Arrhythmias - red flag symptoms

Dr Pipin Singh provides an overview of red flag symptoms in patients with arrhythmias.

(Photo: Witthaya Prasongsin/Getty Images)
(Photo: Witthaya Prasongsin/Getty Images)

Red flag symptoms of arrhythmias

  • Persistent arrhythmias, increasing in frequency
  • Palpitations associated with chest pain or dyspnoea
  • Pre-syncope
  • Syncope with or without palpitations
  • Exertional palpitations
  • Unintentional weight loss
  • Family history of sudden death
  • Recreational drug use
  • Alcohol misuse

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. Commonly, palpitations are a manifestation of underlying anxiety and enquiring about anxiety symptoms may be critical.

Take a detailed smoking, alcohol and caffeine history. Specifically, ask about consumption of energy drinks. If relevant, ask about recreational drug use.

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 symptoms 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?
  • 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?
  • Is there a family history of any cardiac abnormalities or sudden death?
  • How is the patient’s quality of life affected?
  • What is the patient’s work and driving status (if relevant)? Depending on the symptoms, patients may have to temporarily stop work and/or driving until a diagnosis and treatment plan has been established.

Medications and hyperglycaemia

Ensure you have the most recent accurate medication record, including non-prescribed medications. Certain drugs can cause arrhythmias, for example, overuse of salbutamol can cause palpitations or certain combinations of drugs may predispose to long QT syndrome.

Note that hypoglycaemia (if the patient has diabetes and is taking a sulfonylurea and/or insulin) can also present with palpitations, so a blood glucose test at the time of symptoms may be helpful.


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

In the elderly, arrhythmias can present as recurrent falls. They can also be asymptomatic and detected on chronic disease review or the patient may pick up an abnormality on some home kit (there is ever increasing use of home devices such as apps and blood pressure machines).

Bradycardias are more likely to present with pre-syncopal or syncopal symptoms. If syncope is the main symptom then a detailed history of the collapse is necessary, ideally with a third-party history of the event, or even a video if possible.

Remote assessment

If you are assessing the patient via telephone, consider:

  • Can you ask the patient to check their own pulse? If they are able to, what is the rate?
  • Do they have their own blood pressure machine? If so, can they check their blood pressure for you?
  • Do they sound breathless on the phone?
  • If you are assessing the patient via video, consider:
  • How do they appear? Are they breathless?
  • Are there any signs of a goitre?
  • Can you ask them to check their own pulse and blood pressure?

Face-to-face examination

If you are examining a patient face-to-face, using appropriate personal protective equipment, you should:

  • Take radial and apical pulse - note the rate and rhythm
  • Take blood pressure - manual blood pressure measurement if a pulse irregularity is detected
  • Check for any eye changes such as exophthalmos
  • Check whether there is any tremor
  • If the history suggests, assess for a goitre
  • Note whether there are any heaves or thrills
  • Consider whether the apex beat is displaced
  • Auscultate for any added heart sounds
  • Check for any stigmata of chronic liver disease

Investigations: blood and urine tests

Primary care investigations will be dictated by history and examination findings.

If you feel that there may be a physical cause for the patient’s symptoms - for example, if you suspect underlying IHD or there is a strong family history of IHD - then some basic blood work will be necessary, including:

  • FBC
  • UEs
  • cholesterol
  • TSH (if you think the patient may have a tachycardia secondary to thyrotoxicosis)
  • HbA1c
  • LFTs (if you suspect alcohol excess)
  • serum calcium and magnesium (if you suspect any abnormalities from the patient’s history)
  • NtBNP (if you suspect left ventricular systolic dysfunction; note that this would not be suitable in patients with AF).

If you suspect a pheochromocytoma then you may wish to check 24-hour urinary catecholamines.
Examinations: ECG, chest X-ray and echocardiogram

12-lead ECG 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.

24-72 hour ECG is useful for recurrent, persistent daily symptoms and allows an interpretation of rhythm at the time of symptoms, but availability of this test in primary care will depend on locality.

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

Echocardiogram 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 will be useful if you detect a goitre on examination.

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

Investigations: psychological factors

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

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.

When to refer

Refer if there is:

  • Diagnostic uncertainty
  • Confirmed thyrotoxicosis
  • Exertional symptoms
  • Evidence of valvular abnormalities or cardiomyopathy on echocardiogram
  • Complete heart block
  • Family history of significant arrhythmia or sudden death
  • Recurrent falls (in elderly patients)
  • Syncope with no obvious cause established
  • Significant electrolyte disturbance, for example, hyperkalaemia
  • Suspected pheochromocytoma
  • AF that may be suitable for ablation

Possible causes

Common causes of palpitations

  • Excess caffeine use
  • Generalised anxiety disorder
  • Alcohol withdrawal
  • Drug combinations, for example SSRIs with tricyclic antidepressants (TCAs)

Causes of arrhythmias

  • Iatrogenic causes, for example prescription of TCAs, domperidone
  • Recreational drug use, such as amphetamines
  • AF
  • Ventricular fibrillation
  • Supraventricular tachycardias
  • Heart block
  • Cardiomyopathy
  • Long QT syndrome
  • Wolff-Parkinson-White syndrome
  • Electrolyte disturbance
  • Pheochromocytoma
  • Thyrotoxicosis causing AF
  • Significant anaemia
  • Infection leading to AF, for example pneumonia
  • Hypoglycaemia in patients with diabetes who are taking drugs predisposing them to hypoglycaemia

Reviewed and updated by Dr Pipin Singh, a GP in Northumberland, on 14 October 2020.

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

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