How should I evaluate and manage a patient presenting with palpitations?

Evaluation and Management of Palpitations

Immediate Assessment and Risk Stratification

Obtain a 12-lead ECG immediately in every patient presenting with palpitations, as this is the gold standard initial test and may capture the arrhythmia if symptoms are present. 1, 2

High-Risk Features Requiring Urgent/Emergency Evaluation:

• Syncope or near-syncope during palpitations mandates hospitalization for monitoring and evaluation, particularly when ventricular arrhythmia is suspected 3, 1, 2
• Pre-excitation (delta waves) on resting ECG indicates Wolff-Parkinson-White syndrome and requires immediate electrophysiology referral due to sudden death risk, especially if irregular palpitations suggest atrial fibrillation 1, 2
• Wide complex tachycardia of unknown origin mandates immediate specialist referral 1, 2
• Hemodynamic instability requires DC cardioversion 3, 2
• Associated chest pain, dyspnea, or severe symptoms warrant urgent evaluation for structural heart disease 1, 2

Diagnostic Approach Based on Rhythm Pattern

Step 1: Determine if Rhythm is Regular or Irregular

The distinction between regular and irregular rhythm is the most important factor in diagnosing palpitations and fundamentally changes the entire diagnostic approach. 1

Regular Palpitations:

• Sudden onset AND sudden termination strongly suggests AVNRT or AVRT, particularly in younger patients 3, 1
• Gradual onset and termination suggests sinus tachycardia, often triggered by infection, volume loss, caffeine, nicotine, or medications 1
• Atrial flutter with regular ventricular response is another cause of regular palpitations 1
• Ventricular tachycardia presents with sudden onset/offset and may be associated with presyncope or syncope 1

Irregular Palpitations:

• Atrial fibrillation is the most common cause of irregular palpitations and may be paroxysmal, persistent, or permanent 1
• Premature atrial contractions present as skipped beats or extra beats and are often benign 1
• Pre-excitation with irregular palpitations strongly suggests atrial fibrillation with an accessory pathway, requiring immediate electrophysiological evaluation due to risk of sudden death 1

Step 2: Characterize the Pattern

Document the following critical features during history-taking:

• Number of episodes, duration, and frequency 1
• Mode of onset and termination (sudden vs. gradual) 3, 1
• Triggers (exercise, stress, caffeine, alcohol, medications) 1, 2
• Response to vagal maneuvers (termination suggests re-entrant tachycardia involving AV nodal tissue like AVNRT or AVRT) 1
• Associated symptoms: syncope, presyncope, chest discomfort, dyspnea, or polyuria (occurs in ~15% of SVT patients) 3, 1

Step 3: Physical Examination Findings

• Look for irregular cannon A waves and irregular variation in S1 intensity during tachycardia, which strongly suggests ventricular origin 1
• Assess for signs of structural heart disease (murmurs, gallops, jugular venous distension) 2

Ambulatory ECG Monitoring Strategy

The choice of monitoring depends on symptom frequency:

Daily Palpitations:

• 24-48 hour Holter monitoring is recommended for patients with daily palpitations 1, 4

Weekly (but not daily) Palpitations:

• 48-hour ambulatory ECG monitoring is the first-line approach 4
• Event recorders or mobile cardiac outpatient telemetry with patient-activated recording have superior diagnostic yield and are more cost-effective than Holter monitoring for symptoms occurring several times per week 1, 4

Less than Twice Monthly with Severe Features:

• Implantable loop recorder should be considered for symptoms less than 2 episodes per month associated with severe symptoms or hemodynamic instability 1, 4

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

Additional Diagnostic Testing

Echocardiography Indications:

Order echocardiography when:

• Sustained SVT is documented to exclude structural heart disease, which usually cannot be detected by physical examination alone 1, 4
• Clinical suspicion of structural abnormalities like valvular aortic stenosis, hypertrophic cardiomyopathy, or tachycardia-mediated cardiomyopathy 1
• Physical examination suggests structural heart disease 4
• ECG shows LV hypertrophy or other abnormalities 4

Exercise Testing Indications:

• Only if palpitations occur specifically during or immediately after exertion to reproduce symptoms in a controlled environment and identify ischemia-driven arrhythmias 1, 4

Laboratory Testing:

• TSH to exclude hyperthyroidism, a reversible cause that can precipitate atrial fibrillation (occurs in 5-15% of hyperthyroid patients, more common over age 60) 1, 4
• Complete blood count to assess for anemia 4
• Serum electrolytes including calcium and magnesium to identify disturbances that trigger arrhythmias 4
• Renal function (creatinine, GFR) as baseline for medication decisions 1

