What is the best approach to evaluate chest pain in an adult patient with an atrial septal defect (ASD)?

Evaluating Chest Pain in an Adult Patient with Atrial Septal Defect

In an adult with known ASD presenting with chest pain, cardiac catheterization is reasonable to rule out concomitant coronary artery disease in patients at risk due to age or other factors, while simultaneously assessing the hemodynamic significance of the ASD and excluding pulmonary hypertension as a contributor to symptoms. 1

Initial Risk Stratification

The evaluation must address two parallel concerns: whether the chest pain represents acute coronary syndrome (ACS) versus ASD-related complications (arrhythmias, pulmonary hypertension, paradoxical embolism, or right heart failure). 1, 2

Key Clinical Features to Assess

• Atypical presentations of ASD can include angina-like chest pain, as documented in case reports where surgical ASD repair led to dramatic symptom resolution 3
• Assess for symptoms suggesting pulmonary hypertension (progressive dyspnea, syncope, ascites), which occurs in 6-35% of untreated adult ASD patients 4, 5
• Evaluate for palpitations or syncope suggesting atrial arrhythmias, which increase with age and duration of unrepaired defect 1, 6
• Consider paradoxical embolism as a potential cause of chest pain, particularly if associated with neurologic symptoms 2

Diagnostic Algorithm

Step 1: Immediate Triage with Basic Studies

Chest radiography serves as a rapid triage tool and may show RV and right atrial enlargement, prominent pulmonary artery segment, and increased pulmonary vascularity 1

ECG should be obtained immediately, looking for:

• Incomplete right bundle branch block (rSR' pattern in V1), present in 54-57% of moderate-to-large secundum ASDs 7
• Right axis deviation (mean QRS axis ~108 degrees) reflecting RV volume overload 7
• New atrial arrhythmias (atrial flutter, atrial fibrillation) 7
• Note: Absence of typical ECG findings does not exclude significant ASD, as only 57% of hemodynamically significant ASDs show ECG criteria for RVE 7

Step 2: Echocardiographic Assessment

Transthoracic echocardiography (TTE) is the primary diagnostic imaging modality and should be performed urgently to assess: 1

• Resting wall motion abnormalities suggesting ischemic myocardium, though TTE has limited benefit for ACS detection compared to its utility for heart failure, valvular dysfunction, and pericardial effusion 1
• RV size and function to assess volume overload 1
• Pulmonary artery systolic pressure (critical threshold: concern if ≥50% of systemic pressure) 8
• ASD size, location, and shunt direction 1
• Evidence of paradoxical embolism (right-to-left shunting) 1

TEE may be necessary in adults with poor-quality transthoracic images to adequately image the atrial septum and rule out intracardiac thrombus, though it is generally not indicated for acute chest pain workup alone 1

Step 3: Risk-Stratified Coronary Evaluation

For patients at risk for coronary artery disease based on age or other factors, cardiac catheterization is reasonable (Class IIa, Level B) to definitively rule out obstructive coronary disease while simultaneously obtaining hemodynamic data 1

This approach is particularly valuable because it provides:

• Direct assessment of coronary anatomy
• Measurement of pulmonary artery pressures and pulmonary vascular resistance
• Calculation of Qp:Qs ratio to quantify shunt magnitude
• Assessment of pulmonary vascular reactivity if PAH is present 1

For low-to-intermediate probability ACS patients, coronary CTA, stress echocardiography, or SPECT-MPI are appropriate alternatives 1

Step 4: Exercise Testing (When Appropriate)

Exercise testing can be useful to document exercise capacity in patients with symptoms discrepant with clinical findings or to document oxygen saturation changes in patients with PAH 1

Critical contraindication: Maximal exercise testing is NOT recommended in ASD with severe PAH (Level of Evidence: B) 1

Critical Hemodynamic Thresholds

When evaluating chest pain in the context of ASD, assess for these danger zones:

• PA systolic pressure ≥50% of systemic pressure warrants pulmonary hypertension expert evaluation before any intervention 8
• PVR >1/3 systemic resistance (>5 Wood units) requires specialized assessment 8
• PA systolic pressure >2/3 systemic and PVR >2/3 systemic resistance are absolute contraindications to ASD closure 9

Common Pitfalls to Avoid

Do not assume small ASDs are benign in older adults with chest pain. Acquired conditions (hypertension, coronary artery disease, valvular disease) reduce LV compliance and increase left-to-right shunting over time, making previously insignificant ASDs hemodynamically relevant 1, 9

Do not delay evaluation based on absence of typical ASD symptoms. Symptoms lag behind objective cardiopulmonary dysfunction and cannot guide therapy 8

Sinus venosus defects are frequently missed on routine TTE due to their superior location; if RV volume overload is present without clear ASD on TTE, proceed to TEE or alternative imaging 1

Management of Identified Arrhythmias

If atrial fibrillation is discovered during chest pain evaluation:

• Cardioversion after appropriate anticoagulation is recommended (Class I, Level A) 1
• Rate control and anticoagulation are required if sinus rhythm cannot be maintained (Class I, Level A) 1