Exam 4 -- Cardiovascular and PVD Flashcards
What are some of the risk factors for heart failure?
Ischemic cardiomyopathy (#1 risk factor), age, smoking, alcohol abuse, obesity (lack of exercise, poor diet), DM, HTN, high-sensitivity C-reactive protein, dyslipidemia, poor dental health.
What are the most common causes of heart failure? What are some other causes?
Ischemic heart disease is most common, followed closely by dilated cardiomyopathy, then hypertension. It can also be caused by restrictive or hypertrophic cardiomyopathy, valvular heart disease, congenital heart disease, and high output states such as thyrotoxicosis and anemia.
Left ventricular systolic dysfunction (LVSD) is a type of heart failure in which the left heart blood ejection fails. What are the common causes of LVSD?
Ischemic heart disease (heart tissue has died, decreasing the ability of the heart to pump blood), hypertension (heart has a lot more pressure to push against), and valvular disease (the valve is either not opening all the way, requiring more force from the heart to get the blood out, or the valve doesn’t close completely, allowing blood from aorta to come back into ventricle, requiring more force to get enough blood out to body).
Right ventricular systolic dysfunction (RVSD) is a type of heart failure in which the right heart blood ejection fails. What are the common causes of RVSD?
It most common occurs due to LVSD, but can also arise from pulmonary disease or tricuspid valve disease.
Diastolic heart failure is an issue with the heart filling with blood. What are the common causes of diastolic heart failure?
This commonly occurs due to decreased left ventricular wall compliance (the ventricle is either stiffer or thicker), and is more common in elderly hypertensive patients, or with cardiomyopathy (hypertrophic, infiltrative, or restrictive).
What are the two most common symptoms of heart failure?
Progressive breathlessness (dyspnea with ordinary exertion –> dyspnea at rest –> orthopnea (shortness of breath while lying down) –> paroxysmal nocturnal dyspnea (SOB during sleep that causes patient to wake up) and fatigue. Note that reduced renal perfusion –> increased blood volume is another common sign of heart failure.
What are some of the signs of heart failure?
Severe pulmonary edema (evidenced by pulmonary congestion and rale/rattles and nocturnal cough that may produce bloody sputum), tachycardia (due to lack of blood perfusion), anorexia, hepatomegaly, peripheral edema and cyanosis, cardiomegaly (either dilation or hypertrophy), and gallop rhythm (S3 and/or S4).
S1 and S2 are normal heart sounds associated with the closing of valves. Which valve closures cause S1? S2? Which sound is associated with the pulse?
S1 is caused by the mitral and tricuspid valves closing, S2 is caused by the aortic and pulmonary valves closing. S1 is the sound associated with the pulse.
Of S3 and S4 heart sounds, S3 can be normal in younger or pregnant patients, but is always considered pathologic over the age of 30-35. S4 is always pathologic.
Free card.
Which of the extra heart sounds (S3 and S4) is associated with an enlarged ventricle? A hypertrophied ventricle?
S3 = enlarged ventricle, S4 = hypertrophied ventricle
How would heart failure generally be diagnosed?
Chest X-ray, echocardiogram and/or catheterization for chamber, valvular, or blood flow abnormalities, possibly EKG.
What are the four stages of heart failure, according to the ACA/AHA? What determines each stage?
Stages A-D. Stage A = no structural disease or symptoms, but risk factors. Stage B = structural disease present, but no signs or symptoms. Stage C = current or past symptoms of heart failure (SOB). Stage D = patients with heart failure that is difficult to treat with just meds, need to consider transplantation.
What would be recommended as general therapy for a patient in any stage of HF?
Patient education, correct underlying risk factors, flu and pneumococcal vaccines, dietary salt restriction, get enough rest and avoid overexertion, but do get some exercise.
In addition to general therapies of heart failure, what would you include for a patient in stage B?
ACE inhibitor or ARB (these both lower systemic vascular resistance and venous pressure, and decrease level of circulating catecholamines). In some patients you might also add a beta blocker to allow the heart to fill up more and thus contract with more force (Frank-Starling).
In addition to general therapies of heart failure, what would you include for a patient in stage C?
Stage B therapy (ACEi or ARB, and a beta-blocker), diuretics (thiazide first then loop if needed), aldosterone antagonists (decreases fibrosis), cardiac glycoside to increase contractility in some patients (digoxin).
In addition to general therapies of heart failure, what would you include for a patient in stage D?
Inotropes to increase the strength of contraction (beta agonists such as dobutamine; dopamine has been used); biventricular pacemaker if patient has a conduction defect or is not responding to therapy; implantable defibrillator; parachute device if infarction has induced left ventricle dilation; left ventricular assist device to pump blood while waiting for transplant; transplant.
Atherosclerosis is a very common cause of death in the US. It is the most common cause of heart disease (ischemic heart disease and myocardial infarction); it can also cause stroke and possibly increase the risk of dementia.
Free card.
Atherosclerosis involves damage to the endothelium. What sort of trauma might cause endothelial damage?
