Presentation on theme: "FATE (Feline Aortic Thromboembolism, or Saddle Thrombus)"— Presentation transcript:
1FATE (Feline Aortic Thromboembolism, or Saddle Thrombus) De-ale lui Mitik (2008 – 2013)FATE (Feline Aortic Thromboembolism, or Saddle Thrombus)Octombrie 2013
2What is a Saddle Thrombus? What are the Symptoms? De-ale lui Mitik: Case study * (Symptoms Description, Vet Examination, What is a Saddle Thrombus, How can you Know this Before, Treatment, Finish)What is a Saddle Thrombus?What are the Symptoms?What to Expect at the Veterinary HospitalCan Anything be Done to Prevent a Saddle Thrombus?Can a Clot go Anywhere else Dangerous?What Animals are Affected?TreatmentPreventionVet Cardiologists in RomaniaMore Info*based on a true story
3How did we start it? ( Besides our sad story) When we were researching this topic, we found so many sad stories because of the poor outlook or prognosis for a cat stricken with saddle thrombus (also known as saddle thrombosis or aortic thromboembolism). To all of the wonderful pet parents who have suffered a loss, you have our sincerest sympathy.Is thromboembolism present at humans too?Venous thromboembolism (VTE) is a major public health problem worldwide, contributing to an estimated >500,000 deaths in Europe and up to 300,000 deaths in the United States (US) each year. VTE creates a major burden on healthcare systems with management of the condition often extending far beyond the initial event.
4De-ale lui Mitik : case study Symptoms description: In the afternoon you hear a strange crying, meowling and you suddenly realize that your kitty companion is nowhere to be seen. You look everywhere and finally you find him laying down. Immediately, you become alarmed when you reach in to lift him and he lets out a strange and horrible cry you’ve never heard from him before. He was literally fine one minute, and the next, he is dragging himself into the family room by his front paws. You discover that your cat had thrown up, he is kicking his hind legs and when you want to pat his head, he leave out a terrible cry. You immediately take him to the vet. The vet give him an examination and inform us he is pretty sure he had thrown a clot. Vet Examination: The vet performs the fastest physical exam in the world before announcing he’ll be right back with a dose the strongest pain reliever he’s got. A technician is already placing an IV catheter. Another is taking his temperature and preparing the x-ray machine. Meanwhile, Kitty’s eyes are wide with panic. He administers the dose, and less than half a minute later Kitty relaxes. But it’s not enough. A more cautious physical exam reveals that more pain medication is in order. Another dose. Now Kitty looks near-catatonic. Your vet reassures you that the second dose was necessary before taking x-rays. He then launches into what seems to you a too-calm explanation of your cat’s problem:“He’s almost certainly suffering from a saddle thrombus”. Then he explains:
5What is a saddle thrombus: “A thrombus is a clot that forms in the bloodstream, in this case usually in the heart. When it’s dislodged from the heart and enters the aorta it ends up lodging itself at the bifurcation of this large artery as it branches off into the smaller arteries that supply blood to the hind limbs. When it gets stuck it’s now called an embolism, and the result in the case of a saddle thrombus (an embolism at the base of the aorta) is that it cuts off the main blood supply to the back legs; an extremely painful condition.“You touch the back legs and see that they are definitely colder than his front legs.Your vet now shows you the x-rays and you can see no break. Just a larger than normal heart and some fluid in the chest. He explains that Kitty has congestive heart failure along with serious heart disease and this latter issue is what precipitated the formation of the clot. "Nearly 90% of saddle thrombus cases have underlying heart disease," he adds.The congestive failure (the inability of her heart to pump the blood effectively, thereby allowing fluid to accumulate in her lungs) came later, probably as a result of the serious stress she was suffering.How can you know this before? You desperately ask, “But he was just here three months ago. How could you not know he had heart disease?”Sheepishly, your vet explains that some heart conditions do not make themselves known through standard physical examination and laboratory testing.“Performing a cardiac ultrasound is sometimes the only way we can determine this. EKGs are often inconclusive in these cases, though that may have helped,” he concedes. “But it’s just not yet part of our standard screening for cats. Not when everything else checks out fine. A control to the vet cardiologist is mandatory.”
