What is the best course of action for a patient experiencing dizziness with palpitations, with a Holter monitor showing rare Premature Atrial Contractions (PACs) and 1.58% Premature Ventricular Contractions (PVCs)?

Management of Dizziness with Palpitations and Rare PACs/PVCs

Further cardiac monitoring with an external loop recorder or event monitor is recommended for this patient experiencing dizziness with palpitations, as the 7-day Holter monitor showing rare PACs and only 1.58% PVCs is insufficient to establish a definitive correlation between symptoms and rhythm disturbances.

Assessment of Current Findings

The patient's 7-day Holter monitor shows:

• Sinus rhythm
• Rare premature atrial contractions (PACs)
• 1.58% premature ventricular contractions (PVCs)
• Symptoms occurring during sinus rhythm

Significance of Current Findings

• The PVC burden of 1.58% is considered low risk (<10% of total beats) 1
• Low PVC burden (<2,000 PVCs/24h or <1%) has approximately 0% risk of underlying structural heart disease 1
• The current monitoring has not established a clear correlation between the patient's dizziness symptoms and any significant arrhythmia

Recommended Diagnostic Approach

1. Extended Cardiac Monitoring

   • An external loop recorder or event monitor is the most appropriate next step 2
   • This is indicated when:
     • Symptoms are intermittent and not captured during initial monitoring
     • There is a need to establish correlation between symptoms and cardiac rhythm 2
   • The device should automatically record during symptoms without requiring patient activation, as this is inappropriate for assessment of dizziness 2

2. Cardiac Evaluation

   • Echocardiography to assess for structural heart disease 1
   • 12-lead ECG during symptoms (if not already obtained) 2
   • Consider exercise stress testing if symptoms are exercise-related 2

Management Based on Diagnostic Results

If Arrhythmia Correlation is Established:

• For PAC-related symptoms:

  • Evaluate for reversible causes (electrolyte abnormalities, hyperthyroidism) 3
  • Consider beta-blockers for symptomatic management 3

• For PVC-related symptoms:

  • With current low burden (1.58%), if symptomatic:
    • First-line therapy: Beta-blockers or non-dihydropyridine calcium channel blockers 1
    • Lifestyle modifications: Limit caffeine, alcohol, and stimulants 1

If No Arrhythmia Correlation is Found:

• Consider non-cardiac causes of dizziness
• Evaluate for orthostatic hypotension
• Consider neurological consultation if symptoms persist without cardiac correlation

Important Considerations

• Dizziness with palpitations requires thorough evaluation as it may represent a more serious condition than the current low burden of ectopy suggests 2
• The de Asmundis study found that symptom-related arrhythmias were detected in significantly more individuals using patient-activated event recorders than Holter monitors for patients with palpitations or dizziness 2
• Trans-telephonic event monitors are more effective and cost-effective than Holter monitors for most patients with intermittent symptoms 4

Follow-up Recommendations

• If symptoms persist without clear cardiac correlation after extended monitoring, consider:
  • Tilt-table testing for suspected vasovagal syncope 2
  • Carotid sinus massage for patients over 60 years with unexplained syncope 2
  • Neurological evaluation

The key to management is establishing whether the patient's symptoms correlate with a specific arrhythmia, which requires more targeted monitoring than what has been completed so far.