Atrial Septal Defects ASD

1
Atrial Septal Defects ASD

• Presented by Dr. Maysa Abdul Haq
• Directed by Dr. Ali Halabi
• Jordan Hospital
• 11-9-2005

2
Background
An atrial septal defect (ASD) is a deficiency
of the atrial septum. ASDs account for about
10-15 of all congenital cardiac anomalies
. Types of ASDs 1-Ostium secundum defect?70
of ASDs. 2-Ostum primum defect?20 of
ASDs. 3-sinus venosus defect.?10of
ASDs. 4-coronary sinus septal defect? lt 1 of
ASDs .
3

• Normal heart for comparison.

4

• Cardiac Development
• Cardiac tissues are first detectable on the 18th
  or 19th day of fetal life. Cardiac development
  continues for the next several weeks. The atrial
  septum begins to form during the fourth week and
  is complete by the end of the fifth week.

5
Frequency

• Research indicates that the incidence of
  congenital heart disease (CHD) is 0.8 of the US
  population. Approximately 7 of these
  individuals, or about 1 in 1500 live births, have
  an ASD. An estimated 15-30 of healthy adults
  have an unfused foramen ovale in which the valve
  functions normally but has failed to fuse. I
• PFO is of no haemodynamic significant and not
  considered as ASD. Does not need surgical repair
  but increase risk of paradoxical syst.
  embolization.

6
Age of presentation

• ASD, is present at birth however, in most cases,
  a murmur is not audible until the child is a few
  months old. Symptoms usually do not occur in
  individuals with ASD until late childhood,
  adolescence, or adulthood.
• Secundum type, sinus venosus, and unroofed
  coronary sinus defects sometimes are not
  diagnosed until the third decade of life.
• Ostium primum ASDs usually are diagnosed in the
  first few years of life because of the presence
  of a mitral regurgitation murmur.

7
Ostium Secundum

• A defect in the region of the fossa ovalis
• The most common form of ASD
• Associated with structurally normal AV valves.
• It may be single or multiple ( fenestrated
  atrial septum)
• Female male 31 incidence.
• Associated lesions partially anomalous
  pulmonary venous return . Holt- Oram-syndrome.

8
Ostium secundum ASD is the most common type of
ASD. It occurs in the center of the septum
between the right and left atrium. A variant of
this type of ASD is called a patent foramen ovale
(PFO) and is very small
9
Holt-Oram syndrome

• Holt-Oram syndrome (HOS) is a heartupper limb
  malformation complex with an autosomal dominant
  inheritance.
• Musculoskeletal defects
• ?Upper limbs are affected. The most severe
  form is phocomelia with rudimentary limbs.
• ?Hypoplasia of the radius , The most common
  defects are radial thumb anomalies ranging from
  absent thumbs to displaced (distally placed),
  duplicated, or triphalangeal thumbs.

10
Continue

• Heart defects The most common lesion is a
  secundum ASD. Others include ventriculoseptal
  defect (VSD), atrioventricular (AV) block,
  pulmonic stenosis (including peripheral
  arterial), and mitral valve prolapse.

11
Continue

                  
right hand of a 6-month-old infant with Holt-Oram
syndrome, showing hypoplastic right thumb.
12
Pathophysiology

• The degree of left to right shunt depends on
• 1-the size of the defect
• 2-compliance of right and left ventricle
• 3- vascular resistance in
  pulmonary and systemic circulation.
• With large defect , the ratio of pulmonary to
  systemic blood flow QpQs between 21 and 41
• ASD in infants is asymptomatic Right atrial
  mascular wall is thick and less compliant thus
  limiting the left to right shunt as infant
  becomes older , PVR drops , right ventricular
  wall becomes thinner and left to right shunt
  increases .

13
Cont

• Large blood flow through the right side of the
  heart cause enlargement of right atrium and
  ventricle , dilatation of the pulmonary artery
  but pulmonary atrial BP is usually normal (
  absence of high pressure communication between
  Pulm. and Sys. Circulation.)
• PVR may increase in adulthood and result in right
  to left shunt.

14
Clinical Manifistation

• Most often is aymptomatic.
• Subtle failure to thrive , exercise intolerance .
•  
• Physical Findings
• Usually discovered incidentally during general
  physical examination.
• 1-  Right ventricular impulses palpable at the
  left sternal border.
• 2-  Loud S1.
•   3- Fixed and widely split S2 .

15
Continue

• 4-Systolic ejection murmur at middle and upper
  left sternal border.
• 3- Mid diastolic rumbling murmur at the lower
  left sternal border.
• These findings indicate QpQs ratio at least 21 .

16
Diagnosis

• Chest X-Ray shows
• variable degrees of right ventricle and
  atrial enlargement .
• Enlargement of pulmonary artery.
• Increase pulmonary vascularity .
•  
• 2-ECG signs of right ventricle volume overload.
• Right axis deviation
• Right ventricular
  conduction delay
• (rsR).
•  
• 3-Echocardiogram Increased right ventricular
  end diastolic dimensions.
• Abnormal motion
  of ventricular septum
• Location and
  size of ASD
• Confirmation of
  the shunt.

17
Continue

• 3-Echocardiogram
• Increased right ventricular end
  diastolic dimensions.
• Abnormal motion of ventricular septum .
• Location and size of ASD.
• Confirmation of the shunt.
• 4- Cardiac Catheterization
• confirmation of the defect
• Measuring of the shunt and PVP.

18
Continue..

• Note in the case of classical features of ASD
  on physical examination , CXR ,and ECHO which
  Identify isolated secundum ASD , there is no need
  for the cardiac cath before surgery.
• 
  
• left- to- right shunt, is of considerable volume
  when if more than or equals 20L/min/m2.

19
PrognosisComplications

• 15 ostium secundum in term infants close
  spontaneously .
• Symptoms dont usually appear until the third
  decade in life or later
• Pulmonary hypertension, atrial dysrhythmias, AV
  valve insufficiency, and heart failure ,
  initially appears during volume overload in
  pregnancy .
• Infective Endocarditis is extremely rare and
  there is no need for antibiotic prophylaxis.

20
Treatment

• Surgery or transcatheter device closure.
• Indications 1-all symptomatic patients.
• 2- asymptomatic patients
  with QPQS ratio of at least 21.
• Timing elective closure after one year and
  before entry of school.

21
Continue

• Post Op complications (HF , AF )
• The risk is greater if done after 20 years of
  age.
•  
• Post Op prognosis
• 1- symptoms disappear rapidly.
• 2- enhanced physical development and activity.
• 3-Heart size decreases to normal .

22
Ostium primum

• An ostium primum atrial septal defect (ASD) is
  located in the most anterior and inferior aspect
  of the atrial septum.
• Cleft of anterior leaflet of the mitral valve is
  noticed.
• Tricuspid valve is usually functionally normal.

23

• Ostium primum is the next most common type and is
  located in the lower portion of the atrial
  septum. This type often have a mitral valve
  defect associated with it called a mitral valve
  cleft. A mitral valve cleft is a slit-like or
  elongated hole in anterior leaflet

24
Development

• During fetal development, the rudimentary atrium
  is divided by the septum primum, except for an
  anterior and inferior space that is the ostium
  primum. The ostium primum is sealed by fusion of
  the superior and inferior endocardial cushions
  around the fifth week of gestation. Failure to do
  so results in an ostium primum ASD.
• Ostium primum ASDs are most commonly associated
  with Down syndrome (trisomy 21).

25
Continue

• Sex The male-to-female ratio is 11.
• Age Patients with smaller defects and little or
  no mitral regurgitation may present at any age
  with a murmur and/or an abnormal
  electrocardiogram (ECG). Those with more severe
  mitral regurgitation typically present with CHF
  in the first 1-2 years of life.

