Hypertension

Hypertension affects 10 to 15 percent of the school age population. Hypertension often results in cardiac abnormalities even in children. Hypertension can often be controlled by non-drug therapy.

Several studies have suggested that as many as 15% of children and young adults have blood pressures greater than the 95th percentile for age. One third of these individuals will remain hypertensive into adulthood. Children whose parents have hypertension are at greater risk for developing hypertension and require close observation. If one parent is hypertensive, 1/3 of their children may develop hypertension. When both parents have hypertension, the risk is doubled. Left ventricular hypertrophy can be detected in 80% of pediatric patients with hypertension. The long term consequences of this are as yet unknown.

Management of Childhood Hypertension

Diagnosis and Evaluation

Upon documentation of elevated blood pressures on three separate occasions, patients will undergo an evaluation process designed to identify causes of hypertension which can be corrected surgically or medically. The evaluation procedure will include a physical examination, blood chemistry, urinalysis, and non-invasive cardiac testing. When deemed appropriate, a renal scan and ultrasound will be performed as well as further assessment of renal and endocrine function. During this evaluation, the cardiac status will also be assessed to aid in future management.

Treatment

Because the level of hypertension in most pediatric patients is mild, avoidance of drug therapy is desirable.   We have found that several non-pharmaceutical methods are available which can effectively control and even correct hypertension. Weight loss, reduction of salt intake, and exercise training are some of the effective means of reducing blood pressure. These various forms of treatment will be specifically employed to suit the needs of each patient.

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Kawasaki Disease

 Definition

This is a disease in which the immune system of the body attacks ones own tissues for no clear reason. There have been many theories, but non are conclusive. The focus here is on the way the heart is affected.

Effects

There is typically high fever for few days.

The heart is affected by more than one way. There may be abnormal function of the muscles or valves of the heart, or there may be fluid accumulation in the envelop surrounding the heart, or the disease process may affect the arteries supplying blood to the heart (coronary arteries). These coronary arteries may become enlarged and eventually develop clots in them which have the potential of clogging the artery causing a heart attack.

Course

The fever and other symptoms may last for few days. Once diagnosed treatment should be instituted so as to prevent heart involvement, which if occurs is usually few days after the other symptoms. If coronary arteries are involved, which occur in only a small portion of patients, then further damage to the heart may progress.

Treatment

There are two drugs used in this disease. The first is an intravenous medication (immuneglobulin) which is given intravenously. This must be given in the first week or so of illness. This agent significantly reduces the risks of affliction of the coronary arteries.

The second medication is Aspirin, other drugs such as Tylenol are not effective. This is given initially in high doses to reduce the inflammation, then reduced to a smaller dose if heart disease is suspected.

Looking at the coronary arteries using ultrasound machines (echocardiography) is essential, and should be done once the diagnosis is done, then one week later. Repeat studies is then done up to one year after the illness.

Complications

The goal of treatment is to prevent involvement of the coronary arteries because of the potential serious complications (heart attack) secondary to that.

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Rheumatic Heart Disease

Definition

An autoimmune disease in which antibodies produced by the body against streptococcal infection cause damage to various parts of the body including the heart, brain, joints and skin.  It is not clear why it affects a small  percentage  of those infected with streptococcal pharyngitis.

Incidence

Rheumatic fever is no longer common  in the United States.  In the past it used to affect 12 per 100,000 of the population.  These days it affects 2.9 per 100,000.

Effects

The effects of rheumatic fever include (Jones criteria for diagnosis)

Carditis is seen in 50% of patients with rheumatic fever.  In addition to affecting the heart muscle, it also affect cardiac valve.  Damage to these valves may be permanent leading to cardiac valve narrowing (stenosis) or inability to close properly leading to leakage of blood (regurgitation).  Changes noted in the early part of the disease are due to inflammation and dilation of the heart, which in most cases are reversible changes.  Even changes in the cardiac valves may resolve.  However, in a certain percentage, the damage is persistent and narrowing as well as leakage of the valves result.  The mitral valve is the one affected most, followed by the aortic valve.  The pulmonary and tricuspid valves are the least affected.

