The relationship of resting S-T segment depression to the severity of subvalvular aortic stenosis and the presence of ventricular premature complexes in the dog.

Abstract

Electrocardiograms (ECG) from 35 dogs with subvalvular aortic stenosis (SAS) with a left ventricular outflow tract pressure gradient (PG) of > or =50 mm Hg were retrospectively evaluated for S-T segment depression (STD, > or =0.2 mV in lead II). Pressure gradient, age, heart rate (HR), and number of ventricular premature complexes (VPCs) on a 24-hour ambulatory ECG for dogs with STD were not significantly different from those for dogs without STD. The S-T segment deviation did not correlate significantly with PG, age, HR, or VPCs. The significance of STD in the dog with SAS remains uncertain. Long-term prospective studies are needed to fully understand this observation.