ICU Management of Adult Patients with Large Secundum ASD and Persistent Desaturation

Diagnostic Assessment and Management

The American College of Cardiology recommends immediate determination of shunt direction and magnitude using pulse oximetry at rest and during exercise in adult ICU patients with large secundum ASD and left-to-right shunt presenting with constant desaturation 1, 2, 3
The presence of desaturation in a patient with known left-to-right shunt suggests one of three scenarios: shunt reversal to right-to-left, bidirectional shunting with intermittent right-to-left component, or concomitant pulmonary pathology independent of the ASD 1, 3, 4
Urgent invasive hemodynamic assessment is necessary to measure PA systolic pressure relative to systemic pressure, pulmonary vascular resistance relative to systemic resistance, Qp:Qs ratio, and net shunt direction under current ICU conditions 1, 2, 3, 4

The American College of Cardiology states that ASD closure is absolutely contraindicated if PA systolic pressure is >2/3 systemic, PVR is >2/3 systemic resistance, or net right-to-left shunt is present, as this represents established severe pulmonary vascular disease where closure causes acute RV failure 1, 2, 3, 4, 5
In patients with preserved left-to-right shunt and favorable hemodynamics, transcatheter or surgical closure is indicated to reduce RV volume and improve outcomes 1, 2, 3
The American Heart Association recommends consulting pulmonary hypertension specialists immediately in patients with Eisenmenger syndrome or severe pulmonary vascular disease 6

The American College of Cardiology recommends optimizing volume status carefully, treating any acute RV dysfunction, and avoiding medications that increase PVR in patients with large secundum ASD and persistent desaturation 4
Maintaining adequate systemic blood pressure is crucial to prevent right-to-left shunt augmentation 4

Unoperated ASDs carry significant mortality, with 25% mortality before age 27 and 90% mortality by age 60, making closure essential when hemodynamically appropriate 6
Closure with established severe pulmonary vascular disease is fatal, highlighting the importance of accurate hemodynamic assessment before intervention 4, 5

The American College of Cardiology reports improvement in NYHA functional class, reduction in RV systolic pressure, volumes, and dimensions, and low early mortality and serious complications with appropriate ASD closure 4, 6