What is the initial workup and management for a patient presenting with palpitations?

Palpitation Workup

All patients presenting with palpitations require an immediate 12-lead ECG and focused history to identify rhythm abnormalities, pre-excitation patterns, and risk-stratify for serious arrhythmias. 1

Initial Evaluation

History - Key Elements to Elicit

The history must characterize the pattern of palpitations with specific details 1, 2:

• Onset and termination: Sudden onset/offset strongly suggests AVNRT or AVRT, while gradual acceleration/deceleration indicates sinus tachycardia 3, 2
• Regular vs irregular rhythm: This is the single most important distinction—regular palpitations suggest SVT, VT, or atrial flutter; irregular suggests atrial fibrillation, premature beats, or multifocal atrial tachycardia 3, 2
• Duration and frequency: Determines monitoring strategy 1
• Response to vagal maneuvers: Termination with Valsalva or carotid massage suggests re-entrant tachycardia involving AV nodal tissue 3, 2
• Associated symptoms: Syncope occurs in ~15% of SVT patients and suggests hemodynamic compromise, accessory pathway with rapid conduction, or structural heart disease 3, 2
• Precipitating factors: Exercise-induced palpitations require stress testing; emotional stress, caffeine, nicotine, alcohol, and medications (including stimulants, QT-prolonging drugs) must be identified 3, 2

Critical Red Flags in History

Document these high-risk features 3:

• Family history of sudden cardiac death, sudden cardiac arrest, or unexplained drowning in first-degree relatives
• Personal history of syncope with palpitations
• Known structural heart disease
• Symptoms during exertion

Physical Examination During Tachycardia

If you can examine the patient during an episode 3, 2:

• Irregular cannon A waves and irregular variation in S1 intensity strongly suggest ventricular origin of a regular tachycardia
• Assess hemodynamic stability immediately

12-Lead ECG - Mandatory First Test

Obtain a 12-lead ECG on every patient with palpitations 1, 4. Look for 3, 2:

• Pre-excitation (delta waves): If present with history of paroxysmal regular palpitations, this is AVRT requiring immediate electrophysiology referral
• Pre-excitation with irregular palpitations suggests atrial fibrillation with accessory pathway—immediate EP referral due to sudden death risk
• QT prolongation (risk of torsades de pointes)
• Baseline rhythm abnormalities
• Evidence of structural heart disease (LVH, Q waves, bundle branch blocks)

Critical pitfall: Do not rely on automated ECG interpretation—these systems are unreliable and frequently suggest incorrect diagnoses 2

Laboratory Testing

Avoid routine comprehensive laboratory panels—they have no diagnostic utility 4. Order targeted tests only based on clinical suspicion 1, 4:

• Thyroid-stimulating hormone: If symptoms suggest hyperthyroidism 4
• Complete blood count: If anemia is suspected 4
• Serum electrolytes (including calcium and magnesium): If electrolyte disturbance suspected (diuretic use, vomiting, diarrhea) 4
• Fasting glucose: If hypoglycemia suspected 4
• BNP and high-sensitivity troponin: May be considered if cardiac cause suspected, though usefulness is uncertain 4

Laboratory testing is most valuable when volume depletion (dehydration, bleeding) or metabolic causes (thyroid dysfunction, substance use) are suspected 4.

Ambulatory ECG Monitoring Strategy

The frequency of symptoms determines the monitoring approach 1, 2:

Daily Palpitations

• 24-48 hour Holter monitoring 1, 2

Several Times Per Week

• Event recorder or external loop recorder (superior diagnostic yield and more cost-effective than Holter for non-daily symptoms) 2
• Mobile cardiac outpatient telemetry or patch recorders are alternatives 4

Less Than 2 Episodes Per Month

• Implantable loop recorder, especially if symptoms are severe or associated with hemodynamic instability 1, 2

Special Population: Hypertrophic Cardiomyopathy

• 24-48 hour ambulatory monitoring every 1-2 years as part of routine follow-up 1, 2
• Extended monitoring if additional AF risk factors present (left atrial dilatation, advanced age, NYHA class III-IV) 2

Before initiating monitoring 2:

• Stop all caffeine, alcohol, and nicotine
• Review and discontinue medications that may trigger arrhythmias
• Assess for recreational drug use
• Teach Valsalva maneuver and carotid massage to perform during episodes

Echocardiography

Order echocardiography when 1, 2:

• Documented sustained SVT (to exclude structural heart disease not detectable on physical exam)
• Clinical suspicion of structural abnormalities (valvular disease, hypertrophic cardiomyopathy, tachycardia-mediated cardiomyopathy)
• Abnormal physical examination or ECG suggesting structural disease

Exercise Testing

Obtain exercise stress testing when palpitations are clearly triggered by exertion 1, 2

Immediate Management Considerations

Hemodynamically Unstable Patients

• DC cardioversion immediately 2

Stable Patients Without ECG Documentation

• Teach vagal maneuvers 2
• Beta-blocker may be prescribed empirically while awaiting monitoring results, but only after excluding significant bradycardia (<50 bpm) 2
• Never start Class I or III antiarrhythmic drugs without documented arrhythmia due to significant proarrhythmic risk 2

Mandatory Specialist Referral Criteria

Refer immediately to cardiac electrophysiology for 1, 2:

• Wolff-Parkinson-White syndrome (all patients due to potential for lethal arrhythmias)
• Wide complex tachycardia of unknown origin (documented on any rhythm strip)
• Narrow complex tachycardia with drug resistance or intolerance
• Severe symptoms during palpitations (syncope, dyspnea)
• Patients desiring to be free of drug therapy

Critical Pitfalls to Avoid

• Do not start Class I or III antiarrhythmics empirically without documented arrhythmia 2
• Do not order comprehensive laboratory panels routinely—they are not useful 4
• Do not dismiss syncope with palpitations—this requires intensive evaluation 2
• Do not rely on automated ECG interpretation 2
• Do not use Holter monitoring for infrequent symptoms—event recorders have superior yield 2