Test 1- Cardio Flashcards
Normal Cardiac Function
• Maintenance of adequate blood flow (cardiac output)
Delivery of Oxygen, nutrients and hormones to
peripheral tissues
Removal of Carbon Dioxide (CO2) and other metabolic waste products
Maintenance of normal thermoregulation and glomerular filtration rate (GFR)urine output
Compensatory mechanisms available to maintain cardiac function
Cardiac dilatation (stretching of cardiac muscle –> ↑contractile force –>↑stroke volume –> maintain normal cardiac output)
Myocardial hypertrophy
↑in heart rate
↑in peripheral resistance- helps because more blood goes into the peripery
Redistribution of blood flow
Different Types of Injuries:
Some are reversible and some are irreversible; These are all reversible- if we take out the way that these injuries are created, then we can repair them
These injuries are all illreversible- Remember, cardiomyocytes CAN NOT UNDERGO REGENERATION!
Follow the blood pathway from placenta (umbilical vein) to umbilical arteries.
Note the coloration of the different mixes of fetal blood, depending on where one looks at the system.
bypassing- oxygenated blood- umblicial vein
umblical arteries- non-oxgentated blood back
fetal life- connections between the ventricules and the atrium through the foramen ovale- this should disapear after birth
ductus arterious- bypassing the lungs and the blood will go straight into the aorta because the lungs are not functional- this should close and form the ligamentum arterious
Serous atrophy of heart -cow
Common in starving, emanciated animals
Epicardial hemorrhage (petechia, ecchymosis), endotoxemia – cow.
Animals that died from septis
This can also be an antomical change at slaughtering.
Cardiac Failure/Decompensation
Cardiac syncope – acute onset of cardiac failure causing collapse and unconsciouness(abnormal heart rhythm, defective heart valves etc)
Congestive heart failure (CHF)- Develops slowly from gradual loss of cardiac output due to pressure or volume overload or myocardial injury.
Brisket edema, bull, R- sided CHF
L- sided CHF- pulmonary edema will be the main manifestation- this can lead to R-sided CHF because this will lead to pulmonary hypertension
Heifer, idiopathic pulmonary hypertension leading to CHF
fluid in cutaneous tissue
Ascites (hydroperitoneum), dog
transudate
What other conditions in addition to CHF that can result in ascites?
- Hyperproteinemia- kidney disease, liver disease, protein loosing enteropathy
Post-mortem examination of the heart: what are we looking for?
Serous atrophy, coronary groove,
remember to look at the heart while it’s attached to the lungs- also it usually follows the flow of the blood
shape of the valves, aorta, ventricules
Tricuspid valve(right AV)
rupture of the chorade tendenae which can produce a prolapse of the valve
Left Mitral Valve
greyish discoloration is normal
Congenital anomalies
- Can affect the heart or blood vessels
- Animals may die in utero or may present clinical signs after birth
• Clinical signs may include exercise intolerance, cyanosis and stunted body growth.
Congenital valvular anomalies
Valvular hematocyst, mitral valve
Usually seen in ruminants; blood filled cysts in the valves; these are NOT associated with clinical disease
Tetralogy of Fallot
Tetralogy of Fallot: VSD, Overriding aorta (dextroposition of the aorta), pulmonic stenosis,—>right ventricle hypertrophy.
One of the most common cardiac abnormalities in human beings: “blue babies”
Inherited in Keeshonds, also common in English bulldogs
4 things that happen:
- Ventricular spetial defiect
- Displacement of the aorta
- Thickening of wall of the right ventricle
- Narrowing of the pulmonary valves
Results in significant disease
Dog, right ventricular hypertrophy secondary to pulmonic stenosis
heart is enlarged and has a rounded appearance
Left ventricle on the right
Rounded appearance of the heart was secondary to pulmonic stenosis
Blue arrows: aortic valve;
Green arrows: fibrous band. “is among the most frequently encountered anomalies in dogs”. Results in compensatory concentric hypertrophy of the left ventricle and post-stenotic dilation of the aorta. Results in narrowing of the base of the aorta, which leads to L-sided CHF
Common in dogs
Tricuspid dysplasia, dorsal view from the atrium. Most common in cats, but it’s rare.
Either born dead or die very quickly.
