Atrial fibrillation (AFib) is an irregular and often rapid heart rhythm that can increase the risk of stroke, heart failure, and other complications. In critical care, healthcare providers work to control the heart rate, restore normal rhythm when feasible, and administer treatments to prevent complications like blood clots. The treatment of AFib in this setting typically involves heart rate reducing agents that allow the patient to convert to sinus rhythm. Close monitoring and specialized interventions are integral to managing atrial fibrillation effectively.
Critical Care
Critical care is a specialized branch of medicine dedicated to managing and treating patients with severe, life threatening conditions.
Critical care teams work collaboratively to assess, diagnose, and treat patients in critical conditions, including hemodynamic stabilization, organ support when needed, and treating the underlying cause of the illness. Critical care patients require constant medical attention and monitoring due to life threatening conditions or severe injuries.
Atrial Fibrillation
Postoperative Atrial Fibrillation
Postoperative Atrial Fibrillation
Importance of Blunting of Adrenergic (Sympathetic) Stress in Atrial Fibrillation (AF)
The sympathetic nervous system plays a key role in the neurohormonal control of cardiovascular function. It mediates neuronal and hormonal responses to fear, stress, or exercise by regulating cardiovascular function to meet the increasing demands of the body with a commensurate rapid increase in cardiac output (fight or flight response).
The fight or flight response is initiated by release of norepinephrine, from the cardiac sympathetic nerves, and epinephrine, from the adrenal medulla, which bind to β-adrenergic receptors (β-ARs) on cardiomyocytes and α-adrenergic receptors on vessels. The stimulation of β-ARs triggers a signaling cascade which orchestrates the physiological response of the heart:
- increase in heart rate and conduction velocity,
- increased force of contraction and speed of relaxation.4
Although these responses are necessary to meet physical demands, excessive β-AR stimulation is also associated with electrophysiological abnormalities, leading to sometimes lethal disturbances of the cardiac rhythm, particularly in the setting of underlying cardiovascular disease.4
Adrenergic (sympathetic) stress has the central role in both triggering and sustaining atrial fibrillation and explaining why betablockers remain foundational for both rate control, prevention, and in countering stress-induced arrhythmogenic mechanisms.
Beta-adrenergic stimulation influences cardiac electrophysiology and can lead to disturbances of the heart rhythm and potentially severe arrhythmias, particularly in pathological settings. For this reason, β-blockers are widely utilized clinically as antiarrhythmics.4
Postoperative atrial fibrillation (POAF)
Atrial fibrillation (AF) in the postoperative phase is a manifestation of numerous factors, including surgical stress, anesthetic effects, and underlying cardiovascular conditions. Surgery is frequently associated with blood loss and fluid shift, anemia, hypovolemia or hypervolemia and electrolyte disturbance, which are involved in triggering POAF.6
Postoperative atrial fibrillation (POAF) affects nearly 40% of patients and is associated with longer hospitalization stays, and increased mortality, heart failure, stroke, and healthcare costs.6
Beta-blockers are well-identified drugs to treat or prevent POAF and are recommended by the guidelines.7, 8
References:
- Diaconu CC, Marcu DR, Bratu OG, Stanescu AMA, Gheorghe G, Hlescu AA, Mischianu DLD, Manea M. Beta-blockers in Cardiovascular Therapy: A Review. J Mind Med Sci. 2019; 6(2): 216-223. DOI: 10.22543/7674.62.P216223
- Perrett, M., Gohil, N., Tica, O. et al. Efficacy and safety of intravenous beta-blockers in acute atrial fibrillation and flutter is dependent on beta-1 selectivity: a systematic review and meta-analysis of randomised trials. Clin Res Cardiol 113, 831–841 (2024).
- Meyer M, Lustgarten D. Beta-blockers in atrial fibrillation-trying to make sense of unsettling results. Europace. 2023 Feb 16;25(2):260-262. doi: 10.1093/europace/euad010. PMID: 36748952; PMCID: PMC9935022.
- Grandi E, Ripplinger CM. Antiarrhythmic mechanisms of beta blocker therapy. Pharmacol Res. 2019 Aug;146:104274. doi: 10.1016/j.phrs.2019.104274. Epub 2019 May 14. PMID: 31100336; PMCID: PMC6679787.
- Martínez-Milla Juan, Raposeiras-Roubín Sergio, Pascual-Figal Domingo A., Ibáñez Borja, Role of Beta-blockers in Cardiovascular Disease in 2019, Revista Española de Cardiología (English Edition), ISSN 18855857.
- Shah, S.; Chahil, V.; Battisha, A.; Haq, S.; Kalra, D.K. Postoperative Atrial Fibrillation: A Review. Biomedicines 2024, 12, 1968.
- Muehlschlegel JD, Burrage PS, Ngai JY, Prutkin JM, Huang CC, Xu X, Chae SH, Bollen BA, Piccini JP, Schwann NM, Mahajan A, Ruel M, Body SC, Sellke FW, Mathew J, O'Brien B. Society of Cardiovascular Anesthesiologists/European Association of Cardiothoracic Anaesthetists Practice Advisory for the Management of Perioperative Atrial Fibrillation in Patients Undergoing Cardiac Surgery. Anesth Analg. 2019 Jan;128(1):33-42. doi: 10.1213/ANE.0000000000003865. PMID: 30550473.
- Van Gelder Isabelle C, Michiel Rienstra, Karina V Bunting, Ruben Casado-Arroyo, Valeria Caso, Harry J G M Crijns, Tom J R De Potter, Jeremy Dwight, Luigina Guasti, Thorsten Hanke, Tiny Jaarsma, Maddalena Lettino, Maja-Lisa Løchen, R Thomas Lumbers, Bart Maesen, Inge Mølgaard, Giuseppe M C Rosano, Prashanthan Sanders, Renate B Schnabel, Piotr Suwalski, Emma Svennberg, Juan Tamargo, Otilia Tica, Vassil Traykov, Stylianos Tzeis, Dipak Kotecha, ESC Scientific Document Group , 2024 ESC Guidelines for the management of atrial fibrillation developed in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS): Developed by the task force for the management of atrial fibrillation of the European Society of Cardiology (ESC), with the special contribution of the European Heart Rhythm Association (EHRA) of the ESC. Endorsed by the European Stroke Organisation (ESO), European Heart Journal, Volume 45, Issue 36, 21 September 2024, Pages 3314–3414.
- Stoschitzky K, Koshucharova G, Zweiker R, Maier R, Watzinger N, Fruhwald FM, Klein W. Differing beta-blocking effects of carvedilol and metoprolol. Eur J Heart Fail. 2001 Jun;3(3):343-9. doi: 10.1016/s1388-9842(01)00126-x. PMID: 11378006.