ECG Question-1


What is the most probable diagnosis of ECG given below?


James Heilman, MD, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons

A. Hypercalcemia
B. Hyperkalemia
C. Hypocalcemia
D. Hypokalemia






ECG in hyperkalemia

Mikael Häggström, Public domain, via Wikimedia Commons


Mild to moderate hyperkalemia – prolongation of the PR interval and development of peaked T waves.

Severe hyperkalemia- widening of the QRS complex


What is the mechanism of tenting of the T waves in hyperkalemia?


A. Faster depolarisation

B. Slower repolarisation

C. Faster repolarisation

D. Slower repolarisation



What is the mechanism of smaller P waves and widening of the QRS complex in hyperkalemia?


A. Inactivation of potassium channels

B. Inactivation of sodium channels

C. Inactivation of calcium channels

D. Inactivation of Calcium-activated potassium channels



Peaked T waves in hyperkalemia are best seen in

A. Lead -I

B. Lead- II

C. aVF

D. Precordial leads




What are the classic ECG changes associated with hyperkalemia?


  1. Peaked T wave,
  2. Shortened QT interval,
  3. Lengthened PR interval,
  4. Increased QRS duration,

sine wave – absence of the P wave with the QRS complex seen as a ‘sine wave’.


What are the ECG findings associated with adverse outcomes?


Following ECG findings are associated with increased risk of adverse outcomes –


  1. Bradycardia,
  2. junctional rhythms
  3. QRS widening

Hyperkalemia severity –

Degree of hyperkalaemiaPotassium level (mmol/L)
Mild5.3 – 6.0
Moderate6.0 – 6.9
Severe≥ 7.0
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