Abnormal cardiac size and shape

Question 1

What is cardiomegaly and what causes it?

What is the difference between eccentric and _concentri_c hypertrophy?

What is the difference b/t double heart wall thickness vs. double volume of chamber?

Answer 1

It is an enlarged heart due to hypertorphy or dialation of one or more cardic chambers.

Eccentric hypertrophy is outward thickening of myocardium caused by increased cardiac preload (mitral or tricuspid valve insuficiency, PDA).

Concentric hypertrophy is inward thickening of myocardium caused by increased cardiac afterload. (aortic or pulmonary stenosis, hypertension) and is often DIFFICULT to detect on survey rads.

Doubling thickness of a heart wall typically increased the SIZE of the cardiac silhouette by only a small amount, but doubling the volume of a heart chamber causes SIGNIFICANT INCREASE IN SIZE of the cardiac silhouette.

Question 2

Causes of generalized cardiomegaly include. DAMNNN IIITT VV

Apex is shifted to the right= left ventricular enlargement or generalized cardiomegaly.

Answer 2

D- degenerative- cardiomyopathy, chronic atrioventricular valve dz (endocardoisis), end stage left heart fail, Bradycardia (sick sinus syndrome)

A- anomalous (birth defect)- ventral septal defect

M - metabolic- hyperthyroidism (older cats), hypercorticosterism, DM, Acromedgaly (more cats)

N- neoplastic- lymphoma

N- nutrition deficiencies- L- caritine, taurine

N- neuro

I- inflammatory (auto immune)

I- infiltrative- Amyloidosis, Lyipidosis, mucopolysaccharidosis

I- infection- viral (parvo, distemper), bacterial (Streptococcus, brucellosis), Fungal (histoplasmosis, cryptococcosis), parasitic (Bartonellosisi, Trypanosomiosis), Protozoal (Lyme dz)

I- iatrogenic- fluid overload (hypervolemia), Bradycardia caused by anesthesia, sedation

T- trauma

T- toxic- cytotoxic drugs (doxorubicin), heavy metals (lead, mercury)

V- vascular

V- various others- Athletic heart (grey hounds), chronic anemia

Question 3

Severe cardiac dz without cardiomegaly causes: DAMNNN IIIITT VV

Answer 3

D- degenerative-

A- anomalous (birth defect)-

M - metabolic-

M- mimics

N- neoplastic-

N- nutrition deficiencies-

N- neuro

I- inflammatory (auto immune)

I- infiltrative-

I- infection-

I- iatrogenic-

T- trauma- cardiac electrical disturbance (arrhythmias, tachycardia

T- toxic-

V- vascular

V- various others-

Question 4

What would cause Left Atrial enlargement? DAMMNNN IIIITT VV

LA is seen better on the VD in cats

Answer 4

D- degenerative- cardiomyopathy (dialated, hypertrophic, restrictive, arrhythmogenic), hypertension

A- anomalous (birth defect)- congenital heart dz (mitral valve dysplasia, patentductus arteriosus, mitral valve stenosis (rare))

M - metabolic- hyperthyroid (cats)

M- mimics- heart based tumor, hilar mass or lymphadenopathy (push trachea ventrally), pulmonary mass adjacent to hilus (trachea not displaced)

N- neoplastic-

N- nutrition deficiencies-

N- neuro

I- inflammatory (auto immune)

I- infiltrative-

I- infection- mitral valve insufficiencies (bacterial endocardosis- esp. older, small, dog breeds)

I- iatrogenic-

T- trauma- Mitral valve insufficiencies (ruptured cordae tendinae or papillary muscle

T- toxic-

V- vascular

V- various others-

It revealed volume overload of the left ventricle and left atrium and a markedly enlarged main pulmonary artery. In addition, the PDA was visualized

Question 5

Left ventricular enlargement causes: DAMMNNN IIIITT VV

Apex is shifted to the right= left ventricular enlargement or generalized cardiomegaly.

Answer 5

D- degenerative- Mitral valve insufficiency, cardiomyopathy, aortic insufficiency, systemic hypertension,

A- anomalous (birth defect)- patent ductus arteriosus, aortic stenosis

M - metabolic- hyperthyroidism (cats),

M- mimics- sternum rotated to left on DV/VD rads (heart follows sternum), obesity (pericardial fat mimics cardiomegaly), pericardial effusion, right ventricular enlargement with cardiac apex displaced to left

N- neoplastic- neoplasia

N- nutrition deficiencies-

N- neuro

I- inflammatory (auto immune)- myocarditis

I- infiltrative-

I- infection-

I- iatrogenic-

T- trauma- aneurysm

T- toxic- chronic reanal dz

V- vascular- peripheral arteriovenous fistula

V- various others- chronic anemia

It revealed volume overload of the left ventricle and left atrium and a markedly enlarged main pulmonary artery. In addition, the PDA was visualized

