Author + information
- Allan D. Struthers, BSc, MD, FRCP, FESC
We thank Auer et al. for their comments on our paper (1). Auer et al. would like to add atrial fibrillation (AF) after cardiac surgery to the list of cardiovascular disorders that are exacerbated by low serum potassium concentrations. Atrial fibrillation is a common and costly complication after cardiac surgery (2). It is significantly more common when serum potassium falls below 3.5 mmol/l, and avoidance of hypokalemia may reduce its incidence (3,4).
The stress of cardiothoracic surgery increases sympathetic tone, and this may predispose one to the development of AF. Interestingly, experimental evidence suggests that sympathetic activity reduces the arrhythmic threshold of hypokalemic dogs (5). This is unsurprising, given the data that link catecholamines with hypokalemia and the favorable effects of beta-blockade on the renin-angiotensin-aldosterone system (6,7).
Therefore, we agree that avoidance of perioperative hypokalemia in patients undergoing cardiothoracic surgery is likely to reduce the incidence of AF in this setting and avoid unnecessary morbidity and costs. A randomized controlled trial of targeted potassium repletion versus standard care is thus warranted.
- American College of Cardiology Foundation
- Mac Donald J.E.,
- Struthers A.D.
- Aranki S.F.,
- Shaw D.P.,
- Adams D.H,
- et al.