Final answer:
The correct answer is b) From the start of the Q wave to the end of the S wave. The QRS complex represents the depolarization of the ventricles and is measured by the duration from the onset of the Q wave to the end of the S wave, not including the P or T waves.
Step-by-step explanation:
This is because the QRS complex reflects the rapid depolarization of the right and left ventricles, which is a key component in the cardiac cycle.The QRS complex itself is composed of three wave components – a Q wave, an R wave, and an S wave. To measure the QRS complex duration accurately, an EKG technician will identify the beginning of the Q wave and measure straight to the end of the S wave.
This measurement is critical because it reflects the time required for an electrical impulse to travel through the ventricles of the heart, indicating the efficiency of ventricular depolarization. If an increased QRS duration is noted, it could signify an underlying cardiac issue that may require further investigation.
The QRS complex does not include the P wave, which represents atrial depolarization, nor does it include the T wave, which represents ventricular repolarization. Therefore, options a), c), and d) all include waves or segments not relevant to the measurement of the QRS complex.