(YOU CAN HAVE A HUGE LEFT ATRIA AND LEFT VENTRICAL W/O CHF)

Question 6

Right atrial enlargement (usually dialation) why? DAMMNNN IIIITT VV

Answer 6

D- degenerative- Tricuspid- right ventricular dialation/failure, Tricuspid- endocardosis, cardiomyopathy

A- anomalous (birth defect)- Pulmonic stenosis, Tet of Fallot, Tricuspid valve dysplasia, Tricuspid valve stenosis (rare)

M - metabolic-

M- mimics- Pulmonary mass or consoliadated lung (right cranial or middle lung lobe), Cranial mediastinal mass, Lymphadenopathy (hilar/tracheobronchial), heart based tumor, main pulmonary artery dialation, Enlargement of aortic arch

N- neoplastic- Right- atrial tumor

N- nutrition deficiencies-

N- neuro

I- inflammatory or (auto immune)-Tricuspid- Endocarditis

I- infiltrative-

I- infection- Cor pulmonale (dirofilariasis)

I- iatrogenic-

T- trauma- Tricuspid- rupture of the chordae tendinae

T- toxic-

V- vascular- Arteriovenous fistula

V- various others-

Question 7

What is a dialated chamber? Why?

Answer 7

A dialated chamber** is a chamber which is stretched beyond normal dimension. **Dilated cardiomyopathy (DCM) is a disease of the heart muscle that is characterized by an enlarged heart that does not function properly. With DCM, both the upper and lower chambers of the heart become enlarged, with one side being more severely affected than the other. When the ventricle, or lower chamber, becomes enlarged, its ability to pump blood out into the lungs and body deteriorates. When the heart’s ventricle does not pump enough blood into the lungs, fluid begins to accumulate in the lungs. An enlarged heart soon becomes overloaded, and this often leads to congestive heart failure (CHF).

Question 8

What is compensated left heart dz?

Answer 8

compensated Left heart disease. see a huge left atrium on lateral radiograph and heart is huge, but there is no evidence of fluid in lungs or pulmonary

Question 9

Right Ventricular enlargement what causes it? DAMMNNN IIIITT VV

Chronic cough and cynosis- right heart fail (apex is shifted to the left)

Lifting of apex off the sternum - Right ventricular enlargement

Answer 9

D- degenerative- tricuspid insufficiency- endocardosis, dialated cardiomyopathy, Arrhythmogenic right ventricular cardiomyopathy (boxers), Secondary to left heart dz (mitral insufficiency), pulmonary valve insufficiency

A- anomalous (birth defect)- pulmonic stenosis, L->R intracardiac shunt ( PDA, Ventricular septal defect, Atrial septal defect), Tet of Fallot, thoracic deformity (pectus excavatum)

M - metabolic-

M- mimics- Sternum rotated to right on DV/VD view (heart follows sternum), Expiratory rad (increased cardiac sternal contact and dorsal postitioning of the trachea), obesity (pericardial fat may mimic right cardiomegaly), pericardial effusion

N- neoplastic- neoplasia

N- nutrition deficiencies-

N- neuro

I- inflammatory (auto immune)- tricuspid insufficiency- Endocarditis, myocarditis

I- infiltrative-

I- infection- HW

I- iatrogenic-

T- trauma- tricuspid insufficiency- ruptured chordae endinae, aneurysm

T- toxic-

V- vascular- Cor Pulmonale (pulmonary heart dz), pulmonary hypertension, Chronic obstructive pulmonary dz (COPD), Pulmonary throboembolism

V- various others- obesity (pickwickian syndrome), brachycephalic dogs with chronic airway obstruction, Arteriovenous fistula, High altitude DZ,

( Heart worm - increase of right ventricle, see enlargement at the pulmonary outflow tract)

Question 10

What causes Microcardia? DAMMNNN IIIITT VV

Answer 10

D- degenerative- decreased lung profusion, some forms of cardiomyopathy (cats)

A- anomalous (birth defect)-

M - metabolic- HypOadrenocorticosterism (Addison’s dz)

M- mimics- deep-chested conformation, hyperinflated lungs (decreased cardiac-to-thoracic ratio), Deep inspiration (struggling, fear, stress), asthma, emphysema, Manual ventilation during anesthesia, emaciaiton, displacement of heart (megaesophagus, mdiastinal shift)

N- neoplastic-

N- nutrition deficiencies- emaciation/cachexia

N- neuro

I- inflammatory (auto immune)- constrictive paricarditis

I- infiltrative-

I- infection- pneumothorax (especially tension pneumothroax)

I- iatrogenic- post thoracotomy

T- trauma-

T- toxic-

V- vascular- Hyopvolemia (MOST COMMON)- anemia, blood loss , compromised venous return (GDV, vena cava thrombus)

V- various others- shock, dehydration,

Question 11

Dog gagging up white foamy fluid with a mitral murmmer is most likey?

Answer 11

Left heart failure