The Child with Cardiovascular Dysfunction By : Basel AbdulQader RN, MSN, CCRN Murad Sawalha RN, MSN, CCRN

Fetal Circulation

Fetal circulation (prenatal circulation) differs from adult circulation in several ways and is designed to ensure a high oxygen blood supply to the brain and myocardium of the fetus.

Characteristics of fetal circulation Placenta is the source of oxygen for the fetus, it has 2 arteries and 1 vein. Fetal lungs receive less than 10% of the blood volume ; lung don’t exchange gas. Right atrium of fetal heart is the chamber with the highest oxygen concentration.

The three openings that close at birth are: Ductus Arteriosus connects the pulmonary artery to the aorta, bypassing the lungs Ductus Venosus connects the umbilical vein and the inferior vena cava bypassing the liver. Foramen Ovale is the opening between right and left atrias of the heart, bypassing the lungs.

Pattern of fetal circulation placenta inferior vena cava Ductus Venosus. Oxygenated Blood is carried from placenta through the umbilical vein and enters the inferior vena cava thought the Ductus Venosus. right atrium This permits most of the highly oxygenated blood to go directly to the right atrium, bypassing the liver.

….. Continue pattern foramen ovale This right atrial blood flows directly into the left atrium through the foramen ovale an opening between the right and the left atriums.

….. Continue pattern From the left atrium blood flows directly into left ventricle and the Aorta through the subclavian arteries, to the cerebral and coronary arteries, resulting in the brain and the heart receiving the most highly oxygenated blood.

Coronary circulation

….. Continue pattern superior vena cava Deoxygenated blood returns from the heart and the arms through the superior vena cava, enters the right atriums and passes into the right ventricle.

Blood from the right ventricle flow into pulmonary artery, but because fetal lungs are collapsed, the pressure in the pulmonary artery is very high.

….. Continue pattern Ductus Arteriosus Because pulmonary resistance is high, most of the blood passes into the distal aorta through the Ductus Arteriosus, which connects the pulmonary artery and the aorta distal to the origin of the subclavian arteries. From the aorta blood flows to the rest of the body.

Normal circulatory changes at birth

Foramen Ovale: Opening Between Atria; Allows Blood to Bypass Lungs intrauterinely; Closes With Increased Left- Sided Pressure Ductus Arteriosus: Opening Between Pulmonary Artery & Aorta; Allows Blood to Bypass Lungs intrauterinely; Closes Within Hours After Birth With Permanent Closure By Days of Life Physiological changes at birth

….. Physiological changes Cyanosis results from 5 or more Grams of Unoxygenated Hemoglobin per 100 ml of Blood: So, If Hemoglobin is Low, You Won’t See Cyanosis In Spite of Low PaO2!

….. physiologic Polycythemia: Increase in Production of Erythrocytes To Compensate for Chronic Hypoxemia; If Hemoglobin Greater Than 20 g/dl & Hematocrit Greater Than %, Increased Risk for thromboembolism Infants Respond to Severe Hypoxemia With BradyCardia

Normal vital signs at birth Heart rate= beat/min Blood pressure= 65/41 mmHg Respiratory rate= breath/min Temperature= Axillary o C. Oxygen saturation (SpO 2 )= >93%

Congenital Heart Disease (CHD) Approximately 5-8 Per 1000 Live Births; Combination of Genetic & Environmental Factors : X-ray exposure Maternal Rubella Maternal alcoholism Maternal type 1 diabetes Maternal over 40 of age Occur EARLY in Gestation (3-8 Weeks) in the first trimester

CHD Classification of CHD: Acyanotic versus cyanotic Acyanotic Mixed blood flow Pulmonary blood flow Obstruction to Blood flow from ventricles Pulmonary Blood flow Cyanotic Atrial septal defect (ASD) Ventricularr septal defect (VSD) Coarctation of Aorta Aortic stenosis Tetrology of Fallot Tricuspid atresia Transposition Of great vessels Truncus arteriosus

Selected Acyanotic defects (1) ASD, or atrial septal defect: Abnormal opening between atria, allowing blood from Lt atrium (higher pressure) to go to right atrium (lower pressure). Pathophysiology: the new volume in the right ventricle is tolerable because it was sent by a low pressure from the right artium. S&S: Patients may be asymptomatic they may develop heart failure, atrial arrhythmias are present. Surgical treatment: Surgical Dacron Patch Closure. Non-surgical Repair: in catheterization, a repair pad is implanted. Patients with ASD may live several decades without S&S and the prognosis after operation is very high.

