What change is observed in the T wave when taking drugs like quinidine?

• A. Normal
• B. Peaked
• C. Inverted
• D. Flat

Answer: (C)

When quinidine, an antiarrhythmic medication, is administered, one of the notable changes that can be observed in the electrocardiogram (ECG) is the inversion of the T wave. This change occurs due to the drug's effects on repolarization and the myocardial action potentials. The T wave represents the repolarization phase of the ventricles, and quinidine prolongs the action potential duration, leading to altered electrical activity in the heart.

The inversion of the T wave in this context typically indicates that the repolarization process is altered, influencing the characteristic shape of the T wave on the ECG tracing. This inversion can signify drug effects on the heart, making it an essential observation for healthcare professionals monitoring patients on quinidine therapy.

Other potential changes to the T wave, such as a normal appearance, being peaked, or flat, would not specifically correlate with the pharmacological effects of quinidine, thus highlighting the importance of T wave inversion as a relevant marker in this scenario.