What is the appropriate workup for a patient presenting with palpitations?

Diagnostic Approach to Palpitations

The appropriate workup for a patient presenting with palpitations should begin with a 12-lead ECG, detailed history focusing on palpitation characteristics, and physical examination, followed by targeted cardiac monitoring based on symptom frequency. 1, 2

Initial Evaluation

• Obtain a 12-lead ECG as the essential first diagnostic step for all patients with palpitations to identify baseline abnormalities and potential arrhythmias 2
• Take a detailed history focusing on specific characteristics of palpitations:
  • Onset and termination (sudden vs. gradual)
  • Duration and frequency of episodes
  • Associated symptoms (syncope, presyncope, chest pain, dyspnea)
  • Precipitating factors (exercise, stress, position)
  • Pattern of palpitations (regular vs. irregular) 2, 3
• Perform a physical examination to assess for signs of structural heart disease or thyroid dysfunction 2

Cardiac Monitoring Selection Based on Symptom Frequency

• For frequent episodes (daily or near-daily):
  • 24-48 hour Holter monitoring is recommended 2, 1
• For less frequent episodes (weekly):
  • Event recorder or wearable loop recorder is more appropriate 2, 1
• For rare episodes (monthly or less):
  • Implantable loop recorder may be considered 2, 1

Laboratory Testing

• Targeted blood tests should be ordered based on clinical assessment rather than routine comprehensive testing 1
• Consider these essential laboratory tests:
  • Complete blood count (to assess for anemia) 1
  • Serum electrolytes including calcium and magnesium 1
  • Thyroid-stimulating hormone (to rule out hyperthyroidism) 1
  • Fasting blood glucose or glycohemoglobin 1

Additional Testing Based on Clinical Suspicion

• Echocardiography should be performed if structural heart disease is suspected 1, 2
• Exercise testing is recommended when palpitations are triggered by exertion 2
• Extended monitoring (>24 hours) is recommended for patients who develop palpitations or lightheadedness 2

Special Considerations

• Patients with pre-excitation on resting ECG and a history of paroxysmal regular palpitations should be referred to electrophysiology 2
• Wide-complex tachycardia may represent either ventricular tachycardia or supraventricular rhythm with abnormal conduction - correct identification is critical 3
• Patients with structural heart disease require more intensive evaluation, including echocardiography, prolonged ECG monitoring, and possibly electrophysiological studies 2

Indications for Specialist Referral

• Wide complex tachycardia of unknown origin 2
• Narrow complex tachycardia with drug resistance or intolerance 2
• Wolff-Parkinson-White syndrome 2
• Severe symptoms during palpitations (syncope, presyncope) 3, 2
• Suspected structural heart disease 2

Common Pitfalls to Avoid

• Failing to obtain an ECG during symptoms - the key element in diagnosis is capturing the arrhythmia during symptoms 4
• Choosing inappropriate monitoring based on symptom frequency - match the monitoring method to the frequency of symptoms 2, 5
• Missing red flags such as syncope, near-syncope, or dizziness during palpitations, which may indicate more serious conditions 5
• Overlooking non-cardiac causes of palpitations such as hyperthyroidism, anxiety, stimulant use, or medication side effects 5

Diagnostic Yield

• A specialized management approach to palpitations can identify a cardiac arrhythmia in more than 80% of cases 4
• The earliness of ECG recording remains the key element in diagnostic approach 4
• In up to 16% of patients, no cause for palpitations can be found despite thorough evaluation 5