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If the P wave is hidden that implies the atria depolarize at the same time as the ventricles. 2. There are inverted P waves prior to the QRS complex. This is because of retrograde flow to the atria causing depolarization prior to the ventricular contraction. Since the depolarization is occurring in the opposite direction, the P wave deflection ...
The P wave is a summation wave generated by the depolarization front as it transits the atria. Normally the right atrium depolarizes slightly earlier than left atrium since the depolarization wave originates in the sinoatrial node , in the high right atrium and then travels to and through the left atrium.
P waves: Depends on the site of the ectopic focus. They will be inverted, and may appear before or after the QRS complex, or they may be absent, hidden by the QRS. P-R interval: If the P wave occurs before the QRS complex, the interval will be less than 0.12 seconds. QRS Complex: Usually normal in duration and morphology, less than 0.12 seconds.
Both arrhythmias have at least 3 different P-wave morphologies in a single ECG lead, but the heart rate is different. When the heart rate is lower than 100 beats per minute, the heart rhythm is considered wandering atrial pacemaker. When the heart rate is greater than 100 beats per minute, the heart rhythm is considered multifocal atrial ...
The P wave is typically upright in most leads except for aVR; an unusual P wave axis (inverted in other leads) can indicate an ectopic atrial pacemaker. If the P wave is of unusually long duration, it may represent atrial enlargement. Typically a large right atrium gives a tall, peaked P wave while a large left atrium gives a two-humped bifid P ...
Because the retrograde conduction is via the fast pathway, stimulation of the atria (which produces the inverted P wave) occurs very soon after stimulation of the ventricles (which causes the QRS complex). As a result, the time from the QRS complex to the P wave (the RP interval) is short, less than 50% of the time between consecutive QRS ...
During atrial ectopic activity where the P wave is normally rounded can be inverted or peaked. However the QRS complex and T waves appear relatively normal. [10] Conversely, during junctional ectopic activity the P wave is frequently absent or can be hidden in the QRS complex. [11]
In orthodromic AVRT, atrial impulses are conducted down through the AV node and retrogradely re-enter the atrium via the accessory pathway. A distinguishing characteristic of orthodromic AVRT can therefore be an inverted P-wave (relative to a sinus P wave) that follows each of its regular, narrow QRS complexes, due to retrograde conduction.