SIHD and Angina Therapy Flashcards
Risk factors of ischaemic heart disease
Hypertension Smoking Hyperlipidaemia Hyperglycaemia Male Post-menopausal females
Attacks of angina precipitated by
Any stress which increases heart rate, stroke volume or blood pressure
Determinants of oxygen demand
Heart rate
Systolic blood pressure
Myocardial wall stress
Myocardial contractility
Determinants of supply
Coronary artery diameter and tone
Collateral blood flow
Perfusion pressire
Heart rate (duration of diastole)
Demand ischaemia
During stress
Supply ischaemia
At rest
Drugs correct supply/demand imbalance by
Decreasing oxygen demand and increasing oxygen supply
Ischaemic heart disease caused by
Imbalance of oxygen supply/demand
Drugs decrease oxygen demand by
Reducing heart rate, myocardial contractility and afterload
Rate limiting drugs
Beta blockers
Ivabradine
Calcium channel blockers
Vasodilator drugs
Calcium channel blockers
Nitrates
Potassium channel opener
Nicorandil
Anti-ischaemic drug for alleviating stable angina symptoms
Ranolazine
Anti-platelet drugs
Aspirin
Clopidogrel
Tigagrelor
Cholesterol lowering agents
Fibrates
Examples of beta blockers
Bisoprolol
Atenolol
Function of beta blockers
Block sympathetic system by blocking beta 1 and 2 receptors
Contraindications of beta blockers
Asthma Peripheral vascular disease Raynauds syndrome Heart failure Bradycardia/heart block
Effect of beta blockers
Increase diastolic perfusion time
Decrease heart rate, contractility and blood pressure
Increase exercise threshold
Adverse drugs reactions of beta blockers
Tiredness/fatigue Lethargy Impotence Bradycardia Bronchospasm Rebound phenomena
Drug-drug interactions of beta blockers
Hypotension when used with hypotensives
Bradycardia when used with other rate limiting drugs
Cardiac failure when used with negatively inotropic agent
NSAIDS antagonise antihypertensive actions
Exaggerate hypoglycaemic actions of insulin
Examples of calcium channel blockers with types
Diltiazem - rate limiting
Verapamil - rate limiting
Amlodipine - vasodilator
Function of calcium channel blockers
Block L-type calcium channels to prevent calcium influx into myocytes and smooth muscle lining arteries and arterioles
Effect of rate limiting calcium channel blockers
Reduce heart rate and myocardial contractility
Effect of vasodilating calcium channel blockers
Reduce vascular tone, produce vasodilation and reduce afterload
Contraindications of calcium channel blockers
Post MI
Unstable angina
Adverse drug reactions of calcium channel blockers
Ankle oedema
Headache
Flushing
Palpitation
Example of nitrovasodilators
Glyceryl trinitrate (GTN)
Isosorbide mononitrate
Isosorbide dinitrate
Function of nitrovasdilators
Relax almost all smooth muscle cells via NO and cGMP
Effect of nitorvasodilators
Reduce afterload and preload
Relieving coronary vasospasm
Redistributing myocardial blood flow to ischaemic areas
Adverse drug reactions of nitrates
Headache
Hypotension
GTN - syncope
Drug for metabolic modulation
Trimetazidine
Drug for sinus node inhibition
Ivabradine
Drug for late sodium current inhibition
Ranolazine
Drug for preconditioning
Nicorandil
Second line therapy
Nicorandil
Ibabradine
Ranolazine
Function of nicorandil
Activates ATP sensitive potassium channel, the entry of potassium into myocytes inhibits calcium influx and so negative inotropic action
Effect of nicorandil
Relaxation of vascular smooth muscle and coronary dilation
Decreases preload and afterload
Function of ivabradine
Inhibits If pacemaker in the sinoatrial node, slows diastolic depolarisation slip of SA-node
Effect of ivabradine
Reduces heart rate
Ivabradine is used in combination with
Beta-blockers
Function of ranolazine
Inhibits sodium inward current in heart muscle in voltage gated channels leading to reduced intracellular calcium levels
Effect of ranolazine
Reduced tension in the heart wall
Aspirin dosage
75-100mg
Function of aspirin
Inhibits platelet thromboxane production which stimulates platelet aggregation and vasoconstriction
Effect of aspirin
Stops aggregation of platelets
Aspirin is combined with
Beta blockers
Aspirin and clopidogrel reduce
Acute MI and unstable angina mortality, reinfarction
Risk of aspirin and clopidogrel
GI bleed
Function of clopidogrel
Inhibits ADP receptor activated platelet aggregation
Effect of clopidogrel
Prevents platelet aggregation
Examples of cholesterol lowering agents
Simvastatin
Pravastatin
Atorvastatin
Function of cholesterol lowering agents
HMG CoA reductase inhibitors
First line therapy
Beta blockers
Patients with stable angina should be considered for treatment with
ACE inhibitor