Haemodynamic collapse immediately after transcatheter aortic valve implantation due to dynamic intraventricular gradient: a case report and review of the literature.

Background Dynamic intraventricular obstruction after transcatheter aortic valve implantation (TAVI) has been previously reported. There is a risk of haemodynamic collapse in the case of left ventricular outflow tract (LVOT) obstruction due to systolic anterior motion (SAM) of the mitral valve. Case summary An 83-year-old woman with aortic stenosis (AS) was referred to our hospital for TAVI. Transthoracic echocardiography revealed a severely calcified aortic valve with a peak velocity of 6.3 m/s across the valve. Acceleration of blood flow (peak velocity 2.6 m/s) at the LVOT due to a septal bulge was also seen. Transfemoral TAVI was performed, and a 29 mm Evolut PRO was implanted under general anaesthesia. After the implantation, a complete atrioventricular block with junctional rhythm developed, and refractory hypotension occurred immediately. Transoesophageal echocardiography revealed LVOT obstruction due to SAM of the mitral valve associated with severe mitral regurgitation (MR), which was not observed preoperatively. Fluid infusion and catecholamine administration were not effective. However, after performing temporary pacing from the right ventricular (RV) apex, the LVOT obstruction and severe MR improved. Her haemodynamics stabilized, and we could complete the procedure. A dual-chamber permanent pacemaker with beta-blocker administration as a longer-term treatment further improved the LVOT obstruction. The patient was finally discharged to a rehabilitation hospital. Discussion Alertness and recognition of potential LVOT obstruction after TAVI are important. Pacing from the RV apex, as well as dual-chamber pacing, comprise a less invasive and feasible therapeutic option in such cases.