Cath Lab Digest - March 2008 - (Page 58)

58 ASK THE CLINICAL INSTRUCTOR MARCH 2008 Ask the Clinical Instructor A Q&A column for those new to the cath lab Questions are answered by: Todd Ginapp, EMT-P, RCIS, FSICP 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. “Recently, we had a patient in the lab for a cath, and the doctor stated that he suspected the cause of the heart failure to be amyloidosis. What? I’ve never heard of that.” — Email from anonymous to tginapp@rcisreview.com A myloidosis (am’i – loy- doh’sis) is a disease characterized by extracellular accumulation of amyloid in various organs of the body.1 The cause of this disease is the deposit of amyloid, a type of protein, that when abnormally present in the body, can attach itself within the tissues and organs of the body. If these deposits replace or surround muscle sections, it can make it hard for that muscle or structure to work properly. This is a rather rare disease that is sometimes also called an infiltrative disease. There are many types of amyloidosis and cardiac amyloidosis is one of them. Cardiac amyloidosis is more common in men than in women and the disease is rare in people under age 40. This disease can also be known as the “stiff heart” syndrome or secondary cardiac amyloidosis. The primary concern is that when these deposits take the place of normal heart tissue, the heart becomes “stiff.” It is the most typical type of restrictive cardiomyopathy. Other types of restrictive/infiltrative diseases are sarcoidosis (a granuloma disease), hemochromatosis (high deposits of iron in the muscles), fibrosis from radiation, and various tumors and infiltrations of the heart. The cardiac variation of this disease can present with 4 specific syndromes: restrictive cardiomyopathy, systolic heart failure (cardiomyopathy), orthostatic hypotension (very poor prognosis) and a conduction pathway disease. The patient who comes to the lab can have many complaints, but some common ones usually occur, which can include palpitations, swelling of the legs and ankles, a history of excessive urination at night, fatigue, shortness of breath at night or trouble breathing while lying down (orthopnea). Because of the effects of the amyloids on the heart muscle, these patients can have congestive heart failure due to the cardiomyopathy. Unfortunately, the only definitive diagnosis of cardiac amyloidosis is a cardiac biopsy. If you don’t perform those procedures in your lab right now, chances are you never will, since it is usually reserved for transplant and research facilities. With a cardiac biopsy, a special catheter is placed within the heart chambers, and a “bite” is taken out of the tissue (Figure 1). This tissue is then sent to the pathology lab for analysis. Without the use of a biopsy, diagnosis is made by history, signs and symptoms, and by ruling out other diseases. Sometimes a measurement of circulating serum proteins can be helpful in the confirmation of the disease3 or proteins in the urine can provide clues to the cardiologist. Now you know that these patients suffer from cardiomyopathy because their heart muscle is not allowed to function properly. When these patients receive a cardiac catheterization, we might see some specific things. If the heart muscle is “stiff,” we will see an elevated left ventricular end-diastolic (ED) pressure. If the myocardium is diffusely fibrotic or infiltrated with the amyloid, a very high end-diastolic stretching force may be required to produce even a normal end-diastolic sarcomere length.2 Remember that sarcomeres are the components in the heart muscle that contract and relax. There may need to be more pressure placed on them to relax in order to allow the heart to fill with blood and also Figure 1. The catheter will be inserted into a vein or an artery, under fluoroscopy, depending upon from where the sample needs to be obtained. A procedural note: ensure that the jaws, or bioptomes, are CLOSED during insertion. Once the sample is obtained, the bioptomes should also remain closed during catheter removal. (Image courtesy of Cook Medical.) get a proper contraction to expel the blood from the ventricle. This “forced filling” pressure of the ventricle results in higher end-diastolic pressures. On the left ventriculogram, you will likely see the classic cardiomyopathy silhouette (large left ventricle, poor ejection fraction), as well as a large atrium. The large atrium is also part of the cardiomyopathy process due to the inability to get all the necessary flow into the left ventricle. This leaves the atrium “holding the ball.” Over a period of time, the atrium will expand/enlarge to accommodate this flow imbalance. With today’s echocardiogram technology, there is seldom a need to perform a right heart catheterization (RHC) on these patients. If a RHC were performed on the symptomatic patients, there would likely be the classic ‘dip and plateau’ square root sign. This is indicative of the impairment of chamber filling due to the restrictive pathology (Figure 2). There may also be times where these patients come in with what appears to be an acute coronary syndrome (chest pain, dyspnea, electrocardiogram changes, etc.), but after angiography, the coronary arteries appear normal. If the amyloids are deposited in the intramural (in the muscle wall) arteries, particularly in the media and adventitia layers, there can be impairments in coronary perfusion.3 This lack of perfusion can create chest pain due to the lack of proper oxygenation to the muscle. However, the main arteries will appear ‘normal’ during angiograms. These patients have a poor prognosis after symptoms appear and once they are diagnosed. Cardiac involvement generally denotes a high mortality rate, regardless of the method of treatment. The median survival rate from the onset of congestive heart failure is only 6 months.4 Syncope indicates a poor prognosis as well, and is often a precursor of sudden cardiac death.5 In the presentation of cardiomyopathy, these patients may only have a life expectancy of a few years. Heart transplant is generally not an option because amyloidosis will also affect other organs at the same time, excluding the individual from being a transplant patient. Treatments are generally based upon managing the symptoms without interfering with cardiac output. During left ventricular analysis, a left ventricular ED pressure of 25 or more is not uncommon. However, if the increase in ED pressure is treated, a reduction in the sarcomere stretch can occur, and this will result in an equal decrease in cardiac output. Pacemakers and ICDs may be used in cases where cardiac amyloidosis is thought to be in early stages. A recent case study we are familiar with involved a 49-year-old male who

Table of Contents Feed for the Digital Edition of Cath Lab Digest - March 2008

Cath Lab Digest - March 2008 Are You Being Paid Fair Market Value in 2008? A Cardiac Cath Lab Professionals Survey by Cath Lab Digest and the Society of Invasive Cardiovascular Professionals Saint Joseph’s Hospital Invasive Imaging Tools for Optimizing Coronary Stent Deployment Contents Clinical Editor’s Corner A Workflow Revolution in Cath Lab Reporting Advantages of a New Digital Lab at Baystate Medical Center Cardiac Computed Tomography: What Does it Mean for the Cath Lab? The Latest in Cardiac Magnetic Resonance Imaging (MRI) Cellular Cardiomyoplasty and Cardiac Regeneration Intravascular Ultrasound in the Cath Lab: A Powerful — and Underutilized — Tool to Improve Patient Outcomes The Stentplus™ Patient Success Program Cardiac Cath Lab Clutter — or, Spring into Action! Groin Bleeds and Other Hemorrhagic Complications of Cardiac Catheterization: A List of Relevant Issues Ask the Clinical Instructor: A Q&A Column for Those New to the Cath Lab What Do You Think? Experience with a New Guidewire: The Terumo Runthrough NS The Ostial Pro™ Stent Positioning System: Perfecting Aorto-Ostial Stent Placement Precious Minutes The Ten-Minute Interview with…Mark Bowles, BSN, CCRN Vascular Care in the Cath Lab: Planning a Smooth Transition Cath Laughs CMS 2008 OPPS Final Rule Review An Extensive Set of Review Courses for the CCI Basic Science, Non-Invasive Echocardiography and Vascular, and ARDMS Ultrasound Exams Meetings Calendar CEU Education Center Clinical & Industry News STEMI Interventions Classifieds Advertisers Index

Cath Lab Digest - March 2008

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.