapy improved the survival time in DCM dogs with AF.

• Mitral Edt was useful to predict prognosis and survival time in dogs with DCM and AF.