Cardiovascular Pathology 2 Flashcards
What is heart failure?
Heart failure (HF) is a condition in which a problem with the structure or function of the heart impairs its ability to supply sufficient blood flow to meet the body’s needs.
Heart failure can be either right-sided or left-sided.
Describe right- and left-sided heart failure.
Left-sided failure
Backward failure of the left ventricle or left atrium causes congestion of the pulmonary vasculature, and so the symptoms are predominantly respiratory in nature. The patient will have dyspnea (shortness of breath) on exertion and in severe cases, dyspnea at rest. Its causes include ischemic heart disease, hypertension, myocardial diseases, aortic or mitral valvular disease
Right-sided failure
Backward failure of the right ventricle leads to congestion of systemic capillaries. This helps to generate excess fluid accumulation in the body. This causes swelling under the skin (termed peripheral edema or anasarca) and usually affects the dependent parts of the body first (causing foot and ankle swelling in people who are standing up). Its causes include left side failure or pulmonay hypertension often caused by chronic lung disease
Outline the different causes of generalised and localised oedema.
Generalised:
- increased hydrostatic pressure (cardiac dailure)
- reduced oncotic pressure within blood vessels due to decreased serum albumin (nephrotic syndrome, liver failure, malabsorption)
- Sodium and water retention by kidney (prolonged steroid therapy)
Localised:
- increased tissue oncotic pressure due to increased blood vessel wall permeability (inflammation)
- obstruction of fluid clearance via lymphatic system
- Varicosse veins and deep vein thrombosis
Outline Rheumatic fever.
Rheumatic fever is an endocarditis caused by streptococcal group A bacteria that can be fatal or lead to rheumatic heart disease (10%), a chronic condition caused by scarring and deformity of the heart valves.
It is called rheumatic fever as the most common symptoms are fever and joint pain.
Infection generally starts at a stroptococcal throat infection in children ages 5-15, and damages the heart in 50% of cases. Usually occurs 1-4 weeks after an acute episode of tonsilitis.
Diagnosis of rheumatic fever is based on revised Dukett-Jones criteria: two or more major criteria, or one major and two or more minor criteria. List some of these criteria.
Major criteria:
- Migratory polyarthritis (temporary arthritis of large joints, usually starting at the legs and moving upwards)
- Carditis (manifests as congestive heart failure)
- Subcutaneous nodules (painless, firm collections of collagen fibres over bones and tendons, common on back of wrist, outer elbow, and front of knees)
- Erythema marginatum (long-lasting rash that begins on the trunk as macules)
- Sydenham’s chorea (characteristic series of rapid movements without purpose in face and arms)
Minor criteria:
- Fever, arthralgia, previous rheumatic fever, raised ESR, prolonged PR interval on ECG.
Outline the pathogenesis of rheumatic fever.
The exact pathogenesis is unclear, but it produces a diffuse, proliferative, and exudative inflammatory process in the connective tissue of certain structures.
- Bacteria adhere to oral and pharyngeal cells and release degradation products.
- Antigens to streptococcal cells bind to the heart, brain cells, muscles, and joints, which begins the autoimmune response.
- In the heart valves, inflammatory products react with cardiac proteins, affecting cardiac valve tissue and myocardium. All layers of the heart may be involved.
- Endocardial inflammation causes swelling of the valve leaflets, with erosion along lines of leaflet contact. Small, bead-like clumps of vegetation containing platelets and fibrin are deposited on eroded valve tissue and chordae tendineae.
The chracteristic lesion of rheumatic carditis is the Aschoff nodule, which is a granulomatous lesion with central necrotic material surrounded by monocytes and lymphocytes. Some macrophages fuse to form giant cells, while others become catepillar cells.
Manifests as:
- Pericarditis
- Myocarditis
- Endocarditis (leads to valve stenosis)
How is rheumatic fever diagnosed and treated?
Late diagnosis can have serious consequences requiring immediate antibiotic and antiinflammatory treatment. Jones criteria are used for diagnosis, and results of a throat culture for Strep group A are usually positive.
Treatment:
Aspirin may be used to treat the joint manifestations and as a general antiinflammatory agent. Corticosteroids are used when there is a clear case of rheumatic carditis. Antibiotics to remove residual streptococcal infection and long acting penicillin monthly injections for 5 years, 40 years in carditis.
What forms does myocardial ischemia present in? [3]
- Stable angina (exertion-induced angina)
- Unstable angina
- Silent ischemia
Define myocardial ischemia.
Myocardial ischemia occurs when blood flow to your heart is reduced, preventing it from receiving enough oxygen. The reduced blood flow is usually the result of a partial or complete blockage of your heart’s arteries (coronary arteries)
What causes myocardial ischemia?
- Atherosclerosis (most common)
- Thromboemboli (derived from vulvular vegetations)
- Coronary spasm
- Coronary arteritis
- Increased cardiac work load due to underlying condition, e.g. hyperthyroidism, and decrease oxygen delivery to the heart, e.g. anaemia.
Name some modifiable and non-modifiable risk factors for myocardial ischemia.
Non-modifiable
- Age (risk increases with age)
- Sex (male more likely)
- Genetic elements
- Family history
Modifiable
- Hyperlipidaemia (TC/HDL ratio)
- Hypertension
- Smoking
- Diabetes
- Physical inactivity
Give an example of what can cause a gradual and a sudden blood vessel blockage.
- Gradual: fat plaque formation, thrombosis (blood clot formation)
- Sudden: embolism
What is angina pectoralis?
Angina pectoralis is an episodic chest pain caused by inadequate oxygenation of the myocardium.
What are the three forms of angina? Outline each.
- Stable angina (most common) is caused by an exertion and is relieved by rest or vasodilatiors, and results from the severe narrowing of atherosclerotic coronary arteries.
- Unstable angina is prolonged (>10 minutes) or recurrent pain at rest. It is often indicative of imminent myocardial infarction and is generally caused by disruption of an atherosclerotic plaque with superimposed thrombosis. It can also be cause by embolisation.
- Prinzmetal angina is intermittent chest pain at rest, and is generally considered to be caused by vasospasm.
