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Showing posts with label congenital heart disease. Show all posts
Showing posts with label congenital heart disease. Show all posts

Somatic abnormalities in congenital heart disease

  • Polydactyly and syndactyly  is seen in VSD
  • Arachnodactyly - Long thin fingers is seen in ASD
  • Atrio digital anomaly-  fingerisation of thumb and ASD is called Holt oram syndrome
  • Hypertelorism is an increased  interpupillary distance observed in  Pulmonary stenosis
  • Mongolism is associated with endocardial cushion defect/ VSD

Turner syndrome
It is associated with
  • Dwarfism
  • Primary amenorrhoca 
  • Coarctation of aorta.
Noonan syndrome
 It is characterised by
  • Triangular facies
  • Somatic features of Turner 
  • Pulmonary stenosis
Ellis-Van-Creveld syndrome
It is characterised by
  • Dwarfism
  • Chondroectodermal dysplasia  
  • VSD
Williams syndrome 
It is characterised by
  • Elfin facies 
  • Mental retardation
  • Hypercalcemia 
  • Supravalvular AS
Pierre-Robin syndrome 
  • Micrognathia,
  • Glossoptosis 
  • Coarctation of aorta
Marfan syndrome
  • Dissecting aneurysm,
  • ASD
  • MVP
  • AR
TAR syndrome 
  • Thrombocytopenia
  • Absent radius
  • ASD.

Markers of congenital heart disease

In congenital heart disease look for:

Abnormalities in height
  • Upper segment/Lower segment inequality 
  • Dwarfism
  • Gigantism
Hands and arms examination
  • Clubbing
  • Cyanosis
  • Syndactyly
  • Polydactyly
  • Arachnodactyly
  • Absent radius
  • Absent thumb
  • Cubitus valgus
Eye examination
  • Suffused conjunctiva of polycythemia
Face examination
  • Hypertelorism
  • Low set ears
  • High arched palate
  • Webbed neck
Chest examination
  • Pectus excavatum
  •  Scoliosis
  • Shield chest
Abnormalities of abdomen
  • Abdominal hernia
  •  Cryptorchidism

Management of ASD

Definitive treatment of ASD is closure with patch of defect.
Repair of ASD defect is indicated
  • When there is significant shunt from left atrium to left ventricle with pulmonary blood flow to systemic blood flow is >2:1.
Contraindications to surgical treatment are
  • Small ASD with bivial shunt
  • ASD with severe PAH, and right to left shunt pulmonary  vascular resistance to systemic vascular resistances >0.7:1

What is the effect of PAH on physical signs of ASD ?

When the person with ASD develop PAH. The following effects are noticed.
Prominent a wave is present in JVP.
Split of S2 narrows.
Two new sounds appear they are pulmonary ejection click (PEC) and right ventricular S4 (RVS4)
Two murmur disappeares they are pulmonary ejection systolic murmur and tricuspid mid diastolic murmur.
Two new murmurs appear 
  • Tricuspid pansystolic murmur
  • Pulmonary early diastolic murmur
Usually with fixed split of S2 narrows with ASD with PAH, but when ASD with PAH is in RV failure (Right ventricular) wide fixed split is retained.

What are the complications of ASD ?

Common complications in ASD are
  • Pulmonary artery hypertension
  • Cardiac failure
  • Atrial arrhythmia (atrial fibrillation or flutter)
Rare complications in ASD are
  • Rare complications of ASD are infective endocarditis.
Endocarditis is more common in ostium primum defect and in ostium secundum defect associated mitral valve prolapse. Other complications are Eisenmenger syndrome and paradoxic embolism.
The most common cause of death in AD is cardiac failure. 
Right heart failure is seen in ASD in patients above 30 years. It may be precipitated by
  • Decreased LV compliance as a result of hypertension or coronary artery disease
  • Atrial arrhythmia

Read related topics -ASD

What are the investigation findings in ASD (atrial septal defect) ?

The main diagnostic modalities of ASD are ECG, chest X-ray and echocardiogram.
The findings are listed below.
ECG findings in ASD
  • There is right axis deviation in ECG. Axis may be deviated to left in ostium primum defet.
  • Right bundle branch block (RBBB)
RBBB is due to delayed activation of the posterobasal part of ventricular septum and due to enlarged ventricular outflow tract.
Chest X-ray findings in ASD
Chest X-ray will show
  • Enlarged right atria and right ventricle
  • Prominence of main pulmonary artery
  • Pulmonary plethora
Chest X-ray also help to differentiate between mitral stenosis and ASD. Left atrial enlargement is the striking features of MS which is absent in ASD.
Echocardiograpy in ASD
Echocardiography shows  the definitive features of ASD
  • Right ventricular dilatation
  • Paradoxical septal motion
Subcostal echo is best in visualising the defect
2D- echo with Doppler is the confirmatory diagnostic test
Transesophageal echo: Useful in ambiguous transthoracic  Echo.
Cardiac catheterisatiom in ASD is done in case of
  • Coronary artery disease
  • Valvular heart disease
  • Pulmonary artery hypertension.

