What is the initial approach to managing palpitations (irregular heartbeats) in patients?

Initial Approach to Managing Palpitations

Obtain a 12-lead ECG immediately to identify the rhythm and determine if the tachycardia is regular or irregular, as this fundamentally guides acute management and risk stratification. 1, 2

Critical First Steps in History Taking

The history must distinguish whether palpitations are regular or irregular, as this fundamentally changes the differential diagnosis 1, 2:

• Regular, paroxysmal palpitations with sudden onset and termination most commonly indicate AVRT or AVNRT 1, 2
• Irregular palpitations suggest premature depolarizations, atrial fibrillation, or multifocal atrial tachycardia (the latter typically in patients with pulmonary disease) 1
• Gradual onset and termination suggests sinus tachycardia, requiring evaluation for stressors like infection or volume loss 1

Document the pattern precisely: number of episodes, duration, frequency, mode of onset, and possible triggers 1, 2. Ask specifically if vagal maneuvers terminate the episodes, as this strongly suggests re-entrant tachycardia involving AV nodal tissue 1, 2.

Identify High-Risk Features Requiring Urgent Action

Immediate referral to an arrhythmia specialist is mandatory for: 1, 2

• All patients with Wolff-Parkinson-White syndrome (pre-excitation with arrhythmias) due to potential for lethal arrhythmias 1, 2
• Wide complex tachycardia of unknown origin 1, 2
• Severe symptoms during palpitations: syncope or dyspnea 1

Syncope occurs in approximately 15% of SVT patients, typically just after initiation of rapid tachycardia or with prolonged pause after termination 1, 2. These patients require guideline-directed medical therapy 2.

Physical Examination Findings

While physical examination during tachycardia is standard, it usually does not lead to definitive diagnosis 1. Look for:

• Irregular pulse, irregular jugular venous pulsations, and variation in loudness of heart sounds suggesting atrial fibrillation 1
• Evidence of structural heart disease, valvular disease, or heart failure 1
• Signs of hyperthyroidism or other systemic conditions 1

Initial Diagnostic Workup

A resting 12-lead ECG should be recorded in all patients 1. The presence of pre-excitation on resting ECG in a patient with paroxysmal regular palpitations is sufficient for presumptive diagnosis of AVRT and warrants referral without requiring documentation of spontaneous episodes 1.

If the surface ECG is normal and symptoms suggest benign premature beats, review and eliminate precipitating factors: excessive caffeine, alcohol, nicotine, recreational drugs, or hyperthyroidism 1. Benign extrasystoles typically manifest at rest and become less common with exercise 1.

Ambulatory Monitoring Strategy

The choice of monitoring depends on symptom frequency 1:

• 24-hour Holter recording: for frequent transient tachycardias (several episodes per week) 1
• Event or wearable loop recorder: more useful than 24-hour recording for less frequent arrhythmias 1
• Implantable loop recorders: for rare symptoms (fewer than two episodes per month) associated with severe symptoms or hemodynamic instability 1

Additional Investigations

Echocardiographic examination should be considered in patients with documented sustained SVT to exclude structural heart disease, which usually cannot be detected by physical examination or 12-lead ECG 1. Two-dimensional echocardiography should assess LA and LV dimensions, LV wall thickness, and function 1.

Exercise testing is useful only if the arrhythmia is clearly triggered by exertion 1.

Acute Management Considerations

If symptoms and clinical history indicate paroxysmal arrhythmia and the resting 12-lead ECG gives no clue to mechanism, further diagnostic tests may not be necessary before referral for invasive electrophysiological study and/or catheter ablation 1.

Teach patients to perform vagal maneuvers 1. A beta-blocking agent may be prescribed empirically provided that significant bradycardia (less than 50 bpm) has been excluded 1. Due to risk of proarrhythmia, antiarrhythmic treatment with class I or class III drugs should not be initiated without documented arrhythmia 1.

Common Pitfalls to Avoid

• Do not delay obtaining at least a monitor strip before DC cardioversion, even in cases with cardiogenic shock or cardiac arrest 1
• Do not assume all palpitations are arrhythmic; many patients with arrhythmias do not have palpitations but present with syncope, shock, or chest pain 3
• Be aware that SVT persistent for weeks to months with fast ventricular response may lead to tachycardia-mediated cardiomyopathy 1, 2