Congenital Heart Defects

Congenital Heart Defects Notes

Overview

  • Course Title: Congenital Heart Defects (CHA 1)

  • Author: Jim Kobs MSN, RN

  • Copyright: 2017, Elsevier Inc. All Rights Reserved.

Transitional and Neonatal Circulation

  • Major Circulatory Changes at Birth:

    • Gas exchange transitions from the placenta to the lungs.

    • Closure of fetal shunts occurs (may take several days).

    • Pulmonary vascular resistance decreases, while systemic resistance increases.

    • Result: Marked increase in pulmonary blood flow.

Physical Changes After Birth

  • Fetal Structures:

    • Foramen Ovale → Closes.

    • Ductus Arteriosus → Constricts.

    • Ductus Venosus → Closes.

    • Umbilical Vein → Closes.

    • Umbilical Arteries → Constrict.

Congenital Heart Disease Classification

1. Review of Health Alterations

  • Left-to-Right Shunting Lesions:

    • Patent Ductus Arteriosus

    • Atrial Septal Defect

    • Ventricular Septal Defect

    • Atrioventricular Septal Defect

2. Obstructive or Stenotic Lesions**

  • Pulmonary Stenosis.

  • Aortic Stenosis.

  • Coarctation of the Aorta.

New Classifications in CHA 1

Cyanotic Lesions with Decreased Pulmonary Blood Flow:

  • Examples:

    • Tetralogy of Fallot.

    • Tricuspid Atresia.

    • Pulmonary Atresia with intact Ventricular Septum.

Cyanotic Lesions with Increased Pulmonary Blood Flow:

  • Examples:

    • Truncus Arteriosus.

    • Hypoplastic Left Heart Syndrome.

    • Transposition of the Great Arteries.

Complex Congenital Heart Defects

  • Classification of Congenital Heart Disease:

    • Acyanotic:

    • Characterized by increased pulmonary blood flow.

    • Cyanotic:

    • Characterized by decreased pulmonary blood flow with obstruction.

    • Mixed Blood Flow:

    • Examples include Atrial Septal Defect, Ventricular Septal Defect, Coarctation of Aorta.

Specific Defects

1. Tetralogy of Fallot (TOF)

  • Defects Included:

    • Ventricular Septal Defect (VSD): Mixes oxygen-rich and oxygen-poor blood

    • Pulmonic Stenosis: reduces blood flow from the heart to the lungs.

    • Overriding Aorta:

    • Right Ventricular Hypertrophy: wall of the heart is to thick

  • Effects on Cyanosis:

    • Degree of pulmonic stenosis and size of VSD determine cyanosis, shunt direction.

  • Symptoms:

    • Cyanosis, heart murmur, poor growth, "Tet spells," clubbing, syncope.

  • Surgical Repair:

    • Requires bypass machine.

    • Palliative Shunt: Increases pulmonary blood flow.

    • Complete Repair: Closure of VSD, resection of stenosis, pericardial patch.

  • Nursing Care:

    • Monitor growth, signs of heart failure (HF), cyanosis, Tet spells. Manage pre and post-operative care.

2. Tricuspid Atresia

  • Description:

    • Condition where tricuspid valve fails to develop, preventing communication between the right atrium and ventricle.

  • Blood Flow Mechanism:

    • Foramen Ovale or ASD allows blood flow to left side, hence enlarging the mitral valve and left ventricle.

  • Common Comorbidities:

    • Hypoplastic or absent right ventricle, often associated with pulmonic stenosis.

  • Epidemiology:

    • 2-3% of all congenital heart defects.

  • Symptoms:

    • Central cyanosis, tachypnea, murmur, clubbing, polycythemia, poor growth, and hypercyanotic spells.

  • Treatment:

    • Prostaglandin to maintain patency of PDA.

    • Surgical Repair includes atrial septostomy (balloon technique) and a 3-stage surgery leading to single ventricle repair.

  • Nursing Care:

    • Monitor growth, CHF signs, dehydration, cyanosis, and hypercyanotic spells with pre/post-operative care.

3. Patent Ductus Arteriosus (PDA)

  • Definition:

    • Persistent opening of the ductus arteriosus after birth.

4. Transposition of Great Arteries (TGA)

  • Description:

    • Condition where the pulmonary artery arises from the left ventricle and the aorta arises from the right ventricle, resulting in two separate circulatory pathways.

  • Comorbidities:

    • Septal defects or PDA necessary for mixing of blood to occur (VSD occurs in 40% of TGA).

  • Epidemiology:

    • Makes up 10% of all congenital heart defects.

  • Symptoms:

    • Varying degrees of cyanosis, heart failure, cardiomegaly, clubbing, poor growth.

    • Chest X-ray may reveal characteristic "egg on its side" appearance.

  • Early Treatment:

    • Continuous prostaglandin drip or Rashkind balloon atrial septostomy to allow mixing of blood.

  • Surgical Repair:

    • Jatene Procedure: Most common; involves correcting arterial positions and moving coronary arteries.

    • Intraatrial Baffle Repairs: Mustard and Senning techniques.

    • Rastelli Procedure: Closure of VSD with a baffle to direct left ventricle blood through VSD to the aorta.

5. Hypoplastic Left Heart Syndrome (HLHS)

  • Definition:

    • A condition with underdeveloped left heart structures leading to inadequate systemic circulation.

  • Epidemiology:

    • Occurs in approximately 1% of all congenital heart defects.

  • Symptoms:

    • Heart failure, tachypnea, poor feeding, severe cyanosis if PDA closes, leading to low cardiac output.

