acyanotic heart defects

ACYANOTIC

HEART DEFECTSMa. Tosca Cybil A. Torres,

RN

Objectives:At the end of 2 hours of active learning discussion, the

students will be able to: 1. Define acyanotic heart defects

2. Understand atrial septal defect and ventricular septal defect in terms of:a. anatomical defect b. clinical manifestationsc. diagnostics

3. Formulate nursing diagnoses and appropriate nursing care4. Integrate Christian values in the care plan

Defined:

Acyanotic Heart Defects – a congenital disorder manifested with left to right shunting and obstructive lesions. Clinical signs are not always apparent at birth, they manifest anytime during infancy or early childhood.

Defects:a. Left to right shunting lesions, increased pulmonary

blood flow • The blood is shunted through an abnormal opening

from the left side of the heart to the right side of the heart

• Pulmonary blood flow increases because of the extra volume in the right side. There is a “step-up” 02 saturation in the right side of the heart (abnormal increased) because of the addition of more highly saturated blood. Physiologic effects include increased pulmonary blood flow, increased cardiac workload (including ventricular strain, dilation, and hypertrophy).

Examples: Atrial Septal Defect (ASD), Ventricular Septal Defect (VSD), Patent Ductus Arteriosus (PDA), and Atrioventricular Septal Defect (AVSD).

b. Obstructive or stenotic lesions – stenosis of an opening can occur in a valve or vessel constricting or obstructing blood flow through the area. Pressure rises in the area behind the obstruction; blood flow distal to the obstruction may be decreased or absent. Physiologic effects of obstructive or stenotic lesions include increased cardiac workload and ventricular strain, clinical consequence of CHF, decreased CO and pump failure.

Example: Pulmonary stenosis, aortic stenosis, Coarctation of Aorta, and interrupted aortic archs.

Atrial Septal Defect (ASD)Incidence and Pathophysiology:● ASD accounts for approximately 10% of all CHDs. It is seen

more frequently in females than males. ● The lesion consists of an abnormal opening between the

atria

Types of Lesions:1. Ostium Secundum – located at the middle of the atrial

septum (fossa ovalis), the most common type.2. Ostium Primum – located low in the atrial septum, results

from a defect in endocardial tissue formation and is often associated with a left mitral valve malformation.

3. Sinus Venosus – which is located high in the septum close to the SVC

Atrial Septal Defect (ASD)

Atrial Septal Defect (ASD)

Altered Hemodynamics:● Lower right ventricular compliance which is

the ease of ventricular diastolic filling, compared with left ventricular compliance leads to left to right shunting at the atrial level through the ASD. This increased blood flow through the ASD leads to an enlarge RA and RV and increased pulmonary blood flow.

Manifestations:

● Most infants and children are asymptomatic but over years to decades may experience:

1. Fatigue and SOB2. Palpitations or atrial dysrythmias – result of atrial enlargement3. Recurrent respiratory infections can occur when there is a large amount

of pulmonary blood flow4. Systolic murmur is produced by increased blood flow across the

pulmonary valve.5. Diastolic murmur is present with large shunts6. Stroke or major organ damage can occur because of embolization of

thrombus, air or other materials – PARADOXIMAL EMBOLISM

Diagnostics:

1. Echocardiogram2. EKG3. CXR 4. Cardiac Catheterization

Atrial Septal DefectTherapeutic Management:1. Asymptomatic child is followed by cardiologist. Spontaneous closure can

occur in the first years of life for smaller size secundum ASDs.2. Elective surgical repair is performed around 2-5 years of age3. Surgical repair is recommended for all sinus venosus and ostium primum

defects.Medical Management:1. Asymptomatic patients with moderate size secundum ASDs are

monitored for spontaneous closure in the first years of life with medication.

2. Symptomatic infants and children are treated with diuretics and digoxin as indicated

3. Atrial dysrythmias are treated with appropriate antidysrythmics Surgical Management:● Surgical closure using either sutures or a pericardial prosthetic patch is

performed on an elective basis early in childhood. This is an open heart procedure, through a sternal incision.

● Mortality rate is <2%, with most centers near 0%. For the young adult with ventricular dysfunction or pulmonary, the risk can be significantly higher.

● Complications include sinus node and atrial dysrythmias

Ventricular Septal Defect (VSD)

Incidence and Pathophysiology:

● VSDs account for approximately 25% of all CHDs. ● VSD is the most common congenital cardiac lesion and is

often accompanied by other cardiac defects. ● The lesion consists of an abnormal opening between the

right and left ventricles which may vary in size from a miniscule hole to complete absence of the septum, resulting in a common ventricle.

