ECG Abnormalities & Hypokalemia

Educational Objectives

Summary

Are ECG Abnormalities Important in Patients with Hypokalemia?

Hypokalemia is common in hospitalized patients and often is associated with electrocardiogram (ECG) abnormalities. However, the prevalence and clinical significance of these findings have not been established. For a multicenter cohort study in the Journal of Internal Medicine (https://doi.org/10.1111/joim.13757), researchers in Denmark and Sweden enrolled 80,000 adult patients who presented to emergency departments (EDs); patients with hyperkalemia (defined in this study as potassium level >4.4 mmol/L) were excluded.

The incidence of hypokalemia (potassium level, <3.5 mmol/L) was 9.0%. ECG abnormalities were present in 40% of hypokalemic patients and included t-wave flattening/inversion, ST-segment depression, QTc prolongation, longer QRS duration, and high heart rate. Hypokalemia was associated with excess risk for 7-day mortality, intensive care admission, and ventricular arrhythmia/cardiac arrest. However, after adjustment for potential confounders, only heart rate >100 beats per minute (and not the other ECG abnormalities) was associated with those adverse outcomes, and this association was noted only when potassium levels were <3.0 mmol/L.

ECG findings often accompany hypokalemia, but adverse outcomes likely reflect acute illness and not proarrhythmic effects of hypokalemia. As a long-time telemetry director, I anticipate continuous ECG monitoring will remain a recommendation for patients with severe hypokalemia; however, timely recognition of illness severity and appropriate triage to higher levels of care are the interventions that are most likely to confer benefit.

Neil H. Winawer, MD, SFHM

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Disclosures

Acknowledgements

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 0.00 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 0.00 CE contact hours.

Lecture ID:

JW351115

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.

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