Management Based on Etiology

Initial Conservative Management:

Eliminate precipitating factors first—caffeine cessation alone is often sufficient to control palpitations in patients with anxiety and negative cardiac workup. 2

• Remove all caffeine sources including coffee, matcha, energy drinks, and caffeine-containing medications or supplements 2
• Stop alcohol, nicotine, and review medications that may trigger arrhythmias 1, 2
• Assess for recreational drug use 1
• Address anxiety disorders, as depression, poor self-rated health, and anxiety significantly predict palpitations 2

Teach Vagal Maneuvers:

• Instruct patients in Valsalva maneuver and carotid massage to perform during episodes 1, 2
• Termination with vagal maneuvers confirms re-entrant tachycardia involving AV nodal tissue (AVNRT or AVRT) 1

Pharmacologic Therapy:

Beta-blockers may be prescribed empirically while awaiting monitoring results, but only after excluding significant bradycardia (<50 bpm). 1, 2

• Beta-blockers are the preferred initial agent if symptoms persist after trigger elimination, particularly when associated with mild tachyarrhythmias or increased adrenergic symptoms (Class I recommendation) 3, 2
• Non-dihydropyridine calcium channel blockers (verapamil, diltiazem) are effective alternatives for patients who cannot tolerate beta-blockers (Class IIa recommendation) 3, 2
• Adenosine is the drug of choice for terminating AV nodal re-entrant tachycardia (Class I recommendation), but should be used with caution in severe coronary artery disease and may produce AF with rapid ventricular rates in patients with pre-excitation 3, 2

Never start Class I or III antiarrhythmic drugs without documented arrhythmia due to significant proarrhythmic risk. 1, 2

Management of Documented SVT:

Patients with documented SVT, despite normal structural evaluation, require referral to a cardiac electrophysiologist for consideration of catheter ablation. 1

• Catheter ablation has a high success rate with <5% recurrence and <1% risk of heart block, and is potentially curative 1
• A young patient with documented SVT and a normal structural heart is a good candidate for curative therapy rather than lifelong medication 1

Special Consideration: Hyperthyroidism

Patients with overt hyperthyroidism must be treated urgently, and restoration of euthyroid state is the primary goal, as this usually results in spontaneous resolution of arrhythmias. 1

• Beta-blockers are the preferred initial agent for rate control in hyperthyroidism, but use with extreme caution 1
• If beta-blockers are contraindicated or cardiac function is impaired, use a non-dihydropyridine calcium channel blocker instead 1
• Assess stroke risk using CHA₂DS₂-VASc score if atrial fibrillation is documented 1
• Most patients with thyrotoxicosis-induced arrhythmias will spontaneously convert to sinus rhythm once euthyroid 1
• Never abruptly withdraw beta-blockers once started, as this can precipitate thyroid storm 1

Mandatory Cardiology/Electrophysiology Referral Criteria

Refer immediately for:

• Pre-excitation on ECG (Wolff-Parkinson-White syndrome) due to potential for lethal arrhythmias 1, 2
• Syncope or severe symptoms during palpitations 1, 2
• Wide complex tachycardia of unknown origin 1, 2
• Evidence of structural heart disease 2
• Documented complex or sustained ventricular arrhythmias 2
• Symptoms persisting despite caffeine elimination and beta-blocker therapy 2
• Patient desires definitive therapy (catheter ablation) rather than chronic medication 2
• Drug resistance or intolerance in patients with documented arrhythmias 2

Critical Pitfalls to Avoid

• Never rely on automatic ECG interpretation systems—they are unreliable and commonly suggest incorrect arrhythmia diagnoses 1, 2
• Do not delay obtaining 12-lead ECG during tachycardia—encourage patients to seek immediate evaluation during episodes to capture the arrhythmia 2
• Avoid empiric antiarrhythmic therapy without documented arrhythmia, as Class I and III agents carry significant proarrhythmic risk 1, 2
• Do not assume benign etiology in patients with irregular palpitations and pre-excitation—this suggests atrial fibrillation in WPW syndrome, which carries sudden death risk 2
• Recognize that palpitations frequently occur during normal rhythm—symptom-rhythm correlation through ambulatory monitoring is essential 2
• Do not order comprehensive laboratory panels routinely—target testing based on clinical suspicion 1
• Do not dismiss syncope with palpitations—this warrants urgent evaluation 1

Special Populations

Hypertrophic Cardiomyopathy:

• 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 heart failure) 1

Elderly Patients:

• Older patients with paroxysmal SVT are more prone to syncope or near-syncope than younger patients, independent of tachycardia rate 3