Unusual Rare Indication for Extracorporeal Membrane Oxygenation Immediately after successful sequential bilateral lung transplantation for the Treatment of Severe Systolic Anterior Motion and Mitral Valve Regurgitation Induced Cardiogenic Shock
We report an unusual case of primary graft dysfunction grade III following uneventful off-pump bilateral sequential lung transplantation (LTX) caused by paradoxical left ventricular failure due to systolic anterior motion (SAM) of the mitral valve-induced left ventricular outflow tract obstruction.
A 53-year-old man with idiopathic pulmonary fibrosis and moderate secondary pulmonary arterial hypertension underwent uncomplicated LTX. The patient was transferred to intensive care on norepinephrine (0.08 µg/kg/min) and vasopressin (0.8 units/min) with very restrictive iv fluid maintenance.
Ischemia-reperfusion injury-induced primary graft dysfunction after LTX is a major cause of early morbidity and mortality; it is characterized by pulmonary edema with diffuse alveolar damage manifesting clinically as progressive hypoxemia with radiographic pulmonary infiltrates.
Discussion of what was actually done and the challenges, deaths and complications encountered (unless case is still pending):
Despite aggressive volume resuscitation and additional inotropic support (epinephrine 0.15 µg/kg/min), cardiac index remained below 1.5 L/[min·m2]. TTE demonstrated severe mitral valve regurgitation (MR). Persistent hemodynamic and respiratory instability required further resuscitation and emergency VA-ECMO. Intra-op TEE confirmed severe MR but also documented near total LVOT obstruction by the very elongated anterior mitral valve leaflet (3.4 cm). SAM disappeared and MR immediately improved. Our case of transient heart failure was paradoxically induced by extreme dehydration and catecholamine therapy precipitating intraventricular obstruction and significant MR, and thereby inducing an acute drop in cardiac output. Classically, cardiogenic shock is characterized by increased pulmonary capillary wedge pressure (PCWP) and decreased cardiac output, whereas hypovolemic shock includes low PCWP and reduced cardiac output. Due to different management strategies, distinguishing between cardiogenic and hypovolemic shock is critical. In the present case, pulmonary infiltrates were notable and were considered a consequence of elevated PCWP due to increased left arterial pressure which resulted from intracardiac dynamic obstruction and significant MR.
Hypovolemia together with a hyperdynamic state resulting from catecholamine administration may result in the development of dynamic LVOT obstruction secondary to SAM. Early detection and intensive efforts to reverse the underlying conditions including cessation of catecholamine therapy and correction of hypovolemia are essential.