Palpitations
Differential Diagnosis
Common Diagnoses
- Anxiety (Increased Awareness of Normal Heartbeat)
- Sinus Tachycardia (e.g. Stress, Fever, Exercise)
- Atrial Ectopics
- Ventricular Ectopics
- Supraventricular Tachycardia (SVT)
Occasional Diagnoses
- Structural Heart Disease (e.g. Valvular Problem, Cardiomyopathy)
- Thyrotoxicosis (Combination of Sinus Tachycardia and Increased Awareness Even if Ventricular Ectopics are Absent)
- Menopause (Due to Sudden Vasodilation)
- Atrial Fibrillation (AF – Various Causes, e.g. IHD, Mitral Valve Disease, Alcohol)
- Iatrogenic (e.g. Digoxin, Nifedipine)
- Atrial Flutter
- Postural tachycardia syndrome (PoTS)
Rare Diagnoses
- Heart Block (Especially with Changes in Block)
- Sick Sinus Syndrome
- Drug Abuse
- Ventricular Tachycardia (VT)
- Phaeochromocytoma
- Carcinoid Syndrome
Ready Reckoner
Key distinguishing features of the most common diagnoses
| Anxiety | Sinus Tachycardia | Atrial Ectopics | Ventricular Ectopics | SVT | |
|---|---|---|---|---|---|
| Sudden Onset | Possible | No | Possible | Possible | Yes |
| ‘Heart Racing’ | Yes | Yes | No | No | Yes |
| ‘Heart Misses a Beat’ | Possible | No | Yes | Yes | No |
| Underlying Beart Disease | No | No | No | Possible | Possible |
| Rate/Rhythm Abnormal During Episode | No | Yes | Yes | Yes | Yes |
Possible Investigations
Likely:ECG, TFT.
Possible:U&E, 24 h ECG or event monitor, Tilt table test.
Small Print:Echocardiography, further secondary care cardiac investigations, 24 h urinary 5-HIAA, 24 h urinary-free catecholamines and VMAs.
- ECG: May show arrhythmia itself or evidence of ischaemic heart disease or Wolff– Parkinson–White syndrome.
- TFT: Thyrotoxicosis can cause palpitations or exacerbate other causes.
- U&E: Electrolyte disturbance can precipitate or aggravate some arrhythmias.
- 24 h ECG or event monitor: To provide ECG evidence of the arrhythmia.
- Echocardiography: To investigate possible structural lesions such as valvular problems or cardiomyopathy.
- Further secondary care investigations: Might include investigation for underlying ischaemic heart disease.
- 24 h urinary 5-HIAA: If carcinoid syndrome suspected.
- 24 h urinary-free catecholamines and VMAs: If phaeochromocytoma suspected.
- Tilt table test: if suspicion of PoTS
Top Tips
- Take time to obtain a clear history, as the patient’s perception of a ‘palpitation’ may differ markedly from yours.
- In paroxysmal cases, suggest that the patient attends the surgery or casualty urgently during an attack to obtain an ECG.
- Patients can easily be taught to take their own pulse. Self-reported pulse rates can help considerably in establishing a diagnosis or they can measure their pulse using one of the various pieces of electronic gadgetry available for domestic use, though beware of fuelling neurosis.
- Most patients with palpitations fear heart disease, and this anxiety exacerbates the symptoms. Ensure this fear is resolved whenever possible.
Red Flags
- Multiple, or multifocal, ventricular ectopics suggest significant ischaemic heart disease – and may herald VT or fibrillation if they follow an infarct.
- Sudden onset of tachycardia in a young adult with breathlessness, dizziness, chest pain and polyuria suggests significant SVT.
- Take very seriously patients with palpitations which are linked with syncope, or which come on after exercise, or who have an existing cardiac history, or who have a family history of sudden death in under 40s. All need referral.
- Remember that digoxin can aggravate as well as resolve some arrhythmias.