What condition is indicated by a spiked "T" wave on an ECG?

A spiked "T" wave on an ECG is indicative of hyperkalemia, which is an elevated level of potassium in the blood. When potassium levels rise, it affects the electrical conduction in the heart, leading to characteristic changes in the ECG tracing, including tall, peaked T waves. This is a vital clinical sign as it can indicate that the heart may be under stress due to electrolyte imbalance, potentially leading to serious complications like arrhythmias.

In contrast, hypokalemia, although it affects the T wave, typically presents with flattened or inverted T waves rather than peaked ones. A heart attack (myocardial infarction) can lead to various changes in the ECG, including ST segment elevations or depressions and abnormal Q waves, but not specifically spiked T waves. Bradycardia is identified by a slow heart rate and does not alter the morphology of the T wave in the same way hyperkalemia does. Understanding these distinctions helps recognize the clinical implications of each finding on the ECG.