Course

Children with rheumatic heart disease develop a chronic illness due to damaged cardiac valves.  Every time there is recurrence of rheumatic fever, there is a good chance for further damage of cardiac valves.   If significant cardiac damage develops, then congestive heart failure may result

Treatment

Eradicate streptococcal infection by antibiotics (penicillin) and prevent the occurrence of future streptococcal infection by taking preventive doses of antibiotics.

If carditis is suspected

Significant valve damage may warrant surgical repair or replacement with prosthetic valves.

Complications

Recurrent rheumatic fever will further damage cardiac valves leading to worsening of heart disease.

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Cardiomyopathy

Dilated Cardiomyopathy

Definition

Disease of the myocardium causing damage to the heart muscles and resulting in dilation (enlargement) of the heart.  The ventricles can not pump blood efficiently resulting in poor cardiac output.  The causes of dilated cardiomyopathy are several, an important cause is viral infection.  It is not known why certain individuals develop viral infection of the heart's muscle while the majority who develop the same viral infection do not develop heart affliction.

Incidence

Seen in 36.5 per 100,000 of the population.

Effects

The dilated and poorly contracting left ventricle will not be able to pump enough blood out to the body, this is termed poor cardiac output.  The body deals with this shortage of blood supply by reducing the blood flow to non-essential parts of the body such as the skin, musculoskeletal system and intestinal tract.  Therefore patients with poor cardiac output would manifest with:

Course

Viral myocarditis may resolve completely and the child can lead a normal life thereafter.  It is thought that one third of patients get better, one third stay the same and one third get worse.

Treatment

Reduce inflammation of the myocardium in the early stages is important in reducing the amount of damage and scarring to the heart muscles.  This is achieved through using anti-inflammatory drugs such as steroids.  In addition medications to help the heart function better could be used, these include:

Complications

In addition to reduced ability of the heart to meet the demands of the body, the stretched and scarred heart muscles may precipitate abnormal heart rhythm, which may be fatal.

 

Hypertrophic Cardiomyopathy

Definition

Thickening of the muscles of the heart, resulting in obstruction of blood flow.   The causes are many, some are genetic with or without a familial tendency.

Incidence

3.2 to 33 per 100,000 of the population.

Effects

Thickening of the muscle of the heart, particularly the left ventricle will lead to obstruction to blood as it flows out.  This may result in heart failure and fainting spells (syncope) due to sudden reduction of blood flow.

Course

If progresses, it may cause abnormal heart rhythm or fainting spells.  Sudden death due to abnormal heart rhythm or obstruction to blood flow may occur.

Treatment

Reduction of left ventricular outflow obstruction and abnormal heart rhythm are the main goals.  The latter should be closely monitored and aggressively treated if encountered.  Reduction of outflow obstruction could be achieved by one of the following methods:

Complications

Sudden death due to abnormal heart rhythm or sudden reduction of blood flow out of the left ventricle due to increase in obstruction.

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Endocarditis

Definition

Inflammation of the lining layer of the heart, causing damage to valves and other structures.  This occur in children with congenital heart disease and is seen in association with some congenital heart diseases more than others. It is rarely seen in the absence of pre-existing heart defect.

Effects

Damage to cardiac valves will result in leakage and narrowing of these valves which may precipitate heart failure.

Course

Damaged cardiac valves may be permanent or temporary.  Prompt treatment with proper antibiotics may reduce the rate of significant damage to the heart valves. 

Treatment

Long coarse of multiple intravenous antibiotics is used to eradicate bacterial infection.  Surgical repair or replacement of damaged cardiac valves may be necessary.

Complications

Inflammatory tissue attached to the heart lining may detach causing damage to other organs such as stroke.