What are the next steps for a patient experiencing intermittent right sternal border fluttering for 3 days, potentially related to underlying cardiac issues or pre-existing conditions?

Evaluation and Management of Right Sternal Border Fluttering

Obtain a 12-lead ECG immediately to document the rhythm, as this symptom likely represents palpitations from an underlying arrhythmia, most commonly atrial fibrillation, atrial flutter, or another supraventricular tachycardia. 1

Initial Diagnostic Approach

The sensation of "fluttering" at the right sternal border for 3 days represents palpitations that require electrocardiographic documentation to establish a diagnosis. 1

Essential First Steps

• Obtain a standard 12-lead ECG as the essential tool for confirming any arrhythmia, as electrocardiographic documentation is required to establish the diagnosis. 1
• If the patient is not experiencing symptoms at the time of evaluation, consider ambulatory rhythm monitoring (telemetry, Holter monitor, or event recorder) to capture the arrhythmia during symptomatic episodes. 1
• Assess hemodynamic stability immediately: Check blood pressure, heart rate, and signs of hemodynamic compromise (chest pain, dyspnea, altered mental status, hypotension). 1

Key Physical Examination Findings to Assess

• Irregular pulse suggests atrial fibrillation. 1
• Regular and rapid pulse suggests atrial flutter or other supraventricular tachycardia. 1
• Irregular jugular venous pulsations and variation in intensity of the first heart sound suggest atrial fibrillation. 1
• Assess for signs of heart failure: pulmonary congestion, peripheral edema, elevated jugular venous pressure. 2

Management Based on Rhythm Diagnosis

If Atrial Fibrillation or Atrial Flutter is Confirmed

For hemodynamically unstable patients (hypotension, acute heart failure, ongoing chest pain):

• Immediate synchronized cardioversion is the treatment of choice without delay for anticoagulation. 1
• Initiate intravenous unfractionated heparin or subcutaneous low-molecular-weight heparin before cardioversion. 1

For hemodynamically stable patients with symptoms for 3 days:

Rate Control Strategy

• Intravenous or oral beta blockers, diltiazem, or verapamil are useful for acute rate control in stable patients with atrial flutter. 1
• Beta blockers are preferred in patients with myocardial ischemia, myocardial infarction, hyperthyroidism, or post-operative state. 3
• Non-dihydropyridine calcium channel blockers (diltiazem or verapamil) are preferred in patients with bronchial asthma or chronic obstructive pulmonary disease. 3
• Avoid beta blockers, calcium channel blockers, and digoxin if pre-excitation (Wolff-Parkinson-White syndrome) is present on ECG, as these can precipitate ventricular fibrillation. 3

Rhythm Control Strategy

• Elective synchronized cardioversion is indicated in stable patients when a rhythm-control strategy is pursued. 1
• Oral dofetilide or intravenous ibutilide is useful for acute pharmacological cardioversion in patients with atrial flutter, though cardioversion converts approximately 60% of cases. 1

Anticoagulation Considerations (Critical for Stroke Prevention)

Since symptoms have been present for 3 days (>48 hours):

• Anticoagulation is recommended for 3 weeks prior to and 4 weeks after cardioversion for patients with atrial fibrillation or atrial flutter of unknown duration or lasting longer than 48 hours. 1
• Alternative TEE-guided approach: Perform transesophageal echocardiography to exclude left atrial appendage thrombus, allowing earlier cardioversion if no thrombus is present, followed by anticoagulation for 4 weeks post-cardioversion. 1
• Ongoing anticoagulation should be determined by CHA₂DS₂-VASc score for long-term stroke prevention. 4

Additional Workup Required

Beyond the ECG, complete the following evaluation:

• Transthoracic echocardiogram to detect structural heart disease, assess cardiac function, and evaluate atrial size. 1
• Chest radiograph if pulmonary disease or heart failure is suspected (pulmonary congestion on chest radiograph is associated with increased adverse events). 2
• Laboratory tests: serum electrolytes, thyroid function, renal function, hepatic function, and complete blood count. 1

Common Pitfalls to Avoid

• Do not delay cardioversion for anticoagulation in hemodynamically unstable patients—cardiovert immediately and start anticoagulation concurrently. 1
• Do not assume rate control alone is adequate without documenting the specific rhythm, as atrial flutter often requires different management than atrial fibrillation. 1
• Do not miss pre-excitation on ECG (delta waves), as standard AV nodal blocking agents are contraindicated and procainamide is the drug of choice. 3
• Do not forget that atrial flutter carries similar stroke risk to atrial fibrillation and requires the same anticoagulation approach. 1
• Be aware that positional ST-segment changes can occur and should be evaluated in the supine position if ST monitoring shows changes. 1

Definitive Management Considerations

• Catheter ablation is increasingly used as first-line therapy for atrial fibrillation, with up to 80% of patients remaining arrhythmia-free after one or two treatments. 4
• For atrial flutter, catheter ablation of the cavotricuspid isthmus is the preferred management with success rates exceeding 90%. 4