⭐⭐ AORTIC REGURGITATION ⭐⭐

    ⭐⭐ AORTIC REGURGITATION ⭐⭐

1) AORTIC VALVE - 

  - Aortic valve is a semilunar valve present

    between left ventricle and aorta. It 

    directs the flow of blood from left 

    ventricle into the aorta during

    ventricular systole.

  - During ventricular systole, pressure 

    rises in the left ventricle. When the 

    pressure in the left ventricle exceeds the

    pressure in the aorta, the aortic valve

    opens and the blood flows from the

    left ventricle into the aorta.

    

                    ⭐⭐⭐⭐⭐⭐⭐

2) DEFINITION OF AORTIC                                  REGURGITATION :- 

  - Regurgitation means backward flow of

    blood from aorta into left ventricle                during diastole due to damage to the          aortic valve.

          

                     ⭐⭐⭐⭐⭐⭐

3) ETIOLOGY OF AORTIC                                    REGURGITATION:-

    (a) Acute causes :- 

       (I) Rheumatic fever :- 

          - Rheumatic fever is an autoimmune              inflammatory disease which                          affects many connective tissues                  including heart.

          - It causes inflammation and 

            damage to aortic valve.

       (II) Infective endocarditis :- 

           - It is the infection of heart valves 

             and endocardium caused by 

             bacteria, fungi or rickettsia. 

           - Organisms can infect already

             damaged heart valves (less 

             virulent organisms) or normal

             heart valves ( more virulent

             organisms)

       (III) Trauma to the aortic valve

       (IV) Dissecting aneurysm of aorta -

           - There is tear in the inner layer of 

            aorta due to causes like high BP, 

            atherosclerosis ,etc.

           - Blood enters the tear and causes

             seperation of inner and middle

             layers of aorta .Blood starts

             accumulating between these two

             layers.

           - 

          - The unsupported intimal flap which 

           is formed due to accumulation of 

           blood prolapses sags and crosses               the aortic valve.

         - The swinging motion of the

           unsupported intimal flap through

           the aortic valve causes regurgitation

    (b) Chronic causes :- 

       (I) Common causes:- 

          # Rheumatic fever - It can be acute 

            as well as chronic cause.

         

          # Atherosclerotic aortic valve :- there

            is chronic inflammation, lipid 

            deposition, thickening of fibrosa

            layer and hence damage to valve.

          # Syphilis - There is dilatation of

            aortic ring with incompetence of

            the valve due to inflammation.

          # Bicuspid aortic valve - Normally,

            aortic valve has 3 cusps. But in 

            case of Bicuspid valve, there are 

            only 2 cusps. Third leaflet doesn't

            develop properly. This abnormal

            valve causes regurgitation as it 

            doesn't close properly.

      (II) Uncommon causes :- 

         # Infective endocarditis - can be

            acute as well as chronic cause.

 

         # SLE ( systemic Lupus

            erythematous) - It is Autoimmune

            disease. It can cause inflammation

            in the heart valve and can damage 

            it.

   

         # Ankylosing spondylitis :- It is 

            autoimmune and chronic

            Inflammatory disease which affects

            joints. It can also affect heart .

 

         # Reiter syndrome :- It is an 

           autoimmune response to Infections

           like gastrointestinal infection. The

           inflammation can spread to heart.

 

         # Takayasu syndrome - It is a rare 

           autoimmune disease which causes

           inflammation of large arteries.

        # Ehler Danos syndrome :- It is an 

          inherited disorder which mostly 

          affects connective tissue of skin, 

          joints, blood vessels, heart valves, 

          etc. There is problem in formation of

          collagen, thus connective tissue

          formation is affected.

        # Marfan syndrome :- It is autosomal

          dominant disease with mutation in

          FBN1 gene. It causes dilatation of

          the aortic root. This dilatation leads

          to stretching of the aortic valve

          cusps and hence the valve fails to

          close.

        # Hypertension :- the pressure causes

          direct damage to the valve leading to

          fibrosis and stiffening of valve.

        # Rheumatoid arthritis - It is an

           autoimmune and inflammatory

           disease . It can cause inflammation

           and damage to the arteries and

           heart valves.

