Cardio and hema

• Types of cardiovascular disorders

  • Congenital Heart Disease
  • Acquired Heart Disorder
• At birth, there are already problems anatomically, physiologically, or both in Congenital Heart Disease
• There is an anatomic derangement in Congenital Heart Disease
• Congenital Heart Disease is a common cause of heart problems in children
• Acquired Heart Disorder


  Heart problems acquired at birth with secondary causes, common in adult patients
• Congestive Heart Failure (CHF)


  Inability of the heart to pump an adequate amount of blood to the systemic circulation at a normal filling pressure to meet the metabolic demand of the body
• When not treated or there is progression, the end stage of CHF is heart failure
• In CHF, the heart loses its ability to pump adequate blood to the circulation
• Causes of CHF


  • Patent ductus Arteriosus
  • Ventricular Septal Defect
  • Truncus Arteriosus
  • Atrial Septal Defect
• Causes of CHF


  • The heart muscle is not strong enough to pump a normal amount of blood
  • A major cause is when the structures on the left side of the heart are so small or narrowed that blood has a difficult time ejecting from the heart leading to backup into the lungs, seen in critical aortic stenosis, critical coarctation of the aorta or hypoplastic left heart syndrome
• Hypoxemia


  An arterial oxygen tension that is less than normal and can be identified by a decreased arterial saturation, a lack of oxygen
• Hypoxia


  A reduction in tissue oxygenation that results from low oxygenation and results in impaired cellular process
• Normal heart flow


  1. Deoxygenated blood from body enters superior and inferior vena cava

  2. Right Atrium – tricuspid valve – Right Ventricle

  3. Right Ventricle – pulmonary valve – Pulmonary artery

  4. Pulmonary artery – Lung for gas exchange

  5. Oxygenated Blood from Pulmonary vein – Left atrium – mitral valve/bicuspid valve – Left ventricle

  6. Left Ventricle – aortic valve – aorta

  7. Aorta – different parts of the body

  
• Fetal heart circulation


  1. Pulmonary circulation not functioning

  2. Increase of pressure in lungs

  3. Flow of Blood from higher to lower pressure

  4. Presence of HYPOXIC VASOCONSTRICTION

  5. Shunted from Right to Left

  6. Basic unit of lungs is ALVEOLI

  
• Fetal shunts


  • Ductus Venosus
  • Foramen Ovale
  • Ductus Arteriosus
• Ductus Venosus


  Shunt that connects umbilical cord and inferior vena cava, closed and not functional when umbilical cord is cut
• Foramen Ovale


  Shunt that connects right atrium and left atrium, skips the blood to flow in the lungs, closes at first 6 months of life anatomically, not functional at birth

  
• Ductus Arteriosus


  Shunt that connects pulmonary artery and aorta, closes at 2-3 weeks of life anatomically, not functional at 12-24 hours of life
• Classification of congenital heart disease

  • ACYANOTIC
  • CYANOTIC
• Acyanotic congenital heart diseases

  • Increase pulmonary blood flow - Atrial septal defect, Ventricular septal defect, Patent ductus arteriosus, ventricular canal
  • Coarctation of the Aorta, Aortic stenosis, Pulmonic stenosis
• Cyanotic congenital heart diseases

  • Decrease pulmonary blood flow - Tetralogy of Fallot, Pulmonic atresia
  • Mixed blood flow - Transposition of the great arteries, Total anomalous pulmonary venous return, Hypoplastic left heart syndrome
• Atrial septal defect (ASD)


  An abnormal opening between the atria, allowing blood flow from the higher pressure left atrium to the lower pressure right atrium
• ASD occurs in about 5 to 10% of congenital heart disease
• ASD is more common in female children
• Types of ASD


  • Ostium secundum
  • Ostium primum
  • Sinus venosus
• Ostium secundum ASD


  Most common type, 50 to 70%, in the middle of the septum in the region of the foramen ovale
• Ostium primum ASD


  30% of ASDs, low position, form of AV septal defect
• Sinus venosus ASD

  Least common type, 10%, at the entry of Superior vena cava into right atrium
• Diagnosis of ASD


  • Chest X-ray - Mild to moderate cardiomegaly, enlarged right atrium and right ventricle, prominent pulmonary artery segment, increased pulmonary vascular markings
  • Echocardiogram - Position, size, signs of right to left shunt flow
  • Electrocardiogram (ECG) - Increased pulmonary blood flow, cardiomegaly concentrated on right side

  
• Clinical manifestations of ASD


  Most infants and children are asymptomatic, but over years to decades may experience symptoms like tiredness during feeding, shortness of breath, fatigue, sweating, palpitations, stunted growth, no cyanosis
• Management of ASD


  1. 20% close spontaneously in first year or as child grows

  2. For defects 3-8mm, supportive medical management is sufficient

  3. For defects >8mm, surgical repair is required

  4. Surgical repair - defect closed with stitches or special patch, using patient's own pericardium, bovine pericardium or synthetic material
• Ventricular Septal Defect (VSD)

  An abnormal opening in the ventricular septum, allowing oxygenated blood from the left ventricle to mix with the oxygenated blood into the right ventricle
• VSD is the most commonly occurring type of congenital heart defect, occurring in 14-17% of babies born each year
• Types of VSD


  • Supracristal VSD
  • Membranous VSD
  • Muscular VSD
• Supracristal VSD


  Occurs just beneath the aortic valve at the left ventricular outflow tract
• Membranous VSD


  The most common type, originate inferior to the crista supraventricularis
• Muscular VSD


  Occur in the mid to apical interventricular septum
• Diagnosis of VSD


  • Chest X-ray - cardiomegaly and increased pulmonary vascular marking
  • Auscultation - pansystolic murmur, S1 marked by murmur, S3 at apex
  • Murmur indicates disturbance in normal blood flow

  
• Clinical manifestations of VSD

  Signs and symptoms vary with size of defect, usually not seen at birth due to high pulmonary vascular resistance, in infants with moderate to large defects become symptomatic in first few weeks - cyanosis, clubbing, respiratory distress, shortness of breath while feeding, poor growth, failure to gain weight, pounding heart, frequent respiratory tract infections
• Management of VSD

  1. Surgical repair - close the chest or use special patch

  2. Interventional cardiac catheterization - septal occluder

  3. Outcome - 95% success rate, growth of child catches up in 1-2 years, size of heart reduces, murmurs can be heard 2-3 months postoperative