Altered Hemodynamics:● The degree of left to right shunting through the VSD

depends on the size of the defect and the pulmonary vascular resistance compared with the systemic vascular resistance. The pulmonary vascular system is high in the newborn. Over the first few weeks of life, the resistance decreases. As this occurs, an increased amount of blood shunts left to right of the VSD level. The pulmonary vascular circulation receives increased pulmonary blood flow. With large defects the pulmonary arteries are exposed to systemic pressures, causing pulmonary hypertension, and over time, progressive pulmonary vascular disease.


Ventricular Septal Defect (VSD)Manifestations:● Signs and symptoms vary with the size of

the defect and the presence of associated cardiac lesions. Clinical symptoms are usually not seen at birth because of continued high pulmonary vascular resistance in the newborn. Infants with moderate to large defects will become symptomatic within the first few weeks of life.

● Children with small defects will remain asymptomatic.

Clinical Manisfestations

• Tachypnea, dyspnea• Poor growth• Palpable thrills• Systolic murmur at left lower sternal border• Shortness of breath • Failure to gain weight • Fast heart rate • Pounding heart • Frequent respiratory infections

Complications:

• Congestive heart failure. • Growth failure, especially in infancy. • Bacterial endocarditis• Irregular heartbeat or rhythm• Pulmonary artery hypertension

Diagnostics:• Chest x-ray -- looks to see if there is a

large heart with fluid in the lungs • ECG -- shows signs of an enlarged left

ventricle • Echocardiogram -- used to make a definite

diagnosis • Cardiac catheterization (rarely needed,

unless there are concerns of high blood pressure in the lungs, in which case surgery to close the defect is generally not recommended)

• MRI of the heart -- used to find out how much blood is getting to the lungs

Ventricular Septal Defect (VSD)Therapeutic Management:● From 20%-80% of all VSDs closed spontaneously.1. Many small lesions do not require surgical intervention.2. If there is aortic valve regurgitation related to VSD position near the

valve and even if the defect is small, surgery is indicated to reduce the progression of valve insufficiency.

3. Antibiotic prophylaxis is indicated for all VSDs. Medical Management:1. Infants who develop CHF- digoxin diuretics, ACE inhibitors to

reduce afterload.2. Nutritional supplements are added to infant formula to increase

caloric intake.NGT feeding or gastrostomy tube feeding for infants who are unable to obtain adequate calories orally

3. Avoid exposure to respiratory infections.

Ventricular Septal Defect (VSD) Surgical Management:1. Pulmonary artery banding for children with multiple muscular VSDs. In this

palliative procedure, a band is placed around the main pulmonary artery, decreasing blood flow, reducing the severity of CHF and decreasing the risk of pulmonary vascular disease.● The current trend is to perform corrective surgery earlier in life, and consequently, pulmonary artery banding is performed less frequently than in the past.

3. Total correction is accomplished by placing sutures to close small defects or by placing a pericardial or prosthetic patch over moderate to large defects.

● The surgical approach is usually through the RA to avoid a right ventricular incision which could impair the contractility of the ventricle.

● VSDs just below the pulmonary valve are closed through an incision in the main pulmonary artery. Mortality is 5%-8%, depending on the age and type of VSD.

● Complications include residual VSDs, pulmonary hypertension in the postoperative period, heart block that may require a pacemaker and an abnormal rhythm called junctional ectopic tachycardia.

●CO can be significantly decreased if dysrythmias are persistent. Post pericardiotomy syndrome can also occur.

Nursing Diagnosis and Care of the Child with Left-to-Right Shunting (Acyanotic)

Impaired gas exchange• Monitor intake and output• Limit fluids as ordered• Administer diuretics as ordered• Position changes every 2 hours or as

ordered


Risk for impaired growth and development• Treat child as normally as possible• Teach parents that children are more

comfortable when they know what to expect

• Promote age-appropriate activities as condition allows


Altered nutrition: less than body requirements• Offer small, frequent feedings• Use soft nipple for infant to ease the stress

of sucking• Organize care to allow for rest


Risk for infection• Limit exposure to individuals with

infections• Promote good pulmonary hygiene• Prophylactic antibiotics when undergoing

surgical or dental treatment to prevent subacute bacterial endocarditis

• End of discussion