The prognosis is a gloomy one for patients with asymmetric septal hypertrophy (ASH). When the condition is severe enough to cause outflow tract obstruction, it is known as idiopathic hypertrophic subaortic stenosis (IHSS). Typically, patients with IHSS are asked to curtail their physical activity drastically and may be treated with β-adrenergic blocking agents or by surgical resection of the hypertrophied septum. Despite these interventions, they often experience progressive debility and live at risk of sudden death.
Now a team in Rochester, NY, has discovered a form of the disease that is not only treatable but curable.
Clinically indistinguishable from the familial form (which predominates in males and is transmitted as an autosomal dominant trait), the newly identified form of ASH is secondary to hypothyroidism (which predominates in women), rather than genetic in origin. It disappears completely with full thyroid replacement therapy.
R. Paul Miller, MD, assistant professor of medicine at