Ischemic Heart Disease - Part 1 Flashcards
What are other ways to say ischemic heart disease?
- coronary heart disease
- coronary artery disease
What is the most common cause of ischemic heart disease?
- atherosclerotic plaques
What may ischemic heart disease present as?
- ischemia without clinical symptoms
- chronic stable angina pectoris
- acute coronary syndromes (ACS)
What are the modifiable risk factors for ischemic heart disease?
- tobacco use/smoking history
- dyslipidemia
- diabetes
- hypertension
- chronic kidney disease
- physical inactivity
- poor diet
- obesity
- depression
- drugs (cocaine, steroids, progestins, NSAIDs)
What are the non-modifiable risk factors for ischemic heart disease?
- age >40 years old (men)
- age >50 years old (women)
- male sex
- family history of premature CV disease
- ethnicity
What change in the heart would come from a narrowing of the aorta?
- more pressure in the aorta means that there will be an enlarged large ventricle
What is the definition of ischemia?
- mismatch between coronary oxygen supply and demand
usually more demand than is delivered
What determines myocardial oxygen demand?
- heart rate
- contractility
- intramyocardial wall tension
What determines myocardial oxygen delivery?
- coronary blood flow
- oxygen extraction
- oxygen availability
What are some things that will increase the myocardial oxygen demand?
- left ventricular hypertrophy
- tachycardia
- hypertension
- aortic stenosis
- cardiomyopathy
- hyper/hypothermia
- hyperthyroidism
- cocaine use
- anxiety
What are some of the things that will decrease myocardial oxygen delivery?
- coronary artery disease
- coronary spasm
- anemia
- hypoxemia
- pneumona
- asthma
- COPD
- sleep apnea
What are the clinical symptoms that are associated with chronic stable angina?
- chest pain/discomfort
- sensation of pressure, variability described as strangling, squeezing, heavy crushing, burning, a band-like sensation, knot in the centre of the chest,
- SOB
- sweating
- nausea
- fatigue, light headedness, weakness
- onset is gradual
- duration between 0.5-30 minutes
- usually left sided radiation to arm, shoulder or jaw
- precipitating factors: exercise, cold environment, walking after a large meal, emotions, coitus
- responsive to nitroglycerin: relief of pain within 45s to 5 minutes
What is considered to be class 1 angina?
- ordinary physical activity does not cause angina, such as walking or climbing stairs
- angina occurs with strenuous, rapid or prolonged exertion at work or recreation
What is considered to be class 2 angina?
- slight limitation or ordinary activity. Angina occurs on walking or climbing stairs rapidly, walking uphill, walking or stair climbing after meals, or in cold, or in wind or under emotional stress or only during the few hours after waking. Walking more than 2 blocks on the level and climbing more than 1 flight of ordinary stairs at a normal pace and in normal condition
What is considered to be class 3 angina?
- marked limitations of ordinary physical activity
- angina occurs on walking 1-2 blocks on the level and climbing 1 flight of stairs in normal conditions and at a normal pace
What is considered to be class 4 angina?
- inability to carry on any physical activity without discomfort- anginal symptoms may be present at rest
What is diagnosis of stable angina based on?
- based on patients reported symptoms, their risk factors, and diagnostic tests
- stress tests: aimed at measuring the heart’s reaction to increased oxygen demand, exercise or pharmacologic agents to induce stress, ECG and BP taken before, during and after stress introduced
What is a MIBI stress test?
- use of radioisotope with stress test
- imaging taken to record pattern of radioactivity distribution to various parts of the myocardium, difference in uptake in certain areas indicate potential ischemic sites
What is a echocardiography?
- indicated when heart failure is suspected
- measure left ventricular systolic function
What is a angiogram?
- procedure in which a contrast material that can be seen using an x-ray equipment is injected into the coronary arteries in order to visualize blood flow through the heart
- provides real-time visualization of coronary blood flow
- indicated in patients with high risk features during the stress test, or if there is severe angina - also in diabetics
What is the role of beta blockers in ischemic heart disease?
- reduce oxygen demand
- decrease HR
- decrease contractility
- decrease intramyocardial wall tension (via decreased BP)
- reduces occurrence of angina symptoms
What is the first line therapy for the treatment of chronic stable angina?
- beta blockers
Beta blockers improve survival in patients with _______ dysfunction or history of MI
left ventricular
Beta blockers improve survival in patients with _______ dysfunction or history of MI
left ventricular
What are beta blockers usually used in combination with?
nitrates and CCBs (long acting or slow release dihydropyridines)
Beta blockers may worsen what?
