A 77-year-old man comes to the emergency room complaining of shortness of breath
and feeling his heart bouncing all over the place.
In the emergency room he’s seen and it’s noted that his heart rate is a 144 per minute, quite abnormal.
His blood pressure is slightly elevated at 150/78 and the pulse is very irregular.
So instead of the pulse being pum pum pum pum,
the pulse is this -- you can here it’s very fast and very irregular.
So what’s critical in this history?
First of all he has dyspnea, secondly he has a tachycardia that’s very abnormal in its rhythm
because it’s very irregular and he also of course has a little bit of hypertension
and of course the critical point is the irregular pulse so we obtained an electrocardiogram.
Please look at the electrocardiogram and tell me what is going on here.
Well, I hope you noticed that this is a markedly irregular heart rate with no clear P waves
otherwise the QRSs are normal so it’s not a myocardial infarct and this is atrial fibrillation.
And you can see here with the normal ECG underneath P wave followed by QRS
and look at atrial fibrillation above, totally irregular so instead of pum pum pum pum,
you're seeing -- completely random occurrences of the QRSs
and the ventricular contractions.
The EKG is otherwise normal but the QRSs do not show a myocardial infarct
and of course when your heart rate goes at 140 to a 150 the filling pressures in the heart
go up transmitted back to the lung and make you short of breath.
So the first treatment is to give him a beta blocker, metoprolol
which will slow the heart rate, slow the ventricular rate.
He's admitted to the coronary care unit and overnight his heart rhythm stabilizes,
he could go back to sinus rhythm or he may have slowed atrial fib
and he’s discharged with prescriptions with metoprolol to prevent it if he went back to sinus rhythm
or to keep the rate slow and then anti-coagulants
because of the high risks for a blood clot forming in the left atrium that can get out and cause a stroke.
If he were still in atrial fib but slow we would then want to see him in a few weeks
after he’d been anticoagulated for a few weeks
to makes sure any clots in the left atrium were dissolved
and he would then undergo electrical cardioversion, it turned out in this case,
as often happens, giving him some metoprolol usually given intravenously during the night
converts him back to sinus rhythm
and of course he needs an outpatient appointment with a cardiologist for follow up,
he needs to continue on his anticoagulation cause once having atrial fib he’s at high risk
to do it again even when he tells you, "Oh,
I never feel it again." Maybe it occurs during sleep,
he can still get a blood clot in the left atrium and still get a stroke.
He needs to continue he’s anticoagulation and we almost always continue he’s beta blocker metoprolol.
What’s very important here is that if metoprolol didn’t control his atrial fib
we have other drugs which can be administered to help keep the patient in sinus rhythm,
regular rhythm, and if that fails the cardiac electrophysiologist or the cardiac electricians
can actually consider an ablation procedure
which markedly increases the likelihood that he would remain in sinus rhythm.