Chapter 20

The Heart

Position of the Heart

Mediastinum

Pericardium

Epicardium

Myocardium

Endocardium

Heart Surface

Human heart

Heart Posterior

Heart Interior

Human Heart Interior

Surface of Valves

Valves

Circulation

Circulation

Coronary Arteries

The Echo Image

Echo Images

Echo - Doppler

Mitral Valve Prolapse

Coronary Veins

Human Heart

Heart Tissue

Conduction System

Pacemakers

• Located in the right chest wall, a catheter is threaded through the subclavian vein, into the brachiocephalic vein, into the superior vena cava , then into the right atrium.

• The pacemaker overrides the impulse from the SA node.

Action Potentials

Action Potential – Ventricle

P= wave from SA node through atria

QRS = ventricular depolarization

T wave = ventricular repolarization

P-Q interval = time from atria contraction to beginning of ventricular contraction.

Q-T interval = ventricular depolarization to repolarization.

Note:Systole

& Diastole

Heart Valve Locations

Cardiac Output

CO = SV x HR

SV = ml/beatHR = Heart Rate

Cardiac Output Affected By

• Frank-Starling Law / Marey’s Law

• Cardiac Reserve (Max CO – CO at rest)

• Contractility (hormones, drugs, sympathetic reactions, etc.

• Afterload (remaining blood in ventricles)

• Congestive heart failure

Regulation of Heart RateAffected/Monitored by:

• Cardiovascular center (sympathetic and parasympathetic systems)

• Proprioceptors• Chemoreceptors• Baroreceptors• Blood pH• Hormones• Ions• Age, gender, temp, etc.

Nervous System Control

Risk Factors for CAD

• High blood cholesterol

• High blood pressure

• Smoking

• Obesity

• Diabetes mellitus

• Type “A” personality

• Sedentary lifestyle

Cardiac Catherization

Terms to Know

• Fossa Ovalis

• Coronary artery disease

• Arteriosclerosis

• Atherosclerosis

• PTCA

• Ischemia

• Myocardial infarction

More Terms

• Hypoxia

• Angina pectoris

• Coarctation of the aorta

• Arrhythmia

• Heart Block

• Flutter and fibrillation

• Bradycardia and tachycardia

More Terms

• Cardiac arrest• Cardiomegaly• Cor pulmonale• Palpitation• Asystole• Endocarditis / myocarditis• Mitral valve prolapse• Auscultation