  • Treatment:

    • Prostaglandin to maintain PDA.

    • Surgical repair involves 3 stages: Norwood, Bi-directional Glenn shunt, Fontan-Kreutzer.

    • Heart transplantation might be considered.

6. Other Defects

  • Atrioventricular Canal Defect (AVCD):

    • Involves ASD, VSD, and abnormal AV valves; accounts for 5% of CHD cases, with 30% prevalence in children with Down syndrome.

  • Truncus Arteriosus:

    • Failure of truncus arteriosus division into aorta and pulmonary artery; comprises 2% of all CHD cases.

  • Total Anomalous Pulmonary Venous Connection (TAPVC):

    • Rare condition, 1% of all congenital heart defects.

Nursing Considerations in Cardiac Surgery

Pre-operative Care

  • Teaching:

    • Directed at both the child and parents, tailored to developmental level.

    • Focus on sensory experiences for younger children.

    • Parents need specific information on defects, repairs, ICU stays, recovery, and follow-up care.

Post-operative Management

  • Monitoring Needs:

    • Cardiac output, respiratory function, fluid and electrolyte balance, and promoting overall comfort during recovery.

Discharge Instructions Post-Surgery

  • Care of Incision:

    • Teach to pat the area gently, avoid rubbing, and to refrain from bathing until cleared by the physician.

  • Activity Restrictions:

    • Avoid contact activities and falls for 4-6 weeks; limit exposure to crowded places.

  • Dietary Guidance:

    • Encourage proper nutrition for recovery and growth; monitor intake rigorously.

  • Return to School:

    • Typically permitted within 2-3 weeks, often for half days; provide clear guidelines to parents regarding when to contact the physician.

Infective Endocarditis Prevention

  • Prophylactic Antibiotics for At-Risk Children:

    • Criteria include dental procedures, surgeries involving respiratory or intestinal mucosa and surgery/biopsy of infected tissues.

    • Usual treatment is oral penicillin taken one hour before the procedure.

Heart Failure Management

Manifestations of Heart Failure

  • Difficulty in feeding, poor weight gain.

  • Symptoms include tachypnea, tachycardia, cardiomegaly, galloping rhythm, poor perfusion, and edema.

  • Potential to notice liver and spleen enlargement, mottling, cyanosis, and pallor.

Heart Failure Definition

  • Defined as the heart's inability to pump sufficient blood to meet metabolic demands.

  • Treatment options include:

    • Digoxin (administered twice a day for infants/children).

    • ACE inhibitors and diuretics.

    • Oxygen therapy, fluid restrictions for older children, managing oxygen demand through proper care arrangements.

Feeding Strategies for Infants/Children with Heart Failure

  • Environment should be calm and relaxed for feeding.

  • Frequent, smaller feedings may reduce exertion and fatigue.

  • An upright position during feedings reduces compressions for improved respiratory function.

  • If the child fails to feed adequately, nasogastric supplementation should be considered.

  • Monitor feeding intolerance and consider caloric density adjustments through formula concentrating methods.

Patient and Parent Education

  • Signs of Heart Failure to Monitor:

    • Increased cyanosis, dehydration, infection, dysrhythmias, decreased nutritional intake.

Conditions Associated with Congenital Heart Defects

1. Pulmonary Hypertension

  • Overview:

    • Elevated pressures in the pulmonary blood vessels, leading to right-sided heart failure and cyanosis.

    • Further detail covered in the respiratory unit.

2. Hypoxemia

  • Symptoms and Definitions:

    • Cyanosis manifests with 5 g/dl of unsaturated hemoglobin.

    • Polycythemia increases blood viscosity, necessitating hydration to prevent cerebrovascular accidents (CVAs).

    • Potential for finger clubbing and hypercyanotic spells ("Tet spells").

    • Management during a "Tet spell" includes calming measures, knee-chest positioning, high-flow oxygen, morphine administration, and notifying a physician immediately.

    • Nursing concerns include hydration, nutrition education, monitoring general development, and appropriate disciplinary approaches.

Kawasaki’s Disease

  • Definition:

    • Kawasaki’s Disease (Mucocutaneous Lymph Node Syndrome) is an acute, febrile, generalized vasculitis occurring in infancy/early childhood.

  • Etiology:

    • The cause is unknown but is estimated to be immune-mediated with potential genetic and seasonal influences.

Clinical Symptoms of Kawasaki’s Disease

  • Key Symptoms:

    • Fever lasting at least five days accompanied by at least four of the following:

    • Bilateral non-purulent conjunctivitis.

    • Alterations in oral mucosa (fissured lips, "strawberry tongue").

    • Redness of hands and feet, followed by skin peeling.

    • Rash on the trunk.

    • Cervical lymphadenopathy (enlarged lymph nodes).

  • Stages of Disease:

    • Acute, Sub-acute, and Convalescent stages.

  • Complications:

    • 15-25% risk of developing coronary arterial aneurysms leading to myocardial infarction (MI) if untreated.

Nursing Care for Kawasaki’s Disease

  • Diagnostics:

    • Laboratory findings include elevated white blood cells, platelet count, sedimentation rate, increased T4/T8 ratio.

    • Cultures for throat, urine, and cerebrospinal fluid should return negative.

  • Nursing Responsibility:

    • Provide a restful environment, maintain fluid intake, monitor temperature and cardiac status while being vigilant for signs of MI and CHF.

  • Treatment Guidelines:

    • Administer IV gamma globulin and aspirin for its anti-inflammatory properties and platelet inhibition.

    • Teach parents that no live immunizations should be given for 11 months post-IVIG therapy.