What is a symptom of a non-conducted PAC?

• A. Normal t-wave shape
• B. Spiky t-wave
• C. Regular rhythm
• D. Absence of P waves

Answer: (B)

In the context of a non-conducted premature atrial contraction (PAC), the characteristic symptom is a spiky T-wave. A non-conducted PAC occurs when an early impulse arises from an area in the atria and is not followed by a ventricular contraction. This results in irregularities in the normal rhythm and can affect the morphology of the T-wave.

The spiky appearance of the T-wave can be attributed to the impact of the PAC on the repolarization of the ventricles, indicating that there was electrical activity in the atria that affected the heart's overall electrical conduction pattern without producing a corresponding QRS complex. This alteration leads to changes observable in the T-wave, reinforcing the notion of a non-conducted PAC having distinctive electrocardiographic features.

Understanding this can assist in recognizing abnormal rhythms and diagnosing cardiac issues effectively.