        # Aortic aneurysm :- weak spot in

          the aortic wall begins to bulge. This

          leads to increased pressure of blood

          over the aortic valve and causes 

          damage to the valve. There is also 

          risk of aortic dissection.

       # Ventricular septal defect (VSD) :- 

          Note - Venturi effect states that 

          velocity of a fluid passing through

          constricted area will increase and 

          it's static pressure will decrease.

           

            Similarly , blood flowing through

           VSD from left ventricle to right

           ventricle flows with increased speed

           and decreased pressure.

           This decreased pressure causes 

           prolapse of the aortic valve and 

           it's inability to close thus causing

           regurgitation.

 

                    ⭐⭐⭐⭐⭐⭐

 

4) PATHOPHYSIOLOGY OF AORTIC                  REGURGITATION :-

    (I) Due to regurgitation, some amount 

       of blood enters the left ventricle from         the aorta during the diastole. Thus,               end  diastolic volume of left ventricle           increases. This  causes dilatation of           left ventricle. As a result, the stroke             volume increases. (Frank Starling's               law states that  the stroke volume of           the left ventricle will increase as the           left ventricular volume increases due         to the muscle  stretch causing a more         forceful systolic contraction)

       However, efficiency of left ventricle             decreases gradually & stroke volume           decreases.This results in further                   dilatation & finally Left Ventricular               Failure.

  (II) Due to left ventricular failure , there is          backpressure into the left atrium                  leading to rise in left atrial pressure,            then pulmonary venous pressure, the          pulmonary artery pressure and lastly            pressure in the right heart increases.

        

                  ⭐⭐⭐⭐⭐⭐⭐

          

5) SYMPTOMS OF AORTIC                                REGURGITATION :- 

    (I) Initially asymptomatic.

    (II) Palpitations, Pulsations in neck -

    due to increased stroke volume because

    of increased force of pumping. (Frank

    Starling law)

    (III) Angina -

     As efficiency of left ventricle 

    decreases, cardiac output decreases          which decreases the blood flow to the        coronary artery leading to Angina.

    (IV) Syncope - Decreased efficiency of        left ventricle leads to decreased cardiac      output and hypotension which leads to

    loss of consciousness. It is seen

    afterwards.

    (V) Dyspnea (exertional) - As the LV end-

    diastolic pressure increases rapidly,            there is increase in pulmonary venous        pressure . As pressure increases                  throughout the pulmonary circuit, the          patient develops dyspnea. Also,                    decreased pumping efficiency causes 

    decreased oxygen supply  to tissues 

   (VI) Orthopnea - it occurs due to                    pulmonary congestion in supine                    position. It occurs because in supine          position there is redistribution of blood      volume from the lower extremities and

    splanchnic vessels to the lungs. In case      of AR, this redistribution of blood                  worsens the already present pulmonary      congestion.

   (VII) Signs of Right ventricular failure - 

     Seen late - see pathophysiology.

     

                    ⭐⭐⭐⭐⭐⭐⭐

6) SIGNS OF AORTIC REGURGITATION:- 

    (I) Rosenbach sign - Increased liver

    pulsations during systole. It is caused 

    due to increased stroke volume.

    (II) Gerhardt sign - Increased spleen

    pulsations due to increased stroke 

    volume.

    (III) Muller sign - Increased uvula

    pulsations due to increased stroke

    volume.

    (IV) Becker sign - Increased retinal

    artery pulsations.

    (V) Landolfi sign - Alternate 

    constriction & dilatation of pupil with

    cardiac cycle.

    During systole the stroke volume 

    increases which leads to increase in

    systolic B.P. Thus, parasympathetic

    response gets activated to decrease the

    B.P. It also leads to constriction of

    pupil.

    During diastole, stroke volume 

    decreases which leads to decrease in

    BP. Thus, sympathetic response is

    activated to increase the BP It also

    leads to dilatation of pupil.

    (VI) Quinke's sign - When nail bed is 

     pressed slightly, there is alternate

     flushing & paleness of nailbed with

     cardiac cycle , i.e. flushing during 

     systole (increased stroke volume) & 

     paleness during diastole.

