Cardiovascular Disease Flashcards
Cardiac Cycle - How it works!
1. Diastole
2. Systole
- Diastole:
Heart muscle is relaxed and all chambers fill with blood - Systole:
Heart muscle contraction wave beginning at atria and then through ventricles moves blood from heart chambers into great vessels
Electrocardiography
What can it record?
How does the activity move across the heart?
- It can record:
- Electrical activity by an ECG - Movement:
- Electrical activity moves across heart from the SA node and AV node
Muscle contraction of heart is carefully orchestrated by an electrical system called ____.
Electrocardiography
SA node and AV node’s role in the heart
SA Node: The pacemaker
AV Node: The signal booster
P wave:
QRS wave:
T wave:
- P wave: Atria contraction
- QRS wave: Ventricles contract
- T wave: Muscle relaxation
Sinus rhythm
Normal, steady rhythm
Arrhythmia
Abnormal heart rhythm
Tachycardia
Fast heart
Asystole
No contraction
Bradycardia
Slow heart
The two categories of heart disease are:
1. Myocardial Dysfunction
2. Circulatory Failure
What are they?
- Any disease that leads to “pump failure”
- Inadequate/ineffective circulating fluid volume
Clinical signs of cardiovascular disease. Must have one or more of the following eight:
- Exercise intolerance or weakness (dropping in tracks).
- Tachypnea or dyspnea
- Coughing (soft may = heart issue)
- Syncope (fainting)
- Abnormal HR or heart rhythm
- Abnormal pulse quality or pulse deficit
- Prolonged CRT
- Ascites (free fluid in abdomen)
Ascites
Free fluid in abdomen
What is heart failure?
Non-specific term referring to any heart disease that leads to very significant “heart pump” insufficiency and compensatory mechanisms of the body cause fluid to accumulate in the tissues
- Take away:
“any heart disease that leads to very significant “heart pump” insufficiency”
Circulatory failure pathology (2)
- Insufficient blood vol to deliver to tissues.
- Insufficient vascular pressure to deliver oxygen to tissues.
Circulatory failure causes (5)
- Anemia (HCT <15)
- Dehydration (>12%)
- Vasculitis (inflam of blood vessel walls)
- Hypotension (MAP <60)
- Shock
Free fluid accumulates in pleural cavity &/or abdominal cavity is ____ heart failure.
Fluid accumulates in the lungs is ____ heart failure.
- Right side heart failure
- Left side heart failure
Dilated Cardiomyopathy (DCM)
1. Pathology
2. Dx
3. Hereditary in dog breeds
- Pathology:
- Heart muscle becomes thin & flabby
- Heart chambers enlarge to compensate
- Heart arrhythmias are common - Dx:
- Radiographs, ultrasound, EKG consistent with heart enlargement &/or heart failure - Hereditary dogs:
- Doberman, Boxers, Cocker Spaniels, St. Bernard’s (etc)
Dilated Cardiomyopathy of Cats (3)
- Rare in US, caused by taurine deficient diets
- Can be reversed if high diet provided & cat survives 1st two weeks of heart failure
- Extreme care is needed when handling heart failure cats to prevent SVDDEN DEATH!!
Hypertrophic Cardiomyopathy (HCM)
1. Pathology:
2. Dx:
3. Hereditary in cats:
- Pathology:
- Thickened heart muscle with very small chamber size.
- Thromboembolism* to caudal aorta is possible fatal complication (*obstruction of blood vessel by blood clot) - Dx:
- Radiographs, ECG, echocardiogram - Hereditary:
- Maincoons & ragdolls
T/F: HCM can be common due to hyperthyroidism. Although, if the hyperthyroidism is successfully treated , the condition can be reversed.
True!
Myocarditis
What is it?
How is it caused? (4)
- It is:
- Myocarditis is inflammation of heart muscle due to any infection or inflammatory process. - Causes:
- Heartworm disease
- Tetanus or other toxin
- Lyme disease or other bacterial infection
- Trauma
Heart murmur
what does it sound like?
- “Swishing” sound heard on auscultation of heart due to turbulent blood flow
- Location of sound in cardiac cycle and “type” of murmur may be consistent with certain anatomic defects
Mitral Valve Insufficiency
1. Pathology:
2. Dx:
- Pathology:
- Nodular thickening of the heart valve causes leaking of the valve during systole & increased work load on the left atrium and the potential for heart failure.
- Most common cause bacterial infection of the mitral valve due to chronic dental disease - Dx:
- Systolic heart murmur
- Cough, esp at night or with exercise
- Rads &/or ultrasound showing left atrial enlargement with/out heart failure (pulmonary edema)
