What are palpitations?

Understanding Palpitations

Palpitations are an uncomfortable awareness of the heartbeat, which may be described as a sensation of a rapid, irregular, strong, or skipped heartbeat. 1, 2

Clinical Characteristics

Palpitations can present in various forms:

• Regular vs. Irregular: Patients may describe either regular or irregular heartbeats 1
• Sudden onset/offset: Particularly characteristic of paroxysmal supraventricular tachycardias (PSVT) 1
• Descriptions: Often described as:
  • Pauses followed by strong beats (premature beats)
  • Irregularities in heart rhythm
  • Fast heart rate
  • Fluttering sensation 2

Causes of Palpitations

Cardiac Causes

1. Arrhythmias - Most common cardiac cause:

   • Premature beats (atrial or ventricular)
   • Supraventricular tachycardias (AVRT, AVNRT)
   • Atrial fibrillation
   • Sinus tachycardia
   • Ventricular tachycardia 1, 3

2. Structural Heart Disease:

   • Valvular heart disease (e.g., mitral valve prolapse)
   • Cardiomyopathy
   • Congestive heart failure 3, 4

Non-Cardiac Causes

1. Physiological:

   • Normal response to exercise
   • Emotional stress or anxiety
   • Fever 2

2. Endocrine:

   • Hyperthyroidism
   • Hypoglycemia 3

3. Substances:

   • Caffeine
   • Nicotine
   • Alcohol
   • Stimulant drugs
   • Medications (adrenergic or anticholinergic) 2, 3

4. Hormonal:

   • Menstrual cycle variations
   • Pregnancy
   • Perimenopause 4

Clinical Significance

The clinical significance of palpitations depends on:

• Associated symptoms: Palpitations with syncope, pre-syncope, chest pain, or dyspnea are concerning 1
• Underlying heart disease: More serious in patients with structural heart disease 5
• Pattern: Sudden onset/offset pattern suggests arrhythmias like PSVT 1

Evaluation Algorithm

1. Detailed History:

   • Pattern: regular vs. irregular
   • Onset: sudden vs. gradual
   • Duration and frequency
   • Triggering factors
   • Associated symptoms (syncope, chest pain, dyspnea) 1

2. Physical Examination:

   • Vital signs (heart rate, blood pressure)
   • Cardiac examination for murmurs, gallops, or irregular rhythm 6

3. Initial Testing:

   • 12-lead ECG (first-line diagnostic tool) 1, 6
   • Basic laboratory tests (thyroid function, electrolytes)

4. Further Cardiac Evaluation (if initial evaluation inconclusive):

   • Ambulatory ECG monitoring:
     • 24-48 hour Holter monitor (for daily palpitations)
     • Event recorder or loop recorder (for infrequent episodes)
     • Implantable loop recorder (for very rare episodes) 1, 3
   • Echocardiogram (to assess structural heart disease) 1

Red Flags Requiring Urgent Evaluation

• Palpitations with syncope or near-syncope (15% of SVT patients) 1
• Family history of sudden cardiac death 1
• Palpitations during exercise
• Palpitations with chest pain or dyspnea
• Known structural heart disease 6, 5

Management Considerations

Management depends on the underlying cause:

• Benign causes: Reassurance, lifestyle modifications (reducing caffeine, stress management)
• Arrhythmias: Specific treatment based on the type of arrhythmia
• Referral to cardiology: Indicated for patients with concerning symptoms, abnormal ECG findings, or suspected serious arrhythmias 6, 5

In up to 16% of patients with palpitations, no specific cause can be identified despite thorough evaluation 3.