THE CARDIOVASCULAR

SYSTEM

and Myocardial Infarctions

Anatomy: The Heart

• Size

• about the size of a person’s

fist; hollow and cone-

shaped; weighs less than a

pound (9-12 oz)

• Location

• within the mediastinum

• Orientation

• tilts toward the left side of

the body

Anatomy: Structure

• Wall

• Epicardium: outer

layer (“on the

heart”)

• Myocardium:

middle layer

• Endocardium:

interior layer of

the myocardial

wall

Anatomy: Structure

• Chambers

• Atria: two superior chambers

• Ventricles: two lower

chambers

• Valves

• Aortic semilunar valve

• Pulmonary semilunar valve

• Tricuspid valve

• Mitral (bicuspid) valve

Anatomy: Blood Vessels

• Vessels

• Arteries/arterioles

• Veins/venules

• Capillaries

• Structure

• Tunica Externa: outer

layer

• Tunica Media: middle

layer

• Tunica Intima: inner layer

Anatomy: Blood

• Plasma

• Red Blood

Cells

(erythrocytes)

• White Blood

Cells

(leukocytes)

• Platelets

Physiology

• Function: transports nutrients, waste, gases,

and hormones through the body, with the

heart acting as a “pump”, the blood vessels

acting as the “highway system”, and the

blood as the essential fluid tissue

Physiology: The Heart as a Pump

• Deoxygenated blood enters the heart into the

right atrium and is pumped into the right

ventricle.

• It is then pumped through the pulmonary artery

into the lungs where it will absorb oxygen.

• Blood is transported back into the heart

through the pulmonary vein, into the left atrium

and left ventricle.

• Then, blood is pumped out the aorta and into

the far reaches of bodily circulation once again.

Physiology: Pumping

• De-polarization of muscle cells (myolemma)

makes the heart contract, forcing blood out.

• Re-polarization of these same cells

increases volume of the heart and allows

blood to fill its atria.

Physiology: ECG Complex

• P WAVE

• SA node: Delivers impulse to contract right

and left atria

• PR INTERVAL

• AV node: Creates an essential delay in

signal transmission so heart beats correctly

Physiology: ECG Complex

• QRS INTERVAL

• Purkinje fibers: Each node tapers these fibers which

stimulate group myocardial cells into contraction

• S-U WAVE

• Displays the heart’s depolarization of ventricles

Physiology: Blood Vessels

• ARTERIES: Carry oxygenated blood from

heart to tissue

• CAPILLARIES: Transport oxygen from blood

to tissue; carbon dioxide from tissue to blood

• VEINS: Carry carbon dioxide-rich blood to

heart to rid itself of it and to be re-

oxygenated

Physiology: Blood

• PLASMA: Proteins, electrolytes and lipid

solids dissolved in water

• RED CELLS: Erythrocytes are filled

hemoglobin which makes them excellent

oxygen transports

• WHITE CELLS: Leukocytes are defense cells

that target and eliminate foreign objects and

infections

• PLATELETS: Thrombocytes stop unwanted

blood flow by executing blood clotting

Myocardial Infarction

• More commonly

known as “heart

attack” or “coronary”

• ALWAYS A

MEDICAL

EMERGENCY - DIAL

911

• Caused by blocked

blood flow into any

section of coronary

arteries (usually an

embolism)

Myocardial Infarction

• Symptoms

• Chest pain (described as “crushing”, or “like there is

a VW Beetle sitting on my chest”)

• Referred pain (usually in the left arm, abdomen, or

neck)

• Nausea

• Fear of dying

• Shock (characterized by skin appearing pale, cool,

and diaphoretic)

Myocardial Infarction

• Risk factors

• Age

• Weight

• Diet

• Gender

• Lifestyle habits (i.e. smoking)

• Pre-existing conditions (i.e. hypertension, diabetes,

hypercholesterolemia)

Myocardial Infarction - ECG

Sample

• Myocardial

ischemia classified

by elevated or

depressed ST

segment

• Hyperacute T

waves

Research & Treatment: AMI

• Holistic Treatment

• Complimentary Acute Medicine (CAM)

• Beta-blockers (Metropropol)

• Nitrates (Nitroglycerin)

• Calcium channel blockers

• Antiplatelet agents (aspirin)

• ACE Inhibitors (Lisinopril)

Research & Treatment: AMI

• Controversial treatments

• Reperfusion Therapy

• PCI (Percutaneous Coronary

Intervention)/Angioplasty - arteries are

pushed open

• Fibrinosis (Thrombolysis)Controversial

treatments - blockage removed by

medication

Research & Treatment: AMI

• Controversial Treatments (cont’d)

• CAB (Coronary Artery Bypass Graft

Surgery)

• Arteries or veins elsewhere in body are

grafted as new coronary arteries (done

when heart is STOPPED!!)

Research & Treatment: AMI

Research & Treatment: AMI

• Treatment Success Rate

• Stents

• CAMs

• Secondary prevention and rehabilitation

• changes in diet, exercise, and other

lifestyle habits