Typical atrial flutter in a man with COPD — case discussion

Presentation

Practice case (not a real patient). A 71-year-old man with hypertension and COPD presents with three days of breathlessness and palpitations. His ECG shows a regular tachycardia at 150 beats per minute with negative saw-tooth waves in the inferior leads and positive waves in V1.^[1] His blood pressure is 132/84 mm Hg and he is alert. He has no implanted device, his QTc interval is normal, and he has never had AF documented.^[1]

Step 1 — What is the rhythm?

ESC 2019 describes counter-clockwise flutter as regular atrial activation from 250–330 b.p.m., with negative saw-tooth waves in the inferior leads and positive waves in V1.^[1] That pattern is typical of common (counter-clockwise) flutter, which ESC 2019 describes as a macro-re-entry circuit around the tricuspid annulus that uses the cavotricuspid isthmus (CTI) as a critical passage at the inferior boundary.^[1] ACC/AHA 2023 notes that AFL is significantly more likely in patients with underlying HF or COPD.^[4]

Step 2 — Rate or rhythm, today

He is haemodynamically stable. ESC 2019 says i.v. beta-blockers or i.v. verapamil or diltiazem should be considered for control of rapid ventricular rate (Class IIa, Level B), but warns that rate control is particularly difficult in flutter.^[1] For conversion to sinus rhythm, ESC 2019 recommends i.v. ibutilide or i.v. or oral (in-hospital) dofetilide, or low-energy (≤100 J biphasic) electrical cardioversion (each Class I, Level B).^[1] The footnotes to the ESC 2019 recommendations for macro-re-entrant atrial arrhythmias say i.v. ibutilide and i.v. and oral dofetilide are contraindicated with a prolonged QTc interval; his QTc is normal.^[1]

ESC 2024 AF Recommendation Table 15 (Recommendations for general concepts in rhythm control) has two rows on anticoagulation around cardioversion that name atrial flutter.^[3] ESC 2024 AF recommends therapeutic oral anticoagulation for at least 3 weeks (adherence to DOACs or INR ≥2.0 for VKAs) before scheduled cardioversion of AF and atrial flutter to prevent procedure-related thromboembolism (Class I, Level B).^[3] If cardioversion is unscheduled, it says initiation of therapeutic anticoagulation should be considered as soon as possible to prevent procedure-related thromboembolism (Class IIa, Level B).^[3] Earlier, ESC 2019 said the anticoagulation recommendations extend to the acute setting for cardioversion when flutter lasts for >48 h; his flutter has lasted three days.^[1] For typical (CTI-dependent) AFL, ACC/AHA 2023 says that after successful cardioversion restoring sinus rhythm, anticoagulation should be continued for at least 4 weeks postprocedure (COR 1, LOE C-LD).^[4]

Step 3 — Long-term anticoagulation

ESC 2024 AF recommends oral anticoagulation in patients with atrial flutter at elevated thromboembolic risk to prevent ischaemic stroke and thromboembolism (Class I, Level B).^[3] For typical (CTI-dependent) AFL, ACC/AHA 2023 recommends anticoagulant therapy according to the same risk profile used for AF (COR 1, LOE B-NR).^[4] ESC 2019 adds that the value of CHA2DS2-VASc in preventing ischaemic stroke in flutter has not been established.^[1]

Step 4 — Ablation

He is cardioverted, and this was his first episode of symptomatic typical flutter. ESC 2019 says catheter ablation should be considered after the first episode of symptomatic typical atrial flutter (Class IIa, Level B).^[1] ACC/AHA 2023 says catheter ablation is useful in symptomatic or clinically significant AFL to improve symptoms (COR 1, LOE A).^[4] ACC/AHA/HRS 2015 explains that a line of ablation between the tricuspid valve annulus and the inferior vena cava can effectively interrupt the circuit.^[2] It says successful ablation is often heralded by interruption of the arrhythmia during the procedure and then EP demonstration of bidirectional block across the ablated tissue.^[2]

ESC 2019 Table 11 gives average rates for CTI-dependent flutter ablation: acute success 95%, recurrence 10%, complications 2% (vascular complications, stroke, myocardial infarction and pericardial effusion) and mortality 0.2%.^[1] In a recent registry, ESC 2019 says, ablation for flutter had a higher mortality than ablation for AF (0.3 vs. 0.05%), but this might have been due to the comorbidities or advanced ages of patients referred for flutter ablation.^[1]

Step 5 — After a successful CTI ablation

He has no known previous AF. ACC/AHA 2023 says that patients with typical AFL after successful CTI ablation who are at high thromboembolic risk, without known previous AF, should receive close follow-up and arrhythmia monitoring to detect silent AF if they are not receiving ongoing anticoagulation (COR 1, LOE B-NR).^[4] ACC/AHA 2023 says that if he is at high risk of developing AF, for example with COPD, it may be reasonable to prescribe long-term anticoagulation if thromboembolic risk assessment suggests high risk (>2% annual risk) for stroke (COR 2b, LOE B-NR).^[4] ESC 2024 AF says the majority (50%–70%) have manifested AF during long-term follow-up in observational studies after AFL ablation, so all patients with AFL need long-term dynamic re-evaluation.^[3]