How does wide-angle, phased-array echocardiography characterize the systolic anterior motion of the mitral apparatus and left ventricular dynamic geometry in patients with idiopathic hypertrophic subaortic stenosis?
Wide-angle phased-array echocardiography provides detailed spatial resolution of the mitral apparatus in IHSS, supporting specific mechanisms for systolic anterior motion and abnormal LV geometry.
A wide-angle, phased array ultrasonic sector scanner was used to view the heart in 18 patients with idiopathic hypertrophic subaortic stenosis (IHSS). The rapid systolic anterior motion (SAM) of the mitral apparatus appeared quite separate from movement of either the left ventricular posterior wall or prominent papillary muscles. The SAM always occurred in a location judged to be the chordal end of the mitral leaflets. The SAM involved the whole mitral apparatus more extensively in patients with high outflow tract gradients at rest (> 60 mm Hg), and in all patients during Valsalva maneuver or amyl nitrite inhalation. The mitral apparatus, including the papillary muscles, was anteriorly displaced in short-axis images of these patients' hearts. True end-systolic cavity obliteration was not seen at rest in any patient, since a small space persisted posteriorly between the papillary muscles in short-axis images. We believe these data support some and negate other previously proposed mechanisms for the mitral valve SAM and abnormal left ventricular dynamic geometry in patients with IHSS.
Martin et al. (Fri,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: