Cardiac Lecture

Jan Bazner-Chandler CPNP, CNS, MSN, RN

Cardiac

Ball & Bindler

Health History

 Family history of defects / early cardiac disease / siblings with defects  Maternal history of stillborns or miscarriages  Congenital anomalies / genetic anomalies / fetal alcohol syndrome / Down Syndrome and Turner Syndrome  Maternal exposure to rubella

Present Health History

 Heart murmur  Tires while eating  Low weight for height  Sweats while eating (diaphoretic)  Cyanosis, worsens with feeding or activity level  Irritable weak cry

Health History

 In the older child additional symptoms may include:  Chest pain  Decreased activity level  Syncope  Slight of build

Heart Sounds

Heart Sounds

 Use both the bell (for low frequency) and the diaphragm (for high frequency)  Quality: distinct S1 and S2  Rate matches radial pulse  Intensity  Rhythm

Heart Sounds

 Heart sounds should be crisp and distinct in children.

  S1 is the first heart sound, produced by closure of the tricuspid and mitral valves when ventricular contraction begins. S2 is produced by the closure of the aortic and pulmonic valves.

Heart Murmurs

 These sounds are produced by blood passing through a defective valve, great vessel, or other heart structure.

 Murmurs are classified by: intensity, location, radiation, timing, and quality.

Clubbing of Fingers

Clubbing of Fingers Whaley & Wong Bowden text

Knee-chest Position

Nurse puts infant in knee-chest position. Whaley & Wong Child with a cyanotic heart defect squats (assumes a knee-chest position) to relieve cyanotic spells. Some times called “tet” spells. Ball & Bindler

First Breath

• • • • • • Pulmonary alveoli open up Pressure in pulmonary tissues decreases Blood from the right heart rushes to fill the alveolar capillaries Pressure in right side of heart decreases Pressure in left side of heart increases Pressure increases in aorta

Treatment Modalities

 Palliative procedures  Pulmonary artery banding  Shunts  Corrective procedures

Diagnostic Test

  Chest x-ray to define silhouette of the heart.

 Heart size, shape, pulmonary markings, and cardiomegaly.

Electrocardiogram to define electrical activity of the heart.

 Echo-cardiogram to visualize anatomic structures.

Non-invasive

Cardiac Conduction

Cardiac Catheterization

 An invasive test to diagnose or treat cardiac defects.

 Visualizes heart and vessels.

 Measures oxygen saturation of chambers.

 Measures intra-cardiac pressures.

 Determines muscle function and pumping action of the heart.

Pre-cardiac Catheterization

 Assess vital signs with blood pressure.

 Hemoglobin and hematocrit  Pedal pulses  NPO  Hold digoxin  IV if child is polycythemic

Post-cardiac Catheterization

 Vital sign, with apical pulse, and blood pressure q 15 minutes for first hour.

 Apical pulse for 1 minute to check for bradycardia or dysrhythmias.

Toxicity to Dye

 Watch for signs of toxicity to the dye used during the procedure.

 Increased temperature      Urticaria Wheezing Edema Dyspnea Headache *Allergy response

Home Care Instructions

 Keep dressing in place for 24 hours.

   Keep site dry and clean.

Observe site for redness, swelling, drainage, or bleeding.

Check temperature.

  Avoid strenuous exercise.

Acetaminophen for pain.

  Keep follow-up appointment Pre-procedure medications as ordered.

Post-cardiac Catheterization

 Assess pulses below the cath site.

 Record quality and symmetry of pulses.

 Assess temperature and color of affected extremity.

 Check dressing for bleeding or hematoma formation.

Right to Left Shunts

 Occurs when pressure in the right side of the heart is greater than the left side of the heart.  Resistance of the lungs in abnormally high  Pulmonary artery is restricted  Deoxygenated blood from the right side shunts to the left side

Right to Left Shunt

 Hole in septum + obstructive lesion = Deoxygenated blood from the right side of the heart shunts to the left side of the heart and out into the body.

Clinical Manifestations

 Hypoxemia = the result of decreased tissue oxygenation.

 Polycythemia = increased red blood cell production due to the body’s attempt to compensate for the hypoxemia.

 Increase viscosity of the blood = heart has to pump harder.

Potential Complications

 Thrombus formation due to sluggish circulation.

 Brain abscess or stroke due to the un oxygenated blood bypassing the filtering system of the lungs.

Left to Right Shunt

 Pressures on the left side of the heart are normally higher than the pressures in the right side of the heart. If there is an abnormal opening in the septum between the right and left sides, blood flows from left to the right.

Clinical Manifestations

 The infant is not cyanotic.

 Tachycardia due to pushing increased blood volume.

 Cardiomegaly due to increased workload of the heart.

Clinical Manifestations

 Dyspnea and pulmonary edema due to the lungs receiving blood under high pressure from the right ventricle.

 Increased number of respiratory infections due to blood pooling in the the lungs promoting bacterial growth.

Congestive Heart Failure

 Major manifestation of cardiac disease.

 Under 1 year of age due to congenital anomaly.

