EKG – 4 – Atrial Enlargement

A 17 yr old female presents to the HUM ED with acute onset left sided weakness approximately 6 hours prior to arrival.  On exam, she was found to have a left sided facial droop, left arm and left leg weakness (able to walk but does so with significant limp). Her overall examination was consistent with an acute stroke.

An EKG was performed and is attached.  What does this EKG suggest and what other bedside test should it prompt you to perform?



RATE: around 100bpm
AXIS:  Right axis deviation (I-, II +, III+). Axis approximately +120 degrees (most isoelectric lead AvR, -150 degrees, axis must be approximately 90 degrees from most isoelectric lead, with I being negative, axis must be around +120 degrees).
RHYTHM:  Regular w/ p waves always followed by QRS complex, QRS complex always preceded by P wave
INTERVAL:  QRS narrow — around 120ms (3 small boxes), this is the upper limit of what is considered “narrow.”
SIZE:  normal
ST SEGMENTS: unremarkable

This EKG has the morphology of a Right Bundle Branch Block, or RSR’ waves in lead V1 – V3, often appearing like an “M,” and wide slurred S wave in V6, often appearing like a “W.”

Our patient’s EKG does have the pattern of a right bundle branch block, however the reason we should really call it INCOMPLETE is that in order to be a true right bundle branch block, the QRS should be wider than 120ms.



Our patient’s QRS looks to be just under 120ms (or 3 small boxes, each small box .04s), so technically we should call it incomplete (but the most important thing is to remember what a RBBB looks like!)

Even more important given the clinical presentation of stroke is that this EKG suggests ATRIAL ENLARGEMENT.   Remember that the first 1/3 of the p-wave represents right atrial activation, the final 1/3 represents left atrial activation and the middle 1/3 represents a combination of the two.  P wave abnormalities will most easily be seen in the inferior leads (II, III, AvF) and V1, where the p waves are most prominent.  In the inferior leads, an enlarged right atria will lead to “peaked” p waves and an enlarged left ventricle will create “notched” p waves.



Looking at lead II of our patient’s EKG suggests a combination of the two.



There are more complicated criteria to help determine whether this patient has right atrial, left atrial, or biatrial enlargement, however the most important thing whenever you see a “peaked” or “notched” p-wave (or a combination of the two) is to place this in the context of the patient’s clinical presentation.  Does the patient have cor pulmonale or other such lung disease causing high right atrial pressures?  Does the patient have heart disease causing enlargement of the left ventricle?   Our patient presented with a stroke.
ALL stroke patient’s should receive an ECHO of the heart, however a patient with an EKG that suggests atrial enlargement and presents with a stroke DEFINITELY MUST have a cardiac echo performed, as enlarged atria increases risk of clot formation and embolic stroke.
During this patient’s stay in the HUM ED, a bedside cardiac echo was performed and is attached.  Please take a look at the parasternal view of the patient’s heart.
We that this echo demonstrated significant mitral stenosis, which was probably responsible for this patient’s stroke presentation, and sent the video to our cardiologist for his opinion and this is what he wrote:

“Great job. Yes – the findings are consistent with mitral stenosis:

1. Thickened mitral valve leaflets
2. Calcification of the mitral valve (valve appear white on echo)
3. Posterior MV leaflet is fixed (does not move well)
4. Anterior leaflet is domed (hockey stick or elbow morphology)



Too bad the patient has a stroke. Mitral stenosis definitely places patients at increased risk of stroke. We generally give patients with mitral stenosis aspirin for prevention of stroke. It would be best to give the patient warfarin – though this is challenging in Mirebalais…

Other than treatment for stroke prevention, HR control with atenolol is very important. Add atenolol 25 mg daily and up-titrate until the HR is in the 60s. As the patient develops symptoms, she may be a candidate for mitral balloon valvuloplasty or replacement.”

We worked to help this young woman receive rehabilitation for her neurologic deficits and she will now be followed by our cardiology team. While she currently shows no clinical symptoms of heart failure, the echo that the resident cleverly performed will hopefully lead to early treatment for her heart condition and improved quality of life for her in the future.

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