Rescue alcohol septal ablation for dynamic left ventricular outflow tract obstruction and haemodynamic collapse after transcatheter aortic valve implantation

An 84-year-old woman with severe aortic stenosis (AS) developed profound hypotension and hypoxia requiring intubation immediately after transfemoral transcatheter aortic valve implantation (TAVI) with a 29-mm CoreValve EVOLUT PRO+ (Medtronic, Minneapolis, MN, USA). Emergency transoesophageal echocardiogram (TOE) demonstrated prominent septal bulge with systolic anterior motion (SAM) of the mitral leaflet and associated severe mitral regurgitation (MR) (Panels A and B). Despite aggressive medical therapy with intravenous alpha-agonist and beta-blocker overnight, hypoxia persisted, and she could not be extubated. Edge-to-edge mitral valve repair to prevent SAM was precluded because of prohibitively small mitral valve area (<3 cm2). Instead, alcohol septal ablation to debulk the left ventricular outflow tract (LVOT) was pursued. Left ventricular outflow tract gradients were 40 mmHg, provocable to 80 mmHg with ectopy (Panel C). The left main coronary was selectively engaged through the CoreValve frame (Panel D). Echo contrast was injected through an over-the-wire balloon inflated in the first septal artery (Panel D arrow), lighting up the target septal myocardium on TOE (Panel E arrow), followed by a total of 3 mL of ethanol, occluding the artery (Panel F arrow). Left ventricular outflow tract gradient fell to 10 mmHg, and higher gradients were no longer provocable with ectopy (Panel G). Systolic anterior motion resolved and MR decreased from severe to mild (Panel H). She was successfully extubated 6 h post-procedure and discharged home 5 days later. In patients with severe AS and prominent septal bulge, relieving the stenosis with TAVI may unmask LVOT obstruction causing SAM and haemodynamically significant MR, for which alcohol septal ablation may be an effective rescue strategy.