First things first.
Before I even review what the important rhythms are, I’ll review the basic reading of the rhythms.
So with regards to time:
- One box is equal to 0.04 seconds
- 5 boxes add up to 0.2 seconds
- And 75 boxes together equate to 3 seconds
Next is a review of the waves that are seen on the EKG rhythms:
- First is the P wave, which under normal circumstances should be upright
- Next is the QRS interval, the Q wave is a negative deflection, the R is a positive deflection, and the S is another negative deflection
- Third is the upright T wave
- And last is a U wave in some cases
These diagrams and descriptions are extremely basic and don’t go into too great of detail. For this information I mainly referred to a PDF I found online from a copy of ECG Interpretation Made Incredibly Easy 5th Edition I have no idea if this copy has been posted online without violation of any copyrights, I just googled “ECG for Dummies” and this was one of the sources that came up so I can’t guarantee that it will always be made available forever, but in the meantime it’s there.
Next I’m going to review the rhythms that we’re required to be able to recognize according to ACLS guidelines, the list given in the manual from the American Heart Association includes the following:
- Sinus Rythm
- Atrial fibrillation and flutter
- Atrioventricular (AV) block
- Pulseless electrical activity (PEA)
- Ventricular tachycardia (VT)
- Ventricular fibrillation (VF)
The images above are of rhythms that I traced from the American Heart Association’s ACLS manual.
Those rhythms are also some of the most confusing rhythms for me because all any of it looks like to me are squiggles and it confuses my brain to try and make out one type of squiggle from another type of squiggle.
I may still be wrong now, but perhaps I finally understand to some small degree some of the differences in these rhythms.
In the case of v-fib there is no particular rhyme or reason to the rhythm, it really is just squiggles, on the other hand the v-tach, which can either be monomorphic or polymorphic has more of a pattern to it (in the case of the monomorphic form it has a singular appearance in its pattern whereas in the polymorphic form the pattern varies to some degree).
Next I’ll review pulseless electrical activity which has a sort of broad definition being that the rhythm is organized, but that no pulse can be detected. The list of pulseless electrical activity that is provided in the ACLS manual includes:
- Idioventricular rhythms
- Ventricular escape rhythms
- Postdefribrillation idioventricular rhythms
- Sinus rhythm
This most recent image is of the various types of AV blocks. The main resource I used for this is the Youtube video: AV Blocks (1st, 2nd, and 3rd Degree).
All the AV blocks are also forms of bradycardia and since I’m on the topic of bradycardia I will add the signs and symptoms of symptomatic bradycardia since knowledge of them is useful to me in my work as a bedside nurse:
Symptoms include chest discomfort or pain, shortness of breath, decreased level of consciousness, weakness, fatigue, light-headedness, dizziness, and presyncope or syncope.
Signs include hypotension, drop in blood pressure on standing (orthostatic hypotension), diaphoresis, pulmonary congestion on physical examination or chest x-ray, frank congestive heart failure or PE, and bradycardia-related (escape) frequent premature ventricular complexes or VT. (Donnino et. al: 122)
I won’t do much review on tachycardia, but I will quote another section of the ACLS manual regarding symptomatic tachycardia because once again, this information is pertinent to my work and care as a bedside nurse:
- Acutely altered mental status
- Signs of shock
- Ischemic chest discomfort
Last of the rhythms that I’ll review are a-fib and a-flutter.
“The ACLS Cases.” ACLS PROVIDER MANUAL, 2016, by Michael W Donnino et al, American Heart Association, 2016, pp. 122 and 131.