What is the appropriate evaluation and management for a patient presenting with palpitations?

Evaluation and Management of Palpitations

Immediate Assessment

Every patient presenting with palpitations requires an immediate 12-lead ECG to identify the rhythm, detect pre-excitation patterns, assess QT interval, and determine whether the tachycardia is regular or irregular—this single distinction fundamentally changes the entire diagnostic approach. 1

Critical Red Flags Requiring Urgent Evaluation

• Syncope or presyncope accompanying palpitations mandates immediate cardiac evaluation for potentially life-threatening arrhythmias and may require hospitalization 1, 2
• Chest pain or dyspnea during episodes suggests cardiac origin and requires urgent work-up 1, 2
• Wide complex tachycardia documented on any rhythm strip requires immediate electrophysiology referral 1
• Pre-excitation with irregular palpitations strongly suggests atrial fibrillation with an accessory pathway (Wolff-Parkinson-White), requiring immediate electrophysiological evaluation due to sudden death risk 1
• Palpitations occurring during exertion in patients with known structural heart disease (hypertrophic cardiomyopathy, aortic stenosis) constitute high-risk presentations 1, 2

Mandatory Initial Workup

• 12-lead ECG in every patient to identify baseline rhythm, pre-excitation, and conduction abnormalities 1
• Vital signs with orthostatic measurements to assess hemodynamic stability 2
• Baseline laboratory tests: complete blood count, serum electrolytes (especially potassium), renal function, hepatic function, and thyroid function tests (hyperthyroidism is a common non-cardiac cause) 1
• Chest radiography to evaluate pulmonary pathology and vasculature 1

Pattern Characterization: The Key to Diagnosis

Regular vs. Irregular Rhythm

The distinction between regular and irregular rhythm is the single most important diagnostic factor. 1

Regular palpitations with sudden onset/offset:

• Suggests AVNRT or AVRT, particularly in younger patients 1
• Termination with vagal maneuvers (Valsalva preferred over carotid massage) confirms re-entrant tachycardia involving AV nodal tissue 1, 2
• Ventricular tachycardia also presents with sudden onset/offset and may be associated with presyncope 1

Regular palpitations with gradual onset/offset:

• Suggests sinus tachycardia triggered by infection, volume loss, caffeine, nicotine, or medications 1

Irregular palpitations:

• Suggests atrial fibrillation (look for irregular pulse, irregular cannon A waves, variable S1 intensity) 1, 2
• Premature atrial contractions present as skipped or extra beats 1

Essential History Elements

• Frequency and duration of episodes (daily, weekly, monthly) 1
• Mode of onset and termination (sudden vs. gradual) 1, 2
• Triggers: caffeine, alcohol, nicotine, exercise, large meals, emotional stress, sleep deprivation 1, 2
• Response to vagal maneuvers during episodes 1
• Associated symptoms: syncope, presyncope, chest pain, dyspnea, or polyuria (occurs in ~15% of SVT patients) 1, 2
• Medication review: QT-prolonging drugs, stimulants (cocaine, amphetamines), anabolic steroids, over-the-counter supplements 1
• Family history of sudden cardiac death or inheritable heart disease 2

Physical Examination Findings

• Irregular peripheral pulse and jugular venous pulsations point toward atrial fibrillation 1
• Variability in first heart sound intensity or loss of fourth heart sound supports atrial fibrillation 1
• Irregular cannon A waves and variable S1 intensity during tachycardia strongly suggest ventricular origin 1
• Assess for valvular disease, heart failure signs, and structural cardiac abnormalities 1

Ambulatory ECG Monitoring Strategy

The frequency of symptoms dictates the monitoring approach:

• Daily palpitations: 24-48 hour Holter monitoring 1
• Several times per week: Event recorders have superior diagnostic yield and are more cost-effective than Holter monitoring 1
• Less frequent arrhythmias (not daily): Event or loop recorders rather than Holter 1
• Less than 2 episodes per month with severe symptoms: Consider implantable loop recorder 1

