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A3512 - A Hidden Etiology of Preventable Heart Failure
Author Block: M. Ali1, M. Sattar2, J. Finkel3, C. Geller4; 1Internal medicine, Crozer-Chester Medical Center, Secane, PA, United States, 2Internal medicine, Crozer-Chester Medical Center, secane, PA, United States, 3Cardiology, Crozer-Chester Medical Center, Secane, PA, United States, 4Cardiothoracic Surgery, Crozer-Chester Medical Center, secane, PA, United States.
Introduction:Elevated aortic valve velocities measured by doppler echocardiography can be due to subaortic stenosis, aortic valvular stenosis, supravalvular aortic stenosis, hypertrophic cardiomyopathy and coarctation of aorta. The most common etiology is aortic valvular stenosis, however it is important to consider other less common causes.Case:A 69 yr old female with past medical history of hypertension initially presented five years ago with dyspnea and leg swelling. A transthoracic echocardiography (TTE) at that time showed hyperdynamic LV function with aortic valve velocities of 4.57m/s, mean gradient 46mmHG, and what appeared to be a normally opening aortic valve. Transesophageal echocardiography (TEE) was recommended but patient declined. She represented five months ago with heart failure. TTE showed normal LV function, aortic valve velocities >4m/s, and mild aortic regurgitation. She presents a third time with heart failure, and consented to TEE which showed a subaortic membrane and normally opening aortic valve. In addition, she had developed severely decreased left ventricular systolic function and moderate- severe aortic regurgitation (AR). She was referred for cardiac surgery who performed resection of the subaortic membrane extending down into outflow tract with release of fibrosis primarily under the left and right leaflets. Aortic valve appeared normal and intra-op TEE showed only mild AR, so the valve was not replaced. Pathology showed dense hypocellular collagenous connective tissue. Repeat echocardiography showed improvement in LV function, decrease in aortic valve velocity to 2.8 m/s, and mild AR.Discussion:Our patient had a fibrous subaortic membrane which caused outflow tract obstruction and eventually aortic insufficiency and rapid decline in LV function. Aortic regurgitation due to subaortic membrane is common but usually mild and nonprogressive[2]. Damage to the aortic valve due to the subvalvular systolic jet appears to be the main cause of AR but as in our patient, direct extension of subvalvular fibrous tissue into the aortic valve has been rarely described [2]. Resection of the membrane lead to restoration of normal aortic valve geometry and improved the AR without valve replacement. Membrane resection is recommended for patients with subaortic stenosis and a peak gradient of 50 mm Hg or a mean gradient of 30 mm Hg on echocardiography[3]. Valve replacement may be necessary depending on the amount and etiology of the AR.Conclusion:It is important to consider subaortic stenosis in differential of elevated aortic outflow velocity and prompt early diagnosis and treatment as per guidelines to prevent heart failure.