Ch 11: Intro and CHF Flashcards
Which coronary artery is infarcted in a posterolateral MI affecting the lateral wall of the left ventricle?
Left circumflex
Which coronary artery supplies the right ventricle, and base of the heart including the posterior half of the inter ventricular septum and papillary muscle?
Right coronary
Which coronary artery supplies the anterior left ventricle and anterior half of the interventricular septum?
LAD
Your 82 y/o pt presents with dyspnea on exertion, and admits to waking up in the middle of the night because he can’t breathe.
Dx and pathophys of his symptoms?
Left CHF.
Dyspnea=pulmonary congestion (backward failure) due to high end-diastolic pressure in the left heart.
Paroxysmal nocturnal dyspnea=lung blood volume increases when the pt lies down
What is the mechanism of edema in LEFT sided CHF? Confusion? Fatigue?
- Poor renal perfusion causes decreased GFR and retention of sodium and water.
- Inadequate cerebral perfusion
- Reduced skeletal muscle perfusion
- Basically, inadequate perfusion of vital organs (forward failure)
What is the mechanism of edema in RIGHT sided CHF?
Increased right atrial and systemic venous pressures increase; increasing hydrostatic pressure and forcing fluid into the interstitial space.
What is a nutmeg liver and in which kind of heart failure do you see it?
Hepatic congestion leads to distended, red, central veins in contrast to the yellow liver cells.
Right HF (other symptoms include JVD and anasarca/generalized edema)
What are some causes of RIGHT sided heart failure?
Left?
Right: Left heart failure, intrinsic pulmonary disease, pulmonary HTN (creating resistance to blood flow through lungs)
Left: more common, due to ischemic or hypertensive damage to cardiac cells
What are some cellular and gross pathologic changes seen in heart failure?
Cellular: chronically injured myocytes show loss of myofibrils, and increase their cytosol and glycogen (called myocytolysis)
Gross: Ventricular hypertrophy, dilated ventricles (if systolic HF)
Which type of heart failure is commonly seen in elderly patients, and occurs because the ventricles stiffen with age?
Diastolic heart failure; stiff ventricles require greater diastolic filling pressure.
These patients may have signs and symptoms of HF with normal heart size and systolic contraction function.
What develops in the heart as a compensatory response to pressure or volume overload, increasing heart workload?
How does this occur?
Pathological hypertrophy; heart is structurally and functionally deficient
(As opposed to physiological in highly trained athletes)
Enlargement of myocytes by making new sarcomeres.
Which ONE of the following characteristics describes a normal myocardial cell NOT a hypertrophied cell?
Fetal isoforms of myofibrillar proteins, interstitial fibrosis, active B-adrenergic receptors, decreased ryanodine calcium receptors, greater likelihood of apoptosis.
Active B-adrenergic
In hypertrophied cells,constant NE stimulus of B-adrenergic receptors causes desensitization of receptors and a decrease in the number and responsiveness. Strangely, treatment with B-blockers is helpful in CHF b/c B-receptors lead to cardiotoxic effects on the cell.
How do ‘heart failure cells’ form?
In left HF, small capillaries in the lungs burst because of congestion, causing intraalveolar hemorrhage. Macrophages then take up the blood and accumulate hemosiderin.
