No4 lecture: Idiopathic dilated cardiomyopathy in infant


 Idiopathic dilated cardiomyopathy in infant is very difficult name to understand the disease. In brief, the heart does not work due to the damage of its muscle and then the heart does not push out the blood into the vessels. Therefore blood
circulation in the body does not work properly. Idiopathic dilated
cardiomyopathy is one of the serious heart diseases.

It is even more serious problem if this disease occurred in the baby. The heart
disease in baby means that the baby cannot live long and the whole life of the
baby will be affected by the disease. Although the etiology of this disease is
still unknown, the disease is identified after the happy birth possibly the damage
of heart muscle during fetal life. Recently as known that obstetricians are
able to monitor the fetus by 4 D echo in the uterus. However the disease is
identified after birth suggesting that fetal life is very important for this disease.
 In other words any medications during pregnancy should be considered in
relation to the possible effects on the fetal heart.


 Drugs used in pregnancy for the treatment of preeclampsia and preterm labor
are known to have toxic effects on fetal (pup’s) heart muscle. They are both
beta-2 stimulant such as terbutaline an ritodoline and magnesium sulfate.
Both drugs are known to be toxic to the pup heart.
 Last year, FDA prohibited the use of terubutaline (beta-2 stimulant) more than
 72 hours for treating preterm labor because of the risk of possible toxic effects
on maternal heart. We are concerned about the negative effects of beta-2
stimulant on fetal heart, since the drug can easily cross over placenta and reach
to the fetus.
 The needs of treatment for preeclampsia and preterm labor obliged us to use
both drugs. Without the use of both drugs we are not able to treat both
preeclampsia and preterm labor and to save the fetus. Obstetricians are in
a dilemma for saving the lives of both mother and fetus simultaneously in
this acute disease conditions.


 From 1970s obstetricians started to use intensively beta-2 stimulants and
from 1990 magnesium sulfate for the treatment of preterm labor.

For preeclampsia, the use of magnesium sulfates started much earlier.
Since both drugs easily cross over placenta and reach to the fetus,
the harmful effects of these drugs on neonatal heart cannot be
underestimated. The neonatal exposure of the drugs in uterus might have
resulted in the development of serious heart disease, namely idiopathic
dilated cardiomyopathy in infant.

 The transplantation of heart is the most effective for the treatment of
idiopathic dilated cardiomyopathy in infant. The advancement of heart
surgery including immunosuppressive drugs and environment of human
organ donor system has recently contributed to the increased number of
infant heart transplantation practices. (Fig1).


 This is good news for both mother and infants of idiopathic dilated
cardiomyopathy. However we must ask ourselves why such infants of
the case have increased recently.

 It is an urgent needs to develop an ideal drug for the treatment of
preeclampsia and preterm labor for the sake of saving the life and
health of mother and her babies .


Fig1 Number of infant heart transplantation by year by age group (world total)



no4図







International Society for Heart Transplantation registry 2011


##Hokegard KH et al. (1979) ECG –changes in the fetal lamb during asphyxia in
relation to beta-adrenoreceptor stimulation and blockade .
Acta Physiol Scand 105:195-203.

Ishii M et al.(2009) The effect of recombinant aminopeptidase A(APA) on
hypertension in pregnant spontaneously hypertensive rats(SHRs).
Early Hum Develop85:589-594.
##Mizutani S et al.(2011) A new approach regarding the treatment of
preeclampsia and preterm labor. Life Sci88:17-23.




今回のテーマは「小児(しょうに)拡張型(かくちょうがた)心筋症(しんきんしょう)」についてです。

 小児(しょうに)拡張型(かくちょうがた)心筋症(しんきんしょう)というたいへん難しい名前の病気は、平たく言うと、心臓の筋肉がダメージをうけて正常に動かなくなり、心臓が血液を送り出すときに正常に働かず血液循環がうまく機能しなくなることです。つまり重症の心臓病です。

 

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