angina pectoris usw

ANGINA PECTORIS

ANGINA PECTORIS

Angina pectoris is the result of myocardial ischemia caused by an imbalance between myocardial blood supply and oxygen demand

occurs when the Oxygen Supply to the Myocardium is insufficient for its needs.

ANGINA-CORONARY OCCLUSION

CORONARY OCCLUSION

Classification

Stable angina= effort angina, = angina related to myocardial

ischemia. Typical presentations :

chest discomfort and associated symptoms precipitated by some activity (running, walking, etc.) with minimal or non-existent symptoms at rest.

STABLE ANGINAOccurs on exercise, emotion or eating.Caused by increase demand of the heart and

by a fixed narrowing of coronary vessels, almost always by atheroma.

Coronary obstruction is ‘fixed’Blood flow fails to increase during increased

demand

a form of acutely developing and rapidly reversible left ventricular failure results which is relieved by taking rest and reducing the myocardial workload.

ClassificationUnstable anginaUnstable angina (UA) (also "crescendo angina;"

this is a form of acute coronary syndrome) is defined as angina pectoris that changes or worsens.

It has at least 1 of these 3 features:it occurs at rest (or with minimal exertion),

usually lasting >10 min;it is severe and of new onset (i.e., within the prior

4–6 weeks); and/orit occurs with a crescendo pattern (i.e., distinctly

more severe, prolonged, or frequent than before).

UNSTABLE ANGINAThis is characterized by pain that occurs with

less excertion , cumulating pain at rest.The pathology is similar to that involved in

Myocardial Infraction, namely platelet-fibrin thrombus associated with a ruptured atheromatous plaque, but without complete occulation of the vessels.

ClassificationMicrovascular angina= Syndrome X characterized by angina-like chest painThe cause of Microvascular Angina is

unknown, but it appears to be the result of poor function in the tiny blood vessels of the heart, arms and legs.

prognosis is excellent.

ANGINA: SYNDROME XTypical , exertional angina with positive

exercise stress testAnatomically normal coronary arteriesReduced capacity of vasodilation in

microvasculatureCalcium channel blockers and Beta blockers

are effective.

VARIANT ANGINA (PRINZMETAL’S ANGINA)

UncommonOccurs at rest generally during sleepCaused by Large Coronary Artery SpasmUsually associated with atheromatous diseaseAbnormally reactive and hypertrophied

segments in the Coronary ArteryDrugs aimed at preventing & relieving

Coronary spasm.

ANGINAL EQUIVALENT SYNDROME

Patient’s with exertional dyspnea rather than exertional chest pain

Caused by exercise induced left ventricular dysfunction

ANGINA: SILENT ISCHEMIAVery Common

More episodes of Silent than Painful angina in the same patient.

Difficult to diagnose

Generally Exercise testing.

DIAGNOSIS1. STRESS (EXERCISE) TEST.2. ECG3. CHEST X-RAY4. CARDIAC ANGIOGRAPHY/ CARDIAC

CATHETERIZATION5. ERGONOVINE TEST6. BLOOD TEST (BIO-MARKERS)

1. EXERCISE TEST/STRESS TESTUsed to measure heart’s response to exerciseAlternatively the patient recieves an injection

of a radioisotope (generally Thallium) which makes the heart visible to a special-linked camera

90% accuratedoesn’t identify the exactly where and how

the coronary arteries are blocked.

2. ECGProvides info about the changes or damages

to the heart muscleDoesn’t detect the narrowing of the coronary

arteriesDuring an Anginal attack the ECG may show 1. S-T phase depression.2. T- phase inversion and/or3. Ventricular arrythmia ECG- more abnormal with Unstable Angina

where the elevation in S-T segment is found.

STABLE ANGINA

At Rest

After Excercise

3. CHEST X-RAY

Performed to rule out any lung disease or heart damage that may be causing the pain.

Also may reveal enlargement of heart

4. CARDIAC ANGIOGRAPHY/ CARDIAC CATHETERIZATIONShows the precise size and location of

blockages within the Coronary arteriesA cathereter is inserted through the blood

vessels from the forearm or groinIt is snaked through arteries till it reaches

the heartA fluid is pumpedSo the arteries and the heart are clearly

visible

5. ERGONOVINE TEST

Generally done if the person is assumed to suffer from Coronary Spasm

Done along with angiographyThe artery-narrowing drug—Ergonovine or

Ach is given to cause Coronary SpasmThe persons response to ergonovanine is

measured

6. BLOOD TEST/BIOMARKERS

Lipid profileC-reactive protein and B-type natriuretic

proteinThese tests are predictive of the moratality of

heart disease

TREATMENT3 Classes of drugs used according their mode

of action

1. NITRATES2. - ADRENOCEPTOR ANTAGONISTS3. CALCIUM CHANNEL ANTAGONISTS4. ANTIPLATELET DRUGS

NITRATESProdrugsSources of Nitric OxideEg:- Nitroglycerin, Isosorbide Dinitrate Isosorbide-5-Mononitrate

TOXICITY OF NITRATESHeadacheIncreased mortalityRecurrence of Myocardial InfractionDizzinessFlushingRapid heart beatRestlessnessDry mouthSkin rashNausea

CALCIUM CHANNEL ANTAGONISTSDisrupt Ca++ through Ca++ channels-ve ionotrpic effect2 types:-1. Dihydropyridine (amlodipine, nifedipine,

nicardipine)2. Non-Dihydropyridine

1. Phenylalkylamine (verapamil, gallopamil)2. Benzodiazapenes (diltiazem)3. Non-selective (bepridil, mibefradil)

MECHANISM OF ACTION

-ADRENOCEPTOR ANTAGONOSTS

Important in prophylaxis of angina and treating unstable angina

Decrease O2 consumption by the heartEffects on coronary vessels-not importantAvoided in variant angina as they increase

the chances of spasm

PHARMACOLOGICAL ACTIONS

MECHANISM OF ACTION

COMPARITIVE TOXIC EFFECTS

COMBINATION THERAPY1. Nitrates + -blockers :- in stable angina2. Ca++ channel blockers + -blockers :-in

stable angina when the treatment with nitrates and -blockers has failed.

3. Ca++ channel blockers + Nitrates :- in unstable angina

4. All 3 together:- when the combinations of 2 drugs has failed, where:-

1. Nitrates:- decrease Preload2. Ca++ channel Blockers:- decrease Afterload3. -blockers:- decrease heart rate and

myocardial contractions