New Onset Atrial Fibrillation

You are the cardiothoracic CT1 and are asked to see a 60year old gentleman who underwent recent CABG. He is tachycardic at 120bpm and complaining of shortness of breath and one of the nurses asks for you to review the patient.

Example answer introduction

In this scenario, in a patient who is tachycardic following cardiac surgery, I would be concerned of possible arrhythmia such as atrial fibrillation. I would assess this patient using an A-E approach according to the CCRISP algorithm followed by a focused history and examination. I would arrange further investigations to confirm my diagnosis depending on my clinical suspicions and escalate to the cardiothoracic registrar.

Initial Assessment and Simultaneous Resuscitation


On arrival, manage the patient using an A to E approach according to the CCISP Algorithm:

A - Patent, no stridor or stertor

B - Check oxygen saturations, respiratory rate, listen to chest, assess work of breathing, breathing depth - if concerns give high flow oxygen 

C – Pulse, Blood pressure, capillary refill time, mucus membranes, skin turgor, fluid input/output 

  • Bloods - FBC, U&E, LFTs, calcium, magnesium, TFTs, blood cultures need to be done if septic (sepsis can cause atrial fibrillation. 

  • IV access - large bore 

  • IV fluid resuscitation with crystalloids if hypotensive

  • Catheterise patient to assess urine output urine output >0.5L/kg/hr

D – Glasgow Coma Score, temperature, pupillary response, blood glucose

E – Expose patient and look for rashes, systemic signs of shock. 

During this acute phase state remember to provide constant reassessment

Focused history​

  • Allergies

  • Medications - anticoagulants, antiplatelets

  • Past medical history – previous bowel surgery

  • Last meal

  • Events leading up to this point – 

    • Operation and anaesthetic notes- did the patient ave intraoperative AF?

    • Indication for surgery 


  • Cardiac examination

  • Assess for any evidence of compromise e.g. signs of heart failure, shock, syncope, myocardial ischaemia

  • Look for possible precipitant e.g. hyperthyroidism, pneumonia, sepsis


  • Blood tests– FBC, U&E, Calcium, Magnesium, LFTs, clotting, thyroid function tests, troponin, blood cultures if septic

  • 12 lead ECG and cardiac monitoring

  • CXR

Example questions to progress the station

Q1 What are the common causes of atrial fibrillation?

Cardiac causes:

  • Ischaemic heart disease

  • Hypertension

  • Sick sinus syndrome

  • Pre-excitation syndrome e.g. Wolf-Parkinson- White

  • Cardiomyopathy

  • Pericardial disease


Non- cardiac causes:

  • Acute infection especially pneumonia

  • Electrolyte disruption

  • Lung carcinoma

  • Other intrathroacic pathology

  • hyperthyroidism


Q2 The ECG you take demonstrates evidence of new atrial fibrillation at a rate of 128bpm what would be your            initial steps to manage this patient?

Initial management

  • Treat any reversible causes e.g. electrolyte imbalance, infection

  • Contact cardiothoracic registrar and also medical/cardiology registrar

    • The patient will need rate control – initially with pharmacological measures e.g. beta-blockers, diltiazem

    • If unstable may even require cardioversion

  • If evidence of MI discuss with medical registrar to discuss initiation of acute coronary syndrome (ACS) treatment and consideration of transfer to coronary care unit for monitoring

  • Asess thromboembolic risk and consider prophylaxis

  • Continually assess patient to ensure rate stabilises and the patient is not unstable

  • Document

  • Inform patient and family


Consider discussion with:

  • ​General Surgical registrar

  • Medical registrar/Cardiology registrar on call

    • For pharmacological advice

    • If refractory, the patient may even need cardioversion either electrical or pharmacological


Atrial fibrillation is the most common post-operative arrhythmia and in CABG can occur in up to 40% cases. 

Fast atrial fibrillation can result in haemodynamic instability and may require pharmacological intervention. Refractory cases may even require cardioversion.

Overall, the presence of the AF after surgery not only results in prolongation of hospital stay but may also increase risk of heart failure, stroke, or thromboembolism, and greater hospital costs. The incidence of postoperative AF depends on many risk factors apart from the type of procedure, such as age and the patient’s preoperative physiology and electrolyte balance 

Useful Resources

Advanced life support – tachycardia algorithm

NICE: Atrial Fibrillation Management

Note: You may need an institutional or personal access to view some of these resources. Your medical education department or local NHS library may be able to help with access.
core surgical training interview

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