Tracey Blanchard
Herzing University
Unit 2 Discussion – Electrocardiogram
July 17, 2024
SC254-8F
Dr. Amanda Little
My assigned component for this discussion is the P wave since my last name starts with a B. The
P wave and PR segment are important to the electrocardiogram (ECG). The heartbeat or heart rate can be
broken down into different segments and the P wave is the segment that the atrium within the heart is
depolarized. When looking at the heart rate, the P wave is at the start and is normally around 120 to 200
milliseconds (ms) before the beginning movement of the QRS complex (Douedi, 2023). When examining
a healthy person, the P wave starts with electrical impulses in the sinoatrial node (SA node) before
moving into the left and right atria. Depolarization in the right atrium is found in the beginning portion of
the P wave and the left atrium is found within the middle and ending portions of the P wave.
An imbalance that may disrupt the P wave can be found in the timing between the PR segment.
The shape and makeup of the P wave may vary depending on each individual and any underlying
conditions that may cause a change in the length of the wave. A normal wave is usually small, upright
followed by a baseline period (Enabnit A, 2023). A prolonged P wave may signal irregularities within the
atrial conduction such as an enlargement of the atria or signal delays. One abnormality seen over the years
is first-degree atrioventricular (AV) block. The ECG shows a prolonged PR interval greater than 200 ms
and has a 1 to 1 relationship between the P and QRS complexes but the QRS complex has not dropped
anything within the complex. This abnormality usually shows a delay within the electrical signal that
travels from the atria through the AV node into the ventricles. The abnormality is common and may not be
considered an issue such as second-degree or third-degree AV block. Medical professionals may or may
not require further information or interventions to be completed.
