Treatment for Newborns with Hypertrophic Cardiomyopathy (HCM)
- As the development of hypertrophic cardiomyopathy is usually correlated with growth, signs, and symptoms of the disease may not be seen until a patient is in their teens or until adulthood.
- For newborns with HCM, the preferred first-line treatment is Propranolol, a class of medication known as a beta-blocker (a type of medication that slows down the heart).
- If hypertrophic cardiomyopathy appears to be persistent for your newborn, your doctor will create a multidisciplinary team of professionals that will likely consist of a cardiologist, pediatrician, a geneticist (if needed), as well as any other subspecialists related to your child’s condition.
HCM in Newborns – At a GlanceHypertrophic cardiomyopathy (HCM) is a condition that results in the heart being enlarged and thickened. Dr. Ashita Dwivedi, a cardiologist at Lenox Hill Hospital explains “when the walls of the heart get very thick and abnormal, your heart becomes stiff and becomes less compliant and is not able to accept the blood as it should”.
Although it is relatively common in adults, the diagnosis in infancy is rare. The Pediatric Cardiomyopathy Registry estimates hypertrophic cardiomyopathy occurs in 5 out of every 1 million child.Read More
Common Treatment Principles for HCM in Newborns
The Journal of Pediatric and Neonatal Individualized Medicine notes that 40% of infants with symptomatic cardiomyopathies require heart transplantation or they will die within 2 years.
The mainstay of treatment for newborns with HCM is medications used to prolong survival and reduce associated symptoms.
For newborns, the preferred first-line treatment is propranolol. Propranolol is a beta blocker used to control heart rate and decrease the amount of power that is being used to pump the heart.
Unlike older patients with hypertrophic cardiomyopathy, your healthcare team will not utilize verapamil as a treatment option. Although verapamil can be effective in older children and adults, it is avoided in newborns due to the increased risk of life-threatening heart slowing (bradycardia) and low blood pressure (hypotension).
Septal myectomy, a surgery that decreases the size of the septum, is not generally performed in infants due to the size of their aorta and other heart muscles. If surgery is needed, your healthcare team may discuss alternative surgical methods.
At What Age Does Hypertrophic Cardiomyopathy Develop?
The development of hypertrophic cardiomyopathy is usually correlated with growth. As a result, the enlargement of the heart may not be seen until a patient is in their teens or until adulthood.
According to the Hypertrophic Cardiomyopathy Association, the average age of diagnosis is roughly 39 years of age. Because of this, there is less knowledge on the development of HCM in patients that are born with the disease and become symptomatic shortly thereafter.
- Assessment by a geneticist
- Newborn metabolic screening
- Specific metabolic assays
- Genetic testing
Most Common Cause of Hypertrophic Cardiomyopathy in Newborns
The majority of hypertrophic cardiomyopathy (HCM) cases that are seen in newborns and pediatric patients are thought to be caused by specific genetic mutations in the heart muscles.
Other genetic conditions that may cause HCM in infancy include, but are not limited to, the following:
When the cause of hypertrophic cardiomyopathy is not caused by a genetic abnormality, it is generally thought to be an acquired cause that occurs when the child is in the womb. Acquired causes are generally thought to be acute and generally resolve over time.
Acquired Hypertrophic Cardiomyopathy
Twin-to-Twin Transfusion Syndrome (TTTS)
Identical twins can sometimes develop a condition known as twin-to-twin transfusion syndrome. This issue occurs whenever there is an imbalance of blood flow within the placenta between the two twins. As a result, one twin does not receive enough blood, causing malnutrition, and the other is receiving too much blood, resulting in the heart overworking itself.
TTTS is usually identified during ultrasounds within the second trimester. The treatment of TTTS begins while the babies are still in the womb. Treatment options usually include the following:
- Selective laser photocoagulation: Stops the sharing of blood between twins
- Amnioreduction: Removes excess fluid from the placenta
Once born, the postnatal team will treat the newborns with traditional symptomatic medications, if symptoms of HCM are present. If patients with TTTS undergo perinatal intervention, most newborns will be able to leave the hospital relatively healthy and symptom-free.
