Case Study

Cardiac thyrotoxicosis, congestive heart failure (CHF) and pleural effusion in a 14 year old MN DMH cat

A 14-year-old MN DMH cat with a history of hyperthyroidism being treated with methimazole was presented for evaluation of anorexia and weight loss. On survey radiographs consolidation of the left caudal lung lobe, cardiomegaly, and hepatomegaly were present. CBC was within reference range.

Sonographic Differential Diagnosis

Hyperthyroidism – associated cardiac thyrotoxisis, severe atrial enlargement, myocardial dysfunction Congestive Heart Failure – pleural effusion

Image Interpretation

The left ventricular chamber measures normal in size with diffuse myocardial dysfunction. The myocardial thickness measures normally diffusely. The myocardium is mildly hyperechoic. The visible right heart appears mildly to moderately dilated, subjectively. There is severe biatrial enlargement (La:Ao >2.00). Spontaneous echogenic contrast is visualized within the right atrium. Atrial thrombi are not visualized. There is physiologic TR and trivial MR. There is low normal, laminar flow across the RVOT/PV and LVOT/AV (RVOT 0.20m/s, PA 0.32m/s, LVOT 0.56m/s, Ao 0.44m/s). There appears to be a sinus tachycardia present with average heart rate of 220bpm. At least a moderate amount of pleural effusion is present.

DX

Hyperthyroid, cardiac thyrotoxicosis, CHF

Clinical Differential Diagnosis

Uncontrolled hyperthyroidism with myocardial hypertrophy/failure
Cardiomegaly – cardiomyopathy, pleural effusion
Lung – pneumonia, edema, neoplasia
Hepatomegaly – congestion, neoplasia, lipidosis