Respiratory and Cardiovascular Diseases Flashcards
What is asthma?
A common lung diseases varying in intensity that causes intermittent breathing difficulties. If not managed effectively, it involves periods of short breath and coughing. Usually inherited, can be late onset.
How can asthma be exacerbated?
Catching a cold can make the cough worse, cold air and dampness can set it off.
How can asthma be controlled?
Inhalers containing bronchodilators and antiinflammatory glucocorticosteroids. Severe asthmatics don’t really respond and require emergency treatment. There are many guidelines like UK NICE and international GINA. Outcome much depends on treatment compliance
Describe the pathophysiology of asthma
Mucus plugs (mucus, inflammatory cells, plasma exudate) occlude the bronchi. The epithelia become fragile and there’s goblet cell hyperplasia. The basement membrane thickens, and there’s smooth muscle and submucosal gland hypertrophy. Blood vessels become congested with blood, and there’s inflammatory cells. Increased bronchoconstriction coupled with mucus plugs completely blocks the airways
Describe COPD
A group of lung diseases that causes breathing difficulties, where the patient can’t breathe out quickly so has trouble increasing ventilation. Caused by inhaling noxious material.
What are the processes that occur in COPD?
Chronic bronchitis - Airway damage and mucus hypersecretion. Also small airway fibrosis which leads to a smaller lumen that alveoli cannot keep patent due to increased fibrosis of walls.
Emphysema - Broken down alveoli -> baggy lung, full of holes, air trapped, person can’t exhale properly.
Lung blood vessel damage - Can’t get O2 properly, puts strain on heart.
How can COPD be treated?
Stop smoking, flu jabs to prevent from serious flu complications, pulmonary rehab - push limits of breathlessness, stay active. Inhalers used properly and be prepared for flareups. Same treatments as asthma but less effective because no bronchoconstriction. Also COPD inflammation seems to be resistant to glucocorticosteroids
What processes do most cardiovascular diseases originate from?
Endothelial injury, mostly caused by: inflammation (infectious or immune mediated), apoptosis and necrosis from toxins, oxidative stress from hypoxia and reoxygenation, mechanical injury from shear stress and stretch
Describe atherosclerosis
A disease of the arterial wall where the layer thickens, narrowing the lumen and impairing blood flow. Most serious when occuring in heart, or blood vessels that go to brain. It’s caused by excessive fibroproliferative response to vascular injury. It’s the principle cause of myocardial infarction, stroke, gangrene in extremities.
Describe Pulmonary Hypertension
High BP in pulmonary arteries (supplying the lung), causing by narrowing of arteries, leading to increased resistance and increased workload for RA, leading to enlargement. If untreated, prognosis is poor, and it affects mainly females. The most serious case is in thin walled peripheral arterioles where they undergo remodelling, thickening the smooth muscle - pulmonary arterial hypertension
What are the symptoms of PH?
Chest pain, fatigue, ankle, abdomen, leg swelling, bluish lips and skin. The disease is not easily detectable as it requires a RV catheter into pulmonary artery to detect pressure. The symptoms are non-specific making it hard to diagnose.
What are the 5 classifications of PH according to WHO?
Group 1 - Pulmonary Arterial Hypertension
Group 2 - Due to left heart disease
Group 3 - Due to lung disease/hypoxia
Group 4 - Chronic thrombotic/embolic disease
Group 5 - Unclear, multifactorial (inflammation, obstruction/compression)
What are the causes of PH?
Genetic, COPD, high altitude, inflammation/acute respiratory distress syndrome, congenital heart disease, idiopathic
Describe animal models of PH
Hypoxia induced PH in rats, pigs, cattle and KO/transgenic mice. Most treatments work in pre clinical models, but there is no cure. No single animal model is a good representation for PH in humans.