6“Our job now is to decide how we treat this “Our job now is to decide how we treat this. Why don’t we focus on that for the moment?” he urges.Treatment: That’s when he gives you two choices:1) Immediate intensive care at the specialty hospital, where they’ll place your Kitty in an oxygen cage and supply drugs to support the heart and treat the congestive failure, and administer blood thinners to help dissolve the clot.Surgery can sometimes be effective when the clot is caught very early on. In this case surgery’s not likely an option due to his congestive heart failure.There will be more x-rays, more labwork and an ultrasound of his chest. In 35-40% of treated cases, cats will recover well enough from the damage done to their nerves (a result of the poor blood supply) to be able to use their hind legs again. Because of his congestive heart failure, however, his chances are slimmer than that. He may well die during treatment.2) The only other choice: euthanasia.Finish: The first 24 hours are decisive. You leave the cat at the vet for 24 hours intensive care but after five hours your vet calls you and gives you the worst news ever: he dies in spite of the internal medicine specialist’s best efforts.
7What is a Saddle Thrombus? This is a condition that affects cats and occur very suddenly and often without any previous signs or symptoms.One tends to feel apprehensive about a condition with the acronym of FATE. Rightly so. FATE (feline aortic thromboembolism) is a serious and painful condition with serious implications. It comes on suddenly and appears to paralyze the cat, causing one or both rear legs to become useless and even noticeably cold. The cat will hyperventilate and cry out with extreme pain. Despite the extreme presentation, the cat may be able to recover from the episode but it is important to understand how it came to be in order to make decisions.A thrombus is a large blood clot.What is a Saddle Thrombus?The aorta is the largest artery in the body. It stems from the heart itself, where it arches back and runs down the length of the back, ultimately splitting into the arteries supplying the back legs. The split where the aorta becomes the left and right iliac arteries is called the saddle.A saddle thrombus is a blood clot that breaks off from a larger blood clot in the heart, travels down the aorta and lodges at the saddle. Not only is the blood supply to one or both rear legs cut off but a metabolic cascade results leading to the release of assorted inflammatory mediators, especially serotonin. The muscles of the rear legs become hard, and the foot pads become bluish in color; the condition is extremely painful. The inflammatory mediators readily lead to circulatory shock.72% of cats with a saddle thrombus have both rear legs affected.
8Where the Saddle Thrombus Came From The saddle thrombus comes from a larger clot in the left atrium of the heart. This obviously begs the question as to why there would be a large blood clot in a cat’s heart. In fact, 89% of cats with a saddle thrombus have heart disease. Heart disease leads to turbulent blood flow which encourages the formation of clots.Not every cat with heart disease will form an abnormal clot, in fact most will not; but there is presently no clear why to predict which cats will form these clots and which ones will not. In cats with hypertrophic cardiomyopathy, the most common form of feline heart disease, the size of the left atrium is one factor that is considered. The presence of “smoke” in the atrium during echocardiography is another factor. (Smoke is the wispy material seen in the circulating blood.) Both these factors are considered controversial.What sort of heart problems can cause the clot?Hypertrophic Cardiomyopathy (HCM) – by far the most common.Restrictive Cardiomyopathy (RCM)Dilated Cadiomyopathy (DCM)Mitral Valve Disease (MVD)Atrial Tumours/Other Cardiac Tumours.Sadly many of these heart problems (HCM, RCM and DCM) can often be present without any clinical signs or overt signs of cardiac disease. This means that often neither the owner nor your vet may know or be suspicious that a heart problem is present. Rather alarmingly, a thromboembolism can sometimes be the very first symptom of a heart problem.In 76% of cats with saddle thrombus, the FATE episode was the first sign of heart disease.
