What does the Q wave represent in an ECG?

The Q wave in an electrocardiogram (ECG) represents the first negative deflection following the P wave. This negative deflection is important as it indicates the initial phase of ventricular depolarization, which is critical for the proper functioning of the heart. Specifically, it reflects the electrical activity as the depolarization wave moves through the ventricles, which is a key event in the cardiac cycle leading to contraction and thus enabling the heart to pump blood effectively.

Recognizing that the Q wave is typically followed by the R wave, which is the first positive deflection, highlights its position in the sequence of ventricular depolarization. This sequence is essential for interpreting the overall rhythm and electrical activity of the heart as represented in the ECG waveform. Understanding the significance of the Q wave helps in identifying potential abnormalities in cardiac function, making it a crucial aspect of EKG analysis.