IHD Flashcards
What are the risk factors for IHD?
Male gender Family history Smoking Diabetes mellitus Hypercholesterolaemia Hypertension Sedentary lifestyle Obesity
What is stable angina pectoris?
Atherosclerotic disease, which limits heart’s ability to respond to increased demand
Symptoms on exertion but are relieved by rest
What is unstable angina pectoris?
Generally due to plaque rupture and the formation of non-occlusive thromboembolism, or less commonly vasospasm (prinzmetal angina)
Symptoms at rest
How is IHD diagnosed?
In stable angina- pain induced by exercise, relieved by rest/GTN
ECG- ST-segment depression is associated with ischaemia
Angiography of coronary arteries reveals stenosis
What is lifestyle management for IHD?
Smoking cessation
Increased exercise
Healthy diet
Weight reduction if appropriate
What is the medical management of IHD?
Coronary artery bypass grafting (CABG) is the most effective approach
Angioplasty with stenting is also used (using a balloon catheter to dilate/destroy the stenosis and insert a cage intraluminally to prevent restenosis)
What are nitrates?
Realease of nitric oxide
Venodilation, leading to a decrease in preload and a reduction in cardiac work
Coronary vasodilation, improves coronary blood flow
What are b-blockers?
First choice drugs for prevention
-ve inotropic and chronotropic effects reducing cardiac work and preventing symptoms
Coronary flow only occurs during diastole, then by slowing the heart the diastolic period will be increased, as will the time for coronary blood flow
Anti-arrhythmic effects and reduce the risk of myocardial infarction
What are calcium channel blockers?
Vasodilatation and improve coronary blood flow, so preventing symptoms
Verapamil (lesser extent dilimiazem) also have myocardial depressant and bradycardia actions, reducing cardiac work
What does verapamil exert?
Class IV anti-arrhythmic activity
What did the HOPE trial indicate?
Ramirpil reduced mortality in patients with IHD
What are potassium channel activators?
Nicorandil: combined NO donor and activator of ATP-sensitive K-channels
The target is the ATP-sensitive K+ channel (K ATP)
What are antiplatelet drugs?
Low dose aspirin
Clopidogrel
What does low dose aspirin do?
Favours prostacyclin production over thromboxane as inhibits both endothelial and platelet cycle-oxygenase
Endothelial cell as nucleated and can regenerate COX, platelets lack nuclei and cannot
Ibuprofen may oppose beneficial actions
What does clopidogrel do?
ADP receptor antagonist (presents platelet aggregation)
Equally effective as aspirin
Used in patients who can’t have aspirin (asthma)
