CORONARY ARTERY BYPASS GRAFT 2° MYOCARDIAL INFARCTION (APK & MEDICAL BACKGROUND) 2024/2025

CORONARY ARTERY BYPASS GRAFT 2° MYOCARDIAL
INFARCTION (APK & MEDICAL BACKGROUND) 2024/2025




CORONARY ARTERY BYPASS GRAFT 2° MYOCARDIAL INFARCTION (APK & MEDICAL BACKGROUND)
2024/2025

o CLASS IV CALCIUM CHANNEL BLOCKERS

 VEPARAMIL AND DILTIAZEM

 Addresses abnormalities in the SA and AV nodes and are also
used for supraventricular arrhythmias

 Decrease conduction and increase the refractory period

 Are also used for angina and as antihypertensives

 Dilates the coronary arteries and peripheral arteries and assist
is decreasing force of contraction and cardiac workload.



• ANTIHYPERTENSIVES used to control hypertension not necessarily to cure or
reverse the disease o THIAZIDE DIURETICS (Chlorthiazide, hydrochlorthiazide,
chlorthalidone, indapamide, and metolazone)

o Thiazides lower blood pressure by reducing blood volume and
preventing reabsorption of sodium. Sodium is excreted and pulls along water
eliminated in the urine.

o BETA BLOCKERS lowers blood pressure by decreasing heart rate, force
of contraction and cardiac output

o CALCIUM CHANNEL BLOCKERS (diltiazem, verapamil, nifedepine)
lowers BP by virtue of vasodilating effect and are suitable for chronic use in
hypertension of any severity.

o ACE INHIBITORS (enalapril, captopril, lisopril) decreases
vasoconstriction, is accomplished by reducing formation of angiotensin from
angiotensinogen through ACE inhibiton. o ARBs (temisartan, losartan,
valsartan) as effective as ACE inhibitors and lower blood pressure by
countering the pressor effects of angiotensin II s affecting HR

o DIRECT VASODILATORS (hydralazine, diazoxide, nitroprusside sodium,
minodoxil) are used for resistanr or refractory hypertension

,CORONARY ARTERY BYPASS GRAFT 2° MYOCARDIAL
INFARCTION (APK & MEDICAL BACKGROUND) 2024/2025

 HYDRALAZINE while causing BP lowering also tends to increase
heart rate and cardiac output; can be used in pregnancy o ALPHA
ADRENERGIC AGENTS (methyldopa)

 METHYLDOPA is used for mod to severe hypertension often
with a diuretic, DOC for hypertension in pregnancy



• CORONARY VASODILATORS (nitrates: nitroglycerin, isoborbide) o Anti angina
drugs that reduce ischemia of the myocardium resulting from obstruction or
constriction of coronary arteries

o Relieves chest pain by causing the coronary arteries to dilate and
improve oxygenated blood delivery to the myocardium and relieve the chest
pain

o NITRATES are most often used in an acute angina attack and also for
long term prophylaxis

• ANTI LIPEMIC AGENTS are used to lower serum levels of cholesterol (LDL,
VLDL,tryglycerides and Phospholipids which lead to coronary artery disease when
elevated o STATINS OR HMG-COA REDUCTASE INHIBITORS (artorvastatin, simvastatin,
fluvastatin, pravastatin)

 Lower lipid levels by interfering cholesterol synthesis by
inhibiting conversion of HMG-CoA to mevolonate, an early stage in
cholesterol formation

 Effective reducing levels of LDL and modestly effective for
lowering triglycerides

 HDL levels are increased by statins

 They are the most potent anti lipemic o BILE ACID
SEQUESTRANTS (cholestyramine, colestipol, colesevelam)

 These are resins that remove bile acids in the intestines and
prevent reabsorption back to the liver

 Removes excess bile acids from fat deposits under the skin

 Can be used together with statins o NICOTINIC ACID (NIACIN)

 These water soluble vitamin that decreases triglyceride levels
and VLDL, total cholesterol and LDL and increases HDL levels