 Over 1 year with no congenital anomaly may be due to acquired heart disease.

Cardinal Signs of CHF

 Tachycardia  Cardiomegaly  Tachypnea  Hepatomegaly

Digoxin Therapy

 Digoxin increases the force of the myocardial contraction.

 Take an apical pulse with a stethoscope for 1 full minute before every dose of digoxin. If bradycardia is detected.

   < 100 beats / min for infant and toddler < 80 beats in the older child < 60 beats in the adolescent * Call physician before administering the drug.

Signs of Digoxin Toxicity

 Bradycardia  Arrhythmia  Nausea, vomiting, anorexia  Dizziness, headache  Weakness and fatigue

Interventions

     Fluid restriction Diuretics – Lasix (potassium wasting) or Aldactone (potassium sparing) Bed rest Oxygen Small frequent feedings – soft nipple with supplemental NG for adequate calorie intake   Pulse oximeter Sedatives if needed

Supplemental Feeding

Infants with cardiac conditions often require supplemental feeding to provide sufficient nutrients for growth.

Ball and Bindler

Cardiac Heart Defects

 http://www.cincinnatichildrens.org/health/hear t-encyclopedia/anomalies/

Patent Ductus Arteriosus

 PDA  Incidence 10%  One of the most common benign defects  Ductus normally closes within hours of birth  Connection between the pulmonary artery (low pressure) and aorta (high pressure)  High risk for pulmonary hypertension

Diagnosis and Treatment

 Diagnosis by   Chest x-ray – enlarged heart and dilated pulmonary artery Echo-cardiogram – show the opening between pulmonary artery and aorta

Treatment

   Indomethocin given po – constricts the muscle in the wall of the PDA and promotes closure Cardiac Catheterization – coil is placed in the open duct and acts like a plug Closed heart surgery – small incision made between ribs on left hand side and PDA is ligated or tied and cut

Atrial Septal Defect

 ASD  10% of defects  Blood in left atrium flows into right atrium  Pulmonary hypertension  Reduced blood volume in systemic circulation  If left untreated may lead to pulmonary hypertension, congestive heart failure or stroke as an adult.

Diagnosis and Treatment

 Diagnosis: heart murmur may be heard in the pulmonary valve area because the heart is forcing an unusually large amount of blood through a normal sized valve.

 Echocardiogram is the primary method used to diagnose the defect – it can show the hole and its size and any enlargement of the right atrium and ventricle in response to the extra work they are doing.

Treatment

 Surgical closure of the atrial septal defect  After closure in childhood the heart size will return to normal over a period of four to six months.

 No restrictions to physical activity post closure

Ventricular Septal Defect

 VSD  30% of defects  Opening in the ventricular septum  Left-to-right shunt  Right ventricular hypertrophy  Deficient systemic blood flow

VSD

 Small holes generally are asymptomatic  Medium to moderate holes will cause problems when the pressure in the right side of the heart decreases and blood will start to flow to the path of least resistance (from the left ventricle through the VSD to the right ventricle and into the lungs)  This will generally lead to CHF

Diagnosis and Treatment

    Diagnosis – heart murmur – clinical pearl a louder murmur may indicate a smaller hole due to the force that is needed for the blood to get through the hole.

Electrocardiogram – to see if there is a strain on the heart Chest x-ray – size of heart Echocardiogram – shows size of the hole and size of heart chambers

Treatment VSD

 CHF: diuretics of help get rid of extra fluid in the lungs  Digoxin if additional force needed to squeeze the heart  FTT or failure to grow may need higher calorie concentration  Will need prophylactic antibiotics before dental procedures if defect is not repaired

Surgical Repair

 Over a period of years the vessels in the lungs will develop thicker walls – the pressure in the lungs will increase and pulmonary vascular disease   If pressure in the lungs becomes too high the un-oxygenated blood with cross over to the left side of the heart and un-oxygenated blood with enter the circulatory system.

If the large VSD is repaired these changes will not occur.

Coarctation of Aorta

 COA  7 % of defects  Congenital narrowing of the descending aorta  80% have aortic-valve anomalies  Difference in BP in arms and legs (severe obstruction)

Diagnosis and Treatment

 In 50% the narrowing is not severe enough to cause symptoms in the first days of life.

 When the PDA closes a higher resistance develops and heart failure can develop.

 Pulses in the groin and leg will be diminished  Echocardiogram will show the defect in the aorta

Treatment

     Prostaglandin may given to keep the PDA open to reduce the pressure changes The most common repair is resection of the narrowed area with re-anastomosis of the two ends Surgical complications – kidney damage due to clamping off of blood flow during surgery High blood pressure post surgery – may need to be on antihypertensives Antibiotic prophylactic need due to possible aortic valve abnormalities.

Pulmonary Stenosis

 PS  7% of defects  Obstruction of blood flow from right ventricle  Hypertrophy of right ventricle  If severe cyanosis due to right-to-left shunt

Pulmonary Valvar Stenosis

 In pulmonary valvar stenosis the pulmonary valve leads to narrowing and obstruction between the right ventricle and the pulmonary artery.

