Week 7 formative quiz questions Flashcards
Percutaneous coronary stenting improves mortality rates in stable angina.
False – it improves symptoms, but there is no evidence it improves prognosis in stable disease. However, PCI (percutaneous coronary intervention) has a big impact on mortality in acute coronary syndrome.
Rheumatic fever is strongly associated with staphylococcal infection.
False – Rheumatic is associated with infection by Group A beta-haemolytic streptococcal infections (such as strep throat).
Patients with a recent stroke cannot have thrombolysis for a STEMI.
True – the risk of intracranial bleeding is too high.
Myocardial damage is detected by a rise in troponin levels on a blood test.
True – this is one of the standard investigations performed in suspected acute coronary syndromes. Be aware, however, that any state which places stress on the heart (e.g. sepsis, myocarditis, severe tachycardia) can result in a troponin rise, so this is not sufficient to diagnose ACS in isolation.
Hypercholesterolaemia can directly cause endothelial damage leading to atheromatous plaque formation.
True – chronically elevated blood cholesterol levels can damage the endothelium by increasing local production of oxygen free radicals.
The renin-angiotensin-aldosterone system adjusts blood pressure through sodium and water retention.
True, this is one of the ways that the RAAS controls blood pressure. Activation of the RAAS also produces Angiotensin II, which is a vasoconstrictor.
Stage 1 hypertension is defined as a clinic blood pressure of 135/85mmHg or higher.
False – we know that people tend to have higher blood pressure in the doctor’s office (doctor’s appointments are stressful!) than they do at home, and it is the average blood pressure that we are interested in. For that reason, a home ambulatory average blood pressure of 135/85mmHg or higher is termed stage 1 hypertension, while in the clinic it’s an average BP (over several measurements on separate occasions) of 140/90mmHg.
Many ischaemic strokes are caused by atherosclerosis of the carotid artery.
True – commonly, atheromatous debris from carotid artery plaques can embolise and travel to the brain, where it becomes lodged in arterial beds and causes ischaemia.
Regarding thrombus formation: The lines of Zahn are formed from alternating bands of red blood cells and lipid.
False – they are alternating bands of RBCs and platelets.
The term embolisation specifically refers to movement of detached intravascular thrombus to a distant site.
False – emboli can be solid, liquid or gas. The most common embolus in humans is thrombus, however.
In normal laminar blood flow, the cellular component of blood travels at the periphery of the vessel.
False – the cells travel down the centre of the vessel in normal laminar flow, and the plasma is in contact with the vessel walls.
Ischaemic chest pain (angina) often comes on with exercise as exercise drastically reduces the supply of blood to the cardiac muscle.
False – this is usually a combination of a “supply” and a “demand” issue. As the heart rate and stroke volume increases with exercise, the oxygen demand of the tissue increases as it works harder. Supply is unable to increase to meet this demand, often due to narrowing of the coronary arteries by atheromatous disease, and the tissue becomes ischaemic. There may also be a slight reduce in supply, as the coronary arteries fill during diastole (remember that diastole is reduced as heart rate increases), but this does not cause symptoms in a healthy heart.
Statins can be used to help reduce symptoms in stable angina.
False – statins lower cholesterol levels and may slow disease progression in angina and other atheromatous cardiovascular disease, but will not affect symptoms.
Thrombolysis is the first-line treatment for a STEMI.
False – mechanical reopening of the blocked artery by percutaneous coronary angioplasty is the firstline management, with the best evidence base. However for remote and rural patients for whom travel time to the nearest PCI centre is too long, thrombolysis can be used as an alternative.
Total occlusion of an artery lumen causes reversible ischaemia such as that seen in stable angina.
False – total occlusion of an artery often follows plaque rupture, as this exposes the highly thrombogenic plaque contents to the bloodstream and provokes thrombus formation. It causes non-reversible ischaemia, and can lead to tissue infarction.
Blood pressure target in people over 80 should be <135/75mmHg.
False – we tolerate a slightly higher blood pressure in people over 80, as the risks associated with multiple drug treatments including increased risk of falls becomes more of a concern. People over 80 should have a target blood pressure <145/85mmHg.
Regarding atheromatous plaque formation: neutrophils migrate into the arterial intima in response to endothelial damage.
False – monocytes do this, where they transform to foamy macrophages.
Thromboembolism often causes infarction of tissue.
True – this is a very common consequence of thromboembolism, and is seen in stroke, limb gangrene and gut infarction. Some tissues have good collateral blood supply and are less vulnerable to infarction.
Increase in peripheral vascular resistance will lead to a decrease in blood pressure.
False. Blood pressure = Cardiac output x Peripheral Vascular Resistance, so an increase in PVR will increase blood pressure.
A fully-developed atheromatous plaque has a protein core.
False – fully developed atheroma have a lipid core, surrounded by a fibrous tissue cap.
Thyroid function testing is routine in investigation of angina.
True – thyrotoxicosis is a rare cause of angina. It causes increased metabolic demand due to pathologically elevated thyroid hormone levels.
Elevated blood lactate levels are an indication of tissue ischaemia.
True – remember that cells that are deprived of oxygen will undergo anaerobic respiration. Lactate is a product of anaerobic respiration, and can be detected in a blood test. A clinical application of this is that we routinely check lactate levels in patients who have sepsis, as it gives a good indication of how “sick” a person is. Sepsis raises tissue oxygen demand and also limits oxygen delivery due to vasodilation and hypotension.
Calcium channel blockers can cause ankle swelling.
True – these drugs are potent vasodilators, and can cause ankle swelling. This is a common reason for stopping therapy with CCBs.
Furosemide is an aldosterone receptor antagonist.
False – furosemide is a loop diuretic. Examples of aldosterone receptor antagonists (mineralocorticoid receptor antagonists) are spironolactone and eplerenone.