Rotating Intern Texas A&M University Bryan, TX, United States
Abstract:
Background: Echocardiography is the preferred test to diagnose and stage feline cardiac disease, however it may not be available resulting in the desire to use more readily available tests to screen for clinically relevant structural heart disease[HD]. The potential utility of electrocardiography[ECG] and thoracic radiography have not been assessed for this indication.
Objective: Assess the clinical utility of an ECG and radiography to identify cats at high risk for having HD. Animals: Feline telemedicine cardiology case submissions to IDEXX laboratories that included contemporaneous ECG, echocardiogram, and thoracic radiographs (Nf400).
Methods: Echocardiography reports were reviewed, and cats were categorized as structurally normal[SN], equivocal[ED], and HD. Vertebral heart size[VHS] and subjective classification of cardiomegaly[SC] were recorded. Selected ECG findings were recorded from reports and categorized as dysrhythmia[DR], conduction abnormality[CA] and tall R wave[TR]. Discriminatory ability of individual tests/test categories to identify HD versus SN+ED was evaluated.
Results: Prevalence of SN, ED and HD was 40.0%, 33.5%, 26.5% respectively. Cardiomyopathy represented 97.2% (103/106) of HD diagnoses. The area under the curve for VHS to discriminate between HD and SN+ED was 0.763. A VHS cutoff of >=8.5 had 67.5% sensitivity and 78.6% specificity. For radiographic SC, the classification accuracy was 65.8% with 86.4% sensitivity and 58.4% specificity. For the ECG categories DR, CA, and TR the correct classification of HD versus SN+ED was 65.2%, 57.1%, and 69.7% respectively.
Conclusions: Radiography and electrocardiography have acceptable discriminatory ability to detect feline HD and maybe useful as part of a risk assessment screening protocol.
