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Heart Disease in Children

Myocarditis is defined as a cardiac process characterized by an inflammatory infiltrate of the myocardium, with necrosis and/or degeneration of adjacent myocytes, not typical of ischemic damage. It is usually of infectious etiology and hereís an extensive list of the types of organisms which may cause myocarditis. By and large we are talking about viral disease. The others can occur but this is by far the most important category of infectious infiltrates of the myocardium, certainly in this country. We are talking about viral myocarditis, especially the

Myocarditis may present in one of three ways. Either incipient congestive heart failure, sudden arrhythmias or perhaps because of sudden arrhythmias, sudden overwhelming cardiovascular collapse. And we have seen this a number of times. Children who appeared to be healthy a day or two earlier, present in shock and often irreversible shock, with or without arrhythmias. One

The treatment for myocarditis: we treat their congestive heart failure with diuretics, digoxin and after-load reduction. Digoxin we do gingerly because these patients are prone to digoxin toxicity and/or arrhythmias. And I should include along with anticongestive therapy, antiarrhythmic therapy if they present with a variety of ventricular arrhythmias. Immunosuppressive therapy is quite controversial in fact these patients have been treated with prednisone. Theyíve been treated with Cytoxan, theyíve been treated with methotrexate. Other immunosuppressive agents, including cyclosporine. The rationale behind this is that in fact the ongoing inflammation seems to be part and parcel of the development of chronic congestive cardiomyopathy. In fact, in clinical trials - there was a large clinical trial in adults which was based on that

Antiviral therapy is partially experimental. There are some specific antiviral agents. Ribavirin in mentioned here. Interferon, ganciclovir, acyclovir for specific viral agents may be helpful, if you can identify the offending virus and treat it specifically. One thing that does seem to be helpful for any viral myocarditis is intravenous immunoglobulin. It may not be curative but it tends to

This is complicated and Iím not going to go through all the lines here, but Iím going to say pediatric patients with myocarditis, about one-third will present with severe congestive heart failure or cardiovascular collapse. About two-thirds will present with mild to moderate congestive heart failure or less lethal arrhythmias. The patients with severe congestive heart failure or shock, a

Kawasaki disease. It is in interesting disease because, despite a lot of investigation, it is still a poorly understood condition. It is common enough to be encountered by most primary care practitioners now and then. And certainly one that needs to be considered in the differential diagnosis of febrile illnesses in small children. Kawasaki disease is an acute febrile vasculitis which occurs in children. It is characterized by mucocutaneous signs and the original name for Kawasaki disease was mucocutaneous lymph node syndrome, as described in the Japanese literature. Characterized by mucocutaneous signs, fever, a certain set of

Whatís a much more important article, though, was in the New England Journal of Medicine in 1986 - it was in August of 86 - a collaborative multi-center United States study investigating the effect of early treatment of patients with Kawasaki disease with gamma globulin for the specific purpose of preventing the development of coronary artery disease. This was a very well-designed, multi-center clinical trial which was planned as a two year study. But the results of this study were so dramatic,

This is a rash. This is a polymorphous exanthem, usually occurring on the trunk. It may look petechial, it may look urticarial, it may look like measles or it may have this kind of diffuse erythema, erythema multiforme type appearance. The distal extremities are also involved. This is not actually showing the acute swelling and redness of the distal extremities. This is showing the later characteristic peeling that the fingers and toes may go through. This isnít particularly helpful in making the acute diagnosis

These other ancillary findings are not part of the diagnostic criteria but they can be quite characteristic. One is irritability. These children are exceedingly irritable and for those of us who have seen this disease a lot, the irritability seems to be - although they are sick with fever and rash and arenít eating very well and they have these cracked lips and this sore looking mouth, all of those

