AF rate control: beta-blocker vs digoxin choices — structured written assessment

SAQ 1 (10 marks)

Practice scenario. A 71-year-old man presents with breathlessness and AF with a ventricular rate of 132 beats per minute. He is haemodynamically stable with no pre-excitation, and he has no signs of congestion or acute heart failure. Echocardiography shows an LVEF of 30%. He has no history of asthma or bronchospasm.^[4]

1. Which drugs does the 2024 ESC AF guideline recommend for rate control in AF with an LVEF of 40% or less, and with what class and level? (2)^[1]
2. How does the 2026 ESC HF guideline rank beta-blockers and digoxin for rate control in stable HFrEF with AF? Give class and level. (2)^[4]
3. Which drug group should he not receive, and what does each guideline say? (2)^[3][1]
4. State the ESC 2024 initial heart rate target and the ACC/AHA 2023 stricter target, with the conditions for the stricter target. (2)^[1][3]
5. If digoxin is used, what serum level does ACC/AHA 2023 consider reasonable to target, and what does ESC 2024 say to check before starting it? (2)^[3][1]

Model answers — SAQ 1

1. ESC 2024: beta-blockers and/or digoxin are recommended in patients with AF and LVEF of 40% or less (1 mark), to control heart rate and reduce symptoms, Class I, Level B (1 mark).^[1]
2. ESC 2026 HF: beta-blockers are recommended in stable HFrEF and AF as first-line therapy for short- and long-term rate control, Class I, Level C (1 mark).^[4] In stable HFrEF and AF, digoxin should be considered when the ventricular rate remains high despite beta-blockers, or when beta-blockers are contraindicated or not tolerated, to obtain short- and long-term rate control, Class IIa, Level C (1 mark).^[4]
3. Non-dihydropyridine calcium channel blockers (verapamil, diltiazem): ACC/AHA 2023 says that in AF with rapid ventricular response and known moderate or severe LV systolic dysfunction, intravenous nondihydropyridine calcium channel blockers should not be administered (COR 3: Harm, LOE B-NR) (1 mark).^[3] ESC 2024 Table 12 lists verapamil and diltiazem as contraindicated if LVEF is 40% or less (1 mark).^[1]
4. ESC 2024: lenient rate control with a resting heart rate below 110 b.p.m. should be considered as the initial target, with stricter control reserved for continuing AF-related symptoms (Class IIa, Level B) (1 mark).^[1] ACC/AHA 2023: in suspected AF-induced cardiomyopathy or refractory HF symptoms on pharmacological rate control, a stricter strategy of below 80 bpm at rest and below 110 bpm during moderate exercise may be reasonable (COR 2b, LOE B-NR) (1 mark).^[3]
5. ACC/AHA 2023: where measuring serum digoxin levels is indicated, it is reasonable to target levels below 1.2 ng/mL (COR 2a, LOE B-NR) (1 mark).^[3] ESC 2024 Table 12: check renal function before starting digoxin and adapt the dose in CKD patients (1 mark).^[1]

SAQ 2 (10 marks)

Practice scenario. A 78-year-old woman has permanent AF with an LVEF of 58%. Her resting heart rate stays above 110 beats per minute and she remains symptomatic despite bisoprolol and digoxin at the highest doses she tolerates. She is not a candidate for rhythm control and has never been admitted with heart failure.^[1][3]

1. Which strategy does the 2024 ESC AF guideline say should be considered now, and with what class and level? (2)^[1]
2. Give the ACC/AHA 2023 recommendations on the timing of pacemaker implantation and the initial lower rate, with their reasons. (3)^[3]
3. Why was the early post-ablation pacing rate raised? (2)^[3]
4. Which pacing mode does ACC/AHA 2023 advise for her, and what is the alternative it says may be reasonable? (2)^[3]
5. Why is amiodarone not the routine next step in ESC 2024? (1)^[1]

Model answers — SAQ 2

1. Atrioventricular node ablation in combination with pacemaker implantation should be considered in patients unresponsive to, or ineligible for, intensive rate and rhythm control therapy (1 mark), to control heart rate and reduce symptoms, Class IIa, Level B (1 mark).^[1]
2. Pacemaker implantation before the ablation (before or on the same day) is recommended to ensure adequacy of the pacing leads before ablation, COR 1, LOE B-NR (1 mark).^[3] With a persistently rapid ventricular response, initial pacemaker lower rate programming should be 80 to 90 bpm (1 mark), to reduce the risk of sudden death, COR 1, LOE C-LD (1 mark).^[3]
3. ACC/AHA 2023 text: early observational studies showed sudden death after AVNA in 3% to 7% of patients, from VF predominantly due to bradycardia, QT prolongation and heterogeneity of repolarisation (1 mark).^[3] Current protocols specifying higher lower-rate pacing in the early postprocedure period have minimised these deaths, with the lower rate then adjusted over several weeks (1 mark).^[3]
4. ACC/AHA 2023 text: right ventricular pacing is advised in patients with preserved EF undergoing AVNA, because the benefit is less and the risk of complications is higher with biventricular pacing (1 mark).^[3] ACC/AHA 2023: in AF with normal EF undergoing AVNA, conduction system pacing of the His bundle or left bundle area may be reasonable (COR 2b, LOE C-LD) (1 mark).^[3]
5. ESC 2024 reserves amiodarone as a last option when heart rate cannot be controlled even with maximal tolerated combination therapy, or for patients who do not qualify for atrioventricular node ablation and pacing, because of its broad extracardiac adverse effect profile (1 mark).^[1]