Left Ventricular Outflow Tract Obstruction From Proximal Intimo-Intimal Intussusception: A Fatal Complication of...

Acute type A aortic dissection is a highly time-sensitive cardiovascular emergency in which mechanical obstruction of the left ventricular outflow tract (LVOT) by a prolapsing intimo-intimal intussusception flap represents a rare and often fatal complication, producing severe hemodynamic compromise that may be refractory to conventional resuscitative measures. We report a 26-year-old woman with Ehlers-Danlos syndrome who was transferred for evaluation of a large proximal type A aortic dissection and suffered a witnessed cardiac arrest shortly after arrival. Transesophageal echocardiography (TEE) demonstrated a dissection flap prolapsing into the subvalvular LVOT during diastole, disrupting aortic valve coaptation and causing aortic insufficiency (AI), while moving anterograde during systole to obstruct forward flow. Despite transient return of spontaneous circulation, resuscitation ultimately failed, and veno-arterial extracorporeal membrane oxygenation was not pursued because of the underlying aortic dissection, AI, prolonged resuscitation, and concern for hypoxic-ischemic brain injury. This case highlights the diagnostic value of real-time TEE in identifying structural causes of cardiac arrest. This case also illustrates the hemodynamic consequences of a rare and often fatal complication of aortic dissection.