What is the initial assessment and management approach for patients presenting with palpitations?

Initial Assessment and Management of Palpitations

Obtain a 12-lead ECG immediately as the single most critical diagnostic step, as this captures the rhythm during symptoms and identifies life-threatening conditions like pre-excitation (Wolff-Parkinson-White syndrome) that require urgent electrophysiology referral. 1, 2

Immediate Clinical Assessment

History - Pattern Characterization

The diagnostic approach fundamentally depends on whether the rhythm is regular or irregular, as this distinction changes the entire diagnostic pathway 2:

Regular palpitations:

• Sudden onset/termination suggests AVNRT or AVRT, particularly in younger patients 2
• Gradual acceleration/termination suggests sinus tachycardia from stressors (infection, volume loss, caffeine, nicotine, medications) 2
• Response to vagal maneuvers (termination) confirms re-entrant tachycardia involving AV nodal tissue 2

Irregular palpitations:

• Most commonly atrial fibrillation or atrial flutter with variable block 2
• Pre-excitation with irregular palpitations strongly suggests atrial fibrillation with accessory pathway—this requires immediate electrophysiology referral due to sudden death risk 2

Critical Associated Symptoms

Document the following red flags 2:

• Syncope or presyncope (suggests ventricular tachycardia or hemodynamically significant arrhythmia)
• Chest discomfort or dyspnea during episodes
• Polyuria (occurs in ~15% of SVT patients)
• Episode frequency, duration, and triggers

Physical Examination During Tachycardia

• Look for irregular cannon A waves and irregular variation in S1 intensity—these strongly suggest ventricular origin 2
• Assess hemodynamic stability immediately 2

ECG Interpretation - Critical Findings

Pre-excitation (delta waves) on resting ECG:

• With regular palpitations = presumptive AVRT → immediate electrophysiology referral 2
• With irregular palpitations = atrial fibrillation with accessory pathway → immediate electrophysiology referral due to sudden death risk 2

Do not rely on automatic ECG interpretation systems—they are unreliable and commonly suggest incorrect diagnoses 2

Cardiac Monitoring Strategy

Select monitoring based on symptom frequency 1:

Daily palpitations:

• 24-48 hour Holter monitor 1, 2

Several times per week:

• 48-hour ambulatory ECG monitoring 1

Infrequent episodes (less than daily):

• Event recorder, patch recorder, or mobile cardiac outpatient telemetry 1

Recurrent unexplained episodes despite initial monitoring:

• Implantable loop recorder for selected patients at low risk for sudden cardiac death 1

Targeted Laboratory Testing

Avoid routine comprehensive laboratory panels—they are not useful and should not be ordered 1. Instead, order targeted tests based on clinical suspicion 1:

Order selectively when clinically indicated:

• Complete blood count (if anemia suspected) 1
• Thyroid-stimulating hormone (if hyperthyroidism suspected) 1
• Serum electrolytes including calcium and magnesium (if electrolyte disturbance suspected) 1
• Fasting blood glucose (if hypoglycemia or diabetes suspected) 1

Consider if cardiac cause suspected (though usefulness uncertain):

• BNP and high-sensitivity troponin 1

Laboratory testing is most valuable when:

• Loss of circulating volume suspected (dehydration, bleeding) 1
• Metabolic causes suggested by history (thyroid symptoms, medication use, substance use) 1

Echocardiography Indications

Order echocardiography when 1, 2:

• Documented sustained SVT (to exclude structural heart disease not detectable by physical exam alone)
• Clinical suspicion of valvular aortic stenosis, hypertrophic cardiomyopathy, or tachycardia-mediated cardiomyopathy
• History, exam, or ECG findings suggest structural heart disease

Immediate Management Based on Presentation

Hemodynamically unstable patients:

• DC cardioversion immediately 2

Stable patients without ECG documentation:

• Teach vagal maneuvers (Valsalva, carotid massage) 2, 3
• Consider empiric beta-blocker therapy if significant bradycardia (<50 bpm) excluded 3

Caffeine-related palpitations:

• Immediately eliminate all caffeine intake (coffee, matcha, energy drinks, caffeine-containing medications/supplements)—caffeine cessation alone is often sufficient in patients with anxiety and negative cardiac workup 3

Mandatory Immediate Electrophysiology Referral

Refer immediately for 2, 3:

• All patients with Wolff-Parkinson-White syndrome (pre-excitation on ECG) due to potential for lethal arrhythmias
• Severe symptoms during palpitations (syncope, dyspnea, chest pain)
• Wide complex tachycardia of unknown origin
• Drug resistance or intolerance in narrow complex tachycardia
• Patients desiring definitive therapy (catheter ablation) rather than chronic medication

Critical Pitfalls to Avoid

• Never start class I or III antiarrhythmics empirically without documented arrhythmia 2
• Never order comprehensive laboratory panels routinely 1
• Never dismiss syncope occurring with palpitations—this suggests hemodynamically significant arrhythmia 2
• Never rely on automatic ECG analysis systems 2
• Recognize that tachycardia-mediated cardiomyopathy can develop if SVT persists for weeks to months with fast ventricular response—emphasizing the importance of timely diagnosis 2