What is the best course of action for a patient with intermittent right sternal border fluttering, possible palpitations, and a pulsation on the right side at the fifth intercostal space?

Evaluation and Management of Right-Sided Pulsation at Fifth Intercostal Space with Palpitations

A pulsation on the right side at the fifth intercostal space with intermittent fluttering requires immediate 12-lead ECG and echocardiography to rule out structural heart disease, particularly right ventricular pathology, atrial septal defect, or arrhythmogenic right ventricular cardiomyopathy. 1

Initial Diagnostic Approach

Obtain a 12-lead ECG immediately to identify any underlying arrhythmia or conduction abnormalities, as this is the gold standard for diagnosis when palpitations are present. 1, 2 The ECG should specifically be evaluated for:

• Pre-excitation patterns (delta waves) suggesting Wolff-Parkinson-White syndrome, which would require immediate referral to an arrhythmia specialist due to risk of sudden death 1
• Epsilon waves in leads V1-V3, which are highly specific for arrhythmogenic right ventricular cardiomyopathy (ARVC) and represent a major diagnostic criterion 1
• Right bundle branch block patterns, particularly if new, which may indicate right ventricular strain or structural disease 3, 4
• Multiple premature ventricular contractions, which warrant 24-hour Holter monitoring if >2,000 PVCs are detected 1

Physical Examination Findings

The right-sided pulsation at the fifth intercostal space is anatomically significant and suggests:

• Right ventricular volume overload from conditions such as atrial septal defect with left-to-right shunting 1
• Tricuspid regurgitation with right ventricular enlargement 1
• ARVC with right ventricular dilatation 1

Examine for additional signs during the palpitations, including irregular cannon A waves or irregular variation in S1 intensity, which would strongly suggest a ventricular origin of the arrhythmia. 1

Mandatory Echocardiographic Evaluation

Transthoracic echocardiography should be performed urgently to exclude structural heart disease, as this cannot be reliably detected by physical examination or ECG alone. 1, 4 The echocardiogram must specifically assess:

• Right ventricular size and function to evaluate for ARVC, which requires comprehensive cardiac testing including cardiac MRI if abnormalities are found 1
• Atrial septal defect with evidence of right ventricular volume overload, as ASDs with RV volume overload typically require closure to prevent long-term complications 1
• Tricuspid valve function and degree of regurgitation 1
• Left ventricular function to rule out cardiomyopathy 1

Ambulatory Monitoring Strategy

If the initial ECG and echocardiogram are non-diagnostic but symptoms persist, ambulatory monitoring is indicated based on symptom frequency:

• 24-48 hour Holter monitor if palpitations occur daily 1, 5
• 7-day Holter or external loop recorder if symptoms occur weekly 1
• 14-30 day external loop recorder if symptoms occur monthly 1
• Implantable loop recorder if symptoms occur less than once per month, with diagnostic yield of 43-50% at 2 years 1

Risk Stratification and Referral Criteria

Immediate referral to a cardiac arrhythmia specialist is mandatory if any of the following are present:

• Pre-excitation on resting ECG (WPW syndrome), as these patients are at risk for sudden death 1
• Epsilon waves suggesting ARVC 1
• Syncope or near-syncope accompanying the palpitations, which indicates potentially life-threatening arrhythmia 1, 6
• Family history of sudden cardiac death or inherited cardiac disease 1
• Structural heart disease identified on echocardiography 1

Additional Testing Based on Initial Findings

If ventricular arrhythmias are detected, comprehensive evaluation must include:

• Cardiac MRI with stress perfusion study to investigate for myocardial disease including HCM, DCM, LVNC, ARVC, myocarditis, or sarcoidosis 1
• Exercise ECG test to assess for exercise-induced arrhythmias 1
• Minimum 24-hour ECG monitor to quantify arrhythmia burden 1
• Signal-averaged ECG (SAECG) if ARVC is suspected 1

Critical Pitfalls to Avoid

Do not dismiss the right-sided pulsation as benign without structural evaluation, as visible precordial pulsations at the fifth intercostal space on the right suggest significant right ventricular pathology that may be life-threatening. 1

Do not rely on automatic ECG interpretation systems, as they are unreliable and commonly suggest incorrect arrhythmia diagnoses. 1

Do not delay referral if pre-excitation is present, even if symptoms are mild, as patients with WPW syndrome can develop atrial fibrillation with rapid ventricular response leading to sudden death. 1

Ensure the patient obtains at least one 12-lead ECG during symptoms, as this provides definitive diagnosis and guides all subsequent management decisions. 1