Pathology of Cardiovascular System Flashcards
Failure of closure of fetal cardiovascular shunts
✓ patent ductus arteriosus
✓ atrial septal defect
✓ ventricular septal defect
✓ tetrad of fallot
Etiologies of congenital cardiovascular anomalies;
- Failure of closure of fetal cardiovascular shunts
- Failure of Normal Valvular Development
- Malpositioning of Great Vessels
Failure of Normal Valvular Development;
✓ pulmonic stenosis
✓ subaortic stenosis
✓ endocardial cushion defects
✓ mitral and tricuspid malformations in cats
Malpositioning of Great Vessels
✓ persistent right aortic arch
✓ transposition of aorta and pulmonary artery
Specific Congenital Anomalies;
- Patent ductus arteriosis
- Persistent right aortic arch
if PA- aorta shunt remains open, shunting usually occurs from left to right with resultant pulmonary hypertension. Inherited among POODLES, COLLIES, POMERANIANS
- Failure of the ducts arteriosis to close by 3 weeks- normally forms ligamentum arteriosum
Patent ductus arteriosis
A right aorta, instead of the normal left arches over the origin of the right bronchus.
Persistent Right Aortic Arch
(persistent foramen ovale) left to right shunting of blood (of clinical significance)
atrial septal defects
Sites of the Major Cardiovascular Anomalies of the DOG.
AS- Aortic Stenosis
ASD- Atrial Septal Defect
PDA- Patent Ductus Arteriosis
PS- Pulmonic Stenosis
VSD- Ventricular Septal defect
Subvalvular lesions are often more common. Irregular bands or ridge of fibrous tissue stretch across the subaortic endocardium
Aortic and Subaortic Stenosis
May occur at the valve site with or without supra or subvalvular constriction. Leads to right ventricular hypertrophy. Most common in dogs; BULLDOGS, CHIHUAHUA, TERRIER TYPES
Pulmonary Stenosis
Transposition Defects;
✓ Aorta and Pulmonary Artery leaving the right ventricle
✓ Aorta may straddle a septal defect and receive blood from both ventricles
✓ Eisenmengers Complex
✓ Tetralogy of Fallot
whereby the aorta is dextroposed; there is a VSD, right ventricular hypertrophy
Eisenmenger’s complex
has the same defects as Einsenmenger’s complex except with the additional pulmonary stenosis
Tetralogy of Fallot
presternally or intrabdominally located heart. Common in CATTLE and PIGS.
Ectopia Cordis
- Diffuse fibroelastic thickening of the left ventricular endocardium; necrosis and calcification of the adjacent myocardium.
- AV valves and chordae tendinae may be thickened
- Congenital form usually regarded as primary (BURMESE KITTEN). Secondary endocardial fibrosis may occur in mature animals
Endocardial Fibroelastosis
Hematocyst on the margins of the AV valves may be seen in calves
Congenital hematomas
Blood squirting produce valvular incompetence “jet lesions” and right atrial dilatation. May occur singly or in association with other defects such as transposition defects.
Ventricular Septal Defect
Pathology (Ventricular Septal Defect)
- Right ventricular hypertrophy
- Pulmonary hypertension and edema
Tetralogy of Fallot (Tetrad of Fallot)
(mnemonic acronym: ITPR)
Component Defects
- Interventricular septal defect
- Transposition of the aorta
- Pulmonic stenosis
- Right ventricular hypertrophy
Eisenmenger’s Complex (similar with Tetrad of Fallot except no pulmonic stenosis). Component Defects;
- Interventricular septal defect
- Transposition of aorta
- Right Ventricular hypertrophy
CONGESTIVE HEART FAILURE
Right Sided Heart Failure
Causes;
- Myocardial degeneration
- Myocarditis
- Cardiomyopathies
- Congenital abnormalities
- Cor pulmonale
- Hydropericardium
- Pericarditis
- Failure of left side of the heart
Congenital abnormalities
✓ Pulmonic valve stenosis
✓ Tricuspid valve insufficiency
✓ Interventricular septal defect
edema due to increased venous pressure as;
✓ dependent edema in horse
✓ ascites in dog
✓ hydrothorax in cat
Left Congestive Cardiac Failure
Causes;
- myocardial degeneration
- myocarditis
- cardiomyopathies
- congenital abnormalities
Congenital abnormalities (left congestive cardiac failure)
✓ aortic valve stenosis
✓ bicuspid valve insufficiency
✓ patent ductus arteriosis
Associated Pathology of Damming back of blood in the lungs
- pulmonary hypertension
- cyanosis due to impaired gaseous exchange and diminished cardiac output
- coughing and dyspnea
- peripheral circulatory failure
Pulmonary Hypertension leading to;
✓ alveolar edema
✓ interstitial edema
✓ hemosiderosis of lungs
✓ right sided heart failure due to back pressure on pulmonary arterial circulation
am important age-related cardiac disease of dogs
valvular endocardiosis
other name of valvular endocardiosis
valvular fibrosis and myxomatous or mucoid degeneration
Valvular fibrosis and myxomatous or mucoid degeneration
- most common cause of congestive heart failure in old dogs
- more frequent on the mitral that tricuspid valves
- usually a bacterial infection.
- lesions are large and generally present on valves
- grossly, affected valves have large, adhering, friable, yellow to gray masses termed “vegetations” occluding valvular orifices
Endocarditis
Chronic: Irregular nodular masses termed.
“verrucae” (wartlike lesions)
a distinctive lesion common affecting left atrium associated with acute renal insufficiency in dogs
Ulcerative Endocarditis
MYOCARDIAL DISEASES;
Myocardial hypertrophy
2 Anatomic Forms:
- Eccentric Hypertrophy
- Concentric Hypertrophy
enlarged cardiac chambers with normal to decreased wall thickness. Produced by lesions with increased blood volume (i.e valvular insufficiency and septal defects)
Eccentric Hypertrophy
Char. by small cardiac chambers with thick walls. Results from lesions with increased pressure load such as valvular stenosis, systemic hypertension and pulmonary disease.
Concentric Hypertrophy
Three stages of myocardial hypertrophy
- initiation
- stable hyperfunction
- deterioration of function associated with degeneration of hypertrophied muscle
maybe be single or multiple lesion mineralization will occur with Vit. D toxicosis.
Endocardial mineralization and endocardial fibrosis
Fibrosis with or without mineralization will occur in heart chronically dilated with?
Johne’s disease “jet lesions”
Vit. D toxicosis and carcinogenic plants containing
Vit. D analogs (cestrum diurnum, Tristetum flavescens, Solanum torvum)
