Interesting medical tidbits 2

               
                 

Interesting medical tidbits 2

Cardiovascular system

Cyanotic heart diseases

Congestive cardiac failure in Fallots Tetrology is uncommon

Unless associated with

.Pulmonary atrasia

Aortic incompetence

Patent ductus arteriosus

Infective endocarditis

Severe anemia

Endomyocardial fibrosis

 Variants of Fallots tetrology

Acyanotic Fallots(pulmonary stenosis is mild)

Fallots with Pulmonary atresia-clinically no Ejection systolic murmur in pulmonary area but soft continuos murmur below the clavicle or at the back.

Why cyanosis does not occur at birth in Fallots tetrology?

HbF is predominantly in 1^st year of life. It binds less avidly to O₂ and releases O₂ easily at times of need.Hence in first few months (6months) cyanosis is minimal. After 6mths HbF is replaced by HbA which releases O₂ less readily.As the child grows up O₂ need increase and cyanosis is manifest more.

Cyanotic heart diseases with ischemic lung fields in Xray chest

1.Fallots terology

2.Fallots triology(PS with ASD)

3.Tricuspid atresia(LVH)

Cyanotic Heart disease with plethoric lung fields

1.Transposition of great arteries

2.Peristent truncus arteriosus

3.TAPVD

4.Eisenmengers Syndrome

Chamber hypertrophy in cyanotic heart diseases

cyanotic heart defects  withRight ventricular hypertrophy

TOF

PS with ASD

Transposition

Eisenmengers

TAPVD

cyanotic heart diseases withLeft ventricular hypertrophy

Tricuspid atrasia

(the commonest Cyanotic heart disease with LVH is Tricuspid atrasia)

Biventricular hypertrophy in persistant Truncus arteriosis

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Interesting Medical Tidbits 1

               Unidigital clubbing occurs

Following median nerve injury

Rarely –in sarcoidosis

Unilateral clubbing occurs in

Anomalies of aortic arch,aortic or subclavian artery aneurysm

BrachialAV fistula

Rarely in

Pancoats tumor

Recurrent dislocation of shoulder

Recurrent clubbing  occurs in

In pregnancy in other wise healthy women

TECHNIQUE OF CPR

Most important first step in Cardio pulmonary resuscitation

Patients back must be placed on a firm surface

If patient is on a soft surface like soft mattress,a board must be placed under the patients back.

Hemoptysis

Ascultate the heart to rule out MS,rest of the causes are respiratory mostly.

Frank recurrent hemoptysis

Mitral stenosis

Dry bronchiectasis
Bronchogenic carcinoma

Coarctationof Aorta- absence of pedal pulse ina hypertensive

Thyro toxicosis-irregular pulse in the absenc of cardiac cause

Non cardiac causes of bradycardia-ICT,obstructive jaundice,Myxedema,typhoid

-Pericardial effusion- cardiac Dullness extends beyond apical impulse

SVC obstruction-Facial puffiness  with non pulsatile JVP

Tips for O.P. diagnosis

oedema

Above downwards-renal pathology

below upwards-Cardiac pathology

In between -(abdomen)hepatic pathology

Everywhere-nutritional

         Periorbital edema-

CRF

Myxedema

Utricaria

      

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NYSTAGMUS

         

                                             NYSTAGMUS

Definition ;

Involuntary to and fro movements of the eye in  horizontal /vertical or rotary or mixed direction.

Types ; Classified according to the direction of movements :

horizontal           
Vertical               
Rotary                 
Rarer types

Horizontal nystagmus :

Site of the lesion; can be at any one of the following;

1. Retina

2. Vestibular lesions

3. Medullary lesions

4. Cerebellar lesions

5. Medial longtitudinal bundle of the brain stem.

Classification according to the type of movement ;

Pendular

Jerk nystagmus.

Pendular ;amplitutude of the movement is equal in all directions

Jerk Nystagmus : consists of a slow phase and then a fast phase .

-corrective movement. Fast phase determines the direction of nystagmus.

Vertical nystagmus on vertical gaze

Upbeat nystagmus;  fast phase upwards –occurs inmidbrain lesion

Down beat Nystagmus; fast phase downwards; Occurs in medullary lesions.

