Clinical significance of ventricular ectopy and development of dilated cardiomyopathy in Irish wolfhound dogs.

INTRODUCTION/

OBJECTIVES

Cardiac disease is the second leading cause of death in Irish wolfhound (IW) populations (15.27%). Dilated cardiomyopathy (DCM) is a common hereditary disease in IWs. No correlation between ventricular premature complexes (VPCs) and DCM has been noted in IW populations. The authors hypothesized that VPCs on a baseline electrocardiogram (ECG) do not predict the development of DCM.

ANIMALS, MATERIAL AND

METHODS

Twenty-four IWs of breeding age were prospectively recruited in the study. Irish wolfhounds underwent a cardiac examination, echocardiogram, laboratory testing, and 24-h Holter monitor (HM). Enrolled dogs had a normal echocardiogram, at least one VPC on a one-min ECG, and HM placed within 90 days of echocardiogram. Irish wolfhounds were followed up for a minimum of one year and underwent a follow-up HM within 12 months.

RESULTS

Three of 24 IWs (16.67%) developed structural changes and/or atrial fibrillation consistent with DCM during the study period. Ten of 24 dogs (41.6%) developed arrhythmias necessitating medical therapy. There was no significant association between complexity of VPCs and the development of DCM.

STUDY LIMITATIONS: Limitations include the small number of dogs and lack of standardized recheck interval and treatments.

CONCLUSIONS

Three of 24 IWs ultimately developed DCM at least three years after enrollment. No correlation can be made between VPCs on screening ECG and development of DCM within 12 months. Ten of 24 dogs were started on anti-arrhythmic medication, as indicated by arrhythmia complexity. An HM is recommended for all IWs with VPCs noted on surface ECG.