Ebstein's anomaly
The content of the article:
- Causes and risk factors
- Forms of the disease
-
Symptoms
Features of the course of the disease in children
- Diagnostics
- Treatment
- Possible complications and consequences
- Forecast
Ebstein's anomaly (by the name of the pathologist who first described the disease) is a congenital cyanotic heart disease.
With such a defect, the tricuspid valve is not located in a typical place (between the atrium and the ventricle in the right heart), but much lower, "recessed" deep into the cavity of the ventricle. The volume of the right ventricle is significantly reduced due to the protruding valve, while the atrium, on the contrary, is much larger than the norm due to the part of the ventricle, called atrialized, which, due to a change in the position of the valve, has withdrawn to the atrium.
Tricuspid valve for Ebstein's anomaly
In addition to changing the position of the valve, in half of the patients with the indicated defect, a defect of the interatrial septum (violation of integrity) is determined - non-closure of the oval window. The oval window normally functions in the prenatal period, during the first 3-5 hours of a child's life, it closes and completely overgrows within 2-12 months. In this case, the window does not close, which leads to mixing of the venous and arterial blood of the right and left atria and, as a consequence, a decrease in the oxygen concentration in the arterial blood. Despite the decrease in the efficiency of blood circulation, this defect is often life-saving, since it relieves the overstretched right atrium.
In the absence of communication between the chambers, the right atrium can reach gigantic sizes, holding up to 2500-3000 ml of blood - with a normal volume of up to 100 ml.
Also, Ebstein's anomaly is characterized by fusion of the valve petals with the adjacent heart tissue, their fenestrated defects and sagging, as well as deformation of the tendon filaments that ensure the opening and closing of the valve.
The disease is extremely rare: it accounts for no more than 1 case out of 100 (according to some sources - 200) congenital heart defects.
Causes and risk factors
It is assumed that mutations in the locus of chromosome 17q CFA9, duplication of chromosome 15q, and a defect in the ALK3 / BMPR receptor lead to the Ebstein anomaly. Chromosomal abnormalities occur at the stage of fusion of the parental genetic material or in the early stages of pregnancy and lead to the incorrect formation of organs and tissues of the child's body in the prenatal period.
Since the exact causes of the disease have not yet been established, the most likely risk factors are:
- lithium supplementation by the mother during pregnancy;
- maternal intake of benzodiazepines during pregnancy;
- viral diseases transferred in the early stages of pregnancy (flu, rubella, measles);
- multiple spontaneous early termination of pregnancy in the anamnesis;
- chronic intoxication with pesticides, vapors of paints and varnishes, petroleum products, etc. (living in ecologically unfavorable areas, working in hazardous industries);
- parental use of illegal substances, alcohol abuse, smoking.
Viral diseases in early pregnancy can lead to the development of Ebstein's anomaly in the fetus
Forms of the disease
Several classifications of the types of Ebstein's anomaly are proposed, but the most common classification is E. Bacha, which considers various types of valve deformities:
- Type I - the anterior valve flap is large and mobile, the other two are displaced, underdeveloped or absent;
- Type II - all three valves are present, but they are reduced in size and spirally displaced towards the apex;
- Type III - the mobility of the anterior valve is limited, the valve is shortened, the tendon filaments that set it in motion are fused and also shortened, the other two petals are displaced and dysplastic;
- Type IV - the anterior valve leaflet is significantly deformed and displaced into the right ventricle, its tendon chords are absent or partially present, the posterior leaflet is underdeveloped or absent, the medial leaflet is significantly deformed and is represented by a crest-like fibrous outgrowth.
Depending on the severity, there are 3 stages of hemodynamic disorders:
- 1st stage - asymptomatic;
- 2nd stage - hemodynamic disorders (2A - without cardiac arrhythmias, 2B - with cardiac arrhythmias);
- 3rd stage - persistent decompensation.
Symptoms
The clinical manifestations of the disease are diverse; at the heart of hemodynamic disturbances is a decrease in the volume of the right ventricle. The reduced chamber cannot accommodate the normal blood volume during diastole, which ultimately leads to a decrease in pulmonary blood flow, insufficient oxygen saturation of arterial blood and hypoxia of organs and tissues.
