angina and heart attacks Flashcards
what is stable angina
- predictable chest pain/pressure, often precipitated by physical exertion or emotional stress which causes increase in myocardial oxygen demand
- relieved within a few mins of resting
stable angina usually results from
atherosclerotic plaques in coronary arteries which restrict blood flow and oxygen supply to heart
describe the pain in stable angina
- typically occurs in front of chest
- can spread to neck, jaw, left arm, shoulder
complications of stable angina
- unstable angina
- stroke
- MI
- sudden cardiac death
Prinzmetals or vasospastic angina
- rare form of angina, not caused by atherosclerosis
- caused by narrowing or occlusion of proximal coronary arteries due to spasm
- pain is experienced at REST
how to treat acute attacks of stable angina
- sublingual GTN
How to use sublingual GTN for the treatment of angina
- one tab/1-2 sprays under tongue and close mouth
- dose may be repeated at 5 min intervals if needed
- seek urgent medical care if symptoms not resolved 5 mins after second dose, or earlier if pt unwell/pain is intensifying
- max 3 doses
how to use sublingual GTN for angina prophylaxis
1 tablet/400–800 micrograms to be administered under the tongue and then close mouth prior to activity likely to cause angina.
long term prevention of chest pain in pt with angina
- BB (or RL-CCB instead)
- dual therapy of BB + any CCB licensed (Rl/DHP)
avoid verap + BB same time - significant interaction, increased risk adverse CV events
- if either BB or CCB cannot be given, add vasodilator as dual therapy
- if both BB and CCB can’t be given, vasodilator mono therapy
MOA nitrates
- potent coronary vasodilators
- reduce venous return to heart, thus reduce LV work (blood pumped out by heart) = less CO = less strain on heart
Examples of vasodilators
Long acting nitrate (e.g. isosorbide mono/dinitrate), ivabradine, nicorandil, ranolozine
Cautions nitrates - long acting or transdermal preps
- many pt taking these quickly develop tolerance
- constant levels of nitrates in blood = body becomes desensitised
- progressively higher dose needed for same therapeutic effect
- to overcome, choose dose timings that leave blood nitrate free or with very low levels for 4-12 hours everyday
- e.g. remove patches for 8-12h (e.g. overnight)
- when a LA nitrate taken BD, take 2nd dose after 8 h instead of 12 hours so it doesn’t cover a 24h period
- MR isosorbide mononitrate to be taken OD
SE of nitrates
- vasodilators: flushing, throbbing headache, postal hypotension
interactions of nitrates
- SE if hypotension, so taking two or more drugs = increased risk of hypotension
- e.g. antihypertensives, alpha blockers, BBs, antidepressants, antipsychotics, diuretics, SGLT2i (e.g. canag)
- e.g. SEVERE, avoid phosphodiester-type 5 inhibitors (e.g. sildenafil)
when to assess response to treatment
- every 2-4 weeks after initiation or change of drug therapy
- titrate drug doses to max tolerated effective dose
