Tetralogy of Hand lantern

The tetralogy of Hand lantern is most frequent of the congenital cardiopathies cyanogens. It represents nearly 8% of the whole of the congenital cardiopathies. The diagnosis anténatal is possible. Its discovery imposes search for the chromosomal or genetic anomaly. The evaluation of gravity by a cardiopédiatre is essential to discuss the forecast and the assumption of responsibility with the parents.

The name of pathology is associated with Etienne-Louis Arthur Fallot which described it in 1888.

Definition

As its name indicates it, the tetralogy of Hand lantern comprises four signs from which three derive from the original anomaly which is a sténose way of ejection of the ventricle right or infundibulum pulmonary.

the contracting (sténose) of the pulmonary infundibulum is the principal lesion of this cardiopathy. This contracting can be very localized or reach all the infundibulum with or without lesion of the sigmoid Valve. it can even reach all the pulmonary artery and extend to the right and/or left branch from the pulmonary artery. The therapeutic forecast and possibilities depend especially on this anomaly Lésion A.
the presence of a communication enters the right heart and the left heart through the wall interventriculaire (inter-ventricular Communication). This communication interventriculaire is of membranous type i.e. it interests the upper part of the septum interventriculaire at the beginning of the aorta Lésion C. It results from a bad alignment between the aorta or the septum interventriculaire.

Additional anomalies can be associated with these the first two malformations:

the hypertrophy (dilation and thickening) of the ventricle right is seen only in the child. This hypertrophy is the consequence of the communication interventriculaire which makes that the ventricle right works with a pressure level systémique. Lésion D.

the orientation of the point of the heart towards the line or dextrorotation is only the consequence of ventricular hypertrophy.

The sténose infundibulaire being the essential lesion, one speaks sometimes about monology of Hand lantern.

The Trilogy of Hand lantern another type of cardiac malformation associating this time, sténose pulmonary artery and communication enters the two auricles.

Mechanism

In the normal heart of the man:

the hearts right and left are separated, without communication between the two systems.
the pressure of the right heart is quite lower than the pressure of the left heart.
the right heart pumps blood low in Oxygène towards the Poumon S. the left heart pumps blood rich in oxygen towards the bodies.

The association of a contracting of the pulmonary artery and a inter-ventricular Communication involves:

an increase in the pressures on the level of the cavities of the right heart which becomes higher than those of the left heart;
a passage of blood by respecting the difference in pressure, i.e. in this case, of the ventricle right towards the left ventricle. It is about a shunt right-left .

The blood ejected in the aorta by the left ventricle partly contains blood oxygenated and partly of blood low in oxygen coming from the right heart. This blood impoverished of oxygen explains the Cyanose.

The shunt right-left is characteristic of the cardiopathies cyanogens to which belonged the tetralogy of Hand lantern.

Diagnosis

Anténatal

Echographic aspects before the birth

The diagnosis anténatal of this cardiopathy is possible. Most of the time, there does not exist any particular family antecedent. L diagnosis is done on the fetal echography, coupled with Doppler: the cut known as of the four cavities is normal. Only the study of ventriculo-arterial connections will make it possible to highlight:

the reduction of the diameter of the pulmonary Artery. The pulmonary artery is broader of 20% than the aorta. Sometimes the sténose of the pulmonary artery under valvular (Sténose infundibulaire) and is always reached the aortic valve. This sténose can extend on the level from the unit from the pulmonary artery and its branches.
the inter-ventricular Communication is more difficult to highlight
bad alignment between the Septum inter ventricular and the Aorte is a direct consequence of the inter-ventricular communication. It is easier to put in évidence.

The possibilities of diagnosis anténatal depend on several factors:

experiment of the doctor;
term of the pregnancy;
technical quality of the machine;
position of the fetus;
quantity of amniotic liquid;
lubricating mass of the patient.

The careful search for other anomalies must be realized.

The possible differential diagnoses are:

inter-ventricular Communication

Isolated
With Sterility from the pulmonary valves
With Transposition of the large vessels

pulmonary Atrésie with septum open
common arterial Trunk

Assumption of responsibility of the pregnancy

The diagnosis of the cardiopathy will be confirmed by a cardiopédiatre. An evaluation of the possibilities of treatment will make it possible to discuss with the parents. The realization of a chromosomic chart on the fetus to seek a syndrome of Down or of a microdélétion can be proposed. The birth of the child will be carried out in a maternity having a pediatric intensive care unit (in France, of level III).

Assumption of responsibility of the newborn

Postnatal

Private clinic

The cardiac Sounding watch a large breath. The Cyanose is the sign of the disease (" child bleu"). It all the more quickly appears after the birth the cardiopathy is severe. It can appear only at the one year age at the time of walk. Cyanosite is more important with the effort, cold, in digestive period, at the time of the cries and the emotions. The fact of squatting itself after an effort is typical disease but exists only in the final forms of the disease (squatting).
The aggravation of cyanosite involves:

Polyglobulie responsible for cerebral vascular accidents especially if anoxic microcytosis
Malayan being able to lead to the death or with neurological after-effect

Complementary examinations

It is the cardiac echography which makes it possible to make the diagnosis while making it possible to visualize described malformations. It must be made by a cardiopédiatre.

Etiology

Chromosomal anomaly

Syndromes

The tetralogy of Hand lantern is a malformation described in several syndromes.

Genetic anomalies

Apart from the chromosomal anomalies and syndromes comprising this pathology, it exsite several genes whose change causes a tetralogy of Hand lantern.

Treatment

Medical care

systematic Regulation of iron to fight against microcytosis
Use of béta-blocking to prevent anoxic faintnesses

Surgical treatment

The indications of the surgical treatment depend: inter-ventricular communication, quality of the branches of the pulmonary artery, anomaly associated with the coronary artery.

Skirting of the pulmonary contracting by an anastomosis between the artery subclavian and a branch of the pulmonary artery (Anastomosis of Blalock-Taussig, the first intervention of this type going back to November 29th 1944), which is made only exceptionally nowadays compared to one:
complete surgical Treatment: Closing of the inter-ventricular communication and widening of the infundibulo-pulmonary way
Dilation isolated from the pulmonary artery

To become children

Until now, few patients lived after 30 years. Currently, we arrive at a stage where the therapeutic support is such as the heart arrives at the stage of total cardiac decompensation, its fraction of ejection being increasingly weak. That means that the heart loses its faculty to eject blood in the pulmonary artery like in the aorta. The only provision treatment remaining then is cardiopulmonary transplantation.

The genetic Council

In the absence of chromosomal anomaly, the risk of recurrence is of 2,7% is three times the risk of the general population

Sources

Site in French of information on the orphan rare diseases and drugs
Online Mendelian Inheritance in Man, OMIM (TM). Johns Hopkins University, Baltimore, MANDELEVIUM. MIM Number: 187500 == Références ==

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