     (VII) Pistol  Shot femoral sign - Boom 

     like systolic pulsations in femoral 

     artery.

     (VIII) Wide pulse pressure - 

      Pulse pressure = Systolic BP - diastolic

      BP.

      It is increased in aortic regurgitation 

      because

        - the systolic pressure is increased

        due to increased stroke volume.

        - diastolic pressure is decreased 

        because some blood regurgitates 

        back into the left ventricle thus 

        decreasing diastolic blood volume

        in the systemic circulation.

      (IX) Hills sign - The systolic BP at the

       popliteal artery is more than the 

       brachial artery.

          Reason - The lower limb vessels are

          a direct continuation of aorta unlike

          upper limb vessels.

       (X) Waterhammer pulse - Collapsing

        Pulse.

       - Arm is elevated & pulse is felt in the

         radial artery. There is high upstroke

         & high downstroke.

       - It is bounding, forceful pulse with a             rapid upstroke and descent.

       - Eg. There is a tube filled with some 

         water. There is vaccum inside the

         tube. When it is inverted, the water

         hits the bottom of the tube with

         force - Water hammer hitting like

         sound.

        - In aortic regurgitation, increased 

         stroke volume causes rapid 

         upstroke.

        - In similar way, the diastolic pressure

         in the arm is decreased because                   some blood regurgitates 

         back into the left ventricle thus 

         decreasing diastolic blood volume

         in the systemic circulation. This leads

         to rapid emptying of arterial system

         & thus rapid downstroke.

       (XI) Corrigan sign - Similar to 

        Waterhammer, but felt in carotid 

        artery.

       (XII) De Musset sign - Anteroposterior

       movement of head as per cardiac 

       cycle.

 

                     ⭐⭐⭐⭐⭐⭐      

7) INSPECTION & PALPATION :-

    (I) Hyperdynamic precordium & apex -          precordium moves too much ( due to          increased forceful pumping and                    increased stroke volume )

   (II) Pulsations in neck, carotid thrill, 

    pulsation in suprasternal area.( due to        increased forceful pumping and                    increased stroke volume )

                     ⭐⭐⭐⭐⭐⭐

8) AUSCULTATION :- 

These diagrams will be helpful for understanding if information given below is difficult to understand.

    (I) S1 -

Normally, it occurs due to closure of bicuspid, tricuspid valves at the beginning of systole to prevent the entry of blood from ventricles back into the atria. 

S1 is normally a single sound because mitral and tricuspid valve closure occurs almost simultaneously. 

# In aortic regurgitation, S1 may be soft because as the left ventricular end diastolic volume goes on increasing due to regurgitant blood, left ventricular pressure rises earlier than the normal time required. This elevated pressure in the left ventricle causes premature closure of mitral valve during diastole only (still systolic phase is yet to come) whereas normal closure of mitral valve occurs at the beginning of systole. Hence Sound may be soft .

    (II) S2 - 

Normally, it occurs due to closure of semilunar valves i.e aortic and pulmonary valves at the end of ventricular systole and beginning of diastole to prevent the entry of blood from aorta and pulmonary artery back into the ventricles.

 S2 is normally split because the aortic valve (A2) closes before the pulmonary valve (P2) because the closing pressure i.e diastolic arterial pressure is aorta than the pulmonary artery .In addition, the more muscular and stiff and less compliant left ventricle (LV) empties earlier than the right ventricle.

In the normal heart:

During expiration:

The second sound (S2) appears usually single because the split is very narrow.

During inspiration:

The second sound (S2) appears to be made of two component sounds:

Aortic valve closure (A2) which happens first.

Pulmonic valve closure (P2) which happens second.  

Explaination is as follows:-

The venous return to the right ventricle (RV) increases during inspiration due to negative intrathoracic pressure. Hence, volume of blood in right ventricle increases and more time is required to empty the right ventricle.Therefore, P2 is even more delayed. So the split of the second heart sound widens during inspiration and  narrows during expiration.

#In Aortic regurgitation,

 - S2 may be single or narrow splitting or paradoxical splitting may be present.

- Single S2 indicates that there is absence of A2 i.e failure of aortic valve to close due to damage to the valve.

