Hrev_master [page 28] [Emergency Care Journal 2025; 21:13679] Emergency Care Journal 2025 volume 21:13679 Palpitations in a Fontan patient: what now? Catello Sepe, Cristiano Perani Emergency Department Unit, ASST Spedali Civili, Brescia, Italy Question Considering the patient’s medical history, which medication is the most appropriate choice? 1. Adenosine. 2. Non-dihydropyridine calcium channel blockers (Class IV: diltiazem or verapamil). 3. Beta-blockers (Class II: metoprolol or esmolol). 4. Electric cardioversion. Answer Managing PSVT can be particularly challenging due to the sig- nificant variability in the condition and the evolving nature of adult CHD. There is currently no randomized controlled trial data avail- able to guide pharmacological management. Atrial arrhythmias are a well-recognized and common complication associated with Fontan palliation, occurring in approximately 15-60% of patients, with the incidence increasing with age.2 These arrhythmias may result from factors such as suture lines, injury to the sinus node, compromised arterial supply, and atrial remodeling.3 Recommendations are primarily based on expert consensus and retrospective studies, as well as a recent position paper from the European Heart Rhythm Association (EHRA) regarding the diag- nosis and treatment of arrhythmias in patients with CHD. While the general approach aligns with standard guidelines, it necessi- tates specific considerations for this unique patient population. Adenosine is the treatment of choice for the acute management of atrioventricular nodal-dependent mechanisms. However, its use is not recommended in patients with reduced ejection fraction who rely on high heart rates to preserve cardiac output, and caution is warranted in cases of sinus node dysfunction.4,5 Negative inotropic agents such as beta-blockers and non-dihydropyridine calcium channel blockers can lead to cardiovascular collapse in patients with compromised ventricular function. Therefore, an echocardio- A 32-year-old male presented to our emergency department with palpitations. His blood pressure was 95/65 mmHg, heart rate 150 beats per minute, oxygen saturation 87% on room air, and body temperature 36°C. The electrocardiogram (EKG) showed paroxys- mal supraventricular tachycardia (PSVT). He reported a history of heart surgery – Fontan procedure1 – during childhood for a com- plex congenital heart disease (CHD) characterized by a single atri- um, a single ventricle, and a single atrioventricular valve. A focused cardiac ultrasound confirmed a single atrium, a single ven- tricle, no pericardial effusion, and an estimated ejection fraction of 50% (Videos 1 and 2). His current medication regimen included sotalol 80 mg, losartan 12.5 mg, dapagliflozin 10 mg, furosemide 25 mg, and warfarin. Correspondence: Catello Sepe, M.D., Emergency Department Unit, ASST Spedali Civili, Brescia, Italy. E-mail: catello.sepe@asst-spedalicivili.it Key words: paroxysmal supraventricular tachycardia; congenital heart disease; Fontan procedure; cardiac procedure. Contributions: all the authors approved the final version and equally contributed to the work. Conflict of interest: the authors declare no potential conflict of interest. Ethics approval and consent to participate: as this is a descriptive case report and data was collected without patient identifiers, ethics approval is not required under our hospital’s Institutional Review Board guidelines. Informed consent: the patient provided informed consent for access to medical records at the time of admission. Availability of data and materials: all data underlying the findings are fully available upon reasonable request to the corresponding author. Received: 29 January 2025. Accepted: 4 February 2025. Early view: 7 March 2025. This work is licensed under a Creative Commons Attribution 4.0 License (by-nc 4.0). ©Copyright: the Author(s), 2025 Licensee PAGEPress, Italy Emergency Care Journal 2025; 21:13679 doi:10.4081/ecj.2025.13679 Publisher's note: all claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher. graphic assessment is crucial prior to administering these medica- tions, which should be administered via slow infusion rather than bolus injection to minimize risks.5 All patients with hemodynami- cally unstable supraventricular tachycardia require urgent electri- cal cardioversion.6 Our patient was initially treated unsuccessfully with modified Valsalva maneuvers. Subsequently, diltiazem at a dose of 30 mg was infused over approximately 10 minutes, result- ing in the restoration of sinus rhythm (66 bpm), blood pressure of 100/60 mmHg, and SaO2 of 93%. The EKG showed a sinus rhythm with T-wave inversion, consistent with previous EKG findings (Figure 1). After a few hours, the patient was discharged without any symptoms and referred to his cardiology center for follow-up. References 1. Fontan F, Baudet E. Surgical repair of tricuspid atresia. Thorax 197;26:240–8. 2. Laubham M, Blais B, Kamp AN. Atrial Arrhythmias in Adults with Fontan Palliation. Cardiol Ther 2023;12:473–87. 3. Dib N, Chaix MA, Samuel M, et al. Cardiovascular Outcomes in Fontan Patients With Right vs Left Univentricular Morphology: A Multicenter Study. JACC Adv 2024;3:100871. 4. Mariucci E, Bronzetti G, Donti A. Tachiaritmie nel paziente con cardiopatia congenita: diagnosi, presentazione clinica e trattamento. G Ital Cardiol 2023;24. 5. Hernández-Madrid A, Paul T, Abrams D, et al. ESC Scientific Document Group. Arrhythmias in congenital heart disease: a position paper of the European Heart Rhythm Association (EHRA), Association for European Paediatric and Congenital Cardiology (AEPC), and the European Society of Cardiology (ESC) Working Group on Grown-up Congenital heart disease, endorsed by HRS, PACES, APHRS, and SOLAECE. Europace 2018;20:1719-53. 6. Wasmer K, Eckardt L, Baumgartner H, Köbe J. Therapy of supraventricular and ventricular arrhythmias in adults with congenital heart disease—narrative review. Cardiovasc Diagn Ther 2021;11:550–62. Images in emergency [Emergency Care Journal 2025; 21:13679] [page 29] Figure 1. EKG showing sinus rhythm. Online Supplementary Materials: Video 1. Fontan heart. Video 2. Apical 2-chamber Fontan.