Key result
Aortic pressure and LV contractility independently drive left atrial pressure during VA-ECMO, not flow.
Why the study?
VA-ECMO may cause adverse effects including increased LV filling pressure, LV distension, and pulmonary oedema, but the effects of ECMO flow, LV contractility, aortic pressure, and ECMO configuration on left atrial pressure are not quantified.
Does altering aortic pressure, LV contractility, and ECMO flow reduce left atrial pressure in a mock circulatory loop model of VA-ECMO?
Does altering aortic pressure, LV contractility, and ECMO flow reduce left atrial pressure in a mock circulatory loop model of VA-ECMO?
In a mock circulatory loop model of VA-ECMO, left atrial pressure is driven synergistically by aortic pressure and LV contractility, but not by ECMO flow rate or direction.
Answers are grounded in this paper and cite their sources.
May inform VA-ECMO management via aortic pressure and LV contractility targets; hypothesis-generating in mock loop, requires clinical validation.
Background Veno-arterial extra-corporeal membrane oxygenation (VA-ECMO) may cause adverse effects including increased left ventricular (LV) filling pressure, LV distension and pulmonary oedema. We aimed to quantify the effects of ECMO flow, LV contractility, aortic pressure (AoP) and ECMO configuration on left atrial pressure (LAP) during VA-ECMO for cardiogenic shock in a mock circulatory loop (MCL). Methods An MCL simulated a normal state, LV failure, right ventricular failure, and biventricular failure. The ECMO return cannula was placed in the femoral artery (retrograde flow) or ascending aorta (antegrade flow). ECMO flow was incrementally increased from 0 to 5L/min. LAP, mean AoP, ECMO flow and total cardiac output were measured at steady state. Results During VA-ECMO, LAP increased linearly with AoP, with the slope greater in the presence of LV impairment compared to preserved LV function. When AoP was held constant, as is the goal of therapy in clinical management, ECMO flow had no effect on LAP. In multivariable linear regression, AoP and LV contractility (p<0.001 for each) correlated independently with LAP, but ECMO flow did not. ECMO return flow direction had no effect on LAP. Conclusions AoP and LV contractility, but not circuit flow or direction, independently determine LAP under VA-ECMO support. By controlling each of these inputs, vasodilator and inotrope management may combine synergistically to prevent VA-ECMO-related complications.
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Jiang et al. (2023) studied Cardiogenic shock (simulated). Hemodynamic and circuit-related adjustments (Aortic pressure, LV contractility, ECMO flow rate and direction) was evaluated on Left atrial pressure (LAP) at steady state (p=<0.001). Aortic pressure and left ventricular contractility synergistically and independently determined left atrial pressure (p<0.001 for both) during veno-arterial ECMO, whereas ECMO flow rate and direction had no independent effect.
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