Percutaneous Septal Ablation in Hypertrophic Obstructive Cardiomyopathy: From Experiment to Standard of Care
Figure 1
2D-echocardiographic findings in hypertrophic nonobstructed cardiomyopathy (HNCM, (a)) with predominant thickening of the apical segments and a wide open, unobstructed outflow tract (LVOT) and in hypertrophic obstructive cardiomyopathy (HOCM, (b)) with a protruding subaortic septum making systolic contact with the mitral valve (SAM-phenomenon, arrow). (c) shows simultaneous pressure tracing from the LV and the aorta demonstrating the outflow gradient and the Brockenbrough sign. The corresponding Doppler profiles are shown in (d). The gradient increases from 40 to 140 mm Hg. The typical CW-Doppler flow profile of left ventricular outflow obstruction in HOCM has a late-peaking signal indicating dynamic obstruction involving contracting muscle as opposed to the more symmetrical signal of fixed valvular stenosis. The peak pressure gradient equals 4 (peak velocity)2. LA: left atrium; RA: right atrium; LV: left ventricle; Ao: aorta; and IVS: interventricular septum.
