What is the most important determinant of myocardial oxygen demand?
Rate of rise in the intraventricular pressure during isovolumetric contraction
What is myocardial contractility influenced by?
*Autonomic nervous system *Heart rate *Blood cacium level *Temperature
Systolic wall tension is directly related to?
ventricular systolic pressure and ventricular wall radius
Systolic wall tension is inversely related to?
Reducing systolic blood pressure does what to the afterload, decreasing oxygen demand?
reduces the afterload
Reductions in preload reduces what to reduce oxgyen demand?
left ventricular dimension
What is myocardial oxygen supply determined by?
*coronary blood fow *oxygen carrying capacity of the blood
What is the most important determinant of myocardial oxygen supply?
coronary blood flow
When does myocardial ischemia develop?
When narrowing of the epicardial vessels by vasopasm or atherosclerosis results in high enough resistance to restrict coronary blood flow
What are the factors that affect coronary blood flow?
*Duration of systole *Coronary vascular resistance
What is coronary vascular resistance determined by?
*metabolic control *autoregulation *extravascular compressive forces *humoral and neural factors
Angina in which the frequency, severity, duration of symptoms, and time of day have not changed over the previous 2 months
Chronic stable angina
How does angina classically present?
*substernal discomfort that radiates to the neck and left arm *pressure, heaviness, fullness, squeezing, burning, aching, gas, anxiety *gradual onset *lasts a few minutes *relieved by rest or nitroglycerin
A long duration of anginal discomfort implies what?
*severe ischemia *coronary spasm *unstable angina *impending MI
Functional classification of angina pectoris
*Class I - symptoms occur with unusual activity with minimal or no functional impairment *Class II - symptoms occur with prolonged activity with mild functional impairment *Class III - symptoms occur with usual ADL's with moderate functional impairment *Class IV - symptoms occur at rest with severe functional impairment
Myocardial ischemia in the absence of an objective signs of angina
increased heart rate, accelerated AV nodal conduction, increased myocardial contractility
What does stimulation of beta 2 receptors cause?
bronchodilation and vasodilation
What are the beneficial effects of beta blockers in angina?
*reduction in heart rate which reduces cardiac work and decreases oxygen demand *slowing of heart rate also prolongs diastolic filling leading to improved oxygen supply *reduction of myocardial contractility and arterial blood pressure which reduces oxygen demand *reduce frequency of angina episodes, improve exercise tolerance, and decrease need for NTG
What are the cardioselective beta blockers?
Metoprolol, Atenolol, Acebutolol
Nonselective beta blockers should be avoided in patients with?
obstructive lung disease, asthma, poor circulation, and diabetes
Beta blockers with partial agonist activity
Pindolol, carteolol, penbutolol, acebutolol
Beta blockers with partial agonist activity may be detrimental in what patients?
Patients with rest angina or post MI *may not decrease heart rate and blood pressure at rest
Why are beta blockers frequently combined with nitrates?
To attenuate the potential for reflex tachycardia caused by increased sympathetic tone from nitrates
In patients with vasospastic angina, what might beta blockers do?
precipitate an anginal episode
Adverse effects of beta blockers
*sinus bradycardia and sinus arrest *AV block *Reduced LV function *Fatigue *Bronchoconstriction *Depression *Nightmares *Sexual dysfunction *Intensification of insulin-induced hypoglycemia
Patients with what should avoid using beta blockers?
*Block the vasoconstrictor and aldosterone-secreting effects of angiotensin II by selectively blocking the binding of angiotensin II to the AT1 receptor in many tissues
Adverse reactions of angiotensin II receptor antagonists
*much lower incidence of cough, angioedema, and dizziness *higher incidence of URTI, hypotension, renal function impairment, hyperkalemia *fetal and neonatal morbidity and death when administered to pregnant women
What is nitrate tolerance?
A decreased pharmacologic response in the presence of continuously or frequently administered nitrates
How is nitrate tolerance prevented?
Provide a 10-12 hour daily nitrate-free interval with chronic dosing (usually at night except in patients with nocturnal angina)
Four areas in the management of chronic stable angina pectoris
*Correction/treatment of all modifiable cardiovascular risk factors *Alteration in lifestyle *Drug therapy *Revascularization therapy (PTCA or CABG) in patients where medical therapy is not effective in reducing the number of anginal attacks or with underlying severe CAD
What drug is recommended in stable angina and has been shown to reduce the risk of first MI?
What medication should be used in patients with chronic stable angina who cannot take beta blockers?
Calcium channel blocker
What medications are often used with nitrates to prevent angina during the nitrate-free interval?
Beta Blockers and Calcium channel blockers
Why should diltiazem and verapamil be used with caution with beta blockers?
slowing of the AV nodal conduction and decreasing contractility
What is the preferred drug for sinus bradycardia?