This sounds like almost any other serious viral exanthem and actually behaves that way. Itís a self-limited illness which runs a course of irritability, fever, poor feeding, over two to four weeks. But whatís important about it is, as I mentioned, it has a mortality of 2% due to cardiovascular involvement. This is a normal echocardiogram. A short axis view of the aortic root. You donít see the valve here but what you do see here, this is the left main artery dividing then into the circumflex and the left anterior descending coronary artery. It is not very prominent. You do not see the coronary arteries very well in a normal child. In contrast this is a echocardiogram on a child with Kawasaki disease. The aortic root is here. This is the left main artery with is dilated and aneurysmal. The left anterior descending coronary artery is diffusely dilated. Much more prominent. You might have thought those black lines were perhaps some artifact of the ultrasound, but you would believe that this is a real structure. And itís the prominence of the coronary arteries that is quite striking. If we angiogram that patient we will see that his left main coronary artery is in fact dilated as is his circumflex and his LAD. This is far and away not the worst coronary artery aneurysms that we have seen with Kawasaki disease. This child is still with us and doing okay. This child was not. This is an autopsy specimen on a patient that I followed with Kawasaki disease, back in the early 80ís before we had treatment available with IVIG. We knew this child had coronary artery involvement, we knew he had a dilated left main coronary artery, a diffusely dilated LAD. His right coronary artery was involved as well. He died suddenly about six weeks after dismissal from the hospital, after his acute episode of Kawasaki disease.

So we treat Kawasaki disease during the acute phase with aspirin and antiinflammatory doses and then subsequently if there is coronary artery involvement, with antiplatelet doses of aspirin. But most importantly, we treat with intravenous gamma globulin and we use this recommendation: intravenous gamma globulin in very large doses, 2 grams per kilogram. Thatís a lot of IVIG, administered over eight hours. Sometimes you need to pre-treat with Benadryl and Tylenol, because you may get a reaction to the IVIG. The multi-center study in 1986 showed that coronary artery involvement - across the board in the literature - occurs in about 17% to 20% in patients with Kawasaki disease. Thatís in Japan, thatís in Hawaii, thatís in continental United States. The administration of IVIG during the first ten days of the illness reduces the incidence of coronary artery involvement, at least clinical coronary artery involvement, to about 2%. It doesnít eradicate the involvement of the heart entirely but it substantially reduces the development of those aneurysms that I just showed you, from 17% to 20% down to about 2%. If aneurysms do develop in spite of that therapy, then we also add - in addition to anti-platelet doses of aspirin - we add dipyridamole and occasionally Coumadin.

The mortality involved with Kawasaki disease is apparently related to thrombosis of coronary artery aneurysms because of abnormal flow patterns and stasis in the aneurysm. Itís not due to rupture in the aneurysm, itís due to abnormal flow and thrombosis. We echo these patients during the acute illness and we do a follow-up echo at one to two months, and oftentimes do a follow-up echo at one year, although we are doing this less and less frequently because of the beneficial effect of IVIG that we have seen. We know that when the patients are clean at two months that they are generally - in fact always - clean at one year as well.

Echocardiography is not part of the diagnosis of Kawasaki disease. If one makes the clinical diagnosis of Kawasaki disease according to the criteria that I mentioned, they should have an echocardiogram at the time of that acute illness and after one to two months, but one should not delay or defer treatment with IVIG to make the echocardiogram available. We have a number of interactions with physicians who are treating patients out of the metropolitan area where pediatric echocardiography may not be available. Our usual recommendations, after discussion on the phone - if we agree on a diagnosis of Kawasaki disease - we recommend treatment with IVIG, which is available throughout the state, and following that treatment which is important to prevent the coronary artery disease and also makes the children feel substantially better. We do see significant improvement in

Kawasaki disease that often is a source of question - what causes this condition? Whatís the etiology? The reason I didnít mention it is that we donít know the etiology. In many ways it represents a viral infection but Kochís postulates have never been

The first question is what happens to the aneurysms? Dr. Kato has studied this extensively, the same Kato that wrote about the coronary artery involvement in the first place. And many times they do in fact resolve. We will see an echo picture or an

