Normal Blood FlowDexoygenated blood returns from the body through the SVC/IVC → RA → tricuspid valve → RV → pulmonic valve → pulmonary artery → then to the lungs where blood gets oxygenated.This blood then returns via pulmonary veins → LA → mitral valve → LV → aortic valve → and out the aorta to the body.
Newborn Physiology Pulmonary vs. Systemic Pressures In Utero At Birth Fetal Shunts – Ductus arteriosus (conduit from pulmonary artery to aorta) – Foramen ovale (flapped opening between right and left atria) – Ductus venosus (bypass liver)
Pulmonary and Systemic Pressures In utero – ↑ pulmonary pressure before birth: due to lungs being a fluid filled system, the lungs are a higher pressure system than the systemic circulation After birth – ↑ systemic pressure now that the lungs are filled with air, the lungs are a lower pressure system than the systemic circulation The blood will follow the path of least resistance
Assessment: Cardiac Function Inspect chest/Palpate Heart Sounds: murmurs Quality of Pulses/Central Respiratory: effort and quality of respirations Pulses: Extremities (peripheral) – Cyanosis (central also) – Capillary refill time – Temperature /color
Congestive Heart Failure A condition in which the heart is unable to provide adequate cardiac output to meet the circulatory and metabolic requirements of the body. Failure may initially be right- or left-sided but if left untreated, the entire heart will fail
CHF Management Increase cardiac output – Increasing stroke volume Digoxin - ( mcg/kg/24hr.) Increase in force of myocardial contraction and decreases conduction through SA and AV nodes (+ inotropic / - chronotropic) Inotropic support – Dopamine * Dobutamine – Milrinone * Epinephrine
CHF Management Increase cardiac output by: – Decreasing afterload ACE Inhibitors such as Captopril/Enalapril – Blocks conversion of angiotensin I to angiotensin II (vasoconstrictor) Vasodilators – IV (Nitroglycerine, Nitroprusside, Milrinone) – Inhaled -- ?? (there are 2)
CHF Management Control fluid status – Diuretics ( Lasix, Spironolactone – Limit PO intake (initially) fluid/sodium restrictions, daily ( bid) weights and maintain nutritional status Address underlying disorder
Ventricular Septal Defect (VSD) Most Common Most small /close spontaneously Symptoms of congestive heart failure may occur/ especially if significant size Child has failure to thrive/ fatigue, respiratory s/s, pulmonary hypertension Murmur ( turbulent flow through abnormal or obstructive openings
Obstructive Defects Coarctation of Aorta , Incidence Pathophysiology: obstruction of systemic blood flow at the narrowed or strictured part. – Symptoms: high blood pressure and bounding pulses in arms weak or absent femoral pulses, cool lower extremities ↓ blood pressure in lower extremities CHF in infants – Surgical treatment: Timing
Congenital Heart Defects (continued)Defects That Decrease Pulmonary Blood Flow –Tetralogy of Fallot –Pulmonary Stenosis –Pulmonary Atresia
Tetralogy of Fallot has 4 defects1.Right Ventricular Hypertrophy2.Overriding Aorta3.Ventricular Septal defect4.Pulmonic Stenosis
Tetralogy of Fallot (TOF) Symptoms: cyanosis, systolic murmur, Metabolic acidosis , poor growth, clubbing, severe hypoxia (“tet spells”) Surgical treatment: palliative shunts and complete repair
Hyper cyanotic or Tet Spells Occur most frequently in 1st yr of life May be preceded by feeding, crying or defecation, fever, dehydration. ↑stress Characterized by profound hypoxemia, blue extremities, circumoral cyanosis, increased hgb and hct counts. Require prompt assessment and treatment to prevent brain damage or death.
Treatment: “Tet Spells” Place infant in knee-chest position Older child will instinctively squat Maintain a calm comforting approach Administer 100% oxygen Administer Morphine Administer fluids Propanolol for frequent Tet spells
HLHS ( Hypoplastic Left Heart Syndrome Structures on left side of heart underdeveloped Mitral and Aortic valves closed or small Left ventricle non functional 4th most common Congenital heart defect
HLHS Right side of heart is the working part Blood lungs → left Atrium through an ASD to right side of heart. Right ventricle pumps blood to lungs and also to systemic circulation through a PDA. Few days – weeks ductus closed death results.
Symptoms Bluish/ Cyanotic Rapid pulse, murmur and ↑RR Cold hands and feet Lethargic Decreased pulses in extremities, ↓ pulse ox Poor sucking and feeding Increased respiratory effort and WOB Organomegaly
Treatment /Prognsis Prostaglandins in newborn to keep PDA open Multiple Stage surgical repair Blalock-Taussig shunt Glenn procedure Fontan Procedure ( final ) Chronic Health problems , earliest survivors in 30’s→ Heart Transplant
Diagnostic Tools Chest X-ray ECG Echocardiogram – Transesophageal echocardiogram Cardiac Catheterization – Done under conscious sedation – Can be diagnostic or interventional – Post procedural care
Treatments Surgical Intervention Surgical repair/corrective surgery Palliative surgery/ temporary Interventional Cardiac Catheterization 1. Open narrowed passages 2. Closure of openings pp. 907 text , table 26-7.
Purpose of a Cath Diagnostic Interventional Cath – Define anatomy – Close PDA, ASD/PFO, VSD – Measure pressures – Close collateral vessels – Measure O2 content – Balloon dilate narrowed – Calculate shunts, resistance, vessels or valves CO – Place stents in narrowed – All of above is frequently vessels done off and on oxygen, then on NO
Angioplasty/ dilation of Coarctation of Aorta during cardiac catheterization
Cardiac Cath procedure Assess for : Circulation: cool extremities, ↓ pedal pulses, capp refill > 3 sec., decreased Sensation and mobility Complications: bleeding, arrhythmias, hematoma, thrombus, and infection.
Post Procedure VS are q 15” x 4; q 30” x 2; q 1h x 2 then IMC routine Stay on boards/supine x 2 hours With each set of V/S and prn, monitor: – Perfusion (arterial and venous) to distal extremity (pulses, color, CRT, temp) – Bleeding/hematoma formation at site If no bleeding at site and palpable distal pulse, may come off boards/sit up after designated time
Post Procedure Management Antibiotics (Ancef 25mg/kg) x 2 doses Aspirin (3-5mg/kg) to start same night for device placement CXR next morning if ASD or PDA device placed Echo next morning if ASD or PDA device placed “Discomfort” Control - acetaminophen
Going Home May go home 4-5 hours after a diagnostic cath Will stay overnight and get d/c’d in AM after most interventions Will return to school 2-3 days after procedure PE class/sports participation may be limited based on intervention