Ask the Clinical Instructor: A Q&A column for those new to the cath lab

Todd is the Cardiology Manager for Memorial Hermann Southeast in Houston, Texas. He also teaches an online RCIS Review course for Spokane Community College, in Spokane, Washington, and regularly presents with RCIS Review Courses. We recently saw something weird on a heart cath, where the left ventricle was filling up with contrast during a coronary injection. The doctor said that it was a ‘cameral fistula’. What is that? How does it affect the patient? – CV Tech, Virginia From what you describe, it does appear that it could have been a cameral fistula, also known as a coronary artery fistula. Cameral means “of or pertaining to a chamber…” A coronary artery fistula can be a connection from the coronary artery to a cardiac chamber or to the venous system. In this article, we will address the cameral fistula, which is a connection between a coronary artery and a chamber of the heart. Major sites of the cameral fistula are the right coronary artery (55%), left coronary artery (35%) or both arteries (5%).1 It seems that we notice the left coronary artery fistulas more, because they usually appear more pronounced. The fistulas generally pass directly into the chambers of the heart from the left or right coronary arteries, but can also form channels to related organs within the thorax, such as the pulmonary or bronchial circulations.2 In most cases, the fistula is small, and its presence is insignificant. In some cases, however, the fistula can be large, causing a “steal” from the main artery. This can create hypoxia of tissue distal to the fistula as a portion of the blood flow travels through the communication instead of through the normal vessel. Myocardial infarction has been reported in severe cases of a large fistula. When a fistula is present, that area of the myocardial capillary bed is bypassed as the blood flow dumps directly into the chamber. Some additional complications of cameral fistulas can include pulmonary hypertension and congestive heart failure, bacterial endocarditis, rupture or thrombosis of the fistula.4 These fistulas would need to be treated, whereas the ones we typically notice do not need any treatment. Immediate management is generally not needed. Large fistulas that have created the “steal” phenomenon may need to be treated. Ligation, embolization or transcatheter ablations may be necessary if the patient is symptomatic from the fistula, AND the fistula is clearly defined on angiography.3 Coil embolization at the time of cardiac catheterization is rapidly becoming the treatment of choice.4n View two images of left ventricular cameral fistulas at https://www.rcisreview.com/AskTheInstructorDecember09.htm If you have any questions or if you have a photo or movie that would be of educational value to other readers of this publication, please send it to: tginapp@rcisreview.com [Editor’s note: You are also welcome to post questions to the “Ask the Instructor” column on the Cath Lab Digest facebook page, at www.facebook.com/CathLabDigest]

“Ask the Clinical Instructor” Reader Response

I recently received an email pertaining to the October article about pre-procedural groin management. Dale Hansen’s point is well taken, and should be mentioned as it pertains specifically to that article. Thanks, Dale! Please feel free to send any comments or suggestions about any article that can be passed along to other readers. We are all in this together! “I read your article in the October Cath Lab Digest where you discuss shaving vs. clipping. Well done. I recently learned from a physician providing an in-service to our cath lab staff that he advocates not shaving any patients in the cath lab. When I questioned him about it, he said that they should be shaved in the pre-staging area, leaving the hair behind and before reaching the cath lab. He also pointed out that we then place a Bair Hugger* around the patient that blows the clipped hair around the field. And when I think about it, it makes sense. We are blowing dirty hairs under the cover/drape and they will take the path of least resistance.” — Dale Hansen, Cardiac Cath Lab Manager, Conroe Regional Medical Center, Conroe, Texas *Arizant Healthcare, Inc., Eden Prairie, MN