Electrolyte imbalances with special focus on hypokalemia: cellular pathophysiology and clinical manifestations: From basic science to clinical and epidemiological studies

In this thesis, we found that electrolyte imbalances (EIs) are common in unselected adult patients visiting the emergency department (ED), and that they are associated with longer length of stay in the hospital, readmissions, and mortality. Consequently, knowledge of EIs is crucial for optimal diagnosis and treatment of these patients. Hypokalemia is associated with an increased risk of atrial fibrillation (AF). Our results indicate that infusion of KCl with a subsequent rapid increase in plasma-potassium may increase the likelihood of conversion of recent-onset AF to sinus rhythm. Thus, KCl may be as effective as other anti-arrhythmic drugs without their risk or contraindications and without the burden of additional resources related to direct-current cardioversion therapy. Lastly, we investigated the effect of hypokalemia in rat cardiomyocytes and found that hypokalemia increases the susceptibility to arrhythmia by distinct mechanisms in atrial and ventricular cardiomyocytes. We showed that a subgroup of atrial cardiomyocytes exhibits a distinct potassium current and that the blockade of this current may be particularly beneficial in patients with AF who are hypokalemic