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Hello and welcome to Noon Conferences hosted by MRI online. In response

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to the changes happening around the world, and the shutting down of in

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person events, we've decided to provide free daily Noon Conferences to all

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radiologists worldwide. Today we're joined by Dr. Cristina Fuss. She is

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a section chief and Fellowship Director of Cardiothoracic Imaging in the

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Department of Diagnostic Radiology at Oregon Health and Science University

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in Portland, Oregon. After having completed training in both Germany and

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in the US, her interest in aortopathy and heart valves. A reminder that

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there will be time at the end of this hour for a Q&A session.

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Please use the Q&A feature to ask all of your questions,

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and we'll get to as many as we can before our time is

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up. That being said, thank you so much for joining us today, Dr. Fuss. I

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will let you take it from here. Hello. Hello, everybody.

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My name's Christina Fuss, and I'm delighted to be here again.

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So, this is gonna be an imaging primer, and I wanna say upfront that

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I'm gonna talk about devices that I have personally encountered, that I

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have had difficulties with, and this is by far not a complete

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listing of cardiac devices that are available. Also, keep in mind that I

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practice in the United States, so many devices that may be available across

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the world are not available within the United States due to FDA regulations.

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And with that, we're gonna gonna proceed. So the purpose is basically to

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familiarize yourself with novel cardiac devices, how they should be properly

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positioned and the common pitfalls. And I'm not gonna talk about

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TAVR measurements, et cetera, because I think that this is too vast of a

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field to engage, but I'm gonna focus mainly on

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x rays actually, and how these things look like after they have been

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implanted. I'm gonna touch up on pacemakers ICDs, right and left ventricular

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assist devices, both surgical and transcatheter valves and occluder and

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other novel devices. And I'm gonna start with the obvious and the most

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common one that we encounter simply because I just wanna

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get us into the zone. So on this frontal radiograph, you obviously see

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a biventricular pacemaker, and the arrow here is on the

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coronary sinus lead. It's biventricular because the coronary sinus, as you

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know, hugs the left ventricle, and by inserting a lead into that set sinus,

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you can paste the left ventricle without penetrating any inter ventricular

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structures or interatrial structures. This lead obviously within the right

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atrium and this lead within the right atrial appendage receive these every

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day. The importance when you assess these is that you look at

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the intactness of the leads. You also wanna make sure that you always

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have two radiographs to assess the location correctly, because if you don't

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have two radiographs, it's pretty much a weird story. And this is one

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of those cases where we were like, "Okay, now what?" So this lady

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came in with continued chest pain after pacemaker placement and as you can

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see on the frontal radiograph, everything looks fine and dandy. She has

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a left anterior chest full pacemaker generator. Her lead course is downward

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into the projected right atrium, and then the tip is somewhere along the

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cardiac apex. The only problem is that, on the lateral view, you can

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see the lead is going down, but then it's going posterior and it's

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cogging the cardiac slow and posteriorly. Now the question is, where is

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this lead located? And because the patient was experiencing severe chest

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pain, we ended up doing a CT. And I submit to you,

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don't do a CT on every patient, but sometimes you have to,

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to see it better. And again, this is the left anterior chest will pacemaker.

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The lead is in the left subclavian vein, and as we course downward

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into the mediastinum, here in the SVC, we can see the lead appropriately

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positioned. But as we go further down, the lead traverses, the left atrium

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gets out of the coronary sinus, and eventually

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terminates in the left pericardial space. And obviously, this is not a preferred

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location for this particular patient, so the lead was supposed to be in

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the right ventricle, ended up being an extra cardiac, and

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it required extraction in the OR with a cardiac surgeon on standby to

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extract that lead. So keep in mind, if we wouldn't have had the

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lateral radiograph, we would've never seen the malpositioned pacemaker lead.

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So again, if you assess a pacemaker, always

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do that with a two view and not just on a frontal view. This

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is a slightly different device. It's a biventricular ICD defibrillator,

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and how do you differentiate this? It's very simple. It's the thickened,

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padded lead that sort of serves as the defibrillator pad. Again,

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this is biventricular, so you have your right atrial appendage lead, the

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ICD lead or the defibrillator lead is in the right ventricle.

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As you can see on the frontal radiograph, and on the lateral radiograph

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it's anteriorly positioned, and then you have this thinner lead

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going over to the left side. And on the lateral radiograph, you can

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see that it is coursing in the coronary sinus going posterior and eventually

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to the left sided cardiac apex. Again, you want two views to be

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able to assess these. What's the difference with the AICDs? Well,

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obviously, and you know this, but these are patients who are at risk

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of sudden cardiac death, often due to ventricular fibrillation or ventricular

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tachycardia. We have many patients, in our patient population, with hypertrophic

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cardiomyopathy who will receive an implantable defibrillator simply because

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of their increased risk of sudden cardiac death due to their myocardial

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fibrosis and conduction abnormalities. The thick pad or the coil is the

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defibrillator pad, and the vector is between the generator and the thickened

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coil, so keep that in mind. There are newer devices that allow for

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exclusive subcutaneous placement of set defibrillator leads. Remember that

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the defibrillator is the same as you would do when you use these

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external defibrillator paddles in the setting of a code, and you have to

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generate...