Early tall, peaked T waves and progressive QRS widening leading to a sine wave pattern is most consistent with which electrolyte abnormality?

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Multiple Choice

Early tall, peaked T waves and progressive QRS widening leading to a sine wave pattern is most consistent with which electrolyte abnormality?

Rising serum potassium alters how electricity moves through the heart, producing a recognizable progression on the ECG. Early on, the T waves become tall and peaked as repolarization is hastened. As potassium climbs further, conduction slows across the ventricles, causing the QRS complex to widen. If potassium continues to rise, the QRS and T waves merge, creating a sine-wave pattern that reflects severe conduction block and impending cardiac arrest. This sequence—tall, peaked T waves followed by progressive QRS widening to a sine wave—is classic for hyperkalemia. For context, other electrolyte problems show different patterns. Hypokalemia typically shows flattened or inverted T waves with U waves and QT changes toward prolongation, not tall peaked T waves. Hypercalcemia tends to shorten the QT interval, while hypocalcemia prolongs it.

Rising serum potassium alters how electricity moves through the heart, producing a recognizable progression on the ECG. Early on, the T waves become tall and peaked as repolarization is hastened. As potassium climbs further, conduction slows across the ventricles, causing the QRS complex to widen. If potassium continues to rise, the QRS and T waves merge, creating a sine-wave pattern that reflects severe conduction block and impending cardiac arrest. This sequence—tall, peaked T waves followed by progressive QRS widening to a sine wave—is classic for hyperkalemia.

For context, other electrolyte problems show different patterns. Hypokalemia typically shows flattened or inverted T waves with U waves and QT changes toward prolongation, not tall peaked T waves. Hypercalcemia tends to shorten the QT interval, while hypocalcemia prolongs it.

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