9Will the Cat Regain Normal Use of his Legs? The cat with a saddle thrombus is likely in shock. There is a question of survival from the shock as well as a question of whether or not there is heart failure. Obviously, heart failure is potentially life threatening as is circulatory shock. Assuming everything goes well, and the heart failure and/or shock are either not present or are readily controlled, you still end up with a cat with heart disease and big blood clot that could spit off another embolism at any time. Because of the potential for repeat episodes and need for long-term treatment of heart disease, not to mention the seriousness of the cat’s predicament, 25% of pet owners elect euthanasia without attempting treatment.Of the remaining cats who get treatment, the following statistics have been published:- 50% of treated cats survived to be discharged from the hospital. - The median hospitalization time was 2 days. - The median survival time of cats that did not present in heart failure was 223 days. - The median survival time of cats that did present in heart failure was 77 days. - Of cats who used aspirin as their main clot prevention drug after discharge, 25% of them had at least one more FATE episode at some point (usually in 6-12 months). - Occasionally a cat would lose tissue from loss of blood supply or even require limb amputation but these turn out to be exceptions to the rule. Most cats recover normal limb function after their FATE episode.Expect limb function to begin to improve after 2 to 3 weeks. The cat may require a great deal of nursing care until he is able to walk.
10What are the symptoms of a saddle thrombus? The signs will normally come on incredibly quickly (within minutes) and are severe and distressing. Signs may include:Sudden onset severe pain – manifested as howling/crying/screaming.Hiding away and not wanting to be moved or touched. Cats can be quite aggressive due to the pain.They are often “open mouth panting” or showing a marked increase in respiration rate.They usually cannot walk and may drag one or both back legs behind them when they try to move.The affected limb(s) are often very cold to the touch (especially the paws) and the toes may have a blue/pale color to them.After a few hours the limb(s) will effectively be “dead” and then the pain seems to go. If an owner is not present during the early stages of this disease, the cat may present as a cat which is comfortable but cannot use the limb(s).Many people mistake the symptoms for signs of trauma such as a broken back, broken leg or being hit by a car. The signs can come on so quickly that cats can go from being completely normal to being in severe distress in the matter of a few minutes.These symptoms are a TRUE EMERGENCY and your vet should be called as soon as possible.
11What to Expect at the Veterinary Hospital Once the doctor determines that the cat most likely has a saddle thrombus, further diagnostics will be needed as well as treatment. The cat will need medication for the pain and medication to reduce the ability to clot. Usually treatment is started with injections and changed to oral after the cat is eating. The pain of the condition generally is subsiding after the first 24 hours and the muscles become softer after 2 to 3 days.Cats with a rectal temperature of 98.9º or higher have a 50% or higher chance of survival. Body temperature turns out to be a very important parameter for prognosis.Checking to see if a pulse is present on the back toes (a special machine called a Doppler machine is used that detects blood movement in the vessels over the toes).Checking the glucose levels from the affected foot/feet and comparing them to a normal foot. If the blood supply is disrupted, the glucose level from the suspected limb(s) will be considerably lower.
12Fluid therapy is tricky as the heart will be sensitive to being overloaded but the circulatory shock will need intravenous fluids. There is a bit of a tightrope to walk. This is one of the pitfalls in therapy for this condition.Expect radiographs of the chest to be needed to help determine if there is heart failure. It can be difficult to tell if the cat is in heart failure. Almost every cat with a saddle thrombus will appear to pant or at least will breathe rapidly simply from the pain of the condition, so this normally useful parameter is not helpful. Radiographs will help look for fluid in or around the lungs that would indicate that heart failure therapy is needed in addition to treatment for the saddle thrombus. Furthermore, 6% of cats with a saddle thrombus do not have heart disease and instead have cancer. In most of these cancer cases there is a lung tumor; chest radiographs can identify this type of cancer.Blood tests will also be needed to assess the cat’s general health and ability to tolerate medication. It is common to find evidence of liver cell death on basic blood tests, which is a common event after circulatory shock. Kidney function is also often compromised by the shock and must be assessed. Elevated potassium levels tend to bode poorly for survival. Echocardiography is the cornerstone diagnostic of feline heart disease and should be done as soon as the patient is stable enough for it. This will allow for classification of the cat’s heart disease and determine what long-term medicines are needed.
