GP Life is a study guide written by a GP Registrar in NSW. As such, the focus is largely on NSW and central Australian communities for the purpose of studying for the ACRRM CGT StAMPS exam. The below is not to be taken as medical advice or relied upon for the diagnosis or management of real-life patients.
Diagnosis
Feel a radial pulse regularly in patients over 65. If irregular do an ECG.
AF is also commonly diagnosed on symptomatic presentations when doing a Holter etc.
Be sure to consider and treat precipitants of new AF including sepsis, electrolyte derangement, hyperthyroidism, and excessive alcohol use.
Classification
- Paroxysmal: episodes lasting <1 week.
- Persistent: episodes lasting >1 week.
- Long-standing persistent: episodes >12 months.
Note that the non-valvular/valvular distinction “should be abandoned” according to the 2020 ESC guidelines.
Can this patient be managed as an outpatient?
Most cases can, however if the patient is hypotensive, has a ventricular rate of >110, has signs of heart failure, has a history of pre/syncope, or chest pain or ischaemic changes on ECG, they need to be initially managed in the ED.
Initial workup
- Bloods: FBC, EUC, CMP, TSH.
- Echocardiogram (mitral stenosis).
- Holter (to look for pauses and to distinguish paroxysmal from persistent AF).
- Sleep study for patients who are symptomatic.
Management
Treatment of the precipitant in acute presentations is obviously important but other than hyperthyroidism would usually necessitate inpatient treatment.
Rate vs Rhythm Control
Rhythm control has the main advantage of reducing symptoms. Back in the 90s, rhythm control was preferred as it was thought to benefit mortality. The AFFIRM trial in 2002 found no mortality benefit but did show an increased rate of hospitalisation for patients on rhythm control. This is now comping under question, with a 2020 study showing a cohort of recently-diagnosed AF patients have a better composite cardiovascular outcome on rhythm control.
Rhythm control is more likely to be successful in patients who are active, have shorter duration of AF episodes, and do not have significant underlying structural heart disease.
Rhythm control strategies include flecainide, sotalol, and amiodarone, all of which have significant contraindications and side effects. Rate control strategies would include metoprolol (or bisoprolol for people with heart failure), a non-dihydropyridine CCB, or digoxin. Catheter ablation can also be used for AF but only after a patient is non-responsive to at least 1 rhythm control drug.
Catheter ablation often requires multiple procedures. It is 90% successful after the second.
Sources really differ on which is the “superior” option. A 2019 AJGP article says cardiologists and patients tend to prefer rhythm control. I must say this is not consistent with my experience. The relevant LITFL entry from January 2023 argues for rate control and anticoagulation but of course this is an ED perspective. The last time Curbsiders covered this they presented a sensible strategy which is most aligned with my practice:
- Do the above initial workup (plus the Curbsiders’ expert guest actually recommends a wearable for event monitoring; not sure I’m quite on board just yet but as noted in the ESC guidelines the sensitivity is quite good, 97-99%; Sp 83-94%).
- Commence a beta blocker (say bisoprolol 2.5 mg). Target 80 bpm at rest.
- Start the patient on anticoagulation in case they require cardioversion. This is noted as expert opinion by the Curbsiders, however this is in my experience an opinion which is particularly widespread.
- Follow-up in 1 week. If still in AF, refer to cardio with a view to cardioversion after appropriate anticoagulant cover +/- TOE.
Patients need 3 weeks of anticoagulant cover prior to electrical or pharmacological cardioversion. They then need coverage for 4 weeks afterwards.
Anticoagulation
Stroke is the most clinically significant complication of AF. The most widely-used score for stroke risk is CHA2DS2-VA.
- Congestive heart failure
- Hypertension
- Age >75 (2 points; 1 point for >65)
- Diabetes
- Stroke history (2 points; 1 for TIA).
- Vascular disease
If the score is 0, don’t use anticoagulation. If the score is 2 or higher, do use anticoagulation. If the score is 1, think about it.
Note the actual amount of time spent in AF (“burden”) is not actually part of the risk score, but probably does increase stroke risk.
The other factor pushing towards anticoagulation is, as above, whether or not you are going to try to cardiovert them.
A DOAC should be used for anyone except those with a mechanical heart valve or mod-severe mitral stenosis, who should be on warfarin.
Obviously anticoagulation increases bleeding risk. The HAS-BLED score was developed to help you figure out who is at higher risk of bleeding. Note that a couple of these (stroke history, age >65) are also risk factors in CHA2DS2-VA so the actual clinical utility of this to me has always been uncertain vs a vibes-based analysis. At a minimum, the things to consider are renal disease, liver disease, alcohol use, and uncontrolled hypertension.
Lifestyle Modification
It’s also important to consider how we are going to keep these patients well! We need to make sure their comorbidities, particularly those predisposing to CV risk (hypertension, diabetes), are well-managed. Obesity and OSA are independent risk factors for AF and should be managed as much as possible. Smoking cessation and alcohol reduction/cessation should also be discussed.
Patients may be fearful of exercise due to the presence of arrhythmia; on the contrary, within guidelines, exercise should be encouraged.
Practice Question
Jim is a 66-year-old retired accountant. He presents to your clinic with a history of palpitations and lightheadedness. Jim has a past history of hypertension on candesartan 32 mg + HCT 12.5 mg. He is otherwise fit and well and cycles around 100 km a week.
BP 122/68 // HR 88 bpm (irregular) // T 35.6°C // SpO2 99% // RR 14 brpm
- What is your approach to the consult today?
- Jim’s ECG is shown below. Please interpret this ECG and discuss your next steps.
3. Jim is commenced on metoprolol 25 mg BD and apixaban 5 mg BD. While you are discussing lifestyle measures, Jim becomes teary and tells you his drinking is “out of control.” He is drinking a cask of wine a night since his wife left him 8 months ago. How would you approach this problem?
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