Question

What amount of gradient is considered good to end the procedure after septal myectomy between the left ventricle (LV) and the aorta? When should the procedure be stopped and the patient put back on the pump?

Answer 1

A post-procedure gradient of less than 30 mmHg between the left ventricle and the aorta after septal myectomy is generally acceptable. The surgery conclusion depends on intraoperative gradient assessment and ensuring no additional heart complications arise.

Step-by-step explanation:

In septal myectomy for hypertrophic obstructive cardiomyopathy (HOCM), a post-procedure gradient of < 30 mmHg between the left ventricle and the aorta is generally considered acceptable to conclude the surgery. If the gradient remains above this threshold, the patient might need additional resection, and therefore, should not be taken off the pump. Intraoperative echocardiography plays a pivotal role in determining the success of the gradient reduction.

Surgeons should measure the LV outflow tract gradient both at rest and with provocation (e.g., after extrasystoles or with Valsalva maneuver) before concluding the myectomy. The decision to stop or continue with the procedure is based on the achievement of an adequate gradient reduction while ensuring that septal thinning does not compromise the structural integrity of the heart or cause other complications such as aortic insufficiency or heart block.