12-lead ch.9 Flashcards
Which leads are p waves normally positive in?
I, II and V4-V6
Which part of the electrical conduction system does the p wave represent?
The p wave represents electrical conduction through the internodal pathways (3) within the atria from the SA node to the AV node.
What rhythms can cause inverted p’s in II, III and aVF? Why?
Any rhythms that are at or below the AV junction, they cause inverted p’s because the impulse is travelling away from the positive poles in those leads.
What is the criteria for MAT or WAP?
3 different p wave morphologies.
If the p waves are inverted but of normal distance from the qrs, what is the rhythm? Where does this rhythm occur?
Ectopic Atrial rhythm, because the interval is of normal distance, it will be occurring above the AV node but lower within the atria.
What is LAE criteria and the name for the shape?
LAE criteria is a p wave notched and wider than .12sec. The name is p-mitrale.
What is RAE criteria and the name for the shape?
RAE criteria is a p wave which is peaked and greater than 2.4mm high. The name is p-pulmonale.
What is the most common reason for P mitrale? How is the pathology caused? What other pathology can occur?
Severe mitral valve disease. It’s caused by increasing the muscle mass needed to overpower the valve. Dialation occurs which can lead to mitral regurgitation.
What is a common ventricular abnormality with P-mitrale?
A common abnormality would be LVH because of the stenosed valve overfilling the left atrium and the atrium putting pressure against the left ventricle with Frank Starling’s law.
How can you tell if a beat is abberant or not?
When the beat appears to start in the same way and same direction it would be more likely to be abberant than a PVC.
Where is RAE most evident?
in II and III
What EKG findings would exclude a diagnoses of LPH?
P-pulmonale with a right axis deviation. Because right sided disease can alter the axis rather than it being altered from the hemi-block itself.
Why can’t we use the term hypertrophy rather than enlargement?
There is no way to predict whether the enlargement seen on the ECG was due to hypertrophy of the muscle or from dialation.
Describe IACD. How is it useful?
Intraatrial conduction delay. When there is evidence in V1 that there is a non-specific conduction problem in the atria.
What can cause RAE?
COPD, pulmonary emboli, pulmonary hypertension, and mitral, tricuspid or pulmonary valve disease.
