What are palpitations, what are their etiologies, how should they be assessed, and are they typically benign or potentially life‑threatening?

What Are Palpitations?

Palpitations are an uncomfortable awareness of your heartbeat that feels like pounding, racing, skipped beats, or an unpleasant sensation in the chest, throat, or neck. 1, 2

This sensation represents the conscious perception of cardiac activity that is normally imperceptible, and can occur with both normal and abnormal heart rhythms. 3

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What Causes Palpitations?

Cardiac Arrhythmias (Most Common Pathologic Cause)

• Paroxysmal supraventricular tachycardia (PSVT) presents with sudden onset and termination, most commonly AVNRT or AVRT, particularly in younger patients. 2
• Atrial fibrillation causes irregular palpitations and may be paroxysmal, persistent, or permanent. 2
• Premature atrial contractions are common and often benign, presenting as skipped beats or extra beats. 2
• Ventricular tachycardia presents with sudden onset/offset and may be associated with presyncope or syncope. 2
• Wolff-Parkinson-White syndrome with pre-excitation carries a risk of sudden death and requires immediate electrophysiology referral. 2

Non-Arrhythmic Cardiac Causes

• Hypertrophic cardiomyopathy may present with palpitations and requires echocardiographic evaluation. 2
• Mitral valve prolapse can cause palpitations without arrhythmia. 4
• Pericarditis and congestive heart failure are potential cardiac causes. 4

Normal Physiologic Causes

• Sinus tachycardia accelerates and terminates gradually, often triggered by exercise, emotions, stress, infection, volume loss, caffeine, nicotine, or medications. 2
• Dehydration leading to compensatory tachycardia is a potential cause. 2

Non-Cardiac Systemic Causes

• Hyperthyroidism is a common non-cardiac cause that must be excluded with thyroid function tests; atrial fibrillation occurs in 5-15% of hyperthyroid patients. 2
• Hypoglycemia and vasovagal syncope can cause palpitations. 4
• Alcohol can trigger arrhythmias, particularly atrial fibrillation. 2

Psychiatric Causes

• Anxiety disorders are a frequent cause of palpitations, particularly when no arrhythmia is documented. 5, 4

Medications and Substances

• Adrenergic drugs, anticholinergic medications, caffeine, nicotine, and illicit substances can all trigger palpitations. 3, 5

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What to Check for Palpitations?

Immediate Assessment (First Visit)

Obtain a 12-lead ECG immediately to identify the rhythm, look for pre-excitation (delta waves suggesting WPW), assess QT interval, and determine if the tachycardia is regular or irregular. 2, 6

Critical Pattern Characterization

The most important distinction is whether the rhythm is regular or irregular, as this fundamentally changes the diagnostic approach. 2

Document the following features:

• Onset and termination pattern: Sudden onset/offset suggests AVNRT or AVRT; gradual acceleration suggests sinus tachycardia. 2
• Duration and frequency of episodes. 2
• Response to vagal maneuvers (Valsalva, carotid massage): Termination suggests re-entrant tachycardia involving AV nodal tissue. 2
• Precipitating factors: Exertion, caffeine, alcohol, stress, meals, position. 2
• Associated symptoms: Syncope, presyncope, chest pain, dyspnea, or polyuria (occurs in ~15% of SVT patients). 2, 6

Physical Examination Findings

• Look for irregular cannon A waves and irregular variation in S1 intensity during tachycardia, which strongly suggests ventricular origin. 2
• Document vital signs including orthostatic measurements. 6

Laboratory Testing

• Thyroid function tests (TSH, free T4) to exclude hyperthyroidism. 2
• Electrolytes (particularly potassium) if clinically indicated. 2
• Renal function (creatinine, GFR) as baseline for medication decisions. 2

Avoid ordering comprehensive laboratory panels routinely—this is a common pitfall. 2

Ambulatory ECG Monitoring Strategy

The choice of monitoring depends on symptom frequency:

• Daily palpitations: 24-48 hour Holter monitoring. 2
• Several times per week: Event or loop recorders have superior diagnostic yield and are more cost-effective than Holter monitoring. 2, 4
• Less than twice monthly with severe symptoms: Consider implantable loop recorder. 2

Monitoring must continue until symptoms occur while wearing the device—non-diagnostic monitoring should not be considered conclusive. 2

Echocardiography Indications

Order echocardiography when:

• Documented sustained SVT to exclude structural heart disease. 2
• Clinical suspicion of valvular aortic stenosis, hypertrophic cardiomyopathy, or tachycardia-mediated cardiomyopathy. 2

Exercise Testing

Consider exercise testing if:

• Palpitations are clearly triggered by exertion to detect exercise-induced arrhythmias and assess chronotropic response. 2

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Are Palpitations Life-Threatening or Benign?

The vast majority of palpitations are benign, but certain features indicate potentially life-threatening conditions that require urgent evaluation. 7

High-Risk Features Requiring Immediate Evaluation

Refer immediately to emergency department or cardiac electrophysiology if any of the following are present:

• Syncope or presyncope accompanying palpitations. 2, 6
• Chest pain or dyspnea during episodes. 2, 6
• Palpitations occurring with exertion in patients with known structural heart disease (e.g., hypertrophic cardiomyopathy, aortic stenosis). 2
• Wide complex tachycardia documented on any rhythm strip. 2
• Pre-excitation with irregular palpitations (strongly suggests atrial fibrillation with accessory pathway—risk of sudden death). 2
• Family history of sudden cardiac death or inheritable heart disease. 6

Moderate-Risk Features Requiring Prompt Outpatient Evaluation

• Frequent episodes (daily to weekly) that interfere with daily activities. 2
• Any underlying structural heart disease even when symptoms are mild. 2
• Pre-excitation patterns on ECG with history of paroxysmal palpitations. 2

Benign Features

• Premature atrial contractions in structurally normal hearts are often benign. 2
• Sinus tachycardia triggered by identifiable stressors (caffeine, anxiety, exercise) in young patients without structural disease. 2
• First-degree AV block or Mobitz type I block that resolves during exercise in asymptomatic athletes without structural heart disease. 2

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Critical Management Pitfalls to Avoid

• Never start Class I or III antiarrhythmic drugs empirically without documented arrhythmia due to significant proarrhythmic risk. 2
• Do not rely on automatic ECG analysis systems—they are unreliable and commonly suggest incorrect diagnoses. 2
• Never dismiss syncope with palpitations as benign—this combination warrants urgent evaluation. 2
• Do not use ATP testing to select patients for pacing—this is not evidence-based. 2

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Initial Empiric Management While Awaiting Monitoring

• Stop all caffeine, alcohol, nicotine and review medications that may trigger arrhythmias. 2
• Assess for recreational drug use. 2
• Instruct patient in Valsalva maneuver and carotid massage to perform during episodes. 2
• Beta-blocker may be prescribed empirically after excluding significant bradycardia (<50 bpm), but only while awaiting monitoring results. 2