What are the important physical exam findings to elicit in a patient with a potential respiratory and cardiovascular condition, such as an Atrial Septal Defect (ASD)?

Physical Examination Findings in Atrial Septal Defect

The key physical examination findings to elicit in a patient with suspected ASD include a precordial lift, a systolic pulmonary flow murmur, fixed splitting of the second heart sound, and with large shunts, a diastolic flow rumble across the tricuspid valve. 1

Cardiac Auscultation

Heart Sounds

• Fixed splitting of the second heart sound (S2) is the hallmark finding, though it is not invariably present 1
• The splitting remains constant throughout the respiratory cycle, unlike physiologic splitting which varies with respiration 1
• A systolic pulmonary flow murmur is typically present due to increased flow across the pulmonary valve 1
• With large shunts (significant left-to-right shunting), a diastolic flow rumble across the tricuspid valve becomes audible, reflecting increased flow through the tricuspid valve 1

Palpation Findings

• A precordial lift (right ventricular heave) indicates right ventricular volume overload 1
• This finding reflects the chronic volume load on the right ventricle from the left-to-right shunt 1

Jugular Venous Examination

• Irregular jugular venous pulsations may be visible, particularly in patients who have developed atrial arrhythmias 1
• In atrial flutter, venous oscillations may be visible in the jugular pulse 1

Pulse Assessment

• The pulse is typically irregular if atrial fibrillation has developed, which is a common complication in adults with ASD 1
• Pulse oximetry should assess for cyanosis, which would suggest severe pulmonary arterial hypertension with Eisenmenger physiology or right-to-left shunting 1

Signs of Pulmonary Hypertension

• An accentuated P2 (pulmonic component of second heart sound) suggests elevated pulmonary artery pressure 1
• A murmur of tricuspid regurgitation (holosystolic murmur at the left lower sternal border) or pulmonary regurgitation (diastolic murmur) may be present with pulmonary hypertension 1
• In severe pulmonary hypertension, the patient may have no murmur, a single loud second heart sound, and cyanosis with clubbing 1

Signs of Right Ventricular Volume Overload

• Right ventricular heave on palpation indicates RV enlargement 1
• Signs of right heart failure may develop in advanced cases, though this is less common in younger patients 1

Important Caveats

Subtlety of Findings

• The gradual onset of symptoms and subtlety of physical findings with ASDs often lead to late diagnosis 1
• Physical examination findings may be masked by hyperinflation in patients with coexisting pulmonary disease 1
• Abnormal breath sounds can limit detection of cardiac findings 1

Age-Related Considerations

• In elderly patients, vascular changes from aging may normalize the carotid upstroke even in the presence of significant cardiac pathology 1
• Adults with small defects may remain asymptomatic well into the fourth and fifth decades 1

Associated Findings to Assess

• Examine for signs of associated valvular heart disease or myocardial abnormalities 1
• Assess for atrial fibrillation through pulse irregularity and variation in the intensity of the first heart sound 1
• Look for absence of a fourth heart sound that was previously heard during sinus rhythm, which may indicate development of atrial fibrillation 1