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

Evaluation and Treatment of Palpitations

Obtain a 12-lead ECG immediately in every patient presenting with palpitations to identify the rhythm, look for pre-excitation patterns, and determine whether the tachycardia is regular or irregular—this single distinction fundamentally changes your entire diagnostic and therapeutic approach. 1

Initial Clinical Assessment

Critical History Elements

• Pattern characterization is mandatory: Document onset/termination (sudden vs gradual), duration, frequency, response to vagal maneuvers, and precipitating factors (exercise, emotional stress, caffeine, alcohol, large meals). 1

• Associated symptoms determine risk stratification: Syncope, presyncope, chest pain, or dyspnea during palpitations mandate urgent evaluation for potentially life-threatening arrhythmias and hospitalization if ventricular arrhythmia is documented or suspected. 2, 1

• Polyuria occurs in approximately 15% of SVT patients—specifically ask about urinary symptoms as this supports a diagnosis of supraventricular tachycardia. 1

• Medication and substance review is non-negotiable: Stop all caffeine, alcohol, and nicotine immediately; review for QT-prolonging medications, stimulants (including cocaine and amphetamines), anabolic steroids, and over-the-counter supplements. 2, 1, 3

Physical Examination Findings

• Irregular peripheral pulse with irregular jugular venous pulsations strongly suggests atrial fibrillation, as does variability in first heart sound intensity. 1

• Look for irregular cannon A waves and irregular variation in S1 intensity during tachycardia—these findings strongly suggest ventricular origin. 1

• Assess for valvular disease, heart failure signs, and structural cardiac abnormalities that may underlie the palpitations. 1

Mandatory Initial Diagnostic Tests

• 12-lead ECG: Look for pre-excitation (delta waves indicating Wolff-Parkinson-White syndrome), baseline rhythm abnormalities, and QT prolongation. Pre-excitation with a history of paroxysmal regular palpitations requires immediate electrophysiology referral due to sudden death risk. 1, 3

• Laboratory evaluation: Complete blood count, serum electrolytes (especially potassium), renal function, hepatic function, and thyroid-stimulating hormone. 1, 4

• Transthoracic echocardiography: Order when sustained SVT is documented or when clinical suspicion exists for structural heart disease (valvular aortic stenosis, hypertrophic cardiomyopathy, tachycardia-mediated cardiomyopathy)—physical examination alone cannot exclude structural abnormalities. 1, 4

Rhythm Characterization Drives Management

Regular Palpitations

• Sudden onset/termination suggests AVNRT or AVRT, particularly in younger patients—these are re-entrant tachycardias involving AV nodal tissue. 1

• Gradual acceleration/termination indicates sinus tachycardia, typically triggered by infection, volume loss, caffeine, nicotine, or medications. 1

• Termination with vagal maneuvers confirms re-entrant tachycardia involving AV nodal tissue (AVNRT or AVRT). 1

Irregular Palpitations

• Atrial fibrillation is the most common cause of irregular palpitations and may be paroxysmal, persistent, or permanent. 1

• Pre-excitation with irregular palpitations strongly suggests atrial fibrillation with an accessory pathway—this requires immediate electrophysiological evaluation due to sudden death risk. Never assume benign etiology in this scenario. 1, 4

• Premature atrial contractions are common and often benign, presenting as skipped or extra beats. 1

Ambulatory ECG Monitoring Strategy

Monitoring Selection Based on Symptom Frequency

• Daily palpitations: Use 24-48 hour Holter monitoring. 1

• Several times per week: Event recorders have superior diagnostic yield and are more cost-effective than Holter monitoring—reserve Holter only for daily symptoms. 1

• Less than twice monthly with severe features: Consider an implantable loop recorder, especially if symptoms are associated with syncope or hemodynamic instability. 1

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

Immediate Referral to Cardiac Electrophysiology

Mandatory Referral Criteria

• Wolff-Parkinson-White syndrome (pre-excitation on ECG): Immediate referral due to potential for lethal arrhythmias. 1, 3

