Palpitations¶

Chapter 45 | Palpitations

KEY CLINICAL POINTS¶

Palpitations are common and often benign, but may indicate serious arrhythmias or underlying cardiac/psychiatric conditions.
Cardiac causes (43%) include supraventricular/ventricular arrhythmias, mitral valve prolapse, and structural heart disease.
Psychiatric causes (31%) such as anxiety/somatization often present with prolonged (>15 min) symptoms and associated features.
Diagnostic workup includes ECG, Holter monitoring, implantable loop recorders, and patient diary for timing.
Management depends on cause: beta-blockers for benign arrhythmias, lifestyle modifications, and psychiatric intervention.

1. DEFINITION & OVERVIEW¶

Palpitations are subjective sensations of 'thumping,' 'pounding,' or 'fluttering' in the chest, often due to awareness of cardiac rhythm. They may be intermittent or sustained, regular or irregular. Most patients perceive skipped beats or abnormal heartbeats, with concern when they feel 'missing' beats. Hyperdynamic states (e.g., exercise, pheochromocytoma) or enhanced myocardial contraction (e.g., caffeine, alcohol) may amplify the sensation.

1.1 Clinical Significance¶

Palpitations may reflect benign arrhythmias (e.g., premature beats) or serious conditions (e.g., atrial fibrillation, ventricular tachycardia). The primary goal is to exclude life-threatening arrhythmias, especially in patients with CAD or risk factors.

1.2 Physical Examination¶

Key findings include abnormal vital signs, jugular venous pressure, pulse abnormalities, and cardiac auscultation. Post-extrasystolic potentiation may explain the sensation of a 'pounding' beat after a pause.

2. EPIDEMIOLOGY¶

Palpitations are extremely common in patients presenting to internists. Prevalence is 2-3% in the general population, with higher rates in athletes (especially older endurance athletes) and those with hyperdynamic states. Risk factors include CAD, anxiety, substance use, and conditions like thyrotoxicosis or pheochromocytoma.

2.1 Demographics¶

Common in middle-aged adults; athletes may experience palpitations due to hyperdynamic circulation. Older adults may present with syncope or lightheadedness as associated symptoms.

2.2 Causes Distribution¶

Cardiac (43%), psychiatric (31%), miscellaneous (10%), and unknown (16%) causes. Structural heart disease, arrhythmias, and substance-induced triggers are most frequent.

3. ETIOLOGY & PATHOPHYSIOLOGY¶

Palpitations arise from cardiac, psychiatric, or miscellaneous causes. Cardiac mechanisms include premature beats, tachycardias, and structural disease. Psychiatric causes involve anxiety, panic attacks, or somatization. Miscellaneous factors include substance use, thyrotoxicosis, and systemic conditions (e.g., mastocytosis, post-COVID syndrome).

3.1 Cardiac Mechanisms¶

Premature atrial/ventricular contractions, supraventricular/ventricular tachycardias, mitral valve prolapse, and structural abnormalities (e.g., aortic regurgitation, pulmonary embolism) are common. Post-extrasystolic potentiation enhances the perception of subsequent beats.

3.2 Psychiatric Triggers¶

Anxiety, panic attacks, and somatization often present with prolonged (>15 min) symptoms and associated features (e.g., sweating, chest tightness). Patients may report 'skipped' beats due to heightened awareness.

4. CLINICAL FEATURES¶

Symptoms include chest discomfort, skipped beats, or a 'fluttering' sensation. Signs may include hyperdynamic precordium, jugular venous distension, or abnormal pulses. Complications include syncope, dyspnea, or hemodynamic instability in severe cases.

4.1 Positional Palpitations¶

Often due to structural processes (e.g., atrial myxoma) or mediastinal masses. May be associated with dyspnea from increased left atrial/pulmonary venous pressure.

4.2 Associated Symptoms¶

Syncope, lightheadedness, or angina may indicate hemodynamic compromise. Alcohol, tobacco, or illicit drug use may precipitate episodes.

5. DIFFERENTIAL DIAGNOSIS¶

Cardiac causes: arrhythmias, structural heart disease, myocarditis. Psychiatric causes: anxiety, panic disorder, somatization. Miscellaneous: thyrotoxicosis, pheochromocytoma, systemic mastocytosis, post-COVID syndrome, or spontaneous chest wall contractions.

6. INVESTIGATIONS & DIAGNOSIS¶

Diagnostic approach includes resting ECG, exercise stress testing, Holter monitoring, implantable loop recorders, and mobile cardiac telemetry. Patient diary to correlate symptoms with ECG findings is essential. Criteria for testing depend on symptom frequency and suspected cause.

6.1 Diagnostic Algorithms¶

Assess for life-threatening arrhythmias (e.g., ventricular tachycardia). 2. Use Holter monitoring for infrequent episodes; implantable loop recorders for long-term monitoring. 3. Exercise ECG for exertion-induced arrhythmias. 4. Telephonic/remote monitoring for real-time data.

6.2 Laboratory Tests¶

Thyroid function tests, troponin, BNP, and urine metanephrines. Rule out thyrotoxicosis, myocardial infarction, or pheochromocytoma.

7. MANAGEMENT & TREATMENT¶

Management depends on cause: beta-blockers for benign arrhythmias, lifestyle modifications (e.g., alcohol/tobacco cessation), and psychiatric intervention. Pharmacologic agents for drug-induced palpitations require alternative therapies. Reassurance is critical once serious causes are excluded.

7.1 Pharmacologic Therapy¶

Beta-blockers (e.g., metoprolol) for premature beats or sustained tachycardias. Antiarrhythmics (e.g., amiodarone) for life-threatening rhythms. Antianxiety medications for psychiatric causes.

7.2 Non-Pharmacologic Interventions¶

Avoidance of triggers (e.g., caffeine, alcohol, illicit drugs). Cognitive therapy for anxiety/somatization. Regular follow-up for patients with recurrent episodes.

8. PROGNOSIS & COMPLICATIONS¶

Most palpitations are benign and do not affect prognosis. However, severe arrhythmias (e.g., ventricular tachycardia) or underlying structural disease may lead to complications like syncope, heart failure, or sudden cardiac death. Early diagnosis and management reduce risks.

8.1 Long-Term Outcomes¶

Benign causes (e.g., premature beats) have excellent prognosis. Patients with CAD or structural disease require monitoring for progression.

8.2 Complications¶

Syncope, hemodynamic instability, or cardiac arrest in severe cases. Chronic conditions like heart failure may develop from prolonged arrhythmias.

9. SPECIAL CONSIDERATIONS¶

Pregnancy: Monitor for arrhythmias or cardiac disease. Pediatrics: Consider congenital heart defects or arrhythmias. Elderly: Assess for CAD, medication side effects, or psychiatric comorbidities. Athletes: Evaluate for hyperdynamic states or structural abnormalities.

10. KEY POINTS & CLINICAL PEARLS¶

Palpitations are common but require thorough evaluation to exclude life-threatening arrhythmias. 2. Cardiac causes (43%) are most frequent, followed by psychiatric (31%). 3. Holter monitoring is limited for infrequent episodes; implantable loop recorders are more effective. 4. Beta-blockers are first-line for benign arrhythmias. 5. Reassurance is critical after ruling out serious causes.