A child is admitted on 7 days of life with severe respiratory distress and shock. He was discharged 2 days back healthy. What could be the probable diagnosis –
VSD large
Hypoplastic left heart syndrome
Ebstein anomaly
AP window defect
livpolastic left heart syndrome 

Hypoplastic left heart syndrome occurs when parts of the left side of the heart (mitral valve, left ventricle, aortic valve, and aorta) do not develop completely. The condition is present at birth (congenital).
Hypoplastic left heart is a rare type of congenital heart disease. It is more common in males than in females. As with most congenital heart defects, there is no known cause. About 10 % of patients with hypoplastic left heart syndrome also have other birth defects.
The problem develops before birth when the left ventricle and other structures do not grow properly, including the:

(i) Aorta-the blood vessel that carries oxygen-rich blood from the left ventricle to the entire body
Entrace and exit of the ventricle
Mitral and aortic valves

This causes the left ventricle and aorta to be poorly developed, or hypoplastic. In most cases, the left ventricle and aorta are much smaller than normal.
In patients with this condition, the left side of the heart is unable to send enough blood to the body. As a result, the right side of the heart must maintain the circulation for both the lungs and the body. The right ventricle can support the circulation to both the lungs and the body for awhile, but this extra workoad eventually causes the right side of the heart to fail.
The only possibility of survival is a connection between the right and left side of the heart, or between the systemic

arteries and pumonary arteries (the blood vessels that carry blodd to the lungs). Babies are normally born with two
of these connections:
(i) Foramen ovale (a hole between the right and left atrium)
Ductus arteriosus (a small vessel that connects the aorta to the pulmonary artery)

Both of these connections normally close on their own a few days after birth.
In babies with hypoplastic left heart syndrome, blood from the right side of the heart travels through the ductus arteriosus. This is the only way for blood to get to the body. if the ductus arteriosus is allowed to close in a baby with hypoplastic left heart syndrome, the patient may quickly die because no blood will be pumped to the body.
Babies with known hypoplatic left heart syndrome are usually started on a medicine to keep the ductus arteriosusopen.
Because there is little or no flow out of the left heart, blood reaming to the heart from the lungs needs to pass through the foramen ovale or an atrial septal defect (a hole connecting the collecting chambers on the left and right sides of the heart) back to the right side of the heart. If there is no foramen ovale, or if it is too small, the baby could die. Patients with this problem have the hole between their atria opened, either with surgery or using a thin, flexible tube (heart catheterization).

Symptoms

At first, a newborn with hypoplastic left heart may apper normal. Symptoms usually occur in the first few hours of life, although it may take up to a few days to develop symptoms. These symptoms may include:


Bluish (cyanosis) or poor skin color
Cold hands and feed (extremities)


Lethargy


Poor pulse
Poor suckling and feeding
Pounding heart
Rapid breathing
Shortness of breath.
Since the systemic circulation is dependent on the patent ductus arteriosus the closure of ductus arterious leads to shock.
Signs of heart failure usually appears within the first few days or weeks of life and include dyspnoea, hepatomegaly and low cardiac output. When PDA closes suddenly shock occurs all the peripheral pulses may be weak or absent.

Ventricular septal defect

These patients with VSD's become symptomatic around 6-10 weeks of age.
They usually present with congestive cardiac failure.

Ebstein's anomaly 

Ebstein's anomaly consists of downward displacement of an abnormal tricuspid value into the right ventricle.
These patients usually present in teenage/adolescent years.
They may also present in infancy but they usually do not present with shock or severe hypoperfusion.

Aorticopulmonary window defect

An Aorticopulmanry window defect consists of a communication between the ascending Aorta and the main pulmonary artery.
In these cases minimal cyanosis is present and they may present with heart failure in infancy.