• Wide complex tachycardia of unknown origin: Document on any rhythm strip. 1

• Severe symptoms during palpitations: Syncope, presyncope, or marked dyspnea. 1, 3

• Drug resistance or intolerance in patients with documented narrow complex tachycardia. 1

• Patient preference for definitive cure rather than lifelong medication—young patients with documented SVT and normal cardiac structure are excellent candidates for catheter ablation. 1

Medical Management

Empiric Therapy While Awaiting Monitoring

• Beta-blockers may be prescribed empirically after excluding significant bradycardia (<50 bpm)—metoprolol or atenolol are reasonable first-line agents. 1, 3

• Never start Class I (flecainide, propafenone) or Class III (sotalol, amiodarone) antiarrhythmics without documented sustained arrhythmia and exclusion of structural heart disease due to substantial proarrhythmic risk. 1

Documented SVT Management

• Verapamil terminates acute SVT in approximately 93% of cases and is effective for chronic suppression, though beta-blockers are often preferred for long-term use. 1

• Avoid digoxin as first-line therapy—it is less effective than beta-blockers or calcium-channel blockers and carries higher toxicity risk, especially with renal impairment. 1

• Never use calcium channel blockers (verapamil, diltiazem) to terminate wide-QRS-complex tachycardia of unknown origin, especially in patients with myocardial dysfunction. 4

Catheter Ablation Outcomes

• For AVNRT, catheter ablation achieves >95% acute success with <5% recurrence and <1% risk of complete heart block requiring permanent pacing—this high efficacy supports offering ablation to suitable candidates. 1

Special Clinical Scenarios

Hyperthyroidism-Induced Palpitations

• Restoration of euthyroid state is the primary goal—this usually results in spontaneous resolution of arrhythmias. 1

• Beta-blockers are the preferred initial agent for rate control, but use with extreme caution; if contraindicated or cardiac function is impaired, use a nondihydropyridine calcium channel blocker instead. 1

• Atrial fibrillation occurs in 5-15% of hyperthyroid patients (more common over age 60)—assess stroke risk using CHA₂DS₂-VASc score and base anticoagulation decisions on risk factors rather than thyroid status alone. 1

• Never abruptly withdraw beta-blockers once started—this can precipitate thyroid storm. 1

Caffeine-Induced Palpitations

• Immediately eliminate all caffeine intake (coffee, matcha, energy drinks, caffeine-containing medications)—caffeine cessation alone is often sufficient in patients with anxiety and negative cardiac workup. 3

• Energy drinks are particularly problematic as they contain high caffeine loads plus other cardiac stimulants. 3

• If symptoms resolve after caffeine elimination, no further cardiac workup is needed beyond initial evaluation; address underlying anxiety disorder. 3

Hypertrophic Cardiomyopathy

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

High-Risk Features Requiring Urgent Evaluation

• Palpitations occurring with exertion in patients with known structural heart disease (hypertrophic cardiomyopathy, aortic stenosis). 1

• Documentation of wide-complex tachycardia on any rhythm strip—this may represent VT or SVT with aberrancy; look for AV dissociation or fusion complexes diagnostic of VT. 1

• Syncope with palpitations should never be dismissed—this constitutes a high-risk presentation mandating urgent evaluation. 1

Critical Pitfalls to Avoid

• Do not rely on automatic ECG analysis systems—they are unreliable and commonly suggest incorrect diagnoses. 1

• Do not overlook psychological factors (depression, anxiety, panic disorder)—these are significant predictors of palpitations and require concurrent management. Patients with panic disorder experience significantly greater increases in anxiety and palpitations with caffeine. 3, 4

• Recognize that many patients report palpitations when continuous ambulatory ECG shows no arrhythmias—but this does not exclude serious underlying pathology. Palpitations may correlate with VA but are frequently reported during normal rhythm. 2, 4

• Do not order comprehensive laboratory panels routinely—target testing based on clinical suspicion. 1