26
Pathophysiology

• Shunting is predominantly left-to-right in the
  absence of pulmonary vascular disease or
  significant right ventricular outflow tract
  obstruction.
• This results in volume overload of the right
  atrium and ventricle and pulmonary
  overcirculation.
• If the mitral valve cleft causes significant
  mitral regurgitation, the left side of the heart
  becomes volume overloaded. A left ventricle to
  right atrium shunt can be present, which further
  overloads both the right and left heart.

27
Clinical presentation

• Usually asymptomatic and discovered incidentally
  during general physical examination.
• Exercise intolerance , easy fatiguabiltiy ,
  recurrent pneumonia may occur with large shunt
  and severe mitral insufficiency .
• Physical Findings
• 1-Loud S1
• 2-Fixed widely splitted S2
• 3-Pulmonary systolic ejection murmur and mid
  diastolic rumbling murmur
• 4-Apical harsh holosystolic mumur that radiates
  to the axilla ( mitral insufficiency )
•  

28
Treatment

• the primum form of ASD is not amenable to device
  closure in the cardiac catheterization
  laboratory. The device is unable to be adequately
  seated secondary to an inadequate inferior rim of
  atrial septal tissue.
• Definitive management of hemodynamically
  significant primum ASDs and partial AV canal
  defects is operative repair.

29
Continue

• TimingPatients with an isolated ostium primum
  ASD usually are referred for elective repair when
  aged 3-5 years. repair may be recommended at an
  earlier age because of significant CHF or because
  of failure to thrive,
• all patients with documented mitral regurgitation
  be referred upon presentation, as once
  regurgitation develops, making repair less
  successful.

30
Coplications prognosis

• Infective endocarditis remains both a
  preoperative and a postoperative complication. In
  a study from the Oregon Health Sciences
  University, the 30-year postoperative incidence
  of infective endocarditis was 2.8 among patients
  with ostium primum atrial septal defects.
• Surgical repair generally improves life
  expectancy and alters the natural course of the
  disease.

31
Sinus venosus

• Situated in the upper part ofAS,in close relation
  to entry of SVC
• .
• Sinus venosus ASDs account for only 10 of ASDs
• always associated with anomalous pulmonary venous
  drainage of the right upper pulmonary vein into
  the SVC. .

32

• A sinus venosus defect is the least common type
  of ASD and is located in the upper portion of the
  atrial septum. A sinus venosus ASD often has an
  abnormal pulmonary vein connection associated
  with it. Four pulmonary veins, two from the right
  lung and two from the left lung, normally return
  red blood to the left atrium. Usually with a
  sinus venosus ASD, a pulmonary vein from the
  right lung will be abnormally connected to the
  right atrium instead of the left atrium. This is
  called an anomalous pulmonary vein.

33
Continue

• Almost all patients with sinus venosus ASD becom
  symptomatic when they are younger than 40 years.
• The haemodynamic disturbance, clinical
  pictureECG C-X ray are similler to ostium
  secundum.
• Diagnosis by Echocardiography cardiac cath.
• Anatomical correction the insertion of a patch
  to close the defect.
• excellent surgical results with a mortality
  rate near 0 can be expected. If repair done
  before age 15 years.

34
Coronary sinus

• The least common type of ASD is termed an
  unroofed coronary sinus or coronary sinus septal
  defect. A portion of the roof of the coronary
  sinus is missing, allowing shunting of blood from
  the left atrium into the coronary sinus and
  subsequently into the right atrium.
• usually associated with other forms of
  congenital heart disease(eg.persistant LSVC. also
  may be associated with other forms of ASD, such
  as the secundum or primum types,

35
Continue

• Patients usually present with symptoms typical of
  other ASDs or with symptoms related to their
  concomitant defects. In the presence of a LSVC,
  these fenestrations can result in a history of
  brain abscess or cerebral embolism.

36
THANK YOU..