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

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/beat HR = 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 Rate Affected/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