MOD

• Cardiac disorders are a major focus of health promotion and disease prevention measures in both adults and children
• Congenital heart disease


  Occurs as a result of congenital anomaly where the heart developed inadequately in utero or cannot adapt to extrauterine life for some reason
• 8% of term newborns are born with congenital cardiovascular abnormality, the rate is even higher in preterm infants

  
• Usual cause of congenital heart disorders

  Failure of heart structure to progress beyond an early stage of embryonic development
• Maternal Rubella


  Example of an infection known to lead to disorders such as patent ductus arteriosus, pulmonary or aortic stenosis, atrial or ventricular septal defects, or pulmonary stenosis
• Atrial and ventricular septal defects can also be familial
• 10% to 15% incidence rate of a child when parents have aortic stenosis, atrial septal defect, ventricular septal defect, of pulmonic stenosis
• Congenital heart disorders were classified based on the physical sign of cyanosis

  Classified as either cyanotic or acrocyanotic disorder
• Second classification system

  Addresses the hemodynamic and blood flow patterns rather than their effect, allowing a more uniform and predictable set of signs and symptoms
• Four classifications identify disorders with

  • Increased pulmonary blood flow
  • Obstruction to blood flow leaving the heart
  • Mixed blood flow (oxygenated and deoxygenated blood mixing in the heart or great vessels)
  • Decreased pulmonary blood flow
• Congenital heart disorders associated with increased pulmonary blood flow

  Involve blood flow from the left side of the heart (which is under greater pressure) to the right side of the heart (which is under less pressure) through some abnormal opening or connection between the two systems or the great arteries
• Ventricular Septal Defect (VSD)


  An opening is present in the septum between the two ventricles, pressure in the left ventricle is greater than right ventricle, blood shunts from left to right across the septum (acyanotic disorder), right ventricular hypertrophy and increased pressure in the pulmonary artery when blood goes back into the pulmonary circulation
• Ventricular Septal Defect (VSD)


  • May not be evident at birth due to incomplete opening of alveoli and high pulmonary artery resistance, little blood is shunted through defect, shunting begins at 4-8 weeks of age, infants demonstrate easy fatigue and loud, harsh pansystolic murmur becomes evident along the left sternal border at the third or fourth interspace
• Typical murmur of VSD


  Generally widely transmitted, thrill (vibration) may also be palpable
• Diagnosis of VSD


  Based on examination by echocardiography with color flow Doppler or MRI, reveals right ventricle hypertrophy and possibly pulmonary artery dilation from the increased blood flow, ECG will also reveal right ventricular hypertrophy
• VSD outcomes


  • 85% close spontaneously
  • Moderate size may be closed during cardiac catheterization
  • Larger ones require open heart surgery scheduled before 1 year of age to prevent pulmonary artery hypertension
• Closure of VSD is important as if the defect is left open, it can cause cardiac failure from the artery hypertension and endocarditis (infection of the heart) due to the recirculating blood flow
• Atrial Septal Defect (ASD)


  Abnormal communication between two atria allowing the blood to shift from left to the right atrium (acyanotic defect), more common in girls than boys, blood flow is from left to right (oxygenated to deoxygenated) because of the stronger contraction of the left side of the heart, causing an increase in the ventricular hypertrophy and increased pulmonary blood flow
• Types of ASD


  • Ostium primum (ASD1) - opening is at the lower end of the septum
  • Ostium secundum (ASD2) - opening is near the center of the septum
• ASD symptoms


  May be asymptomatic until infection from recirculating blood occurs, harsh systolic murmur heard over the second or third interspace (pulmonic area) because of the extra amount of the shunted blood that crosses pulmonic valve, fixed splitting of the second heart sound as the volume of blood crossing causes pulmonary valve to close consistently later than the aortic valve
• Treatment of ASD


  Surgery to close the defect done electively between 1 and 3 years of age, closure is important as without it the child is at risk for infectious endocarditis and eventual heart failure, important to be repaired in girls as it can cause emboli during pregnancy
• Patent Ductus Arteriosus


  An accessory fetal structure that connects pulmonary artery to aorta, if it fails to close at birth blood will shunt from aorta (oxygenated blood) to the pulmonary artery (deoxygenated blood) because of the increased pressure in the aorta, closure begins with the first breath and complete between 7-14 days of age but may not occur until 3 months of age
• Shunted blood in Patent Ductus Arteriosus


  Returns to the left atrium, passes to the left ventricle, out to aorta, and shunts back to pulmonary artery, causing increased pressure in the pulmonary circulation from the extra shunted blood and leading to right ventricle hypertrophy and ineffective heart action
• Patent Ductus Arteriosus is twice as common in girls than boys and has a higher incidence at higher altitudes, accounting for about 10% of all heart disease
• Physical examination findings in Patent Ductus Arteriosus

  Wide pulse pressure, low diastolic pressure (measure of peripheral resistance) due to the shunt or runoff of blood which reduces resistance, a typical continuous "machinery" (systolic and diastolic) murmur heard at upper left sternal border or under the left clavicle on older children, infants may have a short grade II or III harsh systolic sound