Infants born to diabetic mothers are at a higher risk of developing HCM, with 13-44% of newborns exhibiting signs of the disease. Because insulin signaling within the fetus signals cardiac growth, the heart muscle is more susceptible to growth.
The Journal of Clinical and Experimental Pediatrics explains symptoms begin to resolve within 1-4 weeks and the enlargement of the septum tends to resolve within 3-5 months.
Newborns born with HCM to a mother that experienced high blood sugar throughout pregnancy tend to have a reversal in signs or symptoms by 6 months of age.
This is due to the decrease in insulin signaling that is no longer occurring due to the newborn no longer being exposed to high glucose levels from the mother. As a result, treatment is generally not needed for these newborns with acute hypertrophic cardiomyopathy.
Premature infants treated with steroids shortly after birth may present with HCM. According to the peer-reviewed publication, The Korean Circulation Journal, treatment with steroids within 8 days of delivery had a high risk of causing hypertrophic cardiomyopathy in infants.
Genetic Conditions Associated with Hypertrophic Cardiomyopathy
Treatment of HCM that is linked to an underlying genetic condition focuses on treating the genetic disease while providing standard symptomatic treatment for hypertrophic cardiomyopathy.
Pompe Disease is a rare, autosomal recessive (must possess two copies of the mutated gene) disorder caused by a mutation in the GAA gene. While Pompe disease can manifest at different parts of life, the infantile diagnosis tends to be most severe.
According to the National Organization for Rare Disorders (NORD), infantile Pompe disease carries a life expectancy of fewer than two years if not treated promptly.
Infantile Pompe disease can be treated with enzyme replacement therapy (ERT). ERT is used to slow down disease progression. Clinical data demonstrate this treatment can also reduce cardiac mass, reverse cardiac remodeling seen in HCM and improve heart function.
There are no specific treatments recommended for HCM in those suffering from Noonan Syndrome. Newborn children with HCM should be treated following standard hypertrophic cardiomyopathy guidelines.
Although treatment is standard, neonatal patients with Noonan Syndrome have a higher risk of heart valve dysfunction. As a result, these patients may be more likely to ultimately need surgical intervention in the future.
Fatty Acid Oxidation Disorders
Fatty acid oxidation disorders are a wide range of genetic conditions that all are marked by the inability of the body to properly break down fats. Because the body cannot break down fat, it is hard to produce energy. As a result, those possessing the disorder experience hypoglycemia (low blood sugar), which results in extra stress on the heart that can lead to HCM.
Newborn treatment of these conditions is aimed at preventing episodes of hypoglycemia. The hospital will ensure the newborn is having frequent feedings and will recommend more frequent daily feedings than normal for the first six months of age.
If hypertrophic cardiomyopathy appears to be persistent for your newborn, your provider will create a multidisciplinary team of professionals from a variety of specialties.
While each team will be different, it will likely consist of a cardiologist, pediatrician, a geneticist (if needed), as well as any other subspecialists related to your child’s condition.
Treatment will likely follow the normal treatment paradigm for hypertrophic cardiomyopathy and is aimed at managing the symptoms of the disease.
Dr. Philip Weintraub, a cardiologist at NYU Langone Health explains “treatment depends on the severity of the symptoms and the response or failure to respond to most agents”. Your treatment plan will also incorporate routine heart imaging and evaluation for any new or existing risks of sudden cardiac death.
Moving Forward – Questions to Ask Your Doctor
- Is my child’s hypertrophic cardiomyopathy caused by a genetic mutation?
- Do my other children need to be tested for HCM?
- How do I manage my child’s condition at home?
- Is my newborn’s HCM due to genetics or some other condition?