…. Cont. acyanotic (2) VSD, or Ventricular Septal Defect: It is an abnormal opening between the right and the left ventricles, resulting in a common ventricle. its found that 20% of all VSDs close spontaneously during the first year of life Pathophysiology: the blood turns from the left ventricle (higher pressure) to the right ventricle(lower pressure) causing left-to-right shunt, then to pulmonary Artery, which increases RV pressure causing RV hypertrophy and by time RV failure. S&S : congestive heart failure is common. Surgical treatment: complete repair. Non-surgical treatment: closure devise is usually implanted during cardiac catheterization

Cardiac catheterization lab

Selected cyanotic defect Tetrology of Fallot (TOF) The classic form includes four defects: (1) ventricular Septal Defect, (2) pulmonic stenosis,(3) overriding aorta, (4) right ventricular hypertrophy. Pathophysiology: the altered hemodynamic status depends on the size of the VSD and the pulmonary stenosis, blood get shunted from right to left, if the pressure in the pulmonary is higher than the systemic pressure, and blood gets shunted from left to right if the systemic pressure is higher than pulmonary. Pulmonary stenosis decreases blood flow to lungs making oxygen returns to Lt side of the heart. S&S: cyanosis, clubbing fingers, poor growth. crying during or after feeding. Surgical treatment: complete repair is required, open heart surgery& VSD closure.

CARDIAC SURGERY Discharge Teaching: Activity Tolerance; No Bike Riding Until Sternotomy Healed Signs & Symptoms of Wound Infection Return to School in 2 Weeks Usually, No Further Cardiovascular Problems ALLOW THE CHILD TO LIVE A NORMAL AND ACTIVE LIFE!

Congestive Heart Failure (CHF) Cardiac Output (CO) Inadequate to Support Circulatory & Metabolic Needs Causes: volume overload, pressure overload, decreased contractility, high cardiac output demands Infant Tires During Feeding (OFTEN FIRST Indication of CHF) Symptoms Increase With Progressing Disease Cardiomegaly Occurs As Heart Attempts to Maintain Cardiac Output If Tachycardia Greater than BPM; Ventricles Unable to Fill & CO Falls

CHF CHD Most Common Cause of CHF in Infants S/S: Tachycardia Diaphoresis, Tachypnea, Feeding problem, Crackles & Respiratory Distress; Edema, weight CXR Shows Large Heart. Echocardiogram is Diagnostic.

CHF Medical Management: Digoxin To Make Heart Work More Efficiently Lasix/Diuretics To Remove Excess Fluid Oxygen: Potent Vasodilator which decreases pulmonary vascular resistance. Rest, a neutral thermal environment, semi- Fowler position, cluster care to promote uninterrupted rest

CHF Nursing care Monitor physiologic functions: BP, HR, RR Prevent infection; Group care; Semi-Fowler position. Adequate Nutrition: Feeding Techniques: 45 Degree Angle; Rest Frequently. Promote Development: Play, Age Appropriate Toys, Physical Activities With Rest Periods Emotional Support: Prevent Hypoxia From Agitation or Distress; Consistency of Caregiver for Patient; Refer-Parent-to-Parent Support Groups.

ENDOCARDITIS Patients With CHD, Prosthetic Cardiac Valve, Multiple Invasive Lines, etc May Be at Increased Risk Streptococcus viridan (most common) Insidious onset, low-grade intermittent fever, non-specific: malaise, myalgias Definitive Diagnosis: Blood Cultures Intravenous Antibiotics for 2-8 Weeks Bedrest in Acute Phase Prevention is Best; Inform Dentist & MD for Prophylaxis PRIOR to Procedures

RHEUMATIC FEVER Inflammatory Disease Following Initial Infection by Group A Beta Hemolytic Streptococci; Cause Changes in Heart, Joints, Skin & CNS. Diagnosis:  ESR( erythrocyte segmentation rate), CRP(C- reactive protein), ASLO (anti-streptolysin O-titers) Treatment With Antibiotics To Treat Strep Infection Aspirin To Control Joint Pain & Inflammation Prevention is Best Treatment: Throat Culture & Treat With Antibiotics for 10 Days