A juvenile (estimated 3- to 6-month-old) female Scottish Fold cat was referred to cardiology specialists for evaluation of a murmur detected by a primary care veterinarian. The cat had been obtained several weeks earlier through a social media website and had an undisclosed medical history. The cat had blepharospasm caused by a suspected ocular viral infection and was being treated with topical ophthalmic erythromycin ointment and oral administration of lysine, but the owners reported no clinical signs of cardiac disease. On examination, the cat had a grade 5/6 left parasternal systolic murmur. Heart rate was 260 beats/min, and the rhythm was regular with moderately strong femoral pulses that were synchronous with the heartbeat. Echocardiography revealed mild left ventricular hypertrophy (left ventricular septal wall thickness, 6 mm [reference range,1 < 6 mm]; left ventricular free wall thickness, 7 mm [reference range,1 < 6 mm]) and a thickened and elongated anterior mitral valve leaflet. Systolic anterior motion of the mitral valve was evident, which caused mild mitral valve regurgitation and high left ventricular outflow tract velocity (5.3 m/s; reference range, 1.0 to 1.2 m/s)1 with a scimitar-shaped spectral Doppler ultrasound profile. Given the cat's young age and the echocardiographic characteristics of the mitral valve, a presumptive diagnosis of mitral valve dysplasia with severe outflow tract obstruction and secondary left ventricular hypertrophy was made, although a diagnosis of primary hypertrophic obstructive cardiomyopathy could not entirely be ruled out. On the basis of the cat's tachycardia and suspected J-point deviation noted on the echocardiographic timing lead, 6-lead ECG was performed (Figure 1).
The authors declare that there were no conflicts of interest.
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