Acyanotic heart diseeses (Medicine prospective)

1. Acyanotic congenital heart diseases.
Debashis Priyadarshan Sahoo
PGT, first year
Department of General medicine
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2. Contents:
• Fetal circulation
• Congenital heart diseases
• Pathophysiology of Acyanotic heart diseases
• Different types of Acyanotic heart diseases.
• Eisenmenger Syndrome.
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3. Foetal circulation:
(Fig. 1 : Fetal circulation)
Source : UpToDate 2019
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4. Congenital heart diseases:
• Structural malformations of heart and great vessels, present in birth.
Congenital heart diseases
Acyanotic HD Obstructive HD
ASD
VSD
PDA
TOF
TGA
TAPVC
Cyanotic HD
AS
PS
CoA
(Flow diagram. 1)
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5. Pathophysiology of acyanotic heart disease:
Left to right shunt
Recirculation of
already oxygenated
blood in pulmonary
vasculature
Clinical features
• Depends on shunt size.
• Symptoms and severity α shunt size
(Flow diagram. 2) 5

6. Recurrent respiratory infections Metabolic effect:
Increased Respiratory effort and
increased myocardial work
increased metabolic demand
Failure to thrive
Left to right shunt causes extra
fluid inside thoracic cavity
Difficulty in breathing
Increased respiratory tract
infection
(Flow diagram. 3) (Flow diagram. 4) 6

7. Pulmonary edema Pulmonary hypertension
Increased pulmonary blood flow
Increased pulmonary capillary hydrostatic pressure.
Transudation of fluid to extracellular space.
lymphatic system unable to accommodate
Pulmonary Edema
Increased pulmonary blood flow
Pulmonary vascular remodeling
Overgrowth of vascular smooth
muscle and intimal proliferation
Pulmonary hypertension
(Flow diagram. 5) (Flow diagram. 6)
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8. Atrial septal defect:
• 8-9% of all congenital heart defects.
• This is of three types:
1. Ostium primum ASD
2. Ostium seccundum ASD
3. Sinus venosous ASD
(Fig. 2 : Development of atrial septum)
Source: Braunwald’s heart disease
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9. Hemodynamic:
Left to right shunt
Increased blood flow in RA
Increased blood flow in RV
RA and RV dilation and
hypertrophy
Increased Pulmonary blood flow
(Flow diagram. 6)
(Fig. 3 : Hemodynamics of ASD)
Source : Harrison’s principle of internal medicine
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10. • Small ASD: Asymptomatic
• If large ASD,
1. Pulmonary blood flow/systemic blood flow (Qp/Qs >2:1) causes
congestive heart failure and failure to thrive in childhood.
2. If under detected shunt, Qp/Qs >1.5: 1 causes symptoms in
adulthood and becomes physically weak.
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11. Clinical features:
• Small ASD: asymptomatic throughout
life.
• Large ASD:
1. Recurrent pneumonia
2. Failure to thrive, heart failure
3. Prominent RV impulse
4. Palpable pulmonary arterial
pulsations
5. Wide fixed splitting of S2.
• After pulmonary hypertension
development:
1. Loud P2
2. Pulmonary regurgitation
murmur
3. Cyanosis and clubbing.
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12. • ECG: Right axis deviation and RBBB pattern, atrial arrhythmia and
atrial fibrillation may occur.
• Chest X-ray: Features of pulmonary artery hypertension and dilated
RA, RV.
• Treatment:
1. Small shunts close usually.
2. Arrhythmia and infection treatment
3. Infective endocarditis prophylaxis not required.
(Fig. 4 : Chest Xray of ASD)
Source : UpToDate 2019 12

13. Ventricular Septal Defect:
• Most common congenital, acyanotic heart disease in children.
• Most common congenital heart disease predispose to infective
endocarditis.
• Types:
1. Peri membranous (most common)
2. Muscular
3. Infundibular.
(Fig. 5 : parts of ventricular septum)
Source : Congenital heart disease in adults
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14. Hemodynamic of VSD:
Blood from the left ventricle pass
through pulmonary artery by
right ventricle.
increased pulmonary blood flow
and all blood return to LA and LV
LA and LV dilation and due
course Biventricular dilation
(Flow diagram. 7)
(Fig. 6 : Hemodynamics of VSD)
Source : Harrison’s principle of internal medicine
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15. • Clinical features:
1. Recurrent episodes of pneumonia, tachypnea
2. Heart failure and failure to thrive.
3. Usually present at 6-10week of age.
4. Pan-systolic murmur. (Small VSD, loud murmur)
• ECG:
1. Left axis deviation.
2. Biventricular enlargement without RBBB.
• Chest X-ray:
1. Cardiomegaly with down and out LV apex.
2. Pulmonary plethora.
(Fig. 7 : Chest Xray of VSD)
Source : UpToDate 2019 15

16. • Treatment:
1. Heart failure and infection treatment.
2. Antibiotic prophylaxis for SABE.
3. Small VSD: closes spontaneously.
4. Large VSD: closure by Dacron patch.
Indications:
a. Heart failure, refractory to medical management
b. Pulmonary blood flow : systemic blood flow = 2:1
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17. Patent Ductus Arteriosus:
• Failure of foetal ductus arteriosus to close within first week.
• Predisposition:
1.Hypoxia
2.Pre-term infants.
(Fig. 8 : Blood flow in PDA)
Source : UpToDate 2019
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18. Hemodynamic:
Blood from aorta flows into pulmonary
artery.
Ultimately it returns to left atrium and left
ventricle.
LA and LV have to work more to
accommodate and release extra blood
LA and LV dilation
(Flow diagram. 8) (Fig. 9 : Hemodynamics of VSD)
Source : Harrison’s principle of internal medicine
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19. • Clinical features:
1. Commonly asymptomatic.
2. Symptomatic patients:
a. Tachypnea
b. Feeding difficulties
c. Repeated upper respiratory tract infection
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20. • On auscultation: continuous machinery murmur
• ECG:
1. Left axis deviation.
2. Biventricular enlargement without RBBB.
• Chest X-ray:
1. Cardiomegaly with down and out LV apex.
2. Pulmonary plethora.
3. Main pulmonary artery segment dilation.
4. Diameter of ascending aorta enlarged.
(Fig. 10 : Blood flow in PDA)
Source : UpToDate 2019
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21. • Treatment:
1. Medical management: Indomethacin and PGE2 antagonist
2. Surgical management: (Coil embolization of PDA)
a) When pulmonary blood flow: systemic blood flow = 2.1
b) Heart failure refractory to medical management.
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22. Eisenmenger Syndrome:
• Reversal of shunt in ASD, VSD and PDA patients due to reversible
pulmonary vascular obstructive changes.
Left to right shunt
Increased pulmonary blood flow
(Shear stress/ circumferential stretch)
Endothelial dysfunction and vascular remodeling
(smooth muscle cell proliferation, increased extracellular matrix)
Increased Pulmonary vascular resistance
Reversal of shunt
(Right to left)
Eisenmenger
Syndrome
(Flow diagram. 9)
(Fig. 10 : EM syndrome)
Source : UpToDate 2019 22

23. • Clinical features:
1. Cyanosis, clubbing
2. Activation of RAAS: Erythrocytosis
3. Multiple organ involvement.
• Treatment: CHD should be treated before development of
Eisenmenger syndrome.
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24. Thank You.
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