Question 25.1
The ECG shown on page 11 (Figure 1) is from a 41-year-old female admitted for management of anorexia.
a) List the ECG abnormalities. (10% marks)
b) Give the underlying cause. (10% marks)
c) List four other ECG abnormalities that may be seen in this condition. (10% marks)
College answer
a)
ST depression
T wave flattening and inversion
U waves
Long QT/QU interval (fusion of T and U waves)
b) Hypokalaemia
c)
P wave amplitude increased (>2.5 mm in limb leads, >1.5 mm in chest leads)
P wave width increased (>120 msec)
PR interval prolonged (>200 msec)
Supraventricular ectopics
Ventricular ectopics
Atrial fibrillation
Atrial flutter
Atrial tachycardia
Torsade de pointes
Discussion
The ECG above was stolen from the LITFL archive.
ECG findings of hypokaelmia:
- Ventricular tachycardia: classically, torsades de pointes
- Atrial tachycardias
- PR interval prolongation (>200 msec)
- P wave amplitude increased (>2.5 mm in limb leads, >1.5 mm in chest leads) - a "pseudo-P-pulmonale" pattern
- P wave width increased (>120 msec)
- u-waves (thpough these are not unique to hypokalemia: they are associated with LVH, bradycardia and may occasionally be a normal variant)
- T-wave inversion
- Ectopics (ventricular and atrial)
References
Norgard, Nicholas, Amanda McEvoy, and Thomas Madejski. "Influence of Pharmacologic Agents and Electrolytes on ECGs." Clinical Exercise Electrocardiography (2015): 173.