Essentials Exam 4

• What are the levels of LV and RV pressures during diastole?

  • Throughout most of diastole, the LV and RV pressures are abnormally elevated and equal in the cardiac cath.
• How are the pressures of the heart before birth?

  1. Before birth, the valve only permits right to left flow of blood from the higher-pressured RA to the lower-pressured LA
• Where is the majority of the blood from the placenta sent?

  1. The blood is shunted through the fetal ductus venosus
• In time, what happens to the AV canal?

  1. The AV canal becomes two separate canals, housing the tricuspid valve and the other mitral valve.
• What happens when the septum primum advances?

  1. It leaves a large opening known as the ostium primum between the septum and the endocardial cushions surrounding the AV canal
• The superior edge of the septum primum then gradually regresses, leaving the lower edge to act as a “flaplike” valve that allows only right-to-left flow through the foramen ovale (allows shunted blood)
• Immediately following birth, the newly functioning lungs replace the placenta as the organ of gas exchange, and the three shunts ultimately close. 
• Endocardial cushions initially begin as swellings of the gelatinous connective tissue layer within the AV canal
• Tissue growth occurs primarily horizontally, resulting in septation of the AV canal 
• Symptoms of Eisenmenger Syndrome

  • Hypoxemia (exertional dyspnea and fatigue)
  • Erythrocytosis/hyperviscosity: fatigue, headaches, and stroke
  • Infarction or rupture of the pulmonary vessels: hemoptysis
• There are no treatments that reverse the disease process in Eisenmenger syndrome
• Pulmonary vasodilator therapy can relieve symptoms in Eisenmenger syndrome
• Closure of the shunt allowing reversed right to left flow is generally contraindicated in Eisenmenger syndrome as it eliminates a pathway for blood to exit the RV in the face of high pulmonary vascular resistance and can elevate right heart failure
• The only effective measure for Eisenmenger syndrome is lung or heart-lung transplantation
• With advances in early detection and correction, Eisenmenger syndrome is less common
• Atrial Septal Defect


  Most common symptom in adults are atrial arrhythmias
• What does the blue arrow in A means? Indicates shunted flow from left atrium (LA) into the right atrium (RA)

  
  

  What does the blue arrow in B means? Representation of blood flow through an uncomplicated ASD, resulting in enlargement of the RA, RV, and PA.

  
• Pericardial Synthesis

  1. Echo

  • Detect effusions as small as 20mL
  • Assess ventricular filling
  • Determine volume
  • Assist in pericardiocentesis

  2. Needle insertion
• IVC blood entering the right atrium directed to the LA through the foramen ovale (Crista Dividens)
• Percutaneous ASD repair


  Less invasive alternative to surgery, using a closure device deployed via an intravenous catheter
• In the fetus, the RV is the actual "workhorse" of the heart, providing two-thirds of the total cardiac output
• At birth, the fetal lungs inflate and become functional, making the placenta unnecessary and dramatically altering circulation patterns
• Formation of the cardiovascular system begins during the 3rd week of embryonic development.
• A unique circulation using the placenta as the primary organ of gas, nutrient, and waste exchange. 
• Newborn babies may not have any apparent symptoms but in time can cause issues
• Cause to the type of Pericarditis (infectious vs noninfectious)

  Infectious

  • HIV/Aids
  • Coxsackie Virus
  • Tuberculosis

  Noninfectious

  • Radiation Therapy
  • Cancer
  • Dialysis
• Pericarditis following a myocardial infarction is also known as Dressler's Syndrome. True
• Cardiac catheterization findings for constrictive pericarditis include:

  • Elevation and equalization of the diastolic pressures in each of the cardiac chambers
  • An early diastolic “dip and plateau” configuration in the RV and LV tracings
  • A prominent y descent in the right atrial pressure tracing
• Cardiac tamponade is most likely to occur when pressure in the pericardial cavity rises to equal or exceed the diastolic pressures in the heart
• Classic ECG findings with acute pericarditis include

  • ST elevation in most of the leads
  • PR segment depression in most leads
• The procedure to remove the high-pressure pericardial fluid found with cardiac tamponade is called ___ . Pericardiocentesis
• The functions of the pericardium include all of the following EXCEPT

  impairs left ventricular filling with inspiration
• Match the primative heart chambers with the structures they will form.

  • Truncus arteriosus - Aorta, pulmonary artery
  • Bulbus cordis - Outlet of ventricles
  • Primative ventricle - Inlet of ventricles
  • Primative atrium - Left and right atria
  • Sinus venosus - Part of right atrium, coronary sinus
• The 3 shunts found in the fetal heart are all of the following EXCEPT: Endocardial cushion
• Following birth, the pressure in the LA becomes greater than that in the RA, causing the septum primum to close firmly against the septum secundum. True
• Continued growth and elongation within the confined pericardial cavity force the heart tube to bend on itself on day 23, eventually forming a U-shaped loop with the round end pointing ventrally and to the left by day 28. False
• The result of the heart looping is placement of the atrium and sinus venosus above and behind the truncus arteriosus, bulbus cordis, and ventricle. True
• IVC blood entering the right atrium is directed to the LA through the ___. Foramen Ovale
• The connection between the ___ is termed the atrioventricular (AV) canal. Primitive atrium and ventricle
• The atrioventintricular canal ultimately gives rise to the Mitral and Tricuspid Valves