Elevated shear stress (especially at bifurcations and curved areas, and with high BP), biochemical abnormalities (such as high LDL, which inhibits the release of NO thus resulting in vasoconstriction, which increases damage from shear stress; also in diabetes, the AGEs can damage the endothelium), inflammation (increased platelet adhesion), smoking (toxic damage to BVs), advanced age.
Briefly outline atheroma formation.
Vessel walls become more permeable to LDL, which is then oxidized (which inhibits NO). Macrophages eat up the LDL (and are then called foam cells, which progress to form fatty streaks). Growth factors are released by platelets and the macrophages to cause migration and proliferation of smooth muscle cells, which then develop a fibrous cap.
Of the two types of vascular remodeling (positive and negative), which decreases lumen size?
Negative.
Of the two types of vascular remodeling (positive and negative), which is more commonly associated with unstable lesions, and why?
Positive; this is due to a softer core and a less developed cap.
Of the two types of vascular remodeling (positive and negative), which is associated with stable angina?
Negative.
Of the two types of vascular remodeling (positive and negative), which is more stable, and why?
Negative; its cap is more stable. These types of atherolmas are less likely to rupture.
Of the two types of vascular remodeling (positive and negative), which preserves lumen size?
Positive.
Of the two types of vascular remodeling (positive and negative), which is more likely to cause acute coronary syndrome?
Positive.
What are the three factors that can contribute to plaque vulnerability (and hence potential disruption)?
“Shoulder” of plaque (junction between plaque and less diseased vessel) is where the cap is thinnest and most prone to disruption; macrophage activity (proteolytic enzymes that weaken the cap); cap fatigue (with repetitive stress from pressure, shear stress, stretch from the heart beat).
There are two mechanisms of thrombosis due to atherosclerosis. Briefly describe them. Which is usually more serious?
Supericial endothelium breaks down, and platelets adhere to the underlying collagen, and a thrombus forms. The other form is a deep endothelial fissure tears the atheroma cap. Blood then enters the plaque and starts to form a large thrombus. The deep thrombus is usually the more serious.
What is the first symptom of atherosclerosis?
The first symptom (intermittent claudication) is on exertion due to the reduced oxygen supply for the greater demand.
What are some of the symptoms of advanced atherosclerosis?
PVD, MI, kidney disease, aneurysm, angina, sudden death, stroke.
What are some diagonistic imaging techniques that can be used for atherosclerosis?
Ultrasound, OCT, CT, MRI, angiography.
What sort of laboratory testing can be done for atherosclerosis?
Fasting total cholesterol (want total ~50 mg/dL, want LDL <150 mg/dL). Serum highly sensitive C-reactive protein (hs-CRP) can also be done for patients who have a 10 year CHD risk of 10% or more.
What is C-reactive protein? What is an average CRP value?
It is an indicator of inflammation; average value is about 2 mg/L
How is atheroscleroma managed?
Lifestyle modifications (lose weight, modify diet, increase physical activity), drugs, possibly surgery.
There are a few different classes of drugs used for the treatment of atheroscleroma. Which class(es) help decrease inflammation?
Aspirin, perhaps statins
There are a few different classes of drugs used for the treatment of atheroscleroma. Which class(es) help harden the cap of the lesion?
Statins
There are a few different classes of drugs used for the treatment of atheroscleroma. Which class(es) help lower LDL?
Statins, bile acid binders, niacin
There are a few different classes of drugs used for the treatment of atheroscleroma. Which class(es) help lower TGs and increase HDL?
Fibrates and niacin
Drugs used for the treatment of atheroscleroma may have an impact on the patient’s ocular health. What ocular implications do statins have?
They increase retinal blood circulation, may decrease diabetic neuropathy and retinopathy. (Note: antibiotics like erythromycin and clarithromycin interfere with the breakdown of statins, prolonging their effect.)
Drugs used for the treatment of atheroscleroma may have an impact on the patient’s ocular health. What ocular implications do bile acid binders have?
They could interfere with the absorption of other drugs (beta blockers, tetracycline, oral contraceptives, etc.)
Drugs used for the treatment of atheroscleroma may have an impact on the patient’s ocular health. What ocular implications do fibrates have?
May protect against diabetic neuropathy and retinopathy
Drugs used for the treatment of atheroscleroma may have an impact on the patient’s ocular health. What ocular implications does niacin have?
Can cause macular edema and toxic amblyopia
Ischemic heart disease (IHD) is also known as coronary artery disease (CAD) and coronary heart disease (CHD). What is the major cause of ischemic heart disease?
Coronary atherosclerosis
Although prevalence of ischemic heart disease is equal between genders, which gender is less likely to survive a myocardial infarction, and what pathophysiology of this gender might help account for this difference in survival?
Women; they have smaller coronary arteries (even correcting for body size). Due to this smaller size, women may be affected more by the decrease in NO caused by oxidized LDL. For unknown reasons, women also tend to experience positive remodeling, which is more prone to cause coronary problems.
What diagnostic testing may be done for a women who is suspected of having IHD?
Intravascular ultrasonography, stress echocardiography and stress thallium, and ACh challenge test for endothelial function.
