What does the Q wave represent on an EKG?

The Q wave on an electrocardiogram (EKG) represents the first negative deflection seen after the P wave. This part of the QRS complex indicates the initial phase of ventricular depolarization. During this phase, the electrical impulse moves through the heart's conduction system and triggers the ventricles to contract. The presence of the Q wave is significant, especially in the context of diagnosing certain cardiac conditions, such as myocardial infarction, where abnormal Q waves can indicate damage to the heart muscle.

Understanding the role of the Q wave is vital for interpreting an EKG. While the first positive deflection after the P wave is related to the R wave, the Q wave specifically refers to the negative deflection that signifies the beginning of ventricular contraction. Similarly, the concepts of electrical inactivity and the recovery phase associated with the T wave pertain to different aspects of the cardiac cycle and do not directly relate to the representation of the Q wave.