How would an EKG would look if the bundle of his is severed?

Question

A crazed cardiologist has severed the bundle of HIS fibers in her patient’s heart. In the space below draw a picture of what the patients EKG pattern would look like immediately after surgery (assuming the patient survives). Label the P, QRS and T waves.

Answer 1

http://www.coheadquarters.com/PennLibr/MyPhysiology/lect0/figecg22.gif

Sinus bradycardia with bundle branch block

http://davidge2.umaryland.edu/~emig/ekg01a.html

EKG page 2 Answers - illustration 12

Answer 2

You will be aware that drawings are not carried in this site. The answers are, therefore, not possible in the format that you require. You must also be aware, as you have asked the question, that the P wave is caused by atrial depolarisation and the QRS complex by ventricular repolarisation, and the T wave by septal wall and ventricular depolarisation. The bundle of his is a small band of atypical cardiac muscle that originate in the atrio-ventricular node in the inter-atrial septum. It then passes through the atrio-ventricular junction and then passes beneath the endocardium of the right ventricle on the membranous portion of the intra-ventricular septum. Electrical exitation originates in the SA node and spreads over the heart. Thus the heart will beat even if it’s nerves are severed. With the conduction severed from the AV bundle, the ventricles would beat at the purkenje fibre rate. The Purkinje cells conduct the fastest and AV nodal tissue the slowest. Hence the short QRS duration (Purkinje) and the long P-R interval (AV node). All this, of course, with the assumption that life is present. If you are able to observe Colour Doppler echocardiography, which provides a two-dimensional moving image of the heart, you would see the effect of the movement of the chambers. Some schools / colleges are able to simulate various effects of malfunction.
Hope this answers your question without the aid of drawings.
Matador 89

Answer 3

I would think that a severed bundle of His would resemble a bundle branch block which would be a normal Sinus Rythym with the excpeption of A very wide QRS interval because the current would have to follow another path of conduction. If the atria beat independently of the Ventricles it would look exactly like a 3rd Degree block where the p waves march out and the qrs complexes march out but they have no relation to each other.

Answer 4

If the Bundle of His were severed, there would be no conduction from the AV node into the ventricles... so the ventricles would beat independently of the atria.
So:
-the QRS segment would be wide (over 0.12)
-the rate would be regular but slow (40 bpm)

Hope this helps!

Answer 5

If whole of the bundal of his is severed the SA node beats wud produce only p waves at regular rate
& the ventricles wud start impulse of their own at very slow rate of 30-40 with wide QRS & this is know as IDEDVENTRICULAR RHYTHM & atria will beat at the rate of sinus rhythm.
There wll be no corelation between p waves & QRS complex .

Answer 6

If it is right bundle branch the pattern would be like that of M in all leads & if it is left bundle branch the leads will be W shaped.
in QRS Complex. if both are involved independent rhythm would take place.

Answer 7

P QRS T
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Death should occur immediatly..

A large law suite will occur shortly after..

Im assuming "SHE" severed all of them..