What is the initial approach for a patient presenting with palpitations, including history, physical examination, and diagnostic testing?

Initial Approach to Patients with Palpitations

The initial evaluation of a patient presenting with palpitations should include a thorough history focusing on the pattern and characteristics of palpitations, physical examination with emphasis on cardiovascular assessment, a 12-lead ECG, and targeted laboratory tests based on clinical suspicion. 1, 2

History Taking

Key Elements to Assess:

• Pattern of palpitations: Regular vs. irregular, paroxysmal (sudden onset/termination) vs. gradual, frequency, and duration 1
• Characterization: Ask if palpitations feel like skipped beats, racing, pounding, fluttering, or irregular rhythm 1, 3
• Associated symptoms: Syncope, near-syncope, dyspnea, chest pain, or polyuria 1
• Precipitating factors: Exercise, emotions, stress, body position, neck turning, or specific activities 1
• Alleviating factors: Rest, vagal maneuvers, or specific positions 1
• Medication and substance use: Alcohol, caffeine, illicit drugs, prescription medications (especially antiarrhythmics, antihypertensives), and "alternative therapies" 1, 3
• Family history: Sudden cardiac death, arrhythmias, or structural heart disease 1

Red Flags in History:

• Palpitations associated with syncope or presyncope 1, 4
• Family history of sudden cardiac death 1
• Palpitations during exertion 2
• History of structural heart disease or prior myocardial infarction 1

Physical Examination

Essential Components:

• Vital signs: Heart rate, blood pressure (including orthostatic changes), respiratory rate, temperature 1
• Cardiovascular examination: Heart rhythm, murmurs, extra heart sounds, jugular venous pressure and pulsations 1
• Signs of systemic disease: Thyroid enlargement, exophthalmos, tremor (hyperthyroidism), peripheral edema (heart failure) 1
• Carotid sinus massage: Consider in older patients with palpitations during neck turning (contraindicated with carotid bruits, recent stroke/TIA, or significant carotid stenosis) 1, 2

Initial Diagnostic Testing

First-Line Tests:

• 12-lead ECG: Essential for all patients with palpitations to identify underlying arrhythmias or structural abnormalities 1, 2
• Targeted laboratory tests:
  • Complete blood count (to assess for anemia) 2
  • Serum electrolytes including calcium and magnesium 1, 2
  • Thyroid-stimulating hormone 1, 2
  • Blood urea nitrogen and serum creatinine 1, 2
  • Fasting blood glucose or glycohemoglobin 1, 2

Second-Line Tests (Based on Initial Findings):

• Echocardiography: When structural heart disease is suspected based on history, physical exam, or ECG findings 1, 2
• Chest radiograph: To evaluate cardiac size and pulmonary disease 1, 2
• Ambulatory cardiac monitoring: Selection based on frequency of symptoms 1, 2
  • Holter monitor (24-48 hours): For daily or frequent palpitations 2, 3
  • Event recorder (2 weeks): For less frequent but recurrent episodes 1, 2
  • Implantable loop recorder: For very infrequent episodes 1, 2

Specialized Testing (When Indicated)

• Exercise stress testing: For palpitations occurring during or after exertion 2
• Electrophysiological study: When supraventricular tachycardia is suspected as the cause 1
• Transesophageal echocardiography: Rarely needed for palpitation workup unless atrial fibrillation with planned cardioversion 1

Indications for Referral to Cardiologist/Electrophysiologist

• Palpitations associated with syncope or presyncope 1, 4
• Evidence of structural heart disease 1, 4
• ECG showing pre-excitation (Wolff-Parkinson-White pattern) 1
• Documented sustained arrhythmias 1, 4
• High-risk features: family history of sudden death, significant structural heart disease 1
• Palpitations causing severe symptoms despite initial management 1

Common Pitfalls and Caveats

• Not all palpitations are due to arrhythmias; anxiety and other non-cardiac causes must be considered 3
• Presence of psychiatric comorbidity does not rule out cardiac etiology 4
• Routine comprehensive laboratory testing has limited utility; target tests based on clinical suspicion 2
• Failure to document an arrhythmia during monitoring does not exclude arrhythmic cause if monitoring duration was insufficient 3
• Pre-excitation on resting ECG with history of palpitations requires prompt evaluation due to risk of sudden death 1