Cardiology: Final - Those 24 Questions Gotta Be In Here Somewhere

What are signs of L-CHF on radiographs?

Pulmonary venous distension,

Left sided enlargement, and

Alveolar infiltrate

Where do you look for pulmonary infiltrate on dogs?

Caudo-dorsal/Perihilar

Which side of the lungs are more likely to have pulmonary edema?

Right

T/F: Cats can have pulmonary infiltrate anywhere

True

What are clinical signs of L-CHF?

High HR,

High RR, and

Less than 2 days of respiratory signs

How does left ventricular dysfunction lead to pulmonary edema?

Less blood to aorta dilates the LV, preventing the atrium from emptying and blood pools in veins

What are the treatment goals of L-CHF?

Clear pulmonary edema,

Reduce blood volume (left),

Promote forward movement

Why does L-CHF lead to increased HR and RR?

Fluid in parenchyma decreases gas exchange, leading to hypoxia which induces sympathetic tone

T/F: The RAAS decreases in CHF

False, it increases because less blood is getting to the kidneys, thus it conserves water to make up for the lack of fluid (but really it's all just in the heart)

What are the drug therapies used in hospital for CHF?

Diuretics,

Positive inotropes,

Vasodilators, and

Sedatives

What are the types of diuretics?

Loop (furosemide),

Thiazide, and

Potassium-sparing (spironolactone)

What is your first choice diuretic type for CHF?

Loop diuretics

Loop diuretics are "high ceiling" drugs. What does this mean?

The more you give, the more effect it has

How do loop diuretics work?

They inhibit Na/K/Cl cotransport

What is the difference between furosemide and torsemide?

Furosemide is preferred,

Torsemide is more potent (rescue)

What are the side effects of loop diruetics?

Dehydration (yay), and

Electrolyte loss (hypokalemia)

What urine test becomes ineffective with loop diruetics?

Specific Gravity, doesn't indicate concentrating ability

What do we monitor on a patient on diuretices?

Electrolytes,

Hydration,

Blood pressure

What are effects of long term furosemide?

Tolerance, and

Hypertrophy of distal tubule

T/F: Thiazide diuretics have high ceiling effects

False, Low ceiling effect

How do thiazide diuretics work?

Inhibits Na/Cl co-transport

What is the role of thiazide diuretics?

Restore diuresis when tolerance to furosemide develops

What is a risk of thiazide diuretics?

High risk of azotemia

What is the preferred potassium-sparing diuretic?

Spironolactone

How does spironolactone work?

Antagonizes aldosterone receptor

What is the preferred positive inotrope?

Pimobendan

What are the two effects of pimobendan?

Positive inotropy, and

Vasodilation

How does pimobendan increase inotropy?

Sensitizes to calcium

How does pimobendan cause vasodilation?

Inhibiting PDE III

Contraindications to pimobendan?

Obstruction

What is the other positive inotropy used?

Dobutamine

How does dobutamine work?

Beta 1 adrenergic agonist, which increases cAMP and Ca+

How is dobutamine administered?

CRI

How long can you give dobutamine and why?

48 hours, because it stops working

What is a side effect of dobutamine?

Arrhythmias

What are the indications for vasodilators?

Systemic hypertension

what are the contraindications for vasodilators?

Subaortic stenosis (heart can't compensate)

How does amlodipine work?

L-type Ca+ channel blocker (arteries)

How long until amlodipine takes effect?

2 days, with maximum at 4 - 7

What makes nitroprusside special in its effect?

It is a balanced vasodilator (arteries and veins)

What is an adverse event of prolonged nitroprusside use?

Cyanide toxicity

What must be monitored when giving nitroprusside?

Blood pressure (can decrease too much)

How does nitroglycerin work?

It is a venous vasodilator, increasing venous capacitance and decreasing preload

What drugs are used for sedation in CHF?

Butorphanol, and

Acepromazine

How does butorphanol work?

Partial mu/kappa agonist

T/F: Butorphanol has some cardiovascular side effects

False

What is an advantage of giving acepromazine for CHF?

Decreases hypertension

What is the main reason to give sedation for CHF?

Decrease stress/sympathetic tone

What are the drug therapies used for chronic (at home) therapy?

Diuretics,

Pimobendan,

ACE-inhibitors, and

Spironolactone

How does RAAS work and how does this affect the heart?

Increased angiotensin II and aldosterone increases blood volume using sodium, increasing afterload

What are the two preferred ace inhibitors?

Enalapril and benazepril

What is the difference between enalapril and benazapril?

Enalapril is eliminated 100% in kidneys, benazepril is partially in liver

So what effect do ace inhibitors and spironolactone have together?

Ace inhibitors inactivate RAAS and spironolactone inhibits aldosterone's effect, preventing Na+ resorption and vasoconstriction

What is the first step in treating acute L-CHF?