Ventricular septal defect
Dog, VSD, TAMU,
Dr. J. Edwards
VSD, calf, UCVM, OI, 2010, view from the right ventricle
valvular hemtaocyst on the left
hole= communication between the left and right ventricle
VSD, calf, UCVM, OI, 2010, view from the right ventricle
Jet lesion= the white stripes; trauma to the endocardium; these are individual areas of endocardosis
VSD, calf, UCVM, OI, 2010. “Jet lesions” (endocardial fibrosis) within the right ventricular free wall- this tells us that there is abnormal blood flow in that area
VSD, calf, UCVM, OI, 2010. “Jet lesions” (endocardial fibrosis) within the right ventricular free wall
Patent Ductus Arteriosus
One of the more common defects – recorded in all species
ductus arteriosus- should close and turn into the ligamentum arterious after birth
remember the left side of the heart of the heart is more powerful- blood comes from the aorta into the artery- over time, these animals develop pulmonary hypertension
Normal
Persistent right aortic arch (PRAA). Results in dysphagia(trouble eating) and megaesophagus(constricts the esphagus) . Affected animals often die of aspiration pneumonia.
Calf, persistent right aortic arch (PRAA). Most common in dogs. German Shepherds, Irish Setters and Great Danes are predisposed. Complications of this vascular anomaly?
Hemopericardium
ruptured atrial hemangiosarcoma, dog- This can be a cause of death; this results in cardiac tympany
Pericardial diseases
Pericardial effusion – “mulberry heart disease” Vit. E/Selium def.- pig- presence of transudate
Pig: Myocardial hemorrhagic necrosis, pleural effusion, pulmonary edema. Vitamin E/ Selenium deficiency.
fibrin
heart looks red and pale in certain areas
MDx: Fibrinous pericarditis,
Calf, “black leg”- Clostriudium chaveoi
fibrin around the heart
Fibrinous pericarditis, “black leg”, steer
dots= little bubbles with gas
Hardware disease, cow, TAMU
ingestion of hardware
Cow, Hardware disease, Dr. King’s Cornell files
Foreign bodies, hardware disease, cow, Cornell files
A piece of wire had perforated the cranial wall of the reticulum, OI, UCVM.
The piece of wire penetrated both, the reticulum and the adjacent diaphragm resulting in leakage of ingesta into the peritoneum. Fibrin admixed with suppurative exudate was present in the affected area (fibrino-suppurative peritonitis). N08-B9, UCVM
Chronic (constricted) pericarditis
-Chronic cardiac tamponade, cow
thickened; percardial sack- chronic fibrinos pericarditis that lead to cardiac typany and death
Endocardial Diseases Degeneration
Endocardial mineralization
Occurs secondary to excessive intake of vitamin D or calcinogenic plants (Cestrum, Trisetum, Solanum spp.) that contain Vitamin D analogs. It may also occur in debilitated cattle with Johne’s disease (fibrosis & mineralization of the endocardium of the left atrium).
Valvular endocardiosis (myxomatous or mucoid valvular degeneration)
Age-related disease in middle-age to old dogs (most common in males) characterized by degeneration of valvular collagen. The cause is not known, but a genetically influenced degeneration of connective tissue is suspected.
Cavalier King Charles Spaniels are particularly susceptible.
Dog, valvular endocardiosis, UCVM, OI
present in Cavalier King Charles Spaniel
mostly left- AV(mitral) valve is the main one affected
Develop Left sided CHF; males are more suceptible
Normal mitral valve
Valvular endocardiosis: cusp (leaflet) of right atrioventricular (tricuspid) valve, dog
nodular type of apperance
Dog, TAMU,
Valvular endocardiosis, note endocardial fibro- elastosis within the atrium (“jet lesions”).
Endocardial Diseases Inflammation
Endocarditis (valvular and mural)
Endocarditis (valvular and mural)
Often the result of bacterial infections
The pathogenesis of endocarditis is complicated but endothelial injury, blood turbulence and hypercoagulability are often involved.
Death is the result of heart failure secondary to valve dysfunction or the effects of bacteremia
Dog. Valvular endocarditis and endocardial fibro-elastosis
Dog, TAMU, Endocarditis, aortic valve
Dog, TAMU, Endocarditis, aortic valve
Valvular bacterial endocarditis, cow, right AV valve, H&E
lesions= septic thrombi
Pig,
Etx:Erysipelas,
valvular endocarditis,
(Verrucous) Valvular endocarditis, aortic valve, pig Etiology: Erysipelothrix rhusiopathiae
Dog, ulcerative mural endocarditis, left atrium – uremia, acute renal failure.
Uremic Endocarditis- lesion that we will see in dogs with renal failure
Uremic (ulcerative) endocarditis, dog
Dirofilariasis, dog (Dirofilaria immitis). The parasites are usually found in the pulmonary arteries and right ventricle. Also in the R atrium and venae cavae in heavy infestation. May lead to CHF.
Can damage the pulmonary artery
Myocardial necrosis and mineralization
May be the result of nutritional deficiencies, chemical and plant toxicities, ischemia, metabolic disorders, inherited diseases and physical trauma.
