Can you spend a little more time on the first case, I do note slightly different morphologies of the QRS but to say one is wide and one is narrow is a difficult call for me. Any concerns with cardioverting someone in afib and then an embolic effect?
The example I used on that video I have to agree there is NOT as much QRS width variation as you can often see. The faster the rate the less the variation in my experience. But they are clearly NOT all the same shape like a "normal " atrial fibrillation without a bypass track. We know from Ian Stiell's data from Ottawa and others that less than 48 hours of atrial fibrillation clot/stroke risk is low with cardioversion with new onset atrial fibrillation. In the case of atrial fibrillation and WPW usually these patients feels so bad, so like they are going to die, they present really early and I have NO anxiety about cardioversion as embolic risk is low and that arrhythmia is potentially lethal at any time!
If I would not have the idea that this is an accessory pathway from WPW but rather perhaps an a-fib with rvr with off and on aberrancy, and if a calcium channel blocker was used to try to slow the rate, would this be an example of slowing the rate of conduction through the av node therefore allowing all the conduction through the fast alternate conduction pathway and now making the ventricular rate even faster and the patient more unstable? What are the safe medications that could be used in this scenario?
Right the differentials is AF with some intermittent BBB or AF with WPW. Most of the time I am not smart enough to know which is which. Classically it is said use Procainamide (to slow accessory pathway conduction) - then add an AV blocker (that is complicated and time consuming) I think if in doubt, cardiovert. AV blockers in the face of WPW AF often cause VF. So if you are not sure I think cardioversion is best- but even here people can arrest - WPW is out to get you!
Dr. Metal - January 27, 2023 9:39 AM
Like this format of a "mini series" for learning. Perfect for us ADHD EM types.
Mel H. - January 27, 2023 10:26 AM
Now I know there are at least two people in the world that believe this :)
Adam R. - January 27, 2023 10:11 AM
Can you spend a little more time on the first case, I do note slightly different morphologies of the QRS but to say one is wide and one is narrow is a difficult call for me. Any concerns with cardioverting someone in afib and then an embolic effect?
Mel H. - January 27, 2023 10:26 AM
The example I used on that video I have to agree there is NOT as much QRS width variation as you can often see. The faster the rate the less the variation in my experience. But they are clearly NOT all the same shape like a "normal " atrial fibrillation without a bypass track. We know from Ian Stiell's data from Ottawa and others that less than 48 hours of atrial fibrillation clot/stroke risk is low with cardioversion with new onset atrial fibrillation. In the case of atrial fibrillation and WPW usually these patients feels so bad, so like they are going to die, they present really early and I have NO anxiety about cardioversion as embolic risk is low and that arrhythmia is potentially lethal at any time!
Adam R. - January 30, 2023 3:08 PM
If I would not have the idea that this is an accessory pathway from WPW but rather perhaps an a-fib with rvr with off and on aberrancy, and if a calcium channel blocker was used to try to slow the rate, would this be an example of slowing the rate of conduction through the av node therefore allowing all the conduction through the fast alternate conduction pathway and now making the ventricular rate even faster and the patient more unstable? What are the safe medications that could be used in this scenario?
Mel H. - January 30, 2023 3:16 PM
Right the differentials is AF with some intermittent BBB or AF with WPW. Most of the time I am not smart enough to know which is which. Classically it is said use Procainamide (to slow accessory pathway conduction) - then add an AV blocker (that is complicated and time consuming) I think if in doubt, cardiovert. AV blockers in the face of WPW AF often cause VF. So if you are not sure I think cardioversion is best- but even here people can arrest - WPW is out to get you!
Adam R. - January 30, 2023 3:33 PM
Thank you
Kenneth D. - January 27, 2023 1:28 PM
Could you explain why the QRS in Case 2 was narrow. It looked wide to me. Thanks for your attention.
Natascha N. - January 29, 2023 8:07 AM
Same here
Matia M. - January 30, 2023 10:31 AM
Just updated the ECG graphic for this case to a better one.
Mel H. - January 30, 2023 8:58 AM
You are right. It looks like it could be wide. I will get a better example. The vertical format can also modify the way it looks a little.