Hello young (or old) traveller! Welcome to Moshi, Tanzania. Or at least a vague digital facsimile of it. As promised, this will be the first of a series of short posts documenting some of the patients, cases, and scans I encountered during my recent visit to the Emergency Medicine Department (EMD) of Kilimanjaro Christian Medical Center (KCMC). By way of format, I’ll be keeping things deliberately brief – just a short description of the patient’s presentation, the indication for the point-of-care ultrasound (POCUS) exam, the images/clips themselves, and a very brief interpretation and discussion. Keep in mind that I did not obtain a local medical license for this trip, so I was not actively participating in the care of these patients, but rather acting in the capacity of an educator and/or advisor. As a consequence, I did not obtain detailed demographic information about most of the patients we saw, and the details of many of the cases are based purely on my (admittedly spotty at times) memory. In the end, my vagueness and poor memory also serve to protect the identities of the patients and their families.
With all that being said, let’s jump right in and see the magic of #POCKUS!
Mid-60s female presented to the EMD complaining of shortness of breath. She reported to the registrar (Dr. Abedi Zakayo, who performed this ultrasound) that she had undergone surgery for some kind of rectal fistula about 2 weeks prior, and that last night around midnight she experienced sudden onset of severe shortness of breath while sweeping in her house. She was a known hypertensive, but had no other major medical problems. Vitals on arrival were fairly reassuring, and she was able to tolerate laying flat for the POCUS exam. She did not have any significant leg swelling or pain as far as I can recall.
Indication for POCUS Exam
This patient presented literally 20 minutes after I had finished giving my first lecture on POC echocardiography, during which we discussed how to identify right heart strain. Dr. Zakayo pulled me aside and told me briefly about the patient and asked, “Can we do an echo?” I said, “**** yeah, let’s do it!” (I’d like to think I said that just in my head and what came out aloud was much more professional, but at this point, I really can’t be sure). Given the patient’s HPI and the fact that she was mildly hypoxic and fairly tachycardic (HR in the 120s or so), we were definitely on the prowl for signs of acute right heart strain, which is fairly rare even amongst those with decent-sized pulmonary emboli (PEs), so I wasn’t really that optimistic.
POCUS Images and Interpretation
The parasternal long axis (PSL) view was fairly unremarkable with regard to LVEF, and there was no evidence of a pericardial effusion. The RV did appear a bit large and hypokinetic, but obviously the PSL is an adequate view for determining RV strain, so we quickly moved on to the parasternal short axis (PSS) view.
Now THAT is NOT a subtle finding. The view itself was only a tiny bit tricky to obtain, but once the anatomy revealed itself, the pathology became very evident. The above clip clearly demonstrates a very dilated and hypokinetic RV (chamber on the top left of the screen) with significant paradoxical septal motion (the septum between the chambers collapses towards the LV and forces the LV to form the infamous and rarely seen “D sign”). This image alone basically checks all the boxes to indicate acute right heart strain, which in this case we can assume is due to a large acute PE.
The apical 4 chamber (A4C) view is somehow even more striking. Again, we can see that the RV (chamber in the upper left of the screen) is both dilated and hypokinetic when compared to the LV (TECHNIQUE NOTE: this view is slightly rotated from the ideal view; the ideal view would show the heart perfectly vertical and with all 4 chambers seen, and with both the mitral and tricuspid valves equally represented and opening side-by-side; the downside of being slightly rotated is that the RV in my view could appear to be more dilated only because it’s a mid-sagittal slice compared to an oblique cut through the edge of the LV; this is precisely why we capture multiple views to confirm normal and abnormal findings and avoid unintentionally misleading artifacts). The most striking part of this clip is that it demonstrates and even more rare sign of acute right heart strain: McConnell’s Sign.
McConnell’s Sign is commonly described as “RV hypokinesis or akinesis with apical sparing.” The clip on the left shows hypokinetic walls in most of the RV, while the clip on the right seems to show an RV apex that is cranking away. But don’t be fooled, this is merely an illusion – the RV apex has essentially no intrinsic movement, just like the rest of the chamber; instead, it is mechanically coupled to the LV, and when the LV contracts, it pulls the RV apex along for the ride. This is always true, but typically only becomes apparent when the RV suddenly juts out past the tip of the LV. This finding is quite specific for acute right heart strain.
Based on these images, along with the patient’s HPI, Dr. Zakayo diagnosed the patient with an acute large PE, and immediately began anticoagulation with heparin. Shortly after this, we obtained an EKG, which was really just the cherry on top of the cake.
In a patient with so many zebra-type findings, the EKG showing the classic PE finding of S1Q3T3 (S waves in lead I, pathologic Q waves in lead III, and inverted T waves in lead III) was just perfect. This is the finding that every medical student can quote as the “classic” finding of PE, but rarely realize that it is neither sensitive nor specific, being present in only ~15-20% of acute PEs. In fact, it’s so rare that I’ve only seen it “in the wild” once in my 5 years of training in and practicing emergency medicine. Well…now twice.
Thanks for reading! Feel free to share this post with your friends, or like/share/retweet on your favorite social media platform. See you next time, and until then…happy scanning!