Pediatric Cardiology

Pediatric Cardiology Services in Boerne, Texas

Dr. Riebel sees patients for all outpatient pediatric cardiology concerns in the Boerne area, including syncope, palpitations, chest pain, and a few more listed below. We offer in-house EKG and Echo services. Happy Heart Pediatrics clinic sees cardiac patients from sports cardiology and newborns through adults with congenital heart disease.



Chest Pain In Children

Chest pain in children and teenagers is actually fairly common. Fortunately, 90-95% of chest pain in children and teenagers is not heart related and usually benign. However, it is important to have a Pediatric Cardiologist perform a thorough history and exam on children and teenagers with chest pain to evaluate for any cardiac causes of chest pain. This typically includes an exam, ECG, and sometimes an Echo.

Chest Wall Deformities

Chest wall deformities include pectus carinatum (“pigeon chest”) and pectus excavatum. These types of deformities occur in about 1% of the population and are more common in males however can occur in females as well. In these conditions, the heart forms correctly but in extreme cases, its function can be impaired. Pediatric Cardiologists determine if cardiac function is impaired in any way by exam and Echo. If necessary, we work closely with our colleagues, Pediatric Surgery, who can evaluate your child for corrective surgery.


Facts about cholesterol

Cholesterol is essential to our bodies to maintain our cell membranes but also is vital in the production of certain hormones, bile acids for digestion, and Vitamin D.

Cholesterol and other fats are transported through the blood stream in the form of round particles called lipoproteins. The two most commonly known lipoproteins are low-density lipoproteins (LDL) and high-density lipoproteins (HDL).

What is LDL (low-density lipoprotein) cholesterol?

This type of cholesterol is commonly called “bad” cholesterol and is the type of cholesterol that can cause atherosclerosis, or “clogged arteries”. LDL comes from unhealthy fats we eat and too much can lead to cardiac issues as adults.

What is HDL (high-density lipoprotein) cholesterol?

This type of cholesterol is known as “good” cholesterol, and is a type of fat in the blood that helps to remove cholesterol from the blood, preventing the fatty build up and formation of plaque. We can increase our good cholesterol, or HDL, by eating foods high in healthy fats like fish, olive oil, avacado, and almonds along with regular exercise.


Congenital Heart Disease (CHD)

Congenital heart diseases are related to congenital heart defects that develop during pregnancy and are present at birth. Congenital heart defects are the most common type of birth defect, affecting one of every 100 babies born in the United States. There are many different kinds of defects, some ultimately requiring intervention by surgery or catheterization procedures. It is very important for children to be thoroughly examined and followed for congenital heart disease.

Heart Murmurs

Heart murmurs are sounds made by blood as it flows through the heart or blood vessels near the heart. Most often, a heart murmur is just a normal sound and is therefore and “innocent murmur” that does not indicate any heart problems. However, some murmurs are indicative of underlying heart disease. It is important to have your child thoroughly examined by a Pediatric Cardiologist to determine the type of heart murmur your child has which includes a cardiac exam and sometimes an Echo.

What are the different types of murmurs?

Happy Heart Pediatrics will evaluate a murmur based on several factors. Murmurs are analyzed for pitch, loudness, and duration. They also are graded according to their intensity (on a scale of one to six, with one being very faint and six being very loud). Pediatric Cardiologists have extensive training in differentiating the types of heart murmurs to determine if it is a benign, normal heart sound, or indicative of underlying heart disease.

Types of murmurs include the following:

Systolic murmur – a heart murmur that occurs during a heart muscle contraction. Systolic murmurs are divided into ejection murmurs (due to blood flow through a narrowed vessel or irregular valve) and regurgitant murmurs.

Diastolic murmur – a heart murmur that occurs during heart muscle relaxation between beats. Diastolic murmurs are due to a narrowing of the mitral or tricuspid valves, or regurgitation of the aortic or pulmonary valves.

Continuous murmur – a heart murmur that occurs throughout the cardiac cycle.

Do all murmurs signify heart disease?

Not all heart murmurs are symptoms of heart disease. Many children have what is known as an innocent murmur. These murmurs are not related to congenital heart defects and are just a normal heart sound that will not cause any problems in the future. They are sometimes heard throughout the teenage years depending on your child’s body type. There is no treatment or follow up needed for children determined to have an innocent heart murmur.

Caring for children with heart murmurs

Doctor Riebel is an expert at diagnosing the cause of heart murmurs and will perform an exam on each child and sometimes an Echo. If any underlying congenital cardiac disease is found, Dr. Riebel works closely with the Pediatric Cardiac Surgery team to determine the best surgical repair for your child which may be open heart surgery or a catheterization procedure.