Stabilize by decreasing stress, and IV furosemide

What should you monitor for acute treatment of CHF?

Respiratory rate/edema (radiographs),

Blood pressure, and

Renal values

How does treatment with furosemide differ with R-CHF?

Body cavity effusions are not diminished, need to drain

What is CHF in cats mostly due to?

Diastolic dysfunction

What are the most common congenital defects in dogs?

Subaortic stenosis,

Pulmonic stenosis,

Patent ductus arteriosus, and

Ventricular septal defect

What are the most common feline diseases?

AV valve dysplasia, and

Septal defects

What is an innocent murmur?

Puppy murmurs, loudest is 3/6 basilar with no signs

What does patent ductus arteriosus connect?

Descending aorta to main pulmonary artery

What small breeds are disposed to PDA?

Corgis,

Chihuahua,

Cavalier,

Maltese,

Dachshund, and

Bichon

What large breeds are disposed to PDA?

Germans,

Collies,

Herding breeds

What causes PDA?

Failure of development of ductal smooth muscle

What are the major effects of PDA?

L-CHF, and

Pulmonary hypertension

What signs on PE are diagnostic for PDA?

Left basilar continuous murmur and bounding femoral pulses

How is diastolic pressure affected with PDA?

It is low because pressure in the aorta is decreased, leading more blood to empty the LV

What can be seen on radiographs with PDA?

Left sided enlargement,

Aortic enlargement, and

Pulmonary artery enlargment

What pattern can be seen with PDA on radiographs?

Hypervascular pattern

What is a good way to diagnose PDA?

Echocardiograms

How can we treat PDA?

Closure (else die)

What are the options for PDA closure?

Interventional or surgical

How are the results with patients with occlusion/ligation?

Most have normal lives, but others have severe mitral regurgitation and CHF

What breeds are predisposed to subaortic stenosis (SAS)?

Large breeds: Rots, Germans, Goldens, Bernies, and Boxies

What breeds are affected by Aortic Valve stenosis (AS)

Bull terriers

What are the stages of SAS?

Mild: small raised nodules

Moderate: Narrow ridge of thick tissue, partially encircling LV outflow tract

Severe: Fibrous ridge completely encircling LV outflow tract

What effect does LV outflow tract obstruction have on the left heart?

Pressure overload leads to concentric hypertrophy, myocardial ischemia, and arrhythmias

What effect does LV outflow tract obstruction have on the aorta?

Endocarditis

What can you find on PE for SAS?

Left basilar systolic murmur,

Ventricular premature complexes, and

Weak femoral pulses

T/F: Enlargement is very common with SAS

False, may or may not appear

What can be seen on radiographs with SAS?

Post stenotic dilation due to jet streams

What are the natural outcomes of continued SAS?

LV concentric hypertrophy,

Left heart failure,

Endocarditis, and

Serious arrhythmias

What are treatment options for SAS?

Chronic beta blockers,

Anti-arrhythmics, and

Interventional procedures

What what signs of pulmonic stenosis (PS) appear on PE?

Left basilar systolic murmur

What breeds are affected by PS?

Small breeds, like English Bullies, Boxies, Chihuahuies, Malties, Cavalies, Frenchies, and Beagies

What are the types of PS?

Type A,

Type B, and

Coronary aberrancy

What describes type A PS?

Normal PA annulus diameter,

Thin leaflets

What describes types B PS?

Reduced PA annulus diameter,

Thick leaflets

What is coronary aberrancy?

The coronary artery wraps around the pulmonary artery, constricting it further, often with type B

What breeds are predisposed to coronary aberrancy?

Brachycephalic breeds, like English Bullies, Frenchies, and Boxies

What effect does RV outflow tract obstruction have on the right heart?

Increased pressures lead to concentric hypertrophy, right sided CHF and arrhythmias

What effect does RV outflow tract obstruction have on the pulmonary artery?

High velocity blood flow leads to dilation, possibly with pulmonic insufficiency

What are the clinical consequences of PS?

RV concentric hypertrophy,

Arrhythmias, and

CHF

What are treatment options for PS?

Balloon valvuloplasty (decrease pressure difference), and

Drugs (beta blockers)

When is balloon valvuloplasty contraindicated?

In coronary aberrancy

What is Eisenmenger's syndrome?

When a left to right shunt reverse due to systemic hypertension

T/F: It is easier to correct right to left shunts

False, impossible

What are the treatment options for Eisenmenger's?

Beta blockers to decrease oxygen requirement and sildenafil to remedy pulmonary hypertension

What are goals of treatment for equine cardiology that differ from small animal?

Rider safety and athletic capability

What is the normal resting heart rate for a horse (for this class I know it varies)?

28 - 42