What is the evaluation and management approach for a patient presenting with a pulsating sensation at the right 5th sternal border?

Evaluation and Management of Right 5th Sternal Border Pulsation

Immediate Differential Diagnosis

A pulsating sensation at the right 5th sternal border most likely represents aortic regurgitation (AR) with aortic root dilatation, though right ventricular volume overload and congenital cardiac anomalies must be excluded. 1

The key diagnostic consideration is that a diastolic murmur at the right mid-sternal border is characteristic of aortic regurgitation, particularly when associated with aortic root dilatation, as AR murmurs are typically loudest along the mid-left sternal border but shift to the right sternal border when the aortic root is dilated. 1

Critical Physical Examination Findings

Assess for Aortic Regurgitation

• Auscultate for a diastolic murmur at the right sternal border - this is the hallmark finding for AR with root dilatation 1
• Perform dynamic auscultation by having the patient sit up, lean forward, and hold breath in expiration to accentuate the AR murmur 1
• Assess carotid upstroke - a rapid carotid upstroke with wide pulse pressure strongly supports AR 1
• Check for signs of AR severity: hyperdynamic precordium, displaced apical impulse, S3 gallop 2

Evaluate for Right Ventricular Involvement

• Palpate for a parasternal lift - this indicates right ventricular volume overload, which can occur in severe chronic AR when regurgitant volume causes secondary pulmonary hypertension and right heart strain 1
• Auscultate lung bases for dry crackles - suggests pulmonary congestion from left ventricular failure, a known complication of severe AR 1

Consider Congenital Anomalies

• Examine for features of congenitally corrected transposition of the great arteries (CCTGA), which can present with a parasternal RV lift due to the morphologic right ventricle serving as the systemic ventricle, with a palpable second sound related to the anterior aorta 1
• Note that associated aortic regurgitation occurs in 40-75% of Type A CCTGA cases, which could explain the diastolic murmur at the right sternal border 1

Diagnostic Workup Algorithm

Step 1: Immediate ECG and Risk Stratification

• Obtain a 12-lead ECG within 10 minutes to exclude acute coronary syndrome, as chest symptoms can represent myocardial ischemia 2, 3
• Perform serial ECGs if initial ECG is nondiagnostic and clinical suspicion remains high 2
• Consider supplemental leads V7-V9 to rule out posterior MI if intermediate-to-high suspicion for ACS 2

Step 2: Echocardiography

• Transthoracic echocardiography is the definitive diagnostic test to:
  • Confirm and quantify AR severity 1
  • Assess aortic root dimensions 1
  • Evaluate for regional wall motion abnormalities 2, 4
  • Identify RV volume overload or dysfunction 1
  • Detect congenital anomalies like CCTGA 1

Step 3: Chest Radiography

• Obtain a chest radiograph to evaluate for other potential cardiac, pulmonary, and thoracic causes of symptoms 2
• Look for cardiomegaly, pulmonary congestion, or mediastinal widening 2

Critical Clinical Pitfalls to Avoid

Do not assume murmur intensity correlates with severity - the grade 1/4 intensity of a diastolic murmur does not exclude severe AR, as murmur intensity correlates poorly with severity in chronic regurgitation. 1

The combination of RV and LV findings suggests biventricular involvement, indicating either severe left-sided disease with secondary right heart failure or complex congenital disease - this requires comprehensive echocardiographic evaluation. 1

Do not dismiss the finding based on location alone - while most AR murmurs are heard at the left sternal border, aortic root dilatation shifts the point of maximal intensity to the right sternal border. 1

Management Based on Findings

If Severe AR Confirmed

• Assess hemodynamic stability - look for hypotension, tachycardia, pulmonary crackles, S3 2
• Evaluate for acute vs. chronic presentation based on compensatory mechanisms 1
• Urgent cardiology consultation for consideration of surgical intervention if symptomatic or evidence of LV dysfunction 1

If Congenital Anomaly Suspected

• Comprehensive imaging with cardiac MRI or CT angiography may be needed 1
• Specialized congenital cardiology consultation 1

If Initial Workup Negative

• Consider musculoskeletal causes with reproducible chest wall tenderness 5
• Evaluate for gastrointestinal etiologies if associated with belching or postprandial symptoms 3