High Blood Pressure

High blood pressure in children and adolescents

If a child or teenager is sent to Pediatric Cardiology for high blood pressure, Dr. Riebel will first evaluate how often your child has high blood pressure and then look for the underlying cause. Often, high blood pressure can be managed with lifestyle changes including daily exercise and a heart healthy diet. Dr. Riebel will develop a specific plan best for your child and discuss it thoroughly with you. Dr. Riebel will first make sure that no underlying disease is causing your child’s hypertension, such as kidney problems.

What is blood pressure?

  • Blood pressure is the force of the blood pushing against the artery walls.
  • Two numbers are recorded when measuring blood pressure:
  • Systolic blood pressure is the pressure inside the artery when the heart contracts and pumps blood through the body.
  • Diastolic blood pressure is the measure of pressure inside the artery when the heart is at rest and is filling with blood.

What is high blood pressure?

High blood pressure is also called hypertension. In children and teenagers, normal ranges of blood pressure differs based on sex, height, and age. Pediatric Cardiologists evaluate your child’s blood pressure to determine if their blood pressure is in a normal or high range.

Who is at risk for developing high blood pressure?

Children with underlying medical issues such as prematurity or kidney problems may be at risk for developing high blood pressure. Sometimes children whose parents have high blood pressure are at a higher risk of developing hypertension as well.

Kawasaki Disease

Kawasaki Disease

Kawasaki disease in children

Happy Heart Pediatrics work closely with other pediatric physician experts to diagnose and treat all aspects of Kawasaki disease. Several diagnostic tests may be conducted to confirm Kawasaki disease. Kawasaki disease treatment starts with strategies to help your child feel more comfortable by reducing fever and inflammation. Efforts to prevent clots and other heart effects may also be recommended, including regular monitoring for signs of aneurysm.

What is Kawasaki disease?

Kawasaki disease is the most common form of vasculitis that primarily affects children. The disease produces irritation and inflammation of many tissues of the body, including the hands, feet, whites of the eyes, mouth, lips, and throat. High fever and swelling of the lymph nodes in the neck also are also common Kawasaki disease symptoms. The inflammation is uncomfortable, but resolves with time. However, the main threat from Kawasaki disease comes from its effect on the heart and blood vessels. Heart-related complications can be temporary or may affect the child long-term. The coronary arteries, small vessels that take blood to the heart muscle, are affected in as many as 20 percent of children with Kawasaki disease if not treated with IVIG. Another name for Kawasaki disease is mucocutaneous lymph node syndrome.

How often does Kawasaki disease in children occur?

Kawasaki disease is fairly common in the US. According to the American Heart Association, the illness is a major cause of heart disease in children. About 1,800 new cases are diagnosed in the US each year, and the incidence is on the rise. Kawasaki disease, together with acute rheumatic fever, is the leading cause of acquired heart disease in children in the US and Japan.

Who is affected by Kawasaki disease?

Kawasaki disease occurs more often in Japan than in any other country. In the US, children of Asian or Asian American heritage are affected more often than other races, although Kawasaki disease can occur in any racial or ethnic group.

The vast majority of cases of Kawasaki disease in children are under age 5. The average age child seen with the illness is 2 years old. It occurs in boys twice as often as in girls.

What causes Kawasaki disease?

It is not clear what causes Kawasaki disease. Scientists believe a virus may be responsible, but current research is still underway. Kawasaki disease does not appear to be contagious, nor does it appear to be hereditary. It was once thought that Kawasaki disease  in children was linked to recent rug or carpet cleaning; however, no studies have shown this to be a cause of the disease.

It is rare for more than one child in a family to develop the disease. Less than 2 percent of persons with Kawasaki disease develop the disease more than once.

Why is Kawasaki disease a concern?

Kawasaki disease symptoms can be very uncomfortable causing fever, as well as irritation and inflammation in many tissues of the body. However, these symptoms usually run their course and resolve within a few weeks. The primary concern with Kawasaki disease is heart and blood vessel involvement.

The coronary arteries are the vessels that provide the heart muscle with an oxygen-rich blood supply. Kawasaki disease can weaken the wall of one or more of the coronary arteries, causing it to bulge or balloon out. This weakened, ballooned area is called an aneurysm.

Blood clots can form in the ballooned area and possibly block the blood flow through the coronary artery. When this happens, the heart muscle will no longer receive an adequate supply of oxygen-rich (red) blood, and the heart muscle can be damaged.

The illness may also cause the heart muscle (myocardium) to be irritated and inflamed, as well as the membrane covering the heart (pericardium). Irregular heart rhythms and heart valve problems may also occur with Kawasaki disease.

In most cases, the effects on the heart caused by Kawasaki disease are temporary, and resolve within five or six weeks. However, coronary artery problems may sometimes persist for longer periods of time.

