What is the appropriate evaluation and management approach for a patient presenting with palpitations?

Evaluation of Palpitations

Initial Assessment: History and Physical Examination

Begin with a focused history that determines whether the palpitations are regular or irregular, as this single distinction fundamentally changes your entire diagnostic approach. 1

Critical History Elements

Pattern characterization:

• Onset and termination: Sudden onset with sudden termination strongly suggests AVNRT or AVRT, while gradual acceleration and deceleration indicates sinus tachycardia 2, 1
• Duration and frequency: Document the number of episodes, how long each lasts, and how often they occur 2
• Response to vagal maneuvers: Termination with Valsalva or carotid massage confirms re-entrant tachycardia involving AV nodal tissue 2, 1

Associated symptoms requiring urgent evaluation:

• Syncope or presyncope (occurs in approximately 15% of SVT patients and may indicate hemodynamic compromise) 2
• Chest pain or dyspnea 2
• Polyuria (suggests atrial natriuretic peptide release from atrial contraction against closed AV valves) 2, 1

Precipitating factors:

• Exercise or emotional stress 2
• Caffeine, nicotine, alcohol, or stimulant drugs (cocaine, amphetamines) 2, 1
• Over-the-counter medications or supplements (anabolic steroids) 2

Medication review:

• QT-prolonging medications and potential drug-drug interactions 2
• Antiarrhythmic medications 2

Past medical history:

• Known structural heart disease (coronary, valvular, congenital) 2
• Thyroid disease 2
• Electrolyte abnormalities or renal disease 2
• Epilepsy (arrhythmic syncope can be misdiagnosed as epilepsy) 2

Family history:

• Sudden cardiac death, sudden cardiac arrest, or unexplained drowning in first-degree relatives 2
• Cardiomyopathies (hypertrophic, dilated, ARVC) 2
• Cardiac channelopathies (long QT, Brugada, short QT, CPVT) 2
• SIDS or repetitive spontaneous pregnancy losses (associated with cardiac channelopathies) 2

Physical Examination Findings

During tachycardia (if present):

• Irregular cannon A waves and irregular variation in S1 intensity strongly suggest ventricular origin 1
• Heart rate, blood pressure, and regularity 2
• Jugular venous pressure 2
• Cardiac murmurs 2

Immediate Diagnostic Testing

Obtain a 12-lead ECG immediately on every patient presenting with palpitations. 1

ECG interpretation priorities:

• Pre-excitation (delta waves) with regular palpitations = presumptive AVRT → immediate electrophysiology referral 1
• Pre-excitation with irregular palpitations = atrial fibrillation with accessory pathway → immediate electrophysiology referral due to sudden death risk 1
• Look for QT prolongation (risk of torsades de pointes) 2
• Assess for structural abnormalities or ischemic changes 2
• Do not rely on automatic ECG interpretation—these systems are unreliable and commonly suggest incorrect diagnoses 1

Ambulatory ECG Monitoring Strategy

The choice of monitoring depends on symptom frequency:

For daily palpitations:

• 24-48 hour Holter monitoring 1

For symptoms occurring several times per week:

• Event or loop recorders have superior diagnostic yield and are more cost-effective than Holter monitoring 1

For symptoms less than twice monthly with severe features:

• Consider implantable loop recorder 1

Before initiating monitoring:

• Stop all caffeine, alcohol, and nicotine 1
• Review and discontinue medications that may trigger arrhythmias 1
• Assess for recreational drug use 1
• Instruct patient in Valsalva maneuver and carotid massage to perform during episodes 1

Critical monitoring principle: Continue monitoring until symptoms occur while wearing the device—non-diagnostic monitoring should not be considered conclusive. 1

Additional Diagnostic Testing

Echocardiography indications:

• Documented sustained SVT (to exclude structural heart disease that cannot be detected by physical examination alone) 1
• Clinical suspicion of valvular aortic stenosis, hypertrophic cardiomyopathy, or tachycardia-mediated cardiomyopathy 1

Exercise stress testing:

• Consider if palpitations are clearly triggered by exertion 1
• Can detect exercise-induced arrhythmias and assess chronotropic response 1

Laboratory testing:

• Thyroid function tests (hyperthyroidism is a common non-cardiac cause) 1
• Electrolytes, particularly potassium 1
• Renal function (creatinine, GFR) as baseline for medication decisions 1

Mandatory Immediate Referral to Cardiac Electrophysiology

Refer immediately for:

• All patients with Wolff-Parkinson-White syndrome (potential for lethal arrhythmias) 1
• Wide complex tachycardia documented on any rhythm strip 1
• Severe symptoms during palpitations (syncope or dyspnea) 1
• Drug resistance or intolerance in narrow complex tachycardia 1
• Patients desiring to be free of drug therapy 1

Hospitalization Criteria

Patients presenting with syncope for which ventricular arrhythmia is documented or thought to be a likely cause should be hospitalized for evaluation, monitoring, and management. 2

Empiric Medical Therapy (While Awaiting Monitoring Results)

Beta-blocker may be prescribed empirically after excluding significant bradycardia (<50 bpm). 1

Critical pitfall: Never start Class I or III antiarrhythmic drugs without documented arrhythmia due to significant proarrhythmic risk. 1

Common Pitfalls to Avoid

• Starting antiarrhythmics empirically without documented arrhythmia 1
• Ordering comprehensive laboratory panels routinely (target testing based on clinical suspicion) 1
• Dismissing syncope with palpitations as benign 1
• Relying on automatic ECG analysis systems 1
• Considering non-diagnostic monitoring as conclusive 1

Special Considerations

Tachycardia-mediated cardiomyopathy can develop in patients with SVT persisting for weeks to months with fast ventricular response, emphasizing the importance of timely diagnosis and treatment. 2, 1

For patients with hypertrophic cardiomyopathy presenting with palpitations, perform 24-48 hour ambulatory monitoring every 1-2 years as part of periodic follow-up, with extended monitoring if additional AF risk factors are present (left atrial dilatation, advanced age, NYHA class III-IV heart failure). 1