- may worsen the sx of reactive airway disease or peripheral arterial disease
- abrupt withdrawal may increase severity and number of pain episodes
Beta blockers should be tapers over the course of ________
10-14 days
(reason is that there is an up regulation of beta receptors when using a beta blockers- NEVER d/c a beta blocker suddenly)
Beta blockers have been used to improve _______
ventricular function
Caution beta blockers in ____
diabetes - because they can mask the symptoms of hypoglycaemia
Which beta blocker is more effective in treating angina?
- they are all effective
- cardioselective agents are commonly used to minimize bronchospasm risk in patients with asthma
(metoprolol loses selectivity at doses >200 mg/day)\ - there is evidence for decreased mortality post-MI with timolol, propranolol, metoprolol
What are the cardioselective beta blockers?
- atenolol, bisoprolol, metoprolol
What are the nonselective beta blockers?
- nadolol, propranolol, timolol
What are the beta blockers with both alpha and beta blocker action?
carvedilol
What are the beta blockers that are both cardioselective and vasodilatory?
- nebivolol
If someone has prinzmental angina then we would always treat them with ______
CCBs
What is the action of CCBs?
- reduce cardiac oxygen demand (decrease conduction velocity through SA and AV nodes, decrease blood pressure (arterial dilation), decrease wall tension (due to reduced arterial pressure) and decrease myocardial contractility)
- improve coronary blood flow (vasodilator coronary arteries, decrease coronary vascular resistance, prevent vasospasm)
- as effective as beta blockers in preventing angina
Have CCBs been shown to improve survival rates after an MI?
- no
non-DHPs have less____ than DHPs
peripheral vasodilation
Which medications are non-DHPs
- verapamil and diltiazem
What medications are DHPs?
- nifedipine and amlodipine
_____ do not decrease AV node conduction or myocardial contractility (CCB)
dihydropyridines
What CCB may increase HR?
- nifedipine
What kind of CCB can be used in combination with a beta blocker?
- dihydropyridines
What are the most common SE associated with CCBs?
- hypotension, flushing, headache, dizziness, peripheral edema
What are the main SE associated with non-DHP CCBs?
- bradycardia, worsening heart failure (depress cardiac function)
— verapamil can cause constipation
What are the main effects of nitrates?
- reduce myocardial oxygen demand (ventilation and arterial-arteriolar dilation)
- dilate coronary arteries (increase the coronary blood flow)
What are nitrates mostly used for?
- acute anginal attacks (sublingual, buccal or spray products rapidly absorbed, relieves pain in 3-15 minutes)
- prevent effort or stress induced attacks (use 5 minutes prior to activity- lasts ~30 minutes)
- long acting formulations (3rd line for co
When would it be appropriate to use nitrates as a long acting formulation (as a patch for example)
- 3rd line after using a BB or CCB for controlling sx
- combination with BB or CCB
Should we ever use nitrates (long acting) as mono-therapy?
-
Should we ever use nitrates (long acting) as mono-therapy?
- NO - tolerance can occur with nitrates
What are the main long acting formulations of nitrates?
- isosorbide dinitrate
- transdermal nitroglycerin
What are the main SE associated with nitrates?
- headache, flushing, hypotension
How long until tolerance is developed with nitrates? What can be done to combat this?
- with chronic therapy of 7-10 days
- this can be managed with a nitrate free period of 8-12 hours to avoid tolerance
What is the major interaction associated with nitrates?
- phosphodiesterase inhibitors
- sildenafil, tadalafil, vardenafil
What is the proper way to administer nitrates as a spray?
- spray 5 times first to prime the can
- do NOT shake the container- will forma a layer of foam on top and the efficacy of the drug will be reduced
- spray under the tongue and close mouth as soon after administration
- do not rinse the mouth for 5-10 minutes after spray
What are some important points to remember AFTER the nitrate spray has been administered?
- if there is no relief 5 minutes after 1 dose, call the ambulance and continue to use the spray every 5 minutes for a total of 3 doses/ until the ambulance arrival
What are important storage instructions to counsel on for nitroglycerin tablets?
- store in a location where there is a small amount of moisture
- if using and there is no relief within 5 minutes call 911
Nitrates only treat what?
only treat the symptoms of angina- important for the patients to be on another medication to prevent an MI
What is the rationale behind using an anti platelet therapy?
prevents the formation of a thrombus
ASA 75-325 mg QD have a ____ decrease in MI and sudden death
30%
When is the only time that clopridogrel should be used as an anti platelet?
- if the patient cannot tolerate ASA
What is the benefit of using a statin in heart disease?
- decrease CV death and nonfatal MI in patients with established CHD
What is the action of ACEIs in treating CHF?
- decreased sympathetic adrenergic transmission
- decreased after load (BP lowering)
- increased coronary blood flow
When are ACEIs indicated for use in CHF?
- if BP control is needed in addition to BBs, prior to MI< LV dysfunction (HF), diabetes, chronic kidney disease
