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ECG in Hypokalemia
ECG findings in Hypokalemia
T wave flattens.
U wave amplitude increases. Prominent U waves may become taller than the preceding T waves. When U wave merges with T wave, it may give the appearance of QT interval prolongation.
ST segment depression may be seen.
Clinical significance
In patients under Digoxin therapy, hypokalemia predisposes to Digoxin-induced arrhythmias.
In patients with Long QT Interval Syndrome (LQTS), hypokalemia predisposes
to Torsades de Pointes.
References (with links to sample ECGs)
Chou's Electrocardiography in Clinical Practice. Adult and Pediatric. 5th ed. Philadelphia. WB Saunders. 2001.
Perm J 2012;16(2):57.
Am J Emerg Med 2014 Mar;32(3):286.e1-4.
Ann Noninvasive Electrocardiol 2013;18(6):593-596.
J La State Med Soc 2015;167(3):140-141.
Ann Noninvasive Electrocardiol 2014;19(4):387-390.
Intern Emerg Med 2012;7(2):193-194.
BMJ Case Rep 2012 Sep 30;2012.
J Travel Med 2012 Mar-Apr;19(2):124-126.
Tidsskr Nor Laegeforen 2011;131(4):358-360.
J Gen Intern Med 2013;28(9):1242-1246.
Arch Intern Med 1989;149(11):2592-2594..
ECG 1a. The ECG above belongs to a 69 years-old woman.
She is receving Cisplatin and 5-Fluorouracil.
Cisplatin is a common cause of hypomagnesemia and hypokalemia.
This ECG was recorded in the Emergency Room, when her serum potassium level was measured as 2.4 mEq/L.
The rhythm is sinus tachycardia. Some leads show ST segment depression.
In this ECG, the ST segment depression is not related with coronary artery disease.
Her coronary angiogram last week showed normal coronary arteries.
Her ECHOcardiography is also normal: no structural hart disease.
Dr. Erkan Kısacik has donated the above ECG to our website.
Click here for a more detailed ECG
ECG 1b. The ECG above belongs to the same patient. It was recorded one day after the ECG 1a.
Despite intravenous potassium infusion, her serum potassium level was still low (2.7 mEq/L).
ST segment depression persists, albeit to a lesser degree.
Dr. Meral Turkmen (Internal Medicine) has donated the above ECG to our website.
Click here for a more detailed ECG
ECG 1c. The ECG above belongs to the same patient. It was recorded two days after the ECG 1a.
Despite additional intravenous potassium infusion, her serum potassium level was still low (2.95 mEq/L).
ST segment depression persists, albeit to a lesser degree
Dr. Meral Turkmen (Internal Medicine) has donated the above ECG to our website.
Click here for a more detailed ECG
T wave flattens.
U wave amplitude increases. Prominent U waves may become taller than the preceding T waves. When U wave merges with T wave, it may give the appearance of QT interval prolongation.
ST segment depression may be seen.
Clinical significance
In patients under Digoxin therapy, hypokalemia predisposes to Digoxin-induced arrhythmias.
In patients with Long QT Interval Syndrome (LQTS), hypokalemia predisposes
to Torsades de Pointes.
References (with links to sample ECGs)
Chou's Electrocardiography in Clinical Practice. Adult and Pediatric. 5th ed. Philadelphia. WB Saunders. 2001.
Perm J 2012;16(2):57.
Am J Emerg Med 2014 Mar;32(3):286.e1-4.
Ann Noninvasive Electrocardiol 2013;18(6):593-596.
J La State Med Soc 2015;167(3):140-141.
Ann Noninvasive Electrocardiol 2014;19(4):387-390.
Intern Emerg Med 2012;7(2):193-194.
BMJ Case Rep 2012 Sep 30;2012.
J Travel Med 2012 Mar-Apr;19(2):124-126.
Tidsskr Nor Laegeforen 2011;131(4):358-360.
J Gen Intern Med 2013;28(9):1242-1246.
Arch Intern Med 1989;149(11):2592-2594..
ECG 1a. The ECG above belongs to a 69 years-old woman.
She is receving Cisplatin and 5-Fluorouracil.
Cisplatin is a common cause of hypomagnesemia and hypokalemia.
This ECG was recorded in the Emergency Room, when her serum potassium level was measured as 2.4 mEq/L.
The rhythm is sinus tachycardia. Some leads show ST segment depression.
In this ECG, the ST segment depression is not related with coronary artery disease.
Her coronary angiogram last week showed normal coronary arteries.
Her ECHOcardiography is also normal: no structural hart disease.
Dr. Erkan Kısacik has donated the above ECG to our website.
Click here for a more detailed ECG
ECG 1b. The ECG above belongs to the same patient. It was recorded one day after the ECG 1a.
Despite intravenous potassium infusion, her serum potassium level was still low (2.7 mEq/L).
ST segment depression persists, albeit to a lesser degree.
Dr. Meral Turkmen (Internal Medicine) has donated the above ECG to our website.
Click here for a more detailed ECG
ECG 1c. The ECG above belongs to the same patient. It was recorded two days after the ECG 1a.
Despite additional intravenous potassium infusion, her serum potassium level was still low (2.95 mEq/L).
ST segment depression persists, albeit to a lesser degree
Dr. Meral Turkmen (Internal Medicine) has donated the above ECG to our website.
Click here for a more detailed ECG