Nitrate, long acting DHP CCB
What drugs should be avoided in sinus bradycardia?
Diltiazem, verapamil, beta blocker
Preferred drugs for sinus tachycardia
Beta bocker, verapamil, diltiazem
Drugs to avoid with sinus tachycardia
Preferred drugs for SVT
Verapamil, diltiazem, beta blocker
Preferred drugs for AV block
Long acting CCB, nitrates
Drugs to avoid with AV block
Beta blocker, diltiazem, verapamil
Preferred drugs for A.fib
Beta blocker, verapamil, diltiazem
Preferred drugs for ventricular arrhythmias
Preferred drugs for LV dysfunction
Low dose beta blocker, nitrates DHP CCB
Drugs to avoid with LV dysfunction
Diltiazem and verapamil
Preferred drugs for post-MI
non-ISA beta blocker
Drugs to avoid with post-MI
ISA beta blocker
Preferred drugs for systemic hypertension
Beta blocker, CCB
Preferred drugs for migraine
Beta blocker, verapamil, diltiazem
Drugs to avoid with migraines
Nitrates, DHP CCBs
Preferred drugs for COPD/asthma
Drugs to avoid with COPD/asthma
Preferred drugs for hyperthyroidism
Preferred drugs for Raynaud's
Drugs to avoid with Raynauds
Preferred drugs for Claudication
Drugs to avoid with claudication
Preferred drugs for depression
Drugs to avoid with depression
Preferred drugs for diabetes
Beta 1 selective beta blockers, Nitrates, CCBs
Myocardial ischemia associated with coronary artery vasospasm and not necessarily associated with atheroscleoritic CAD
Variant Angina or Prinzmetal's angina
Decreased myocardial oxygen supply in variant angina is due to?
narrowing of a large coronary vessel
When does variant angina pain usually occur?
Between midnight and 8am
What is used for acute episodes of variant angina?
What is used for chronic prophylaxis of variant angina?
Calcium channel blockers or long acting nitrates with nitrate free period during the day
Combination therapy with what 2 CCBs have shown effective in variant angina but with increased adverse drug effects?
Diltiazem and Nifedipine
Why should beta blockers be avoided in patients with variant angina?
exacerbation of coronary artery vasospasm
How does unstable angina usually present?
*rest angina over 20 minutes in duration *new onset angina which occurs with minimal exertion *angina with increasing frequency/duration
What does an ECG of a patient with unstable angina usually show?
ST Segment changes *elevation with STEMI *depression with UA/NSTEMI
What 3 processes contribute to the decreased myocardial oxygen supply with unstable angina?
*progression of atherosclerosis *platelet aggregation *thrombus formation
What is acute myocardial infarction usually asociated with?
total occlusion of the coronary artery
What is the primary goal in unstable angina?
Prevent MI by inhibiting extension of the thrombus
When a patient is admitted to the hospital for acute coronary syndrome, what does standard medical therapy usually consist of?
What medication is recommended immediately for patients with unstable angina?
Aspirin (chew or swallow)
What is the preferred alternative to aspirin in unstable angina?
Why is Hirudin, a direct thrombin inhibitor, not indicated in unstable angina?
Incidence of intracranial hemorrhage
Why are thrombolytics not indicated in unstable angina?
Clinical studies have shown no beneficial effects
What are the preferred beta blockers in unstable angina?
Metoprolol and atenolol
IV nitroglycerin is recommended for patients with unstable angina when?
Continuation of chest pain after 3 sublingual nitroglycerin tablets and initiation of beta blockers
When are calcium channel blockers indicated in patients with unstable angina?
When patietns are not controlled with optimal doses of nitrates and beta blockers or in patients with a known vasospastic component to their angina
DHP CCBs should be avoided in unstable angina unless they are administered with what?
Class I Recommendations for Anti-Ischemic Therapy
*Bed rest with continuous ECG monitoring *Supplemental Oxygen *SL NTG every 5 minutes up to 3 doses *IV NTG in first 48 hours *Oral BB therapy *If BB contraindicated - nonDHP CCB *ACE-I in patients with pulmonary congestion or LVEF under 40% *ARB in patients intolerant of ACE-I and signs of HF or LVEF under 40% *Discontinue any NSAIDs except for aspirin
Class I Antiplatelet therapy recommendations
*Aspirin given ASAP *Clopidogrel if unable to take aspirin *Proton pump inhibitor in patients with hx of GI bleed to minimize risk with aspirin or clopidogrel *Clopidogrel or an IV GPIIb/IIIa inhibitor in addition to aspirin prior to angiography *Clopidogrel and aspirin for at least 1 month up to 1 year
Class I Anticoagulant Therapy Recommendations
*Enoxaparin or unfractionated heparin (level A) or Bivalirudin or fondaparinux (level B)