Histopathology - Heart Pathology 1

Front 1

Heart is a remarkable organ..

1. Beating?

2. Pumping?

Back 1

1.Beating more than 40 million times a year

2. Pumping over 7500 liters of blood a day.

Front 2

...... is the first organ to become fully functional in utero. When?

Back 2

The cardiovascular system, at approximately 8 weeks of gestation.

Front 3

Define congenital heart disease

Back 3

Congenital heart disease is a general term used to describe abnormalities of the heart or great vessels that are present from birth.

Front 4

Most congenital heart disease arise from?

Back 4

Most such disorders arise from faulty embryogenesis during gestational weeks 3 through 8, when major cardiovascular structures form and begin to function.

Front 5

Etiology / pathogenesis of congenital heart disease

Back 5

The cause is unknown in almost 90% cases . The known etiologic factors, environmental causes including

1. Congenital rubella infection

2. Teratogens

3. Maternal diabetes

4. Genetic factors .... The most common genetic genetic cause - is trisomy 21 i.e downs syndrome.

Front 6

The most common genetic cause of congenital heart disease is

Back 6

Trisomy 21 ( down syndrome) , in which about 40% of patients have one or more heart defects.

Front 7

Classification of congenital heart disease

Back 7

1. Left to right shunts

2. Right to left shunts

3. Obstruction

A. LEFT-TO-RIGHT SHUNT : EG i.Atrial septal defect (ASD) ii.Ventricular septal defect (VSD) iii.Patent ductus arteriosus(PDA)

iv. Atrioventricular septal defect(AVSD)

B. RIGHT-TO-LEFT SHUNT : EG i.Tetralogy of fallot (TOF) ii.Transposition of great vessels (TGV)

iii.Tricuspid atresia (TA)

iv.Total anomalous pulmonary venous connections (TAPVC) v.Truncus arteriosus

C. OBSTRUCTION.

i. Pulmonary stenosis and atresia ii. Aortic stenosis and atresia

iii. Coarctation of aorta

Front 8

........ is the most common type of congenital heart disease

Back 8

Left to right shunts. Esp VSD

Which are -

A. LEFT-TO-RIGHT SHUNT : EG i.Atrial septal defect (ASD) ii.Ventricular septal defect (VSD) iii.Patent ductus arteriosus(PDA) iv. Atrioventricular septal defect(AVSD)

Front 9

.....1.. Typically increase only right ventricular and pulmonary outflow volumes,

While...2.... & ...3.. cause both increased pulmonary blood flows and pressure

Back 9

1. ASD

2. VSD

3. PDA

Front 10

....... Is not an early feature of left to right shunts

Back 10

Cynosis

Front 11

Cynosis, pulmonary hypertension, eisenmenger syndrome and left to right shunts

Back 11

Front 12

ASD Vs patent foramen ovale

Back 12

In contrast to patent foramen ovale, an ASD is an abnormal fixed opening in the atrial septum that allows unrestricted blood flow between the atrial chambers. A majority of ASD ( 90%) are so called ostium secondum defects in which growth of the septum secondum is insufficient to occlude the second ostium.

Front 13

Morphology of ASD

Back 13

Front 14

Over time ASD can lead to

Back 14

1. Right to left shunt

2. HF

3. Paradoxical embolization

4. Irreversible pulmonary vascular disease

Front 15

The ventricular septum normally is formed by

Back 15

The fusion of a muscular ridge that grows upward from the apex of the heart to a thinner membraneous partition that grows downwards from the endocardial cushions.

The basal ( membraneous) region is the last part of the septum to develop and is the site of approximately 90% of VSD .

Front 16

About VSD

Back 16

Front 17

VSD - the........ Region is the last part of the septum to develop and is the site of approximately ...... % of VSD

Back 17

Basal ( membraneous) region, 90%

Front 18

ductus arteriosus arises from?

Back 18

From the left pulmonary artery and joins the aorta just distal to the origin of the left subclavian artery

Front 19

Two of the most important conditions associated with cyanotic congenital heart disease are? List others

Back 19

i.Tetralogy of fallot (TOF) ii.Transposition of great vessels (TGV)

Others; iii.Tricuspid atresia (TA) iv.Total anomalous pulmonary venous connections (TAPVC) v.Truncus arteriosus

Front 20

Discuss AVSD

Back 20

Atrioventricular septal defect(AVSD): Embryologic failure of the superior and inferior endocardial cushions of the AV canal to fuse adequately leading to incomplete closure of the AV septum and malformation of the tricuspid and mitral valves.

