ECG: Hyperkalemia

1. JAGDISH. K
PROF. DR. A. GOWRISHANKAR’S UNIT
ECG OF THE WEEK

2. 30 yr old male was brought with the chief complaints
of fever, altered sensorium for the past 3 days.
Patient was apparently alright 3 days ago.
Known type 1 diabetic on Insulin.

3. Examination
Patient was febrile, dyspneic, tachypneic, disoriented
Pulse : 110/min
BP : 100/60 mm of hg
RR : 38/min
CNS :
disorientation +
Neck rigidity +
Other systems : normal

4. ECG

5. ECG changes in electrolyte imbalance is not very
predictable.
Change depends on the inter individual variation &
on the other electrolytes too.

6. However certain ECG features often develop in
conjunction with increased / decreased potassium
concentration so that ECG may be frequently utilised
for electrolyte disturbances particularly if the
interpreter is thinking of electrolyte
disturbances.

7. Accuracy of observation is enhanced if
Control tracing available
Serial tracings done

8. Hyperkalemia
It has not been definitely established that the
changes are due to
tIntracellular K
+
changes
tGradient across cell membrane
cPotassium level in the serum alone

9. Action Potential
Atrial

10. SA Nodal

11. Ventricular

12. Similarities vs Differences

13. K
+
changes & Action Potential curve

14. Changes during depolarisation & resting
membrane potential

15. Changes during repolarisation

16. ECG changes
Short QT interval
Peaked T wave
ST segment depression
Lowering & widening of P wave
Prolonged PR interval

17. QRS widening
Short R wave & deep S wave
Marching of QRS & T wave towards each other
The Nadir of S wave & peak of T wave is connected by a
straight line.
Sine wave pattern
Atrial fibrillation & Atrial arrest

18. Sinoventricular rhythm

19. Effect of other electrolytes
Low Na
+
High Na
+

20. Low Ca
2+
High Ca
2+

21. ECG

22. Sine wave