 Thickened tissue become less pliable and increases the obstruction  Right ventricle must work harder to eject blood into the pulmonary artery.

Diagnosis and Treatment

 Diagnosis: heart murmur is heard – clicking sound when the thickened valve snaps to an open position.

 Electrocardiogram would be normal   Echocardiogram most important non-invasive test to detect and evaluate pulmonary stenosis Cardiac Catheterization – to measure pressures and measure the stenosis

Treatment

 Cardiac Catheterization to dilate the valve and open up the obstruction.

 Open- heart procedure would only needed for more complex valve anomaly.

Tetralogy of Fallot (TOF)

 6% of defects  Most common cardiac malformation responsible for cyanosis in a child over 1 year

TOF

 Four Components     VSD Pulmonary stenosis – narrowing of pulmonary valve Overriding of the aorta – aortic valve is enlarged and appears to arise from both the left and right ventricles instead of the left ventricle Hypertrophy of right ventricle – thickening of the muscular walls because of the right ventricle pumping at high pressure

Clinical Manifestations

 Dependent on degree of right ventricular outflow obstruction.

 Right-to-left shunt   Clubbing of digits “tet” spells - treated by flexing knees forward and upward  Severe irritability due to low oxygen levels

Diagnosis

 Cyanosis  Oxygen will have little effect on the cyanosis   Loud heart murmur Echocardiogram – demonstrates the four defects characteristic of tetralogy

Treatment

   If oxygen levels are extremely low prostaglandins may be administered IV to keep the PDA open Complete repair is done when the infant is about 6 months of age Correction includes     Closure of the VSD with dacron patch The narrowed pulmonary valve is enlarged Coronary arteries will be repaired Hypertrophy of right heart should remodel within a few months when pressure in right side is reduced

Long Term Outcomes

 Leaky pulmonary valve that can lead to pulmonary insufficiency   Arrhythmias after surgery Heart block – occasionally a pacemaker is necessary  Periodic echocardiogram and exercise stress test or Holter evaluation

Aortic Stenosis

 6% of defects  Aortic valve: has two rather than three leaflets. Leaflets are thickened or fused.

 Obstruction of blood flow from left ventricle  Mild symptoms: dizziness, syncope, angina, fatigue  30% incidence of sudden death

Aortic Stenosis

 Causes obstruction to blood flow between the left ventricle and aorta.

 Most common form is obstruction of the valve itself  When the aortic valve does not open properly the left ventricle must work harder to eject blood into the aorta.

 Left ventricular muscle becomes hypertrophied.

Diagnosis

 Heart murmur or AS is a turbulent noise caused by ejection of blood through the obstructed valve.

 Electrocardiogram is usually normal   Echocardiogram will show the obstruction and rule out other heart anomalies Exercise stress test – provides information on impact of the stenosis on heart function

Treatment

    Cardiac catheterization – balloon dilation of the narrowed valve.

Surgical valvotomy if the closed procedure does not work – often done when patient is older when severe calcium deposits further obstruct the valve. Recurrent valve obstruction is a complication and if valve replacement is done too early the child may outgrow the valve.

Antibiotic prophylaxis especially if valve replacement

Hypoplastic Left Heart

 One of the most complex defects seen in the newborn and the most challenging of all the congenital defects  All the structures on the left side of the heart are severely underdeveloped.

 Mitral and aortic valves are either completely closed or are very small – left ventricle is tiny – aorta is small and often only a few millimeters in diameter

HLH

  Life threatening shock develops when the ductus arteriosis closes Low oxygen saturations – will not increase with oxygen administration  Pulses will be weak in all extremities  Plan to deliver infant in a hospital capable of providing the aggressive treatment needed

Treatment

 Three staged procedure to reconfigure the cardiovascular system  Norwood – right ventricle becomes the systemic ventricle pumping blood to the body  Glenn done at 3-6 months  Fontan done at 2 -3 years of age

Long Term Complications

   Easily tiring when participating in sports or other exercises Formation of blood clots – heparin or Coumadin use Heart arrhythmias – pace maker  Cardiac failure

Bacterial Endocarditis

 Infection of endocardial surface of the heart  History of CHD, Kawasaki Disease, Rheumatic Fever, or prosthetic valves are more susceptible to infection  Prophylactic antibiotics with dental care, throat, intestinal, urinary or vaginal infections or surgery.

Kawasaki Disease

 Acute-self limiting disease  Generalized vasculitis  Peak incidence 6 months to 2 years  More common in males and Japanese http://www.aafp.org/afp/990600ap/3093.html

Clinical Manifestations

 High fever  Conjunctivitis  Strawberry tongue  Edema of hands and feed  Reddening of palms and soles  Lymph node swelling

Edema – Hands and Feet

Peeling Finger Tips

Blood Values

 Elevated WBC  Elevated ESR  Elevated platelets

Management

 Intravenous gamma globulin  High dose of ASA while in hospital  Low dose ASA upon discharge  Base-line echocardiogram to assess coronary artery status