- Narrow splitting indicates that there may be delayed closure of aortic valve as in case of aortic regurgitation due to damaged valve.

- Paradoxical splitting of S2 (P2 is heard before A2)

 Aortic valve (A2) closes after the pulmonary valve (P2).A paradoxical split S2 occurs in cases where there is delay in the closure of  aortic valve as in case of aortic regurgitation. 

Since the respiration only affects P2 (i.e negative intrathoracic pressure during inspiration increases the venous return in right ventricle and thus delays P2) its effect in paradoxical splitting is the opposite of normal, i.e. inspiration causes narrow splitting while expiration causes wide splitting of S2

- paradoxical split S2 heart sound occurs when the splitting is heard during expiration and disappears during inspiration — opposite of the physiologic split S2. 

- In Rheumatic heart disease , there is soft A2 and in syphilis,there is loud A2.

    (III) S3 - (The third heart sound (S3), also known as the “ventricular gallop,” occurs just after S2 . It occurs due to opening of the mitral valve which allows passive filling of the left ventricle during start of diastole. The S3 sound is produced by the large amount of blood striking a very compliant left ventricle. Compliance means how easily the ventricle expands.)

# In aortic regurgitation, S3 is present in patients with left ventricular failure because in case of ventricular failure, the ventricle becomes dilated and overly compliant.

    (IV) S4 -( S4 sound occurs due to atrial contraction in the late diastolic phase .It occurs due to vibration of the ventricular wall during atrial contraction. The sound is associated with a stiffened ventricle due to low ventricular compliance.Therefore it is seen in case of ventricular hypertrophy.)

# In aortic regurgitation, S4 is seen in patients with left ventricular

     hypertrophy.

    (V) Early diastolic regurgitant murmur -

    (Due to backflow from aorta into left

     ventricle during start of diastole)

    Heard good when patient sits, leans

    forward, breath held at deep expiration 

    & hands clenched. It is heard best at the left third intercostal space called erb's point. Soft type in rheumatic

    disease & 'seagull' type in syphilis.

    (VI) Mid diastolic murmur - severe 

    cases of regurgitation. It indicates that regurgitation which had started in the beginning of diastole is still present during mid diastole also because of more severe damage to aortic valve.

    (VII) Ejection systolic murmur - 

    In case of AR, there is increased stroke volume due to increase in end diastolic volume in left ventricle. This increased stroke volume causes ejection systolic murmur.

⭐INVESTIGATIONS AND TREATMENT ARE WRITTEN IN COMMENT SECTION.⭐

                     ⭐⭐⭐⭐⭐⭐⭐

9) INVESTIGATIONS OF AORTIC 

REGURGITATION :-

    (I) Echocardiography.

    (II) Doppler Echocardiography.

    (III) Cardiac catheterization.

    (IV) Coronary Angiography.

    (V) VDRL - for Syphilis.

    (VI) RA factor, ANA, CRP - for 

    connective tissue disorder.

    (VII) ECG.

    (VIII) Chest X-ray - Pulmonary edema,

    Cardiomegaly (Left Ventricle)

                   ⭐⭐⭐⭐⭐⭐⭐

10)TREATMENT OF AORTIC REGURGITATION :-

     (I) Treat the cause.

    (II) Prophylaxis of Rheumatic fever.

    (III) Treatment of Heart failure - 

         # Digoxin - It strengthens the force              of the heart muscle's contractions,              helps restore a normal, steady heart              rhythm

         # Diuretics - Diuretics help the                          kidneys get rid of unneeded water                 and salt. This makes it easier for                 your heart to pump

         # Salt & Fluid Restriction - to prevent

            overload on heart.

    (IV) Reduction of After load -

         # Isosorbide Dinitrate - it causes 

           arterial relaxation & dilatation.

        # Hydralazine -Causes Vasodilation.

        # Captopril - Causes Vasodilation.

    (V) If asymptomatic & normal LV 

    function - 

        # No surgery required.

        # Only monitoring is done.

    (VI) If systolic LV ejection fraction <50%

        & end diastolic LV diameter >55 mm.

         # AORTIC VALVE REPLACEMENT 

          surgery is done.

                      ⭐⭐⭐⭐⭐⭐