What is the recommended approach to evaluate and manage a patient presenting with palpitations?

Evaluation and Management of Palpitations

Immediate First Steps

Obtain a 12-lead ECG immediately on all patients presenting with palpitations—this is the single most important initial diagnostic test. 1, 2 Look specifically for pre-excitation (delta waves suggesting Wolff-Parkinson-White syndrome), baseline rhythm abnormalities, QT prolongation, and evidence of structural heart disease. 1, 2

The critical distinction that drives your entire diagnostic approach is whether the palpitations are regular or irregular—this fundamentally changes the differential diagnosis and management pathway. 1

History: Key Questions That Matter

Focus your history on these specific elements that actually change management:

• Onset and termination pattern: Sudden start/stop strongly suggests AVNRT or AVRT, while gradual acceleration points to sinus tachycardia 3, 1
• Response to vagal maneuvers: Termination with Valsalva or carotid massage confirms re-entrant tachycardia involving the AV node 3, 1
• Associated symptoms: Syncope occurs in ~15% of SVT patients and suggests either very rapid rates, accessory pathway conduction, or structural disease 3, 1
• Polyuria: This specific symptom indicates SVT with atrial contraction against closed AV valves 3, 1
• Frequency of episodes: This determines your monitoring strategy—daily symptoms need different testing than monthly episodes 1, 2

Physical Examination Findings

Look for irregular cannon A waves and beat-to-beat variation in S1 intensity during tachycardia—these strongly suggest ventricular origin. 1 Assess for structural heart disease signs including murmurs, particularly the midsystolic click of mitral valve prolapse. 3

Cardiac Monitoring Strategy: Match the Test to Symptom Frequency

For daily palpitations: Use 24-48 hour Holter monitoring 1, 2

For symptoms several times per week: Event recorders have superior diagnostic yield and cost-effectiveness compared to Holter monitoring 1

For symptoms less than twice monthly with severe features (syncope, presyncope, hemodynamic instability): Consider implantable loop recorder 1, 2

Critical point: Monitoring must continue until symptoms occur while wearing the device—non-diagnostic monitoring should not be considered conclusive. 1 Do not rely on automatic ECG interpretation systems as they are unreliable and commonly suggest incorrect diagnoses. 1

Laboratory Testing: Be Selective

Order thyroid function tests (TSH) to exclude hyperthyroidism, which causes palpitations in 5-15% of hyperthyroid patients, more commonly over age 60. 1 Check electrolytes, particularly potassium, as this affects arrhythmia risk. 1 Assess renal function as baseline for medication decisions. 1

Avoid the pitfall of ordering comprehensive laboratory panels routinely—target testing based on clinical suspicion. 1

Echocardiography Indications

Order echocardiography when:

• Sustained SVT is documented, to exclude structural heart disease that physical examination alone cannot detect 1
• Clinical suspicion exists for valvular aortic stenosis, hypertrophic cardiomyopathy, or tachycardia-mediated cardiomyopathy 1
• Mitral valve prolapse is suspected based on midsystolic click or late systolic murmur 3

Immediate Electrophysiology Referral Required For:

Refer immediately in these scenarios:

• Wolff-Parkinson-White syndrome (pre-excitation on ECG with paroxysmal regular palpitations)—risk of sudden death 1, 2
• Pre-excitation with irregular palpitations—strongly suggests atrial fibrillation with accessory pathway 1
• Wide complex tachycardia documented on any rhythm strip—may represent ventricular tachycardia 1, 2
• Severe symptoms during palpitations (syncope, severe dyspnea) 1, 2
• Drug resistance or intolerance in narrow complex tachycardia 1, 2

Empiric Medical Therapy While Awaiting Diagnosis

You may prescribe a beta-blocker empirically while awaiting monitoring results, but only after excluding significant bradycardia (<50 bpm). 1 Teach patients vagal maneuvers (Valsalva, carotid massage) to perform during episodes. 1

Critical pitfall to avoid: Never start Class I or III antiarrhythmic drugs without documented arrhythmia due to significant proarrhythmic risk. 1

Lifestyle Modifications Before Testing

Stop all caffeine, alcohol, and nicotine. 1 Review all medications for arrhythmogenic potential. 1 Assess for recreational drug use. 1

Special Populations

Hypertrophic cardiomyopathy patients: Perform 24-48 hour ambulatory monitoring every 1-2 years as part of routine follow-up, with extended monitoring if additional AF risk factors present (left atrial dilatation, advanced age, NYHA class III-IV). 1

Hyperthyroid patients with palpitations: Beta-blockers are the preferred initial agent for rate control, but use with extreme caution. 1 If atrial fibrillation is documented, assess stroke risk using CHA₂DS₂-VASc score. 1 Most thyrotoxicosis-induced arrhythmias spontaneously convert to sinus rhythm once euthyroid. 1 Never abruptly withdraw beta-blockers once started, as this can precipitate thyroid storm. 1

Mitral valve prolapse with palpitations: Antibiotic prophylaxis for endocarditis is recommended for most patients with definite MVP, particularly with associated mitral regurgitation or leaflet thickening. 3 Aspirin 75-325 mg daily for those with cerebral transient ischemic attacks. 3

When Documented SVT is Found

Patients with documented SVT require referral to cardiac electrophysiology for consideration of catheter ablation, even with normal structural evaluation. 1 Catheter ablation has high success rates with <5% recurrence and <1% risk of heart block, offering potential cure rather than lifelong medication. 1 This is particularly appropriate for younger patients with normal structural hearts. 1