13Can anything be done to prevent a saddle thrombus? Prevention is certainly the way forward. If your vet is worried about the presence of heart disease then it may be prudent to put the cat on certain “anti-clotting” drugs as a prophylactic measure. Heart disease in cats may present as:An audible heart murmurA change in rhythm (either an abnormal rhythm or a gallop rhythm)Breathing problems due to fluid in the lungs or around the lungs.If your vet suspects heart disease, then it may be necessary to do a blood test, ultrasound scans (echocardiography) or may require referral to a heart specialist.Sadly, as mentioned before, not all cats with heart disease will have symptoms.Can a clot go anywhere else dangerous?Yes it can. Sometime when the clot leaves the heart it can affect one of the front legs and so you get similar symptoms but with a front leg affected rather than a back leg/legs. For anatomical reasons if a front leg is affected it is usually the RIGHT leg.Embolisms can also affect the lungs (which can cause sudden death) the brain (which can cause stroke like symptoms) or other organs such as kidneys, guts etc. These locations are encountered far less frequently than the back legs as described above.
14What animals are usually affected? There are certain breeds which are predisposed to heart disease, and therefore will be more prone to forming a thromboembolism. These are the Maine Coone, Ragdoll and Norwegian Forest Cats. However any cat can suffer from heart disease and so the condition can occur in any breed, especially mixed breeds. It is more common in younger animals (average age 4-10yr old) and male cats do seem to be slightly more likely to suffer from the condition for some reason.Saddle thrombus are seen almost exclusively in cats.Cats are not the only ones that we see with blood clot problems. We are recognizing more dogs with problematic blood clots. We see dogs with blood clots in their lungs, spleens, almost anywhere. They are often due to a host of underlying diseases, too, but the diseases are frequently more manageable than the feline variety. A few disorders you may have heard of include Cushing’s disease (an adrenal gland disorder), some cancers, immune-mediated hemolytic anemia (IMHA), heartworm disease and the medical mouthful of glomerulonephritis (a kidney disorder). More info regarding clots at dogs may be found attached:
15Treatment:Unfortunately, at this time there’s no approach to the treatment of this condition the veterinary community considers adequately effective due to the severity of this condition and the advanced nature of the underlying cardiac disease most of these cats suffer from.Some cats, however, can recover fairly well, especially if they receive immediate treatment, if their cardiac disease is not so severe, the blood clot doesn’t completely occlude blood flow, and additional thrombi are not noted in the heart. These approaches are most often undertaken in these cases:Pain managementTreatment of any concurrent heart failureTreatment of any electrolyte imbalancesSupportive therapy (fluids, feeding, etc.)Treatment of the thromboembolismUnfortunately, studies have thus far shown that treatment designed to “dissolve” or remove the clot is no more effective than supportive care alone. Nonetheless, aggressive treatment through these methods continues as veterinary medicine attempts to find a satisfactory solution to ATE. These following methods are considered most commonly employed in these cases:Heparin and/or aspirin (“blood thinning” drugs to help prevent further clot formation)Thrombolytic drugs (to help “dissolve” the clot itself, sometimes applied to the clot itself)Surgery (to remove the clot)
16Vet Cardiologists in Romania: Prevention:There is no known mode of prevention for most of the cardiac diseases that predispose cats to saddle thrombus formation. The actual prevention of thrombus formation, however, has been the subject of considerable investigation and even dispute within the feline veterinary community over the past decade.Though not yet proven too satisfactorily effective, anti-coagulation treatment is often initiated in an effort to prevent further thrombosis for cats with cardiac disease. This is typically accomplished with medications such as aspirin, warfarin, heparin, clopidogrel, or coumarin.Vet Cardiologists in Romania:Dr Calin Serdean:Dr Florin Leca