What age group is this most prevalent? I have seen Kawasaki disease in a three-week-old. Iím absolutely sure it was Kawasaki disease. It was described in the literature as occurring most commonly in children between four months and six years. Iíve seen it as young as three weeks. I think itís rare under three months. Iíve seen it as old as 18-years. Kawasaki disease certainly occurs in older children and adolescents, but is generally a much more mild condition and much less likely to produce coronary artery involvement. The children you really worry about are the male children with high fever and a

How do you distinguish Kawasaki disease from Stevens-Johnson syndrome? Stevens-Johnson syndrome doesnít usually have the fever that you see. Stevens-Johnson syndrome will present with the polymorphous rash and the conjunctivitis. It usually does not have the severe mucous membrane involvement that Kawasaki disease has, although it can. It doesnít have the lymphadenopathy, it doesnít have the fever and doesnít involve the distal extremities as much. But it can be difficult. Certainly I think thatís part of the differential diagnosis of Stevens-Johnson syndrome. Acute streptococcal infections and

Hypercholesterolemia. Total cholesterol under 170 in pediatrics is within normal limits and relatively low risk. Total cholesterol over 200 is a high risk group. In between we call medium risk. Those numbers are going to be slightly different on a couple of other commercials slides that I have. Routine screening is quite controversial. I think right now the pendulum is sort of against the concept of routine screening of all children, although we do screen cholesterol in high-risk children either because of family history or other positive risk factors, or in patients with known familial hypercholesterolemia. I think itís not practical to screen all children for cholesterol partly because it would identify a large number of children with elevated cholesterol that we arenít sure how to deal with. We may be identifying non-disease if we are identifying children with cholesterol over the 95th percentile.

This is a picture, a graphic of the cholesterol molecule. I told you earlier that I was not a virologist. Iím also not a biochemist. Cholesterol is a risk factor and this is an adult cardiology slide, but what this demonstrates is that serum cholesterol across the

Rheumatic fever is not of great clinical importance in 2000. Rheumatic fever is an acute non- suppurative sequelae. It is a condition, which is a sequelae of group A beta- hemolytic streptococcal throat infections.

Rheumatic fever results from a combination of factors. A certain host of a genetic predisposition in childhood, most commonly a female, most commonly African-American and often of poor nutritional state. When she lives in a temperate climate, usually in an urban area, often under conditions of crowding and in the wintertime. When that person, under those conditions, encounters the

Subcutaneous nodules and erythema marginatum. I personally have never seen subcutaneous nodules. I did see a fair amount of rheumatic fever back in the 70ís and early 80ís when I was training in Houston, but I saw patients with arthritis and a lot of carditis. Iíve seen a fair amount of erythema marginatum which is a difficult characteristic to photograph but I never saw a patient with subcutaneous nodules. Perhaps some of you have.

The timed course of rheumatic fever and the timed course of streptococcal antibody titers is depicted here. From zero time, at the time of the streptococcal infection, you will see the strep titers peak at about five weeks and then decline over the next months. This is the time frame in months. Most of the features of rheumatic fever will appear at about five weeks, during the peak antibody titers. Sydenhamís chorea tends to appear a little bit later. So if you are making the diagnosis based on Sydenhamís chorea, you may see a patient out here at five or six months where the antibody titers have waned. One acquires the evidence of a recent streptococcal infection with a positive culture, which will occur 25% of the time in a patient with rheumatic fever. An ASO titer rise, which will occur 75% of the time, or the most sensitive test which is the streptozyme battery of tests which includes all of these and youíll get evidence of a recent strep infection about 95% of the time. So that helps with

The heart involvement with rheumatic fever may include, most commonly, mitral regurgitation, aortic regurgitation or tricuspid or pulmonary regurgitation less commonly. Chronically we see mitral regurgitation and mitral stenosis along with aortic regurgitation. Acutely we treat rheumatic fever with aspirin, sometimes with corticosteroids and with anticongestive failure if necessary.