Vana 102 Chapter 7.1- The Comparative Vascular System (P.1)

• The arterial duct system doesn’t close after birth. This should be corrected early through a left intercostal incision through the fourth intercostal space. The ductus is carefully isolated and ligated.

  Patent Ductus Arteriosus
• Normal in calves and of no clinical significance if found in necropsy.

  Patent Foramen Ovale
• The part of a calf’s aorta between the brachiocephalic trunk and the entrance of the ductus arteriosus. It is normally smaller than the rest of the aorta and the large ductus arteriosus. Do not mistake the combined pulmonary trunk, the ductus arteriosus and the descending aorta for an aorta coming out of the right ventricle.

  Aortic Isthmus
• Interference with the migration of the heart into the thorax, resulting in the heart being located somewhere other than the thorax (usually in the cervical region).

  Ectopia Cordis
• One type of this defect results when the foramen ovale and second foramen overlap, allowing blood to flow from left to right, resulting in poor oxygenation of blood which can lead to cyanosis.

  Atrial Septal Defect
• The right instead of the left 4th aortic arch becomes the aorta. The aorta is then on the right side of the esophagus instead of the left. The aorta, ligamentum arteriosum and the base of the heart form a ring around the esophagus.

  Persistent Right 4th Aortic Arch
• The correct ventricles do not match up with the correct outflow channels. This is fatal.

  Transposition of the Great Vessels
• Failure of the interventricular septum to close, involving the membranous part of the septum. The most common cardiac anomaly in large animals, it causes systolic murmur.

  Interventricular Septal Defect
• This developmental anomaly has four components:

  o Pulmonic stenosis

  o The aorta over–rides both ventricles

  o Ventricular septal defect

  o Hypertrophy of the right ventricle

  Tetralogy of Fallot
• The structure a surgeon must incise to reach the pericardial cavity (for open heart surgery). It consists of the mediastinal (pericardial) pleura, the fibrous pericardium, and the parietal layer of the serous pericardium.

  Surgeon’s Pericardium
• Acute compression of the heart due to fluid effusion or hemorrhage into the pericardium.

  Cardiac Tamponade
• An excessive production and concurrent retarded absorption of pericardial fluid, caused by pericarditis.

  Hydrops Pericardii
• The circulation through the _______ is important to understand when dealing with problems of the heart. .

  Heart
• Problems in the right side of the heart

  Pulmonic Circulation
• cause blood to back up in the caudal vena cava, filling the abdomen with fluid, in dogs

  Ascites
• Problems in the left side of the heart

  Systemic Circulation
• cause blood to back up into the lungs

  Congestion of the Lungs
• The connective tissue skeleton separating the atria from the ventricles and supplying attachment for the heart valves.It contains cartilage in all species and two bones (ossa cordis) in the ox.

  Skeleton of the Heart
• Listening to heart sounds by means of a stethoscope.Heart sounds are caused by the closing of the different valves.

  Heart Auscultation
• Contraction of the ventricles, occurs between the 1st and 2nd heart sound.

  Systole
• Relaxation of the ventricles, occurs between the 2nd and 1st heart sounds.

  Diastole
• Caused by the closure of the AV valves.

  1st Heart Sounds (“Lub”)
• Caused by the closure of the semilunar valves (aortic and pulmonic).

  2nd Heart Sound (‘Dub”)
• the puncta maxima; the spot on the thoracic wall where a valve sound is loudest.

  Point of Maximum Intensity
• Left 3rd ICS at the level of olecranon (low).

  Pulmonic Valve
• Left 4th ICS at the level of shoulder (high).

  Aortic Valve
• Left 5th ICS at the level of the olecranon (low).

  Left AV Valve
• Right 3rd– 4th ICS at the level of olecranon (low).

  Right AV Valve
• Abnormal sounds caused by blood flow turbulence, due to valvular or nonvalvular problems.

  Heart Murmurs
• A sound due to a leaky or narrowed valve.

  Valvular Murmur
• Caused by turbulence due to backflow through a valve not fully closed.

  Leaky Murmur
• A constriction of the opening causing a turbulence past that opening.

  Narrowing Murmur
• Occurs between the 1st and 2nd heart sounds, when the AV valves should be fully closed and the aortic and pulmonic valves open.


  Systolic Murmur
• Occurs between the 2nd and 1st heart sounds when the aortic and pulmonic valves should be closed and the AV valves opened (AV stenosis or semilunar valve insufficiency).

  Diastolic Murmur
• Diastolic murmur, very rare.

  AV Narrowing
• Diastolic murmur, rare.

  Aortic or Pulmonic Leaking
• A failure of the arterial duct to close; the resulting murmur sounds like a washing machine; it is continuous, thus systolic and diastolic.

  Patent Ductus Arteriosus
• Failure of the opening (oval foramen) between two fetal atria to close.

  Interatrial Septal Defect
• Failure to close; it results in a systolic murmur heard loudest on the right side near the sternum.

  Interventricular Septal Defect
• Dirofilariasis. Adult round worms (nematodes – Dirofilaria immitis) of the dog live in the right ventricle, causing a great strain on the right side of the heart

  Heart Worms