Cardio Medicine Flashcards
Define heart failure
When the heart is unable to maintain adequate cardiac output to supply the body with adequate circulation
What is the most common canine cardiac disease?
Endocardiosis
What breeds are more commonly associated with canine cardiomyopathy?
Large of giant breed dogs
What are some of the general clinical signs of heart failure?
Tachycardia, coughing, exercise intolerance, anorexia, cachexia, cyanosis etc.
What valve does chronic valvular heart disease normally affect?
Mitral > Mitral and tricuspid
Describe the pathophysiology of chronic valvular heart disease in dogs
The valvular lesions grow and lead to insufficiency and therefore regurgitation of the blood from the ventricle into the atrium.
This gradually progresses over many years until we see degeneration .
Regurgitation (and volume overload) leads to the walls of the atria stretching and remodeling,
Enlarged chambers cause the valve leaflets not being able to meet properly, which makes the leak worse
Aortic output suffers
The atrium and the veins draining into it are unable to stretch any more. The left side lymphatic drainage is unable to clear the fluid and pulmonary oedema results -CHF
What is the consequence of a ruptured chordae tendinae?
Pulmonary oedema within 10 mins
What is the consequence of a Atrial tear?
Right sided heart failure also
What are the three factors that determine arterial pressure?
HR, peripheral resistance and stroke volume
What is the first heart sound associated with?
Closure of the AV valves (mitral and tricuspid)
What is the second heart sound associated with?
Closure of the pulmonic and aortic valves
What causes a mumur?
Turbulent blood flow within the heart
What are innocent mumurs?
Haemic or physiologic cause and not associated with a defect e.g. Puppy blood with lowered haematocrit
How should you describe murmurs?
Location, loudness and when
What are some DDx of CVHD? (Chronic valvular heart disease)
Respiratory disease, infective endocarditis, sick sinus syndrome, late-presenting congenital disease
What do you do if you hear a mumur in a happy, healthy dog?
Maybe nothing! If there is no other abnormalities ? do survey radiographs, arterial blood pressure measurement and baseline blood work (PCV, TPP, Creatinine). And if all clear ? client education, routine health maintenance and checkups, avoiding high salt food,
How would you treat a dog with mild to moderate CVHD?
Exercise restriction, frusemide, ACEI (enalapril), pimobendan and eventually spiranolactone, MAYBE digoxin. DO not give frusemide on its own, give with ACEI
What do you need to check when changing dose or starting medication of ACEI?s?
Check that the drug has not increased serum creatinine substantially
How would you treat a dog with severe acute CVHD?
Supplement O2, cage rest, IV frusemide, oral pimobendan, dopamine
When is prognosis poor for a dog with CVHD?
If advanced, non-responsive or severe, or an acute exacerbation of a chronic stable case
In bacterial endocarditis, describe some of the consequences of septic emboli
Kidney infarction
In bacterial endocarditis, describe some of the consequences of Ag-Ab immune complex formations
Protein losing nephropathy, inflammation of joints
What is the cause of infectious endocarditis?
Most commonly bacteria strep, staph etc.
Describe the pathogenesis of infectious endocarditis
Mitral and aortic valves most commonly affected. Leaflets ulcerate, platelets adhere to collagen, fibrin deposition, enlargement, vegetations form and this provide great protection for the nasty bacteria
What are the clinical features of infectious endocarditis?
Fever, new/changing heart mumur, history of a dirty procedure,
How do you diagnose infectious endocarditis?
Diastolic mumur at the heart base is suggestive. Echocardiograph. Two or more positive blood cultures.
How do you collect a blood culture sample?
Needs to be a sterile venepuncture, collect a large volume (10ml), n different veins, an hour apart for each,