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at 5:36 she said that the impulse can travel from the accessory node back to the AV node and cause a tachyarrythmia, my question is, since A/V node has a refractory period and can regulate the rate and rythm, why will the A/ V node cause tachyarrythmia, as in why will it let the impulse from accesory pathway through to begin with?
Is it normal for nodes to have slow and fast pathways?! In the first example, how come the slow pathway doesn't go down the tract? Why is it halted when the fast pathway is going through refractory period?
Very good lecture. The only thing I would change is that the slow and fast pathways are not really "in" the AV node. The slow pathway is between the tricuspid annulus and the coronary sinus and the fast pathway is on the other side of the coronary sinus. Otherwise, excellent presentation.
wow... leaving Thursday morning for mapping study plus or minus ablation with possible cryoballon... my hearts insane... I hope it works. thank you for this video!! would avrt or avnrt cause 17 pauses in 48 hours with the longest being 8.7 seconds?
Just a friendly note: you're sometimes really hard to understand for someone that English is a second language for - as you sometimes really speed up the words you say, especially in long, complex words, that might be clear to you, but are not clear to me. Thanks anyway!
8:14 so does that mean normally impulse conduction in avn down to bundle of h n so forth is done by fast pathway n not slow ? cuz u said slow comes down hits fast which is refractory n it goes refractory itself? plz any help
+Travisfromoregon The whole body works like an electronics device, a very advanced one. That's what humans are, biological machines. Imagine us designing robots, and then far, far, far into the future, when silicon and simple conductors aren't advanced enough, we'd have to start designing our robots out of biological tissue that is far more complex but still operates on similar basic principles.
+Andrei Plopeanu Girl don't loose your hope! Keep on trying. Cardiology is a pain in the ass. I was crying like a little baby the day before my exam. But I assed the exam :) Don't stop trying :) <3 I wish you luck :*
+athena ky λοιπόν απ το όνομα υποθέτω εισαι Ελληνίδα και απ τις απαντήσεις σου καταλαβαινω οτι εισαι σε μεγαλύτερος έτος απο μενα, οποτε θελω να σε ρωτήσω κατι :P απ τη στιγμη που το re-entry mechanism γινεται ξανα και ξανα στο AVNRT, τοτε τι γινεται με τα νέα impulses που φτάνουν στο AV node απο το SA node ενώ ταυτόχρονα γινεται το re-entry? με συγχωρείς που τα μισά στα γράφω στα αγγλικά, αλλά σπουδάζω στα αγγλικά ιατρική και κάποιους όρους δεν τους ξερω στα ελληνικά 🙈
Sorry for my english... I will try to explain it... P waves represent the stimulation of atrium.. Sometimes electric signals from the reentry mechanism will travel towards to the atrium and towards to the ventricles... If this signal stimulate the atriums there will be a p signal which is going to be (-) in the II and (+) avR which means the atriums werent stimulate from sinus
Hi I am thirteen, and last year in November l had my first keyhole ablation, I haven't had any episodes so far and I used to have strange episodes, at least, every two months I was wondering how long it took for your symptoms to come back, in case mine do, because I really don't want to take the meds for it, and I do not want to do nothing as they said as one of the options for me. So I took the option for the surgery because I didn't want it to define me for the rest of my life. You know how people are... "Oh, you came first place in that race, But don't you have that thing wrong with your heart? You didn't feel faint as you crossed the finish line?" I'm sure you know what I mean by those dumb people who assume everything... But yeah my surgeon said after a year they could take out my implant that tracks my heart (reveal device). So I was wondering if it took over a year or under to come back in case mine does (fingers crossed it doesn't) :) .
3rd question, since the reentry phenomenon is going to revolve around the AV node and the accessory pathway in a vicious cycle manner, there will be new electrical signals coming from above (SA node/atrial pacemaker cells) too right? wouldn't that cancel off the reentry mechanism and lead to a normal anterograde conduction again, if that's the case, how can it still be said "the reentry circuit phenomenon takes place over and over and over again".. because it doesnt..??
1.) In AVRT (WPW syndrome), since electrical signals are going to inevitably travel through both the AV node and the accessory pathway, does that mean the person will have a relatively higher resting heart rate even without a premature impulse? (owing to the lack of mechanism that slows down the signals in the accessory pathway)
2.) In 5:12 you mentioned that IF there was a premature beat, it would eventually form a reentry circuit by the signal that undergoes the AV node back up to the accessory tract at the time its refractory period is over , so my question is what if there was a premature beat that travels to the accessory pathway that wasn't in refractory period in the first place? Now does it differ from normal condition without a premature beat? and what determines the refractory period of this accessory pathway? +khanacademymedicine or Anyone kind enough to enlighten me please? Thanks alot in advance!
Thank You so much for the thorough explanation. I was diagnosed in 1998 with AV Nodal Reentry Tachy, had an ablation shortly thereafter to treat the condition. However, after the procedure my doc informed me that the affected area was too close to the a/v node, and he was not able to completely get all of it. So fast forward to today, I average 4 to 6 skipped beats per minute, with the occasional runs of tachy occurring. I am back on the heart meds, taking Metoprolol extended release 100mg 1x per day. I just somehow feel like this will be the bugger that gets me in the end. At least I now know what is happening inside my chest, Thank You :)
If you have AVNRT dont make ablation for it, doctors will tell u its a EASY fix, no complacations bla bla bla.
What they dont tell you is that ablation creates a scar, the SCAR it selfs creates abnormal signals making you have PVC.
And you DONT want pvc, it the absolutely the worst thing u can have, u cant sleep, u cant eat, u cant enjoy anything because of them. If u go back to the doctor the will laugh and say " everybody has them" " in normal heart pvcs is not a issue"
The doctors really dont know what a PVC are, they never experienced it, if they did they would never say something like that.
I rahter have my AVNRT back with another pathway, so i have 3 path ways in my AV node rahter than these PVCS
+Lisa Nicholson . hi i m neeraj. anesthesiologist. indian. in one of my or, i heard that one of the nurse had cof palpitation. so i told her to get an ecg. then we found out that she had wpw , showing short pr interval and delta waves. she was then reffered to a cath lab and then radiofrequency ablation of abberant conduction pathway was done . after the procedure she was ok.
I'm a med student and I wasn't aware of the issue with PVCs; I'll try to make sure I inform my future patients of the risk/ benefit, and take people more seriously when they complain of PVCs. We're taught in school exactly what your other docs said; that they're just no big deal. I'm sorry you're going through this.
The video says that a supraventricular tachycardia involves a narrow QRS <~ 0.12sec. In other readings, I find that normal QRS is < 0.12 seconds. What distinguishes the two? Is it, primarily, the heart beat?
+Lorraine Gary what i was being taught, essentially narrow QRS means that the problem doesnt lies on the ventricular muscles. To make it simple, broad QRS should make you think of either bundle branch block or ectopic(s) that originates from the ventricle if that makes sense?
yes it does. you may find inverted P waves after the R waves in the QRS complexes of AVNRTs (the R comes down and goes just below the baseline like a little hook, before returning to the baseline). This represents the retrograde depolarisation of the atrium from the AV node.
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