Read related topics -ASD

What is the Hemodynamics in ASD ?

The essential hemodynamic feature of ASD is right ventricular volume overload.
When there is RV volume overload it produces the following effect.
  • Right ventricle compress on the let ventricle producing reverse Bernheim effect on the interventricular septum.
  • Right ventricle compress on the coronary arteries.
What are the main fectors that determine the shunt in ASD
Shunt in ASD is determined by
  • Size of septal defect
  • Relative distensibility of the left and right ventricle.
  • Pulmonary as well as systemic vascular resistance.
Large septal defect produce the following effects
  • Cardiomegaly 
  • Load ejection systolic murmur with thrill in the pulmonary area
  • Tricuspid midiastolic murmur
These three factors are used to access the size of ASD
Describe about ASP with bidirectional shunt
This is ASD with shunt occurring in either direction, based on pulmonary and systemic vascular resistance.

What are the Murmurs in atrial septal defect?

ASD is a condition where there is abnormal communication between the right and left atria resulting in shunting of blood from left to right atria.
What is the classical murmur of atrial septal defect ?
The classical murmur is a crescendo - decrescendo ejection systolic murmur in the pulmonary area which peaks in early or mid systole.
This murmur is produced due to the rapid ejection of the large right ventricular stroke volume into the dilated pulmonary artery.
Sometimes flow murmur may be produced due to rapid blood flow through the peripheral pulmonary arteries. This can be heard as a systolic murmur over the right side of chest, axilla or back.
What are the causes of loud murmur in ASD ?
Loud murmur in ASD may be due to 
  • Large defect
  • ASD with mitral stenosis
  • ASD with pulmonary stenosis
What are the differential diagnosis of mid diastolic murmur at apex in ASD ?
Large ASD with tricuspid middiastolic murmur
ASD with acquired mitral stenosis
Differential diagnosis of ASD with PSM (Pansystolic murmur) at the apex - following are the causes ?
Ostium secondum ASD with mitral valve prolapsed
Ostium primum ASD with mitral regurgitation

Why there is Fixed split in ASD

Split is fixed in ASD because of the following reasons.
1.Septal defect produce equalisation of pressure between the atria during the respiratory cycle.
2.The hangout interval is already widened. Ti cannot be further increased during inspiration.
What is the prerequisite before diagnosing wide fixed split 
Before diagnosing the fixed split always examine the patient in the standing or sitting position, because the split tend to be narrow on standing due to shortening of right ventricle ejection time more than left ventricle.

How will you clinically diagnose atrial septal defect?

Atrial septal defect is the most common congenital heart disease in adult.
It can be diagnosed based on clinical symptoms and signs.
The most common symptoms of ASD are
  • Dyspnoea on exertion
  • Palpitation
  • Recurrent chest infection 
Examination will show the following features
Pulse, blood pressure and jugular venous pressure are normal
Precordial bulge may be seen
Apex beat is normal.
P2 is palpable and pulmonary artery pulsation may be felt
Systolic thrill may be present in 2nd left inter costal space
Left parasternal heave present 
On auscultation 
S1 is loud
P2 is loud
Wide fixed split of S2 is present
There may be an ejection systolic murmur (ESM)which is heard at the pulmonary area 
The striking features are
  • Palpable P2
  • Left parasternal heave
  • Systolic thrill in 2nd left intercostals space
  • Wide fixed split S2
  • ESM in pulmonary area
What are the causes of thrill in ASD?

Physical examination findings in PDA

Pulse : High volume collapsing due to the vigorous left ventricular ejection and due to the runoff into the pulmonary artery.
JVP: Prominent JVP with a-v waves are seen
Apex beat: Is forceful with cardiomegaly
Thrill: May be present in infraclavicular area
Flow mid diastolic murmur is present in mitral area.
S2: Paradoxic splitting of S2 occurs.
S3:Left ventricular S3 is present
P2 is usually soft in PDA due to masking of murmur.Split of S2 is normal in small to moderate VSD and paradoxical in large PDA.Split is normal in Eisenmenger syndrome.Paradoxical split is due to the prolonged electromechanical systole which results in delayed A2.
Continuous machinery murmur is heard in 2nd left intercostals area.
This murmur is loud in late systole and is conducted to left clavicle. 

Causes PDA with early systolic murmur or absent murmur

  • New born
  • Preterm with respiratory distress syndrome
  • PDA Eisenmenger syndrome
  • Spontaneous closure.