What are the most common Kawasaki disease symptoms?

The following are the most common Kawasaki disease symptoms. However, each child may experience symptoms differently. Symptoms may include:

  • moderate to high fever (101° F to 104° F) that rises and falls for at least 5 days and up to three weeks
  • irritability
  • swollen lymph glands in the neck
  • rash on the back, chest, abdomen, and/or groin
  • bloodshot eyes
  • sensitivity to light
  • swollen, coated tongue
  • dry, red, cracked lips
  • dark red interior surfaces of the mouth
  • red, swollen palms of hands and soles of feet
  • peeling skin around the nailbeds, hands, or feet
  • swollen, painful joints

The symptoms of Kawasaki disease may resemble other conditions or medical problems.

Marfan Syndrome

Marfan syndrome is a disorder involving the body’s connective tissue. Connective tissue has many important functions, including the following:

  • Assisting with growth and development of the body’s cells, both before and after birth
  • Acting as an adhesive to hold certain tissues together
  • Protecting joints
  • Facilitating the passage of light through the eye

A defective (FBN1) gene associated with Marfan syndrome affects the formation of a protein in connective tissue called fibrillin, which impacts the integrity of many organs and structures in the body. Organs and body systems that can be impacted include, but are not limited to, the following:

  • Heart and major blood vessels
  • Lungs
  • Skeletal system
  • Spinal cord
  • Eyes
  • Skin

An estimated 50,000 people in the United States have Marfan syndrome (or three out of every 5,000 people). Marfan syndrome occurs in equal numbers in males and females, and also appears equally in all races and ethnic groups. It occurs in one in 20,000 live births.

What are the symptoms of Marfan syndrome?

A deficiency of fibrillin in connective tissue creates the abnormalities in organs and body structures that may be seen with Marfan syndrome. An extensive list of abnormalities can occur with the disorder; only symptoms listed as “major criteria” are listed below. Other symptoms may be noted that contribute to the certainty of the diagnosis. Each child may experience symptoms differently. Symptoms may include:

Heart and blood vessels

  • Dilation of the aorta
  • Leakage of the aortic valve (aortic regurgitation)
  • Tears in the aorta (aortic dissection)


  • Deformities of the breastbone
  • Scoliosis – a lateral, or sideways curvature and rotation of the back bones (vertebrae), giving the appearance that the person is leaning to one side
  • Misalignment of certain bones
  • Joint contractures
  • Unusual arm span
  • Long fingers and toes


  • Dislocation of the lens (the transparent structure inside the eye that focuses light rays onto the retina

The symptoms of Marfan syndrome may resemble other problems or medical conditions.

Syncope In Children

Syncope is a temporary loss of consciousness and muscle tone caused by inadequate blood supply to the brain. Syncope is better known as fainting.

Syncope affects people of all ages, from toddlers to the elderly. More than 100,000 adults and children visit a physician each year with complaints of fainting spells.

What causes syncope?

The common reason behind a child’s syncopal or fainting episode is a temporary lack of oxygen-rich (red) blood getting to the brain. However, many different problems can cause a decrease in blood flow to the brain. Types of syncope include:

Vasovagal syncope – The most common type of syncope is called vasovagal syncope. A variety of situations stimulate the vagus nerve, which leads to a slowing of the heart rate and relaxing of the body’s blood vessels. With a slow heart rate and dilated blood vessels, less blood gets to the brain, and fainting occurs. Pain and emotional stress can trigger vasovagal syncope in susceptible people. This type of syncope can happen more often in some families.

Pediatric orthostatic hypotension – Another cause of syncope is orthostatic hypotension. This is a drop in blood pressure that occurs when a person has been standing for a while, or changes from a sitting to a standing position. Blood tends to pool in the legs, keeping a normal amount of blood from being returned to the heart, and thereby preventing a normal amount of blood from leaving the heart and going to the body. A momentary drop in blood flow to the brain occurs, and a person faints.

What are the symptoms of syncope in children?

The following are the most common symptoms of syncope. However, each child may experience symptoms differently. Also, the symptoms of syncope may resemble other conditions or medical problems.

Some children will experience presyncope, which is the feeling that they are about to faint. Your child may be able to tell you that he/she is “about to pass out,” “feels like I might faint,” “feels like the room is spinning,” or “feels dizzy.” These sensations usually occur immediately before fainting occurs. There may be enough warning to enable your child to sit or lie down before loss of consciousness occurs; this can prevent injuries that may occur due to falling during syncope.

In other instances, the child will have no pre-syncopal sensations, but will simply faint.

Some types of syncope are caused by a serious problem, so it is recommended that your child be seen after all fainting spells.