,CORONARY ARTERY BYPASS GRAFT 2° MYOCARDIAL
INFARCTION (APK & MEDICAL BACKGROUND) 2024/2025

 Niacin lowers liver formation of Triglycerides and limits VLDL
secretion by interfering with peripheral tissue breakdown into free
fatty acids

o FIBRIC ACID DERIVATIVES (gemfibrozil, fenofibrate)

 Reduces triglyceride levels and to a certain extent, LDL levels

 Gemfibrozil increases HDL and dissolution of cholesterol in the
blood

 Possible MOA: reduction of cholesterol production and
increase cholesterol excretion, decrease synthesis of triglycerides and
lipoproteins, increase in lipoprotein excretion, mobilization of
cholesterol from peripheral tissues

o CHOLESTEROL ABSORPTION INIHIBITORS (Ezetimibe)

 Ezetimibe is the prototype and this drug acts by inhibiting
cholesterol and bile acid absorption from the intestine.

 Can be used with statins to produce an additive LDL lowering
effect and raise HDL levels especially when statins alone are
inadequate

• VASOCONSTRICTORS (epinephrine, norepinephrine) o Can elevate blood
pressure; they are basically used in tx of shock as IV medications on short term basis

o Pt’s VS are closely monitored when these agents are administered

• ANTICOAGULANTS

o HEPARIN is used to prevent clot formation but cannot dissolve clots that are already formed; it acts
on thrombin to inhibit the action of fibrin in the formation of clots

 Unfractionated Heparin is given by IV or subcutaneously

 Low molecular weight Heparin (ENOXAPARIN) is given only by
subcutaneous route; used for prevention of DVT, for tx of unstable
angina and MI & acute pulmonary embolism

o Antidote for heparin induced bleeding is Protamine Sulfate

o COUMARIN

 Prototype agent is WARFARIN which act by altering ability of
the liver to synthesize vit K dependent clotting factors such as
prothrombin, factors VII, IX, X

, CORONARY ARTERY BYPASS GRAFT 2° MYOCARDIAL
INFARCTION (APK & MEDICAL BACKGROUND) 2024/2025

 Clotting factors already in the blood continue their coagulation
activity until their levels are depleted

 Used mainly for long-term anticoagulation

 Vit K is the antidote for warfarin-induced bleeding

 Prothrombin time is monitored

• ANTIPLATELETS these are prophylactic therapy to decrease clot formation and
prevent arterial thromboembolism esp those with the risk of MI, strokes, and
atherosclerosis o DYPYRIDAMOLE inhibits platelet aggregation by increasing
adenosine which is a coronary vasodilator as well as a platelet aggregation inhibitor

o ASPIRIN inhibit clot formation by blocking prostaglandin synthesis thus preventing formation of
thromboxane A2 which is a platelet aggregating agent; given after an

MI, a TIA for prophylaxis o CLOPIDOGREL reduces atherosclerotic events in those with recent MI,
stroke patients, or PVD

• DIRECT THROMBIN INHIBITORS (argatroban, bivalirudin, lepirudin) o These
medicines are used to prevent blood clot formation by directly inhibiting the action of
thrombin

o They are used for tose undergoing cardiac procedures, including stable angina

• THROMBOLYTICS (streptokinase, urokinase, altepase)

o These drug dissolves clots that have already formed o They convert plasminogen to plasmin which
lysis the clot o 6 hrs after symptom, effectiveness is optimal

• FACTOR Xa INHIBITORS (fondapirinux) o Fondapirinux is the prototypre drug
and is used for prevention of DVT inpatients undergoing hip or knee surgery

o The drug binds to antithrombin III leading to neutralization of factor Xa o This interrupts the
coagulation cascade



ANATOMICAL, PHYSIOLOGICAL, AND KINESIOLOGICAL BACKGROUND

Anatomy of the Cardiac System

a. Structures Mediastinum

- Lies between the right and left pleura of the lungs and near the median sagittal plane of the chest.
From an anteroposterior perspective, it extends from the sternum in front to the vertebral column
behind and contains all the thoracic viscera except the lungs. It is surrounded by the chest wall
anteriorly, the lungs laterally, and the spine posteriorly. It is continuous with the loose connective tissue
of the neck and extends inferiorly onto the diaphragm. It is the central compartment of the thoracic