Development of human Arterial System

Arterial system develop from Pharyngeal arch arteries and Aortic sac.
Aortic sac - remodels to form 2 horns, Right horn forms brachiocephalic artery, left horn forms common carotid artery

Pharyngeal arch arteries
Pharyngeal arch artery 1 and 2 undergoes regression
Pharyngeal arch artery 3 and the associated dorsal aorta form the paired internal carotid arteries, these in turn generate the external carotids
Left pharyngeal arch artery 4 becomes the the aortic arch
The paired dorsal aorta forms from the  paraxial mesoderm 
The head mesenchyme forms aortic arches

Connecting stalk contains umbilical (placental) arteries
The dorsal aortas give rise to two arteries 
  • Vitelline arteries which connect to capillaries on yolk sac
  • Intersegmental arteries located between somites
Venous System

  • Cardinal veins contribute nearly all systemic venous system.
  • Common cardinal veins is  ducts of Cuvier
  • Hepatic veins  drain de-oxygenated blood from the liver into the inferior vena cava.
  • Internal iliac vein drains to hypogastric vein

Development of ventricular and outflow tract separation

Ventricular Septation is done by 2 separate components - superior membranous and inferior muscular septum
Muscular Septum
It is a growth of inferior wall
It is produced due to the fusion of 3 components - right and left bulbar ridges and dorsal endocardial cushion.
Membranous Septum
This is situated above the muscular septum, fusion is continuous with septation of the outflow tract
Outflow Tract Septation
In early stages of development, outflow tract is a single tube called as bulbus cordis.
Bulbus cordis elongates to form proximal conus arteriosus and distal truncus arteriosus.
Two growths from wall in spiral pattern, inferior upwards - separate tract into 2 channels.
The mesenchyme and neural crest contribute to outflow septation process.
The fusion of outgrowths separate aortic and pulmonary outflow.

Changes in the fetus after birth (The two important events)

Immediately after birth two important events occur
  1. Cutting of the umbilical cord
  2. Changes in the lungs after the first breaths.

These two events trigger major functional adaptations in the fetal circulatory system that is given below

  • Blood flow through ductus venosus is eliminated
  • Pulmonary circulation bed expands - which reduce blood flow through ductus arteriosus
  • There is physiological closure of interatrial shunt
  • The closure of ductus venosus in liver is prolonged

Fetal structure produces some remnant in adult
  1. Foramen ovale -fossa ovalis.
  2. Umbilical vein (intra-abdominal part) -ligamentum teres.
  3. Ductus venosus-ligamentum venosum.
  4. Umbilical artery  distal part-lateral umbilical ligaments; proximal part of superior vesical artery.
  5. Ductus arteriosus-ligamentum arteriosum.

Development of interatrial septum

Through all stages of development of fetus blood shunts from right atria to left atrium so it bypass lungs.
Inter atrial septum is developed from  Septum Primum and Septum Secundum
Septum Primum
Septum Primum is a crescent shaped membranous extension of dorso-cranial wall. 
It will grows downward towards endocardial cushions
The opening between the Septum Primum and endocardial cushions is foramen primum (ostium primum), which  serves as a shunt.
A series of perforations will develop in cranial end that coalesce to form foramen secundum (ostium secundum)
In the later stages of development the septum primum fuses with endocardial cushions – this will obliterates foramen primum
Septum Secundum
Septum Secundum is a crescent shaped septum begins to form to the right side of of septum primum
Grows as septum primum downwards, it does not fuse with endocardial cushion, the opening is called foramen ovale
Because of the arrangement of the two septa it act as one-way valve.

Anatomical classification of Ventricular septal defect

TypeI-Defect is in the MEMBRANOUS SEPTUM
Paramembranous / Perimembranous defect or Infracristal, Subaortic, conoventricular)

TypeII- Defect is seen in the MUSCULAR SEPTUM
Inlet,trabecular, central, apical, marginal or swiss-cheese type

TypeIII- Defect is seen in the OUTLET SEPTUM
Supracristal,subpulmonary,infundibular or conoseptal

Septal deficiency –AVseptal defect (AVcanal)

Read related topics

  1. Development of ventricular and outflow tract separation
  2. Heart sounds in ventricular septal defect
  3. Murmur in Ventricular Septal Defect (VSD)
  4. Development of ventricular septum
  5. What are the clinical features of ventricular septal defect (VSD)?
  6. Pathophysiology of ventricular septal defect (VSD)

Clinical features of RIGHT to LEFT shunts (cyanotic congenital heart disease)

Clinical features of cyanotic heart disease depends on whether the lesion is associated with increased or decreased pulmonary blood flow.
Features of Cyanotic heart disease with increased pulmonary  blood flow
  •   Patient is mildly cyanotic
  •    Increased sweating is seen
  •   Congestive cardiac failure is common
  •   Failure to thrive occurs
  •   Plethoric lung fields and cardiomegaly is seen in chest x-ray
  •   Examples are TGA, single ventricle, TA, Total anomalous pulmonary  return w/o obstruction
Cyanotic heart disease with decreased pulmonary  blood flow
  •   Moderate to severe cyanosis is seen.
  •   ESM, delayed and diminished  P2 (PS) is heard
  •   In  Pulmonary hypertension ,accentuated & palpable P2,ESM is heard.
  •   Oligemic lung fields on chest xray
  •   Examples are TOF, PA, TA, total anomalous pulmonary. return w/ obstruction