What every intensivist should know about dynamic left ventricular outflow tract obstruction

Dynamic left ventricular outflow tract obstruction (LVOTO) is an underrecognized, load dependent cause of hemodynamic instability in critically ill patients. Although classically associated with hypertrophic cardiomyopathy, it frequently occurs in the ICU in settings such as septic shock, hypovolemia, postoperative states, and right ventricular failure. Standard shock therapies, including inotropes and afterload reduction, may paradoxically worsen obstruction and lead to escalating hemodynamic instability. Bedside echocardiography is central to diagnosis, typically revealing a small hyperdynamic left ventricle and a late-peaking Doppler profile. Management focuses on restoring preload, increasing afterload, and reducing excessive contractility. In some patients, LVOTO is secondary to right ventricular failure, requiring targeted right ventricular support. Dynamic LVOTO is a reversible and often iatrogenic cause of shock. Early recognition and physiology-guided management can rapidly improve hemodynamics and prevent harmful therapeutic escalation.