Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

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

Kildegaard Jensen, Helene ; Brabrand, Mikkel ; Lundager Forberg, Jakob LU ; Platonov, Pyotr LU ; Lassen, Annmarie Touborg and Ekelund, Ulf LU orcid (2023) In Journal of Internal Medicine
Abstract
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... (More)
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. (Less)
Please use this url to cite or link to this publication:
author
; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
epub
subject
in
Journal of Internal Medicine
publisher
Wiley-Blackwell
external identifiers
  • pmid:38098171
  • scopus:85179726520
ISSN
1365-2796
DOI
10.1111/joim.13757
language
English
LU publication?
yes
id
81eccb4f-1c56-4e23-8add-1803155264df
date added to LUP
2024-01-02 12:14:16
date last changed
2024-01-10 10:12:57
@article{81eccb4f-1c56-4e23-8add-1803155264df,
  abstract     = {{Abstract<br/>Background<br/>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.<br/><br/>Methods<br/>The study was a multicentered cohort study, including all ault patients with an ECG and potassium level &lt;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.<br/><br/>Results<br/>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+] &lt;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 &gt;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 &gt;100 bpm predicted both mortality and ICU admission among patients with [K+] &lt;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.<br/><br/>Conclusions<br/>ECG abnormalities were common in hypokalemic patients, but they are poor prognostic markers for short-term adverse events under the current standard of care.}},
  author       = {{Kildegaard Jensen, Helene and Brabrand, Mikkel and Lundager Forberg, Jakob and Platonov, Pyotr and Lassen, Annmarie Touborg and Ekelund, Ulf}},
  issn         = {{1365-2796}},
  language     = {{eng}},
  month        = {{12}},
  publisher    = {{Wiley-Blackwell}},
  series       = {{Journal of Internal Medicine}},
  title        = {{Prevalence and prognostic value of electrocardiographic abnormalities in hypokalemia: A multicenter cohort study}},
  url          = {{http://dx.doi.org/10.1111/joim.13757}},
  doi          = {{10.1111/joim.13757}},
  year         = {{2023}},
}