Atrial Fibrillation/Flutter · Clinician Decision GuideAF/Flutter · Clinician Decision Guide

Thank you for
your referral.

To prevent undue delays to your patient’s treatment — and to keep cardiology free to see the most acutely unwell sooner — we’ve brought the common pathways together here. You’ve been sent this link because your question most likely relates to rate control or anticoagulation.

Pick the chapter that matches your question.
Each path will walk you through it and produce a plan you can paste into the notes.

§ I Step-by-step

Rate control

How do I treat the heart rate? Step through the trust AEC protocol — exclusions, agent choice, follow-up — and end with a plan ready to paste.

I ↘

§ II Score & decide

Anticoagulation

Should this patient be anticoagulated? Toggle CHA₂DS₂-VASc and ORBIT criteria — get a eCare note ready to paste alongside the dose.

II ↘

West Suffolk Hospital · Cardiology Department

Step 01 of 03 · Instability check

First — is this patient unstable right now?

If any one of these is present, stop — not for the AEC pathway. A fast rate alone isn’t a red flag, and a feature that eases as the rate comes down is rate-driven — rate control is the treatment, so click No.

Shock — SBP < 90 mmHg, or < 100 with poor perfusion (cold, mottled, confused, lactate up)
Syncope — transient loss of consciousness from the arrhythmia
Acute severe pulmonary oedema — florid: distressed, hypoxic, needs a significant amount of O₂ Mild breathlessness that eases as the rate comes down isn’t this — click No.
Ongoing primary ischaemia — ischaemic chest pain with a STEMI-pattern ECG, or ischaemia that does not settle as the rate settles Chest pain with fast AF (> 110) that eases as you slow the rate is demand ischaemia — rate control is the treatment; click No.
Bradycardia or pauses — HR < 60 bpm, or a symptomatic pause (usually ≥ 6 seconds)

Step 02 of 03 · Before you treat

Send the baseline workup.

Send these — and identify the driver. Reversible precipitants are behind a lot of new AF, and fixing the driver alone often lets the patient self-revert without further rate control.

Thyroid function tests (TFTs)

Thyrotoxicosis is a classic precipitant — easy to miss, easy to send.

Potassium — aim 4.0 – 4.5 mmol/L

Replace if below target. Hypokalaemia worsens arrhythmia and rate control alike.

Magnesium — aim > 1.0 mmol/L

Low magnesium often coexists with low K. Replace if below target.

Sepsis or hypovolaemia — treat the driver

Fluid-resuscitate, treat the source — rate often settles once the driver is fixed, without escalating rate control. Digoxin is preferred here — β-blockers and CCBs further drop BP.

Step 03 of 03 · Current rate-control agent

What is the patient on?

Click whichever agents the patient is currently taking.
Leave all blank if the patient is not on any rate-control medication yet.

The plan · Ready to paste into the notes

Your AF rate-control plan.

Rate-control · Discharge plan

For AF in the AEC pathway

Next · Anticoagulation question?Anticoagulation? →

§ II

Anticoagulation · Stroke vs. bleed

Score them. Then decide.

Toggle the criteria that apply. CHA₂DS₂-VASc gives the annual stroke risk if untreated. ORBIT gives the annual major-bleed risk if anticoagulated.

The clinician at the bedside is best placed to weigh one against the other.

CHA₂DS₂-VASc

Stroke risk

Annual stroke risk if untreated. Lip et al, Chest 2010.

Score

Annual stroke risk

0.2/100

≈ 1 in 500 patient-years

Score 0 (male) or 1 (female, sex-only) · no anticoagulant indicated.

ORBIT

Bleed risk

Annual major-bleed risk on anticoagulation. O'Brien et al, Eur Heart J 2015.

Score

Annual major-bleed risk

2.4/100

Low risk band

A high bleed score is not a reason to withhold anticoagulation — it is a reason to address modifiable risk factors.

03 · Renal function

Creatinine clearance — Cockcroft–Gault

For Apixaban dose adjustment. Standard dose is 5 mg BD; reduce to 2.5 mg BD if CrCl 15 – 29 mL/min, or if 2 of 3 of: age ≥ 80 · weight ≤ 60 kg · creatinine ≥ 133 μmol/L.

Age

yrs

Sex

Weight

Height opt.

Creatinine

μmol/L

Output ↘

—mL/min

Enter values to calculate

How this is calculated

1 · Cockcroft–Gault

CrCl (mL/min) = k × (140 − age) × weight / serum creatinine, where k = 1.23 (male) or 1.04 (female) when creatinine is in μmol/L. With creatinine in mg/dL, the equation uses /72 in the denominator and × 0.85 for female sex — same formula, lab-friendly form.

2 · Ideal body weight (Devine)

Male: 50 + 0.9055 × (height_cm − 152.4). Female: 45.5 + 0.9055 × (height_cm − 152.4). Validated for height ≥ 152.4 cm (5 ft) — below that, IBW can dip below the base figure and is less well established; clinical judgement applies.

Height is optional — leave blank to fall back to the standard Cockcroft–Gault calculation using actual body weight directly (no IBW / AjBW / BMI correction).

3 · Adjusted body weight

AjBW = IBW + 0.4 × (ABW − IBW). Captures the partial metabolic contribution of excess adipose — the muscle and visceral organ mass that grows with sustained obesity does produce creatinine, just at a lower rate than lean tissue.

4 · Weight-selection ladder

C-G assumes lean mass ≈ total mass; this breaks in obesity, where adipose inflates the weight term without contributing to creatinine production. The fix is to swap the weight variable:

ABW < IBW (underweight) → use ABW
IBW ≤ ABW ≤ 1.2 × IBW (normal weight) → use ABW
ABW > 1.2 × IBW (obese — > 20 % over IBW) → use AjBW

Body-builders and other supra-muscular patients: do not enter height. The IBW correction assumes typical body composition — applied to someone with supra-normal lean mass, it underestimates CrCl. Leave height blank so the calculator uses actual body weight directly.

5 · Conditionals applied to the output

CrCl ≥ 30 + 0 or 1 BNF flag → Apixaban 5 mg BD
CrCl ≥ 30 + 2-of-3 BNF flags (age ≥ 80 · ABW ≤ 60 kg · Cr ≥ 133 μmol/L) → Apixaban 2.5 mg BD
CrCl 15–29 → Apixaban 2.5 mg BD (reduced for renal impairment)
CrCl < 15 → discuss with nephrology (off-licence Apixaban vs UFH bridge)
BMI > 40 → flagged for ward pharmacist regardless of CrCl band — C-G unreliable in morbid obesity

The BNF 2-of-3 weight criterion uses ABW (a frailty marker), not the weight chosen for the C-G calculation.

04 · eCare note

Stroke prophylaxis · eCare note

Paste straight into the notes

Updates live as you toggle input above

Bottom line

Scores inform. They don't decide. The clinician who knows this patient — their frailty, their falls, their priorities — is best placed to weigh stroke risk against bleed risk and make the call.