Hyperkalemia can lead to

• A. Cardiac arrest
• B. Seizures
• C. Stroke
• D. Pulmonary edema

Answer: (A)

Excess potassium directly disrupts the heart’s electrical system. When potassium outside the cells is high, the resting membrane potential of cardiac myocytes becomes less negative, inactivating some sodium channels and slowing conduction. This shifts the heart’s rhythm from normal to dangerous patterns, with ECG changes such as peaked T waves and widening QRS, eventually progressing to life-threatening arrhythmias that can stop the heart.

That direct progression to severe arrhythmias and potential loss of effective circulation is why cardiac arrest is the most likely outcome with significant hyperkalemia. Seizures, stroke, or pulmonary edema are not immediate, direct consequences of high potassium on the heart, though electrolyte imbalances can contribute to broader health issues in different contexts.