Question

Pseudo P pulmonale on the ECG is associated with which electrolyte abnormality?

• A. Hypokalemia
• B. Hyponatremia
• C. Hypocalcemia
• D. Hypercalcemia

Hint:

A tall peaked P without real RA enlargement, plus U waves and ST depression, points to low potassium.

Answer 1

The Correct Option is A

Step 1: Define the finding. A tall peaked P wave is "P pulmonale" of right atrial enlargement; when the same shape appears with structurally normal atria, it is termed "pseudo P pulmonale".
Step 2: Ask what metabolically mimics it. Low serum potassium changes atrial and ventricular repolarisation enough to peak the P wave without any true RA hypertrophy.
Step 3: Support this with the rest of the hypokalaemia ECG package - ST-segment depression, T-wave flattening, and prominent U waves - which travels together with the pseudo P pulmonale.
Step 4: Exclude the calcium options by their QT effects ($\downarrow Ca^{2+}$ lengthens QT, $\uparrow Ca^{2+}$ shortens it) and hyponatraemia, which gives no peaked P. That isolates hypokalaemia.
\[\boxed{\text{Hypokalemia}}\]