Hypocalcaemia

Calcium disorders mainly affect the QT interval on the ECG.

Hypocalcaemia (low serum calcium) causes a long QT interval. If you look closely at the long QT of hypocalcaemia you will notice that it lengthens the ST segment without greatly affecting the T wave.

It is interesting to note that because low calcium levels seem to affect the ST segment without affecting the T waves, very low calcium levels seem to have a lower risk of developing dysrhythmias than other causes of a prolonged QT interval.

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In the ECGquest archives, this ECG has been tagged with: - Muscle pains 12-Lead Long QT Peaked T waves Hyperkalemia Hypocalcaemia Dr Smith's ECG Blog CC BY-NC
Patient with Dyspnea. You are handed a triage ECG interpreted as “normal” by the computer. ‘Baseline’ ECG 31311

This ECG is from a dialysis patient who presented with diaphoresis and muscle cramps.

This ECG shows subtly peaked T waves and long ST segments causing a long QT interval. The cause was hyperkalemia (6.6) and hypocalcemia.

In the ECGquest archives, this ECG has been tagged with: - Vomiting Weakness 12-Lead Long QT Hypocalcaemia Dr Smith's ECG Blog CC BY-NC
A Pathognomonic ECG. What is it? 30088

This ECG is from a patient of unknown age who presented with weakness, decreased urine output and vomiting.

This ECG shows long QT due to a long ST segment without altering the T wave, caused by hypocalcemia.

In the ECGquest archives, this ECG has been tagged with: - 12-Lead Long PR Long QT Wide QRS Hyperkalemia Hypocalcaemia ECG of the Week CC-BY-NC-SA
ECG of the Week – 31st December 2018 – Interpretation 29024

This ECG is from a woman in her 30s who presented with cramping following thyroid surgery.

This ECG shows prolonged QT due to long ST segment, no U waves, but also a prolonged QRS and PR. There was hypocalcemia, mild hyperkalemia and hypermagnesemia.

In the ECGquest archives, this ECG has been tagged with: - Loss of consciousness 12-Lead Long QT Peaked T waves Hyperkalemia Hypocalcaemia Dr Smith's ECG Blog CC BY-NC
Found comatose with prehospital ECG showing “bigeminal PVCs” and “Tachycardia at a rate of 156” 28775

This ECG is from a patient with a history of diabetes who was found with a GCS of 4.

This ECG shows sinus rhythm with peaked T waves that were so narrow they were mistaken for separate QRS complexes. The cause was hyperkalemia due to acute renal failure.

In the ECGquest archives, this ECG has been tagged with: - Diarrhoea 12-Lead Standard Calibration Inferior ST depression Lateral ST depression Long QT Narrow QRS Normal Axis Normal PR Normal rate Regular Normal Sinus Rhythm Hypocalcaemia Hypomagnesaemia ECG of the Week CC-BY-NC-SA
ECG of the Week – 29th January 2018 – Interpretation 17731

This ECG is from a man in his 60s presented with several weeks of diarrhoeal illness following overseas travel. He had a past medical history of ischaemic cardiomyopathy. His medications included warfarin, a beta-blocker, a PPI, an ACE inhibitor and diuretics.

In the ECGquest archives, this ECG has been tagged with: - Rhythm Strip Long QT Hypocalcaemia LITFL CC-BY-NC-SA
DiGeorge’s syndrome Ca 1.32 650

This ECG is from a patient with DiGeorge's syndrome.

In the ECGquest archives, this ECG has been tagged with: - 12-Lead Long QT Normal rate Hypocalcaemia LITFL CC-BY-NC-SA
Hypoparathyroidism Ca 1.4 648

This ECG is from a patient who had undergone thyroidectomy.

In the ECGquest archives, this ECG has been tagged with: - Chronic kidney disease Weakness 12-Lead Flat ST segment Long QT Normal Axis Peaked T waves Hyperkalemia Hypocalcaemia ECG Guru CC-BY-NC-SA
Electrolyte Effects 968

This ECG is from a woman in her 40s who presented with weakness and hyperglycemia on a background of diabetes mellitus.

In the ECGquest archives, this ECG has been tagged with: - 12-Lead Long QT Hypocalcaemia Dr Smith's ECG Blog CC BY-NC
A Pathognomonic ECG 10157

This ECG is from an elderly woman who presented with altered mental status.

This ECG shows a very prolonged QT interval due to a long ST segment, caused by hypocalcemia.