In veterinary medicine is more commonly seen in cases of vitamin E-selenium deficiency (cattle, sheep, pigs) or ionophore toxicity (horses & ruminants: monensin, lasalocid etc.—-> antibiotics given to promote feed efficiency and prevent coccidiosis in cattle, sheep & poultry), gossypol toxicity (gossypol meal is used as a protein source in pigs), uremia (dogs, cats).
Calf, “white muscle disease”, ;Lesions are “chalky” and have a “gritty” consistency.
fat in the coronary groove- normal; areas of white discoloration on the epicardical surface, but there shouldn’t be fat there- mineralization
COWS- LEFT SIDE OF THE HEART
Lamb, Nutritional myopathy – “white paint brush strokes”,
will mostly be found in the right ventricle
Calf, 2 days-old, heart, nutritional myopathy – Von Kossa stain. Extensive mineralization of degenerated/ necrotic muscle fibres.
whitish discoloration on the left ventricle- white muscle disease
very fatal
Pig, “mulberry heart disease”- results in myocardial degeneration and necrosis
Vit E/ selium deficency
mulberry heart- muddled, dark red discoloration mixed with areas of myocardial degeneration, which is pale
Cow, monensin(antiboditics used as growth promotors) toxicity
small areas of darkish discoloration with some indentation; acute myocardial degeneration and necrosis
myocardial injury
Cardiomyopathies
Cardiomyopathies (Structural or functional abnormalities of the myocardium).
• May be primary or secondary
Primary (idiopathic):
• Dilated – cat, dog, hamster, turkey, pig, cow
- Hypertrophic –cat, dog, rat, pig
- Restrictive -cat
Secondary (specific heart muscle disease):- Most are secondary
• Congenital
• Nutritional deficiencies (taurine deficiency in cats)
• Toxic (e.g. Doxorubicin)
• Ischemic
• Inflammatory
• Endocrine disorders: hyperthyroidism, hypothyroidism, diabetes mellitus
- Neoplastic infiltration
- Systemic hypertension in cats
Primary Cardiomyopathies
Present in a wide range of domestic, laboratory and wild animal species
In veterinary practice are more commonly seen in dogs and cats
Hypertrophic cardiomyopathy is most common in cats
Dilated cardiomyopathy is seen in both, dogs and cats - specially males.
Larger dog breeds like Doberman pinschers, Portuguese water dogs, Dalmatians, Saint Bernards etc., have an increased susceptibility (familial pattern).
Dog, Dilated cardiomyopathy usually in large breed dogs: rounded and enlarged heart
heart will be large, mis-shapened, very rounded
Dilated cardiomyopathy, dog.
Dilated cardiomyopathy, dog.
both the left and right ventricles will be enlarged
Cat, HCM, TAMU
Hyper-trophic cardiomyopathy
younger -middle aged cats
hypertrophy of the left ventricule, so the left ventricular chamber will decrease in size/volume, because these animals develop left-sided HF,
Cat, HCM, Noah’s Arkives
cardiomegaely
hypertrophy of the left ventricular, w
Cat, HCM, Noah’s Arkives
hypertrophy of the left ventricular, which you can see as it is on the right
Cat HCM. Cardiomocytes exhibit variable degrees of hypertrophy and are often arranged in an interweaving rather than parallel pattern.
Marked cardiomegaly. The lungs were congested and edematous.
Heart weight: 38.9 g. Normally it should be no more than 16 g. Note marked enlargement of the left atrium due to congestive left-sided heart failure,
Thrombus at the bifurcation of the abdominal aorta into
the external iliac arteries (“Saddle thrombus” –> Aorto-iliac thrombosis),
classical example
Myocarditis
Often the result of an hematogenous infection:
- Viral- Parvo, FMD(“tiger heart”)
- Bacterial
- Parasitic (Protozoan: Toxoplasmosis, sarcocystosis, neosporosis, encephalitozoonosis, trypanosoma cruzi…; Metazoan: Cysticercosis, trichinosis
Cattle, “black leg”,- can cause lesions in the heart
Etiology: Clostridium chauvoei
Acute necrotizing and suppurative myocarditis –feedlot heifer,
Histophilus somni- produces a vasculitis that results in thrombosis
Acute necrotizing and suppurative myocarditis – feedlot heifer, UCVM, OI
Etiology: Histophilus somni- necrotizing myocarditis in cattle
rim of fibrosis around the necrosis
Heifer, chronic suppurative myocarditis, CHF (H. somni),
Parasitic myositis
cysticercus is the larval stage of a taenia (Platyhelminth
parasite )tapeworm.
The adult stage is in the intestine of the definite host (humans, dogs, wild carnivores). The larval stage (cysticercus) is in the muscle of the intermediate host (pigs, cattle, moose, reindeer etc.,).
