What is the management approach for a patient with echo findings of a dilated coronary sinus, atrial septal defect (ASD), and anomalous drainage of pulmonary veins into the coronary sinus?

Management of Dilated Coronary Sinus with ASD and Anomalous Pulmonary Venous Drainage

This constellation of findings—dilated coronary sinus, ASD, and pulmonary veins draining into the coronary sinus—represents either an unroofed coronary sinus defect or a sinus venosus ASD with partial anomalous pulmonary venous connection (PAPVC), and surgical repair is recommended when there is right ventricular volume overload with a hemodynamically significant shunt (Qp:Qs ≥1.5:1), provided pulmonary artery systolic pressure is less than 50% of systemic pressure and pulmonary vascular resistance is less than one-third of systemic resistance. 1

Diagnostic Clarification and Advanced Imaging

The echo findings require further anatomic delineation before proceeding to intervention:

• CMR or cardiac CT is mandatory to precisely map all pulmonary venous connections and define the exact anatomy of the coronary sinus and atrial septal defect 1
• CMR is superior for identifying anomalous pulmonary venous connections that may be difficult or impossible to visualize by echocardiography, particularly those connecting to the coronary sinus 1
• TEE should be performed to visualize the entire atrial septum, assess for unroofing of the coronary sinus, and identify any persistent left superior vena cava (PLSVC) that drains into the coronary sinus 1, 2
• A PLSVC is present in approximately 17.6% of patients with PAPVC and nearly always drains to the coronary sinus, which can explain coronary sinus dilation 3

Hemodynamic Assessment

Before making surgical decisions, comprehensive hemodynamic evaluation is essential:

• Cardiac catheterization can be useful to define precise hemodynamics including shunt quantification (Qp:Qs ratio), pulmonary artery pressures, and pulmonary vascular resistance 1
• Pulse oximetry at rest and with exercise should be performed to identify shunt direction and detect any right-to-left shunting that would contraindicate closure 1
• Look specifically for evidence of right ventricular volume overload and right atrial enlargement on imaging, which are hallmark findings indicating hemodynamically significant shunting 2, 4

Surgical Indications and Timing

Surgical repair is indicated (Class I recommendation) when: 1

• Functional capacity is impaired AND right ventricular enlargement is present
• Net left-to-right shunt is sufficiently large to cause physiological sequelae (Qp:Qs ≥1.5:1)
• PA systolic pressure is less than 50% of systemic pressure
• Pulmonary vascular resistance is less than one-third of systemic resistance

Repair of the anomalous pulmonary venous connection is mandatory at the time of ASD closure 1

Surgical Approach and Technical Considerations

The surgical repair requires specific technical expertise:

• The defect should be approached through an incision starting from the right atrial appendage extending upward along the atrial crest to the medial wall of the superior vena cava 5
• An autologous pericardial patch is used to close the atrial defect and redirect the anomalous pulmonary venous drainage to the left atrium 5
• A second pericardial patch is typically needed to enlarge the superior vena cava-right atrial junction to prevent superior vena cava stenosis 5
• If a PLSVC is present (17.6% incidence), intraoperative management options include direct cannulation (60% of cases), temporary occlusion, or ligation, with awareness that improper myocardial protection strategies can result in deleterious outcomes 3

Contraindications to Closure

ASD closure should NOT be performed when: 1

• PA systolic pressure is greater than two-thirds of systemic pressure
• Pulmonary vascular resistance is greater than two-thirds of systemic resistance
• There is a net right-to-left shunt (Eisenmenger physiology)

These patients have developed irreversible pulmonary vascular disease, and closure would worsen hemodynamics and potentially be fatal 4

Common Pitfalls to Avoid

• Failing to identify all pulmonary venous connections preoperatively can lead to incomplete repair and residual shunting; cross-sectional imaging with CMR or CT is essential 1
• Missing a PLSVC can compromise cardiopulmonary bypass and myocardial protection; always assess for this with TEE or cross-sectional imaging 3
• Assuming this is a simple secundum ASD amenable to device closure—coronary sinus defects and sinus venosus defects with PAPVC require surgical repair, not transcatheter intervention 6
• Overlooking sinus node dysfunction risk—sinus venosus defects carry a 4-5% risk of postoperative sinus node dysfunction due to proximity to the sinus node 5

Postoperative Monitoring

• Serial ECGs should be obtained to monitor for sinus node dysfunction, which can develop in the immediate postoperative period or later 5
• Follow-up echocardiography at 6 months and 2 years is recommended to assess for residual shunting, pulmonary venous obstruction, and superior vena cava stenosis 5