Results of ambulatory electrocardiography in overtly healthy Doberman Pinschers with equivocal echocardiographic evidence of dilated cardiomyopathy

Objective-To determine results of ambulatory electrocardiography in and outcome of overtly healthy Doberman Pinschers with equivocal echocardiographic evidence of dilated cardiomyopathy, Design-Case series. Animals-44 overtly healthy (25 male, 19 female) Doberman Pinschers. Procedure-24-hour ambulatory electrocardiographic (Holter) recordings with >90% scan quality obtained the same day that echocardiography was performed were reviewed. Results-Holter recordings from 42 of 44 (95%) dogs contained ventricular premature complexes (VPC). Fifteen of 44 (34%) dogs had > 100 VPC, 9 (20%) had > 500 VPC, and 5 (11%) had > 1,000 VPC. Nonsustained (<30 seconds) ventricular tachycardia was detected in 4 dogs. Eighteen of 27 (67%) dogs with > 100 VPC, any couplets or triplets of VPC, or ventricular tachycardia developed dilated cardiomyopathy within 1 year, compared with 8 of 17 (47%) dogs with <100 VPC, no couplets or triplets of VPC, and no ventricular tachycardia, Of the 18 dogs that did not develop dilated cardiomyopathy within 1 year, 11 (61%) did so within 3 years. Conclusions and Clinical Relevance-Results suggest that a high percentage of Doberman Pinschers with equivocal echocardiographic evidence of dilated cardiomyopathy will be found to have VPC during 24-hour ambulatory electrocardiography and that most will develop echocardiographic abnormalities indicative of cardiomyopathy.