Hypo-plastic left heart syndrome

It's characterized by:

1- Under- development of the left cardiac chambers, with atresia of the mitral and aortic valves.

2- Hypoplasia of the aortic artery.

3- Patent foramen ovale between both RA and LA.

4- Flow of oxygenated blood is maintained through the patent formane ovale and the patent ductus arteriosus, which would be closed upon birth, so early diagnosis and administration Prostglandin E2 is essential.

5- As O2 is administered, dilation of the pulmonary artery occurs resulting in low pressure circuit that favors the flow of the blood towards it; therefore it would lead to further oxygenation of the blood.

6- The work right ventricle would remarkably increase, as it's the main pumping source of blood towards both the right and left ventricle and that would result in precordial hyperactivity, right ventricular enlargement (detected on X-ray- ECG, Rt axis deviation)

Also the increased flow of blood would result in accentuated 2nd heart sound and increased pulmonary end systolic pressure.

Management :

through administration of PGE2 to maintain the patency of the ductus arteriosus.

Also, skeletal muscle relaxants in order to prevent hyperventilation, and therefore increasing the pressure through the pulmonary circuit that favors transmission of blood through PDA and foramen ovale towards the systemic circulation

Hearing Loss

Hearing Loss:

a- Etiology of hearing loss:

1- Conductive hearing loss:

-          It's the loss of hearing due to interruption of the conductive pathway from the auricles towards the cochlea.

-          Causes include: impacted ceuremen, middle ear congestion/effusion, otosclerosis, ossicles disruption  , rupture of tympanic membrane

2- Sensorineural hearing loss:

-          Loss of hearing due to interruption or damage in the pathway between cochlea and vestibule-cochlear nerve.

 -          Etiology include: presbycusis, congenital deafness, 8th nerve injury and ototoxixity.

       b- How to diagnose the type of hearing loss:

THE FIRST THING TO DO IS TO PERFORM WEBER TEST, USING 512 MHz fork to detect the presence of Lateralization.

WEBER test is performed via placing the oscillating fork on the temple:

If sound is heard in the midline, i.e. no lateralization, therefore, no hearing loss.

If lateralization is present,

Conductive hearing loss: sound is heard well in the affected ear.

Sensorineural hearing loss: sound is heard well in the normal ear.

To differentiate perform Rinne test , by placing the tuning fork on mastoid bone to test for air conduction AC then when the sound fades away place the tuning fork to test for bone conduction BC.

In conductive hearing loss BC is better than AC

In sensorineural hearing loss AC is better than BC