Red flag symptoms: Arrhythmias

An overview of the red flags in cases of arrhythmias, suitable primary care investigations and when to refer.

It is important to check for goitre in cases of thyrotoxicosis (Photo: SPL)
It is important to check for goitre in cases of thyrotoxicosis (Photo: SPL)

Red flag symptoms

  • Palpitations associated with chest pain or dyspnoea
  • Pre-syncope
  • Syncope associated with or without palpitations
  • Exertional palpitations
  • Unintentional weight loss
  • Family history of sudden death
  • Recreational drug use
  • Alcohol abuse


Arrhythmias can present in many ways. They may be tachyarrhythmias or bradycardias. Palpitations are not an uncommon presentation of tachyarrhythmias and a focused history is essential to establish the diagnosis.

It is important to know what the patient means by 'palpitations'. The true definition is an awareness of one’s heartbeat. Exploring the patient’s ideas, concerns and expectations will give the clinician clearer insight into why the patient has presented now.

With internet self diagnosis being almost the norm, most patients will have already researched the problem and have some thoughts as to what may be causing it.

Questions to ask

  • How often is the patient experiencing their symptoms?
  • When did they start?
  • How long do they last?
  • Ask the patient to 'tap them out'. This may give some clues as to the regularity of the heart rhythm at the time.
  • Does anything trigger them, such as exercise or caffeine?
  • Is there any associated chest pain, shortness of breath, pre-syncope or syncope?
  • Have they had them before and if so, have they been investigated and diagnosed?
  • Has the patient noticed any unintentional weight loss?
  • Have they noticed any neck lumps?
  • Have there been any other systemic symptoms? Ensure you have the most recent accurate medication record including non-prescribed medications. Certain drugs can cause arrhythmias.
  • Is there a family history of any cardiac abnormalities or sudden death?
  • Take a detailed smoking, alcohol and caffeine history. If relevant it may be necessary to ask about recreational drug use.
  • Commonly, palpitations are a manifestation of underlying anxiety and enquiring about anxiety symptoms may be critical.
  • How is the patient’s quality of life affected?

Despite the focus on palpitations, arrhythmias can also present as shortness of breath, pre- syncopal symptoms, syncopal symptoms or drop attacks.

Bradycardias are more likely to present with presyncopal or syncopal symptoms. If syncope is the main symptom, then a detailed history of the collapse is necessary where applicable, and ideally a third party history of the event.


  • Radial and apical pulse - note the rate and rhythm
  • Blood pressure - manual BP if a pulse irregularity is detected
  • Any eye changes such as exophthalmos
  • If the history suggests, assessing for a goitre may be necessary
  • Are there any heaves, thrills?
  • Is the apex beat displaced?
  • Auscultation. Are there any added sounds?
  • Are there any stigmata of chronic liver disease?

Primary care investigations

Investigations will be dictated by history and examination findings and may include the following.

  • Blood work, to include FBC, UEs, cholesterol, TSH, HbA1c, LFTs, calcium and magnesium. If you suspect a pheochromocytoma then you may wish to check 24-hour urinary catecholamines. If you feel that there may be a physical cause for the patient’s symptoms then some basic blood work may be necessary. The above cardiovascular bloods will be useful if you suspect underlying IHD or there is a strong family history of IHD. LFTs will be useful if you suspect alcohol excess. Serum magnesium and calcium may be useful if you suspect any abnormalities from the patient’s history. Undertake TSH testing if you feel the patient may have a tachycardia secondary to thyrotoxicosis.

  • 12-lead ECG. This will be useful if you suspect an underlying cardiac cause for the symptoms being reported. ECGs can often be helpful for patient reassurance, even if you feel clinically there is unlikely to be a physical cause for the patient’s symptoms.

  • 24-hour ECG. This is useful for recurrent persistent daily symptoms and allows an interpretation of rhythm at the time of symptoms.

  • Plain chest film. This will be useful if you suspect an underlying cardiac abnormality such as heart failure.

  • Echocardiogram. This will be useful for assessing left ventricular systolic function, diastolic function, the structure of the heart valves and pulmonary artery pressures. You may wish to arrange this if you suspect heart failure or detect a murmur on auscultation.

  • Neck ultrasound scan. This will be useful if you detect a goitre on examination.

  • Anxiety and depression score. This allows a grading of patients’ anxiety and depression symptoms, if you suspect anxiety may be a contributing factor to their symptoms.

The investigations you choose will be guided by your history and examination. If you feel there is a more psychological component to the symptoms then you may not wish to initiate any investigations, but you will have to take the patient’s concerns and expectations into consideration when negotiating your plan.

If you make a diagnosis of AF, then it will be essential to risk stratify the patient using the CHA2DS2- VASc risk stratification tool.

When to refer

Refer if there is:

  • Diagnostic uncertainty
  • Confirmed thyrotoxicosis
  • Exertional symptoms
  • Evidence of valvular abnormalities or cardiomyopathy on echo
  • Complete heart block
  • Family history of significant arrhythmia or sudden death

Common causes of palpitations

  • Excess caffeine use
  • Anxiety
  • Alcohol withdrawal

Causes of arrhythmias

  • Iatrogenic causes, for example prescription of tricyclic antidepressants, domperidone
  • Recreational drug use, such as amphetamines
  • Atrial fibrillation
  • Ventricular fibrillation
  • Supraventricular tachycardias
  • Heart block
  • Cardiomyopathy
  • Long QT syndrome
  • Wolff-Parkinson-White syndrome
  • Electrolyte disturbance
  • pheochromocytoma
  • Dr Pipin Singh is a GP in Northumberland, UK

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This is an updated version of an article that was first published in July 2014

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