Ebstein's anomaly can be detected in adulthood
The main symptoms are:
- breathing disorders (shortness of breath, asthma attacks, respiratory discomfort) during physical exertion;
- fatigue, exercise intolerance;
- bouts of increased, "wrong" heartbeat;
- rhythm disturbances;
- transient pallor or bluish discoloration of the skin and visible mucous membranes;
- pain in the region of the heart;
- spontaneous increase in heart rate;
- changes in the terminal phalanges of the fingers of the hands (symptom of drumsticks) and nails (symptom of watch glasses);
- heart hump (a round, usually symmetrical bulge located in the front of the chest in the region of the heart);
- enlargement of the liver and spleen.
The disease can be asymptomatic, first detected in adulthood or even old age.
Features of the course of the disease in children
Babies with Ebstein's anomaly are born with cyanotic skin coloration, which may decrease after 2–3 months because pulmonary vascular resistance, which is high in the neonatal period, decreases. But if the defect in the septum is small or absent, the condition of half of the children during this period becomes critical, and they may die from increasing heart failure and complications of cyanosis in the first weeks of life.
Babies with Ebstein's anomaly are born with cyanotic skin staining
Diagnostics
An objective examination of the cardiovascular system determines:
- expansion of the boundaries of cardiac dullness to the right and left;
- deaf, weakened heart sounds, a gallop rhythm is often heard, that is, a three- or four-membered rhythm, due to the bifurcation of I and II heart sounds or the presence of additional III and IV sounds.
The data of instrumental research methods are as follows:
- with low voltage ECG - pronounced peaked P waves, which indicate hypertrophy and dilation of the right atrium, right bundle branch block, signs of Wolff-Parkinson-White (WPW) syndrome;
- on radiography - cardiomegaly, a decrease in the intensity of the pulmonary pattern, in the lateral projection - abnormal filling of the retrosternal space;
- with ultrasound examination of the heart - lengthening, thickening and sagging of the petals of the tricuspid valve, expansion of the right atrium, with Doppler ultrasound - the characteristic "howling" sound of the valve movement;
- with cardiac catheterization (performed in rare cases) - increased pressure in the right atrium;
- at angiocardiography - a giant, sharply expanded cavity of the right atrium with high contrast intensity.
X-ray of Ebstein's anomaly
Treatment
The main method of radical elimination of Ebstein's anomaly is surgical intervention, which can be carried out in one or several stages.
Indications for surgical treatment:
- heart failure III – IV FC (functional classes);
- significant or progressive cyanosis - the level of blood oxygen saturation (saturation index) less than 80%;
- severe cardiomegaly with a cardiothoracic index greater than 0.65;
- concomitant heart anomalies;
- atrial and ventricular arrhythmias;
- a history of paradoxical embolism.
Reconstructive operations include correction of the tricuspid valve, its displacement, replacement (prosthetics), closure of the atrial septum, and plasty of the atrialized part of the right ventricle.
Surgery is the main treatment for Ebstein's anomaly
Surgical treatment improves survival, prognosis, prevents the development or significantly reduces the severity of arrhythmias.
Possible complications and consequences
The most common consequences of the anomaly:
- infective endocarditis;
- heart failure;
- acute life-threatening heart rhythm disturbances;
- sudden cardiac death;
- brain abscess;
- acute violation of cerebral circulation;
- transient ischemic attacks;
- paradoxical embolism.
Forecast
The early onset of the disease in childhood or adolescence is a prognostically unfavorable sign.
When diagnosing gross disorders, the probability of a newborn's survival is 75% during the first month of life. 68% live up to six months, 64% live up to 5 years, and subsequently the lethality curve stabilizes.
The likelihood of a fatal outcome during surgery depends on the severity of the anomaly in each case, the presence of concomitant pathology. In 90% of patients after surgical treatment, there are positive immediate and long-term results. Recovery of working capacity is possible within a year.
Olesya Smolnyakova Therapy, clinical pharmacology and pharmacotherapy About the author
Education: higher, 2004 (GOU VPO "Kursk State Medical University"), specialty "General Medicine", qualification "Doctor". 2008-2012 - Postgraduate student of the Department of Clinical Pharmacology, KSMU, Candidate of Medical Sciences (2013, specialty "Pharmacology, Clinical Pharmacology"). 2014-2015 - professional retraining, specialty "Management in education", FSBEI HPE "KSU".
The information is generalized and provided for informational purposes only. At the first sign of illness, see your doctor. Self-medication is hazardous to health!