Cysticercosis in humans (including neurocysticercosis) is the result of ingestion of taenia eggs, not from ingestion of cysticerci. Ingestion of cysticerci by consumption of raw or incompletely cooked pork completes the cycle: formation of the tapeworm in the intestine.
Pig –Heart & Skeletal muscle,
Cysticercus cellulosae (Taenia solium of humans) Dr. King`s Show & Tell
Pig –Heart & Skeletal muscle,
Cysticercus cellulosae (Taenia solium of humans) Dr. King`s Show & Tell
Cardiac Neoplasia
• Primary
Rhabdomyoma
Rhabdomyosarcoma
Schwanomma
Hemangiosarcoma
Heart base tumors (usually aortic body tumors [chemodectoma] – less often tumors arising from ectopic thyroid or parathyroid tissue)
- Secondary
- Metastatic tumors, including LSA –specially cattle.
Atrial HAS, dog.
HSA, dog, TAMU
Atrial HSA, Dog
Chemodectoma (heart base tumor), dog
7y-old Holstein cow, enzootic leukosis
7y-old Holstein cow, enzootic leukosis
7y-old Holstein cow, enzootic leukosis
2 y-old Sheltie
Major Arterial Diseases
Multiple cutaneous infarcts, Pig –”diamond skin disease”
Etiology: Erysipelothrix rhusiopathiae
Idiopathic necrotizing polyarteritis, “beagle pain syndrome”
What gives arthritis?
- Etiology: Erysipelothrix rhusiopathiae
- Idiopathic necrotizing polyarteritis, “beagle pain syndrome”
What gives fibrinoid necrosis?
- Fibrinoid necrotizing arteritis
- Edema disease (enterotoxemic colibacillosis) in pigs.
Fibrinoid necrotizing arteritis – swine.
Left: “Mulberry heart disease” Bottom: Gastric submucosal blood vesselsedema disease
Edema disease (enterotoxemic colibacillosis) in pigs.
Bacterial enterotoxin (verotoxin) that causes endothelial cell injury in arterioles resulting in fluid loss and edema. Affected animals may exhibit focal bilaterally symmetric encephalomalacia (Cerebrospinal angiopathy of swine).
Arteriosclerosis
Arteriosclerosis (“hardening of the arteries”) is a generic term applied to the thickening and loss of elasticity of arterial walls. Atherosclerosis is the most important pattern of arteriosclerosis and is characterized by the presence of atheromas (or atheromatous (fibrofatty) plaques) within the intima and media. These plaques contain cholesterol and other lipids.
Arteriosclerosis diseases
- Coronary atherosclerosis
2.
Coronary atherosclerosis, dog, Texas A&M Cause: Hypothyroidism
Dog, coronary atherosclerosis
Dog, coronary atherosclerosis,
Dog, coronary atherosclerosis
Coronary atherosclerosis,
Arterial mineralization (arteriosclerosis), cow – Johne’s disease
Arterial rupture
Commonly the result of physical trauma.
Spontaneous ruptures are rare.
Fatal rupture of the uterine artery during parturition occurs occasionally in aged mares with low serum copper levels.
Mycotic vasculitis can lead to rupture of the internal carotid artery in horses with guttural pouch mycosis
Rupture of the aorta in horses is well-known but rare and may occur in periods of excitement and physical activity, such as racing, or in stallions during breeding (thought to be secondary to ↑ intra-aortic pressure).
Dissecting aneurysms are also reported in the coronary and renal arteries of young male racing greyhounds – can lead to fatal arterial rupture
Dissecting aneurysm, pig with Copper deficiency
If you are looking at a cross section of the heart, about how big should the right ventricular wall be compared to the left?
Right venticular free wall should be 1/3 of the thickness of the left
Dissecting aneurysm, pig with Copper deficiency
Virchow triad
Damage to the epithelium, can cause a thrombosis
Coagulation cascade
fibrin- helps to tie the platelets there- secondary platelet plug
normal to seal a blood vessel that is injured
Seen in dogs with severe renal glomerular disease —>protein loosing nephropathy—>Significant loss of Antithrombin III, a major inhibitor of thrombin
Pulmonary thrombosis, dog
Other causes of pulmonary thrombosis- heartworms, DIC
Strongylosis – colon, horse, Cornell files
can cause thrombosis in the cranial mesenteric artery
small black dots= small stronguli
Colonic edema – small strongyles (cyathostomes) encysted in the mucosa,
Horse, UCVM-OI.
Strongylus vulgaris, adults within the colonic lumen, horse, Cornell files
typical lesion of verminous arthritis
right picture- cranial mesenteric artery
Inflammatory response- eosinophilic, maybe granulatamus
chronic response
Histo: Verminous arteritis, (Strongylus vulgaris) cranial mesenteric artery,
Saddle thrombosis, cat with HCM
Associated with hypertrophic cardio myopathy
