Angina pectoris

Sudden,severe,pressing chest pain starting substernal &radiate to left arm.Due to imbalance between myocardium oxygen requirement and oxygen supply.Risk factors : Age,sex,obesity.smoking,diabetes.

Classification of angina Exertional angina, Stable,Atherosclerotic,Classic, Due to obstruction of coronaries by atheroma. 2. Variant, Vasospastic angina due to Spasm of coronaries.3- Unstable angina. Due to spasm and partial obstruction of coronaries.

Determinants of Oxygen Demand

Need to improve ratioCoronary blood flow / cardiac workorCardiac O2 Supply / Cardiac O2Requirement

Angina Risk Factors

ObesityNa+ intakePhysical inactivitySmokingHypertensionStressHigh blood cholesterol

AgeGenderFamily history

Cholesterol Levels

Total cholesterol less than 200 mg/dl desirable200 239 mg/dl borderline high240 mg/dl and over high

HDL cholesterol greater than 35 mg/dl -- desirable, the higher the better

LDL cholesterol less than 130 mg/dl desirable 130-159 mg/dl borderline 160mg/dl or higher high

Ratio LDL:HDL < 3 is desirable

Improving supply/demand ratio

Relaxation of resistance vessels (small arteries and arterioles) BP Afterload (Nitrates, calcium channel blockers and beta-blockers)

Relaxation of capacitance vessels (veins and venules) Venous return, heart size, Preload (Nitrates and calcium channel blockers)

Blockade of sympathetic influence on the heart Contactility, HR, O2 demand (Beta-blockers)

Coronary Dilation - Important mechanism for relieving vasospastic angina - O2 supply (Nitrates)

Nitrates & NitritesFormation of Nitric oxide (NO) activation of guanylate cyclase Ca++ uptake SRToxicity: headache, flushing, hypotension, possible circulatory collapse

Nitrates & NitritesPreparations :1- Short acting: Start within few minutes and total duration of action 15-30 minutes.A) Nitroglycerine (Glyceryl trinitrate) Used as sublingual tablets.B) Isosorbide dinitrate As sublingual spray.C) Amyl nitriteInhalation

2- Long actingNitroglycerine, Isosorbide dinitrate,Isosorbide mononitrate,Erythrityl Tetranitrate.Action of all start within hours and continue for hours .

They are given : Orally,Ointment,Buccal,Transdermal patch,Parenteral.

AbsorptionWell absorbed according to the route:GIT : long acting

Sublingual : short acting Transdermal , inhaLation: long acting

Pharmacological actionsNitrates relax all types of smooth muscles vascular or non vascular .Relax both arteries and veins but more effective on veins.They have no direct effect on cardiac or skeletal muscles.NO released stimulate guanylyl cyclase In platelets causing increase cGMP that decrease platelet aggregation.

Clinical uses Short acting for acute attacks Long acting for prophylactic

All type of angina

Adverse effectsOrthostatic hypotensionheadacheTachycardiaFacial or cutaneous flushingTolerance (Tachyphylaxis)Salt and water retentionCarcinogenicityMethaemoglobinemia only with nitrities

ContraindicationNitrates are contraindicated in increase intracranial pressure.Nitrates can be used safely in increase of intraocular pressure (Glucoma).

Calcium channel blockers1- They block calcium entry in myocardium causing A) decrease myocardium contractility & myocardium oxygen requirement.B) decrease heart rate causing decrease in myocardium oxygen requirement.

2-Block calcium entry in vascular smooth muscles (arterioles) causinga)decrease in peripheral resistance( after load)------ decrease in oxygen requirement.b)Relief of coronary spasm.

Main: Verapamil, Diltiazem, NifedipineOthers: Nicardipine, BepridilToxicitya. Hypotensionb. Effects related to vasodilation (dizziness, flushing, headache)c. Gingival hyperplasiad. Constipation, especially with verapamile. Cardiac depression with verapamil and diltiazemf. Tachycardia with nifedipine and nicardipineg. Arrhythmias and agranulocytosis with bepridil

Clinical usesIn all types of angina but very effective in variant angina .Used mainly in prophylactic therapy.

-Adrenoceptor blocking drugsThey are not vasodilators They are used in treatment of angina : They decrease both heart rate & myocardial contractility that decrease in myocardial oxygen requirement at rest & in exercise so improve exercise tolerance.Propranolol, Atenolol, Nadolol

Clinical uses They are effective in the prophylactic treatment of classic & unstable angina.They are not used in variant angina.They are effective in treatment of silent or ambulatory angina (no pain ).Decrease mortality of patients with recent myocardial infarction.

Drug treatment of angina1- Acute attack :Short acting nitrates or nitritis.2- Prophylactic therapy ;Long acting nitrates.Calcium channel blockers.- adrenoceptors blockers.

Surgical therapyBallonCoronary by pass.

Angina Surgical Treatment(Coronary bypass, angioplasty, stents