As a medical professional with expertise in cardiology, I can explain the significance of a notched P wave in the context of an electrocardiogram (ECG) reading. A notched P wave, also referred to as a "double hump" P wave, can be indicative of certain cardiac conditions. When the notches are one small box width or more apart, it can be a sign of Left Atrial Enlargement (LAE). This enlargement of the left atrium is often a response to increased pressure or volume in the pulmonary veins or the left atrium itself, which can be due to conditions such as high blood pressure, mitral valve disease, or other heart diseases. Additionally, a biphasic P wave, where the downward portion of the P wave is one box or larger in both depth and length, can also suggest LAE. The biphasic nature of the wave indicates that there is a delay in the spread of electrical signals across the left atrium, which can be due to the atrium's increased size. It's important to note that while a notched or biphasic P wave can suggest LAE, it is not definitive on its own. Other ECG findings and clinical information are necessary to confirm the diagnosis. read more >>

A ��double hump�� or notched P wave is diagnostic of LAE if the peaks are one small box or more apart. A biphasic P wave indicates left atrial enlargement if the downward portion of the P wave is one box or larger in both depth and length.read more >>