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

Initial Workup for Palpitations

Obtain a 12-lead ECG immediately as the essential first step for all patients presenting with palpitations, followed by focused history and physical examination to determine rhythm characteristics and guide further diagnostic testing. 1, 2, 3

Immediate ECG Assessment

• Perform 12-lead ECG on presentation to identify the rhythm, detect pre-excitation patterns (Wolff-Parkinson-White), assess for baseline abnormalities, and determine if tachycardia is regular or irregular 1, 2, 3
• Look specifically for pre-excitation with delta waves, as this combined with paroxysmal regular palpitations indicates AVRT and requires immediate electrophysiology referral 1, 2
• Pre-excitation with irregular palpitations strongly suggests atrial fibrillation with an accessory pathway—a potentially lethal condition requiring urgent specialist evaluation 1
• Do not rely on automatic ECG interpretation systems, as they are unreliable and frequently suggest incorrect diagnoses 1

Critical History Elements

Pattern Characterization (Most Important)

• Determine if rhythm is regular versus irregular—this single distinction fundamentally changes the entire differential diagnosis and diagnostic approach 1, 2, 3
• Document onset and termination characteristics: sudden onset/offset suggests AVNRT or AVRT, while gradual acceleration/deceleration indicates sinus tachycardia 1, 2
• Record duration and frequency of episodes, as this guides monitoring strategy selection 1, 3

Response to Vagal Maneuvers

• Ask if palpitations terminate with vagal maneuvers (Valsalva, carotid massage, bearing down), as termination strongly suggests re-entrant tachycardia involving AV nodal tissue (AVNRT or AVRT) 1, 2, 3

Associated Symptoms (High-Risk Features)

• Syncope or presyncope during palpitations occurs in approximately 15% of SVT patients and indicates very rapid tachycardia requiring urgent evaluation 2, 3
• Chest discomfort, dyspnea, or excessive fatigue warrant more intensive workup 1, 3
• Polyuria occurs in approximately 15% of SVT patients due to atrial natriuretic peptide release 1

Precipitating Factors

• Identify triggers including exercise, caffeine, nicotine, medications, stress, infection, or volume depletion 1, 3
• Exercise-triggered palpitations require exercise stress testing 3

Physical Examination

• Look for irregular cannon A waves and irregular variation in S1 intensity during tachycardia, which strongly suggests ventricular origin 1
• Assess for signs of structural heart disease (murmurs, gallops, displaced PMI) or thyroid dysfunction 3

Ambulatory ECG Monitoring Strategy

For Frequent Episodes (Daily)

• 24-48 hour Holter monitoring is appropriate for patients with daily palpitations 4, 3, 5

For Intermittent Episodes (Not Daily)

• Initial two-week course of continuous closed-loop event recording is indicated when palpitations occur unpredictably or less than daily 3, 5
• Event recorders or wearable loop recorders are more cost-effective than Holter monitors for most patients with intermittent symptoms 3, 5

For Rare Episodes

• Implantable loop recorder may be considered when palpitations are infrequent but concerning, or when prolonged external monitoring fails to capture events 3

For Symptomatic Patients

• Extended (>24 hours) electrocardiographic monitoring or event recording is recommended for patients who develop palpitations with lightheadedness, and should not be considered diagnostic unless symptoms occur during monitoring 4, 3

Echocardiography Indications

• Order echocardiography when there is documented sustained SVT to exclude structural heart disease, which usually cannot be detected by physical examination alone 1, 3
• Order when clinical suspicion exists for valvular aortic stenosis, hypertrophic cardiomyopathy, or tachycardia-mediated cardiomyopathy 1, 3
• Patients with structural heart disease require more intensive evaluation including prolonged ECG monitoring and possibly electrophysiological studies 3

Laboratory Testing (Selective Use Only)

• Laboratory tests are only indicated if volume depletion or metabolic causes are suspected (thyroid dysfunction, hypoglycemia, electrolyte abnormalities) 3
• Avoid ordering comprehensive laboratory panels routinely—this is a common pitfall 1

Exercise Stress Testing

• Recommended when palpitations are specifically triggered by exertion to provoke and document exercise-induced arrhythmias 3

Immediate Specialist Referral Criteria (Mandatory)

Refer Immediately to Cardiac Electrophysiology for:

• All patients with Wolff-Parkinson-White syndrome (pre-excitation with arrhythmias) due to potential for lethal arrhythmias 1, 2, 3
• Wide complex tachycardia of unknown origin 1, 2, 3
• Severe symptoms during palpitations (syncope, near-syncope, significant dyspnea) 1, 2, 3
• Narrow complex tachycardia with drug resistance or intolerance 1, 3
• Patients desiring to be free of drug therapy who have documented arrhythmias 1

Critical Pitfalls to Avoid

• Never start class I or III antiarrhythmics empirically without documented arrhythmia—this is dangerous and inappropriate 1
• Do not dismiss syncope occurring with palpitations, as this indicates high-risk features requiring urgent evaluation 1, 2
• Avoid using ATP testing to select patients for pacing 1
• Do not rely solely on patient symptom description without ECG documentation to guide antiarrhythmic therapy 1

Special Considerations

Tachycardia-Mediated Cardiomyopathy

• Can develop when SVT persists for weeks to months with fast ventricular response, emphasizing the importance of timely diagnosis and treatment 1, 2

Patients with Hypertrophic Cardiomyopathy

• Require 12-lead ECG and 24-48 hour ambulatory monitoring every 1-2 years as part of periodic follow-up 4, 3
• Extended monitoring is recommended for those with additional AF risk factors (left atrial dilatation, advanced age, NYHA class III-IV heart failure) 4

When No Cause is Identified

• Up to 16% of patients with palpitations will have no identifiable cause after comprehensive evaluation 5
• For frequent palpitations where prolonged ECG monitoring fails to identify a cause, consider implantable loop recorder 3