?afib
First Glance:
From across the room it looks like an irregularly irregular narrow complex rhythm on the slow side.
Discussion:
We can’t really make much out of the baseline here. It looks fibrillatory, but I’d jack the gain up before I felt secure about it. In a few spots it does look a little tiny bit like some flutter waves might be showing throguh.
The QRS complexes are identical and narrow, and at irregular intervals. This looks like atrial fibrillation, but this same strip could be generated by an atrial rhythm with variable block, wandering pacemaker, a sick sinus node, etc. I doubt it is flutter with a variable block, because there really isn’t a single RR interval which is the same on this strip, and flutter with variable block would generally randomly (or non-randomly) tend to repeat certain RR intervals.
Final Impression?
Irregularly irregular supraventricular rhythm @ 60 bpm, likely afib.
Management implications:
Identify the rhythm. This is on the slow side, so if the patient is hemodynamically compromised it is possible that reducing a rate control drug or increasing her sympathetic tone might shorten the pauses and increase the cardiac output.
The Take-home Point:
How do you count a heartrate in a strip like this? I count 3 second boxes. Here you can see subtle vertical hash-marks along the upper line of the grid which are the standard 3 seconds apart. I count 9 beats in 3 boxes = 9 beat in 9 seconds = 1 beat in 1 second (average) = average 60 bpm.
If you have an irregularly irregular rhythm, the more boxes you count, the more accurate it is.
Two star strip. The meat and potatoes.
This is AFib with a relatively slow ventricular response (ave. rate seems under 50/minute). Althoug fib waves are no more than of tiny amplitude – this is TOTALLY irregularly irregular – ergo it is AFib. It is not wandering pacer or an atrial block. The patient may have SSS (sick sinus syndrome) – as that is a syndrome, and one of the most common rhythms seen with SSS is AFib (esp. slow AFib).
The finding of Slow AFib generates a differential diagnosis. #1,2, & 3 is use of a rate-slowing drug (Digoxin – Verapamil/Diltiazem – Beta-Blocker – Amiodarone – Clonidine – some Herbal meds). Be sure to ask if the patient is on eye drops (beta-blocker eye drops for glaucoma do have some systemic absorption). Once drugs are ruled out – consider recent/acute ischemia/infarction – and hypothyroidism (uncommon but possible). If NONE of these reveal the cause for the slow rate of AFib – then esp. if the patient is “older” – the diagnosis almost certainly is Sick Sinus Syndrome.