1. Partial AVSD :consisting of a primum ASD and a cleft anterior mitral leaflet.

2. Complete AVSD:consisting of a large combined AV septal defect and a large common AV valve

Front 21

Partial Vs complete AVSD

Back 21

1. Partial AVSD :consisting of a primum ASD and a cleft anterior mitral leaflet. 2. Complete AVSD:consisting of a large combined AV septal defect and a large common AV valve

Front 22

About tetralogy of fallot -

1. List four cardinal features

2. Pathology

3. Morphology

4. Clinical features

Back 22

1.Tetralogy of fallot (TOF): The four cardinal features of the tetralogy of Fallot

1.VSD,

(2) obstruction of the right ventricular outflow tract (subpulmonary stenosis),

(3) An aorta that overrides the VSD,(4)Right ventricular hypertrophy.

2. All of the features of tetralogy of Fallot result from anterosuperior displacement of the infundibular septum leading to abnormal septation between the pulmonary trunk and the aortic root.

3. Morphology - the heart is enlarged and boot shaped 👢

4. The clinical consequences depend primarily on the severity of the subpulmonary stenosis, as this determines the direction of blood flow. Classical and mild type.

5. Clinical FeaturesThe hemodynamic consequences of tetralogy of Fallotare 1. right-to-left shunting, 2. decreased pulmonary bloodflow, and 3. increased aortic volumes.

Front 23

Discuss transposition of the great arteries

1. Definition

2. Pathology

3. Dorminat presentation

Back 23

1.Transposition of the great arteries is a discordant connection of the ventricles to their vascular outflow. 2. The Enbryologic defect is an abnormal formation of the truncal and aortopulmonary septa so that the aorta arises from the right ventricle and the pulmonary artery emanates from the left ventricle.The atrium-to-ventricle connections, however, are normal (concordant), with the right atrium joining the right ventricle and the left atrium emptying into the left ventricle.The functional outcome is separation of the systemic and pulmonary circulations, a condition incompatible with postnatal life unless a shunt (such as a VSD) allows delivery of oxygenated blood to the aorta.

3. Dorminat presentation is cynosis

Front 24

About triscupid atresia

Back 24

1. Tricuspid atresia (TA):

Unequal division of the AV canal. Mitral valve is larger than normal, and there is almost always underdevelopment (hypoplasia) of the right ventricle. Circulation is maintained by a right-to-left shunt through an ASD or patent foramen ovale and a VSD.

Front 25

About patent truncus arteriosus

Back 25

Patent truncus arteriosus:

There is Developmental failure of separation of the embryologic truncus arteriosus into the aorta and pulmonary artery . This results in a single great artery that receives blood from both ventricles and gives rise to the systemic, pulmonary, and coronary circulations.

Front 26

About total anomalous pulmonary venous connections

Back 26

Total anomalous pulmonary venous connections (TAPVC): Pulmonary veins fail to directly join the left atrium. This results when the common pulmonary vein fails to develop or becomes atretic. Either a patent foramen ovale or an ASD is always present.

Consequences of TAPVC include 1.volume and pressure hypertrophy and

2. dilation of the right side of the heart, and

3. dilation of the pulmonary trunk.

Front 27

About coarctation of the aorta

1. Define

2. Classic forms

Back 27

1. Coarctation of the Aorta:

i. infantile form(Coarctation of the Aorta with PDA):

has tubular hypoplasia of the aortic arch proximal to a patent ductus arteriosus that is often symptomatic in early childhood.

ii. an adult form (Coarctation of the Aorta without PDA) -

there is a discrete ridgelike infolding of the aorta, just opposite the closed ductus arteriosus (ligamentum arteriosum) distal to the arch vessels.

3. Morphology

Front 28

CONGENITAL HEART DISEASES DUE TO OBSTRUCTION .

About pulmonary stenosis and atresia

Back 28

Pulmonary Stenosis and Atresia: When the valve is entirely atretic, there is no communication between the right ventricle and lungs. In such cases the anomaly is associated with a hypoplastic right ventricle and an ASD; blood also reaches the lungs through a patent ductus arteriosus.Mild stenosis may be asymptomatic & compatible with long life, whereas symptomatic cases require surgical correction.

Front 29

CONGENITAL HEART DISEASES DUE TO OBSTRUCTION

About aortic stenosis and atresia

Back 29

3. Aortic Stenosis and Atresia: Congenital narrowing and obstruction of the aortic valve can occur at three locations: valvular, subvalvular, and supravalvular.

Front 30

CLINICAL FEATURES Of each type of congenital heart disease

Back 30

A. LEFT-TO-RIGHT SHUNT

i.Features of RVF

ii. Eisenmenger syndrome( Late cyanotic congenital heart dx)

B. RIGHT-TO-LEFT SHUNT i.Cyanosis

ii.Clubbing of tip of fingers and toes. iii. Polycythemia

C. Clinical features of Obstructive type of CHD:

i.Asymptomatic if mild ii.Symptomatic if severe

iii.Systolic murmurs

iv.Thrills – occur sometimes

Front 31

Morphology of ASD

Back 31

Front 32

About patent ductus arteriosus

Back 32

Front 33

Clinical features of patent ductus arteriosus

Back 33

Front 34

Intro to right to left shunts

Back 34