Critical caveat: Monitoring must continue until symptoms occur while wearing the device—non-diagnostic monitoring should not be considered conclusive 1

Echocardiography Indications

Order transthoracic echocardiography when:

• Sustained SVT is documented, to exclude structural heart disease 1
• Clinical suspicion of structural abnormalities (valvular aortic stenosis, hypertrophic cardiomyopathy, tachycardia-mediated cardiomyopathy) 1
• Any patient with documented atrial fibrillation to assess left atrial size, ventricular dimensions, systolic function, and exclude valvular or pericardial disease 1

Management Based on Findings

Hemodynamically Unstable Patients

Immediate DC cardioversion is indicated 1

Stable Patients Without ECG Documentation

• Stop all caffeine, alcohol, and nicotine immediately 1
• Teach vagal maneuvers (Valsalva and carotid massage) to perform during episodes 1
• Beta-blocker may be prescribed empirically after excluding significant bradycardia (<50 bpm) 1
• Arrange appropriate ambulatory monitoring based on symptom frequency 1

Documented Supraventricular Tachycardia

Patients with documented SVT require referral to cardiac electrophysiology for consideration of catheter ablation, which has >95% acute success rate, <5% recurrence, and <1% risk of complete heart block. 1

Medical therapy options while awaiting electrophysiology:

• Beta-blockers (metoprolol, atenolol) are first-line after confirming heart rate ≥50 bpm 1
• Non-dihydropyridine calcium channel blockers (diltiazem, verapamil) if beta-blockers contraindicated; verapamil terminates acute SVT in ~93% of cases 1
• Avoid digoxin as first-line due to lower efficacy and higher toxicity risk 1

Hyperthyroidism-Related Palpitations

Restoration of euthyroid state is the primary goal; most patients spontaneously convert to sinus rhythm once euthyroid. 1

• Beta-blockers are preferred for rate control, but use with extreme caution 1
• If beta-blockers contraindicated or cardiac function impaired, use non-dihydropyridine calcium channel blocker 1
• Assess stroke risk using CHA₂DS₂-VASc score if atrial fibrillation documented 1
• Never abruptly withdraw beta-blockers once started, as this can precipitate thyroid storm 1

Mandatory Electrophysiology Referral Criteria

Refer immediately to cardiac electrophysiology for:

• All patients with Wolff-Parkinson-White syndrome due to potential for lethal arrhythmias 1
• Wide complex tachycardia of unknown origin 1
• Severe symptoms during palpitations (syncope, presyncope, marked dyspnea) 1
• Drug resistance or intolerance in narrow complex tachycardia 1
• Patient preference for definitive cure rather than lifelong medication 1
• Pre-excitation with paroxysmal regular palpitations (presumptive AVRT) 1

Critical Pitfalls to Avoid

• Never start Class I or III antiarrhythmics empirically without documented arrhythmia due to significant proarrhythmic risk 1
• Do not rely on automatic ECG analysis systems—they are unreliable and commonly suggest incorrect diagnoses 1
• Do not dismiss syncope with palpitations—this is a high-risk presentation 1
• Do not order comprehensive laboratory panels routinely—target testing based on clinical suspicion 1
• Even when ambulatory monitoring shows no arrhythmia, patients may still report palpitations; this does not exclude serious pathology 1

Special Considerations

Hypertrophic Cardiomyopathy

• Requires 24-48 hour ambulatory monitoring every 1-2 years as part of periodic follow-up 1
• Extended monitoring if additional AF risk factors present (left atrial dilatation, advanced age, NYHA class III-IV) 1

Athletes

• First-degree AV block or Mobitz type I that resolves during exercise does not require therapy in asymptomatic athletes without structural heart disease 1
• Mobitz type II or third-degree AV block warrants comprehensive evaluation and pacemaker when symptomatic or structural disease present 1

Tachycardia-Mediated Cardiomyopathy

• Can occur in patients with SVT persisting for weeks to months with fast ventricular response, emphasizing the importance of timely diagnosis and treatment 1