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Multicenter Study
. 2024 Apr;295(4):544-556.
doi: 10.1111/joim.13757. Epub 2023 Dec 14.

Prevalence and prognostic value of electrocardiographic abnormalities in hypokalemia: A multicenter cohort study

Helene Kildegaard  1 , Mikkel Brabrand  2   3 , Jakob Lundager Forberg  4   5 , Pyotr Platonov  5   6 , Annmarie Touborg Lassen  2   3 , Ulf Ekelund  5   7
Affiliations
Multicenter Study

Prevalence and prognostic value of electrocardiographic abnormalities in hypokalemia: A multicenter cohort study

Helene Kildegaard et al. J Intern Med. 2024 Apr.

Abstract

Background: Hypokalemia is common in hospitalized patients and associated with ECG abnormalities. The prevalence and prognostic value of ECG abnormalities in hypokalemic patients are, however, not well established.

Methods: The study was a multicentered cohort study, including all ault patients with an ECG and potassium level <4.4 mmol/L recorded at arrival to four emergency departments in Denmark and Sweden. Using computerized measurements from ECGs, we investigated the relationship between potassium levels and heart rate, QRS duration, corrected QT (QTc) interval, ST-segment depressions, T-wave flattening, and T-wave inversion using cubic splines. Within strata of potassium levels, we further estimated the hazard ratio (HR) for 7-day mortality, admission to the intensive care unit (ICU), and diagnosis of ventricular arrhythmia or cardiac arrest, comparing patients with and without specific ECG abnormalities matched 1:2 on propensity scores.

Results: Among 79,599 included patients, decreasing potassium levels were associated with a concentration-dependent increase in all investigated ECG variables. ECG abnormalities were present in 40% of hypokalemic patients ([K+ ] <3.5 mmol/L), with T-wave flattening, ST-segment depression, and QTc prolongation occurring in 27%, 16%, and 14%. In patients with mild hypokalemia ([K+ ] 3.0-3.4 mmol/L), a heart rate >100 bpm, ST-depressions, and T-wave inversion were associated with increased HRs for 7-day mortality and ICU admission, whereas only a heart rate >100 bpm predicted both mortality and ICU admission among patients with [K+ ] <3.0 mmol/L. HR estimates were, however, similar to those in eukalemic patients. The low number of events with ventricular arrhythmia limited evaluation for this outcome.

Conclusions: ECG abnormalities were common in hypokalemic patients, but they are poor prognostic markers for short-term adverse events under the current standard of care.

Keywords: ICU; cardiac arrest; electrocardiography; hypokalemia; mortality; potassium; prognosis; ventricular arrhythmias.

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References

    1. Jensen HK, Brabrand M, Vinholt PJ, Hallas J, Lassen AT. Hypokalemia in acute medical patients: risk factors and prognosis. Am J Med. 2015;128(1):60-67.e1.
    1. Paice BJ, Paterson KR, Onyanga-Omara F, Donnelly T, Gray JM, Lawson DH. Record linkage study of hypokalaemia in hospitalized patients. Postgrad Med J. 1986;62(725):187-191.
    1. Conway R, Creagh D, Byrne DG, O'Riordan D, Silke B. Serum potassium levels as an outcome determinant in acute medical admissions. Clin Med Lond Engl. 2015;15(3):239-243.
    1. Gennari FJ. Hypokalemia. N Engl J Med. 1998;339(7):451-458.
    1. Aldahl M, Jensen ASC, Davidsen L, Eriksen MA, Møller Hansen S, Nielsen BJ, et al. Associations of serum potassium levels with mortality in chronic heart failure patients. Eur Heart J. 2017;38(38):2890-2896.

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