Rotary nystagmus; occurs in labyrinthine lesions.

Rarer types of nystagmus ;

Sea-saw nystagmus

Occurs in supra sellar lesions .

Intortion or inward movement of one eye and extortion –outward movement of the other eye.

Convergence/retraction nystagmus:

Occurs in midbrain lesion

Physiology of nystagmus; the normal maintenance of ocular posture depends on a) retinal input to the cortex b) labrynthine input

C) Central connections of vestibular nuclei with brainstem and cerebellum.

Hence Nystagmus can be caused by

1.retinal disease

labrynthine disease

Cerebellar disease

Brainstem disease

Examination  for Nystagmus:

Nystagmoid Movement :

 Occurs normally at extreme of gaze fixation.

True Nystagmus ;to test eyes should deviate just 30°from midline.

Fig   

Degree of nystagmus;

I degree- with eyes deviated to only one side.

II degree: With gaze to one side andin midline also.

III degree; With eyes in any direction

I.Retinal or ocular nystagmus:

                                                                                                                  

Physiological                 Pathological (Ocular nystagmus)

Optokinetic                   In cases with defective vision

 

                                        1.Pendular

                                        2.Rapid

                                        3.Persistant thr’ lifetime

                                        4. Intensifies while looking to side

                                   Causes;

                                   Albinism

                                   Congenital cataract

                                   Congenital macular defect

II. vestibular Nystagmus :

Can arise from natural stimulation of vestibular apparatus

Damage to the vestibular apparatus can cause imbalance between 2 sides.So drift to damaged side and fast compensatory movement to opposite side.

Physiological vestibular nystagmus can be caused by  caloric test.

Pathological by damage to vestibular apparatus or vestibular nuclei.

Fig ;

III .Labrynthine nystagmus ;e.g. Miniers disease ,vestibular neuronitis

1. Slow phase to the side of the lesion
2. Fast phase to normal side
3. In severe cases III degree nystagmus
4. nysagmus intensifies if eye turned to opposite side.
5.  Vertigo can accompany.

IV.  Positional Nystagmus:another form of labrynthine nystagmus

Occurs when patient assumes acertain posture.

To elicit : suddenly reposition the patient from lying to sitting posture or viceversa.

1.   occurs after a delay of seconds

2.   Often rotary

3.   but fatigues on repeated testing .

V. C.N.S. nystagmus

Damage to central  connections of  vestibular nerve

1.Vestibular nuclei in the medulla

2.Brainstem

3.Cerebellum.

C.N.S nystagmus   :  horizontal

                                 Vertical

                                 Dissociated (unilateral only)

1. Direction of fast phase is determined by direction of gaze(multidirectional)
2. Vertigo absent
3. Signs of other nuclei or tract involment in brain stem.

Etiology :

Vascular,demyelinating,tumor,¶Wernicke,s, alcoholic,nutritional,eptoin

   Cerebellar Nystagmus:

 Features: Quick phase to the side of the lesion (as opposed to Labrynthine)

Rebound Nystagmus;

When eyes overshoot on returning to resting position in midline.

Posterion fossa Lesions ;

 This can cause positional nystagmus.D.D:Labrynthine disease.

1.   Absence of delay before onset

2.   2.No fatigue on repeated testing.

3.    Can occur with any  head movement.,not just in one position.

VI. Internuclear ophthalmoplegia (Ataxic Nystagmus)

M.L.F Lesion.

¶MLF Connects 3rd and 6^th nerve nuclei to opposite side nuclei so that coordination of eye movement occurs normally.

Hence MLF lesion causes dissociated nystagmus;i.e. eyes no longer move as one. So there is nystagmus in one eye, not in other.

Features: ✣Failure of adduction (3^rd nerve nucleus is mainly affected)

✣Nyastagmus in the abducted eye.

In Unilateral MLF lesion eye fails to adduct to affected side.

Differential; bilateral 3^rd nerve lesion .

✿ Pupils not affected✿When eyes are tested individually for movements some adducton occurs.

Fig

VII.Congenital Nystagmus:

❊Present from birth.

❊Family history may be present

❊It is important to recognize this so that unnecessary investigations are –avoided.

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