This is a 76 year old female with an extensive medical history including atrial fibrillation who presented to the emergency room with significant epigastric pain, shortness of breath, and fatigue. Elevated cardiac enzymes and her hemodynamic instability were concerning for cardiogenic etiology of shock. She was transferred to the MICU for further stabilization and work up of possible acute coronary syndrome. A formal echo was done shortly after her admission and showed a left ventricular thrombus. This was treated with a heparin drip. After a couple days of treatment her hemodynamics began to stabilize, but she continued to remain dyspneic. A bedside ultrasound was requested to evaluate her heart. This is where I came in the picture. These are some of the views we obtained of the parasternal long axis (PSLA) of the heart.
Ok, so here we can see the RV, LA, LV, LVOT, Ao, MV, AV, and the bright hyperechogenic pericardium. At first glance this looks like we’ve captured every structure and chamber of the heart we need to see in the PSLA and can be confident there’s no pericardial effusion, right? Actually, not so much. Although we’re seeing a great view of the heart, there is one very important structure we -must- see to be confident we aren’t seeing an effusion around the heart. Do you remember which structure? That’s the -descending- aorta (DA). In order to view this, we have to maximize the real estate of the screen.
“Maximizing the real estate” means that in order to get the best view of the structures you’re evaluating, you must adjust the depth accordingly to fit that structure in the -entire- screen without wasting any space. This makes what you’re evaluating maximally magnified. But it’s also important to know what you’re most far field structure should be. This prevents you from missing any important structures. In this case, the DA should be the most far field which means lowest on the screen. Here’s a better PSLA view with the DA in the image:
Ok good! So now we can see the DA in the far field. And look, there’s a large black, anechoic strip coming across the screen. So now can we say there’s a pericardial effusion? Well, not exactly. Recall from my colleague Matthew Stevenson’s case on how to distinguish a pericardial effusion from a pleural effusion, you must look at the anechoic strip relative to the DA. In this case, it is in the same plane, or even posterior, to the DA. That tells us this is a pleural effusion! Here’s a video so you can get a better look at this:
You may notice in this video you can see the coronary sinus (the very small anechoic circle just far field to the LA) which will tell you where to expect to see a pericardial effusion. There may be some evidence here that there is some effusion, but it is only trace at best.
So instead of finding something on the cardiac ultrasound exam to explain this patient’s dyspnea (eg: pericardial effusion causing tamponade, decreased global function/contractility causing pulmonary edema, or even the LV thrombus that was previously seen), the most likely problem in this case is the pleural effusion! Sure enough we decided to scan the left posterior-lateral alveolar pleural syndrome (PLAPS) point to evaluate for pleural effusion and here’s what we saw:
A huuuge effusion! You’ll even notice there is significant lateral and medial lung consolidation giving us one of my all-time-favorite sign names, the jelly fish sign. This effusion extended all the way to the anterior axillary line suggesting it was very very large. With an effusion this large it’s important to evaluate the other side. Here’s the right PLAPS point.
Again we’re seeing another large effusion with some lung consolidation. This lady got a left thoracentesis later that day which significantly relieved her dyspnea, and actually also required a right thoracentesis the next day after being evaluated again with ultrasound. She was transferred out of the ICU after that with pleural fluid labs pending.
So in summary:
– Always maximize the real estate of your image AKA know what structures should be most far field and bring the edge of the image just below that
– In the PSLA view, make sure to have the DA in your far field
– The DA will help you distinguish between a pericardial vs pleural effusion
– If you see a pleural effusion in the cardiac scan, you should further evaluate it at the L PLAPS point