Severe dynamic left-ventricular outflow-tract obstruction unmasked by transcatheter aortic valve implantation: a case report

Relieving the fixed afterload of severe aortic stenosis can unmask a previously concealed dynamic outflow-tract obstruction.

A 69-year-old man with severe aortic stenosis (valve area 0.65 cm²; 109/64 mmHg), mild concentric hypertrophy (septum 15 mm), and no baseline systolic anterior motion (SAM) underwent transcatheter aortic valve implantation (TAVI). The invasive peak-to-peak gradient fell from 64 to 7 mmHg, but echocardiography immediately afterwards showed new SAM and severe dynamic left-ventricular-outflow-tract (LVOT) obstruction (170/67 mmHg) with hypotension. Treatment was load-directed (volume expansion, avoidance of vasodilators and inotropes, beta-blockade), with a cardiac myosin inhibitor as an adjunct. Over 4 months the resting LVOT gradient fell to 22/13 mmHg and the provoked peak to 29 mmHg, with SAM no longer seen and preserved ejection fraction.

Recognizing this load-dependent obstruction during the procedure and restoring loading, rather than escalating inotropes, is the key lesson.