Chapter 13 Heart

Functions of the Circulatory System The heart is the pump that circulates blood to all parts of the body Arteries, veins, and capillaries transport the blood Blood carries oxygen and nutrients to the cells and carries waste products away Lymph system returns excess fluid from the tissues the circulation

Major Blood Circuits Blood leaves the heart through arteries and returns by veins Blood circulation routes General or system circulation Cardiopulmonary circulation Changes in the composition of circulating blood

The Heart About 5 inches long and 3.5 inches wide Weighs about 1 pound Located in the thoracic cavity; the apex of the heart lies on the diaphragm and points to the left of the body

Figure 13-1 The heart is located in the thoracic cavity between the lungs

The Heart After 4 to 5 minutes without blood flow, brain cells are irreversibly damaged Can hear the heartbeat through a stethoscope Cardiac arrest Cardiopulmonary resuscitation (CPR)

Structure of the Heart (1 of 2) Hollow, muscular, double pump Pericardium and pericardial fluid Epicardium Myocardium Cardiac muscle tissue Endocardium

Structure of the Heart (2 of 2) Superior and inferior vena cava Coronary sinus Pulmonary artery Pulmonary veins Aorta

Figure 13-2 Anterior external view of the heart

Figure 13-3 Anterior cross-sectional view of the heart

Chambers and Valves (1 of 2) Separated into right and left halves by the septum; then each half separated into an upper and lower chamber Upper chambers Left and right atria

Chambers and Valves (2 of 2) Lower chambers Left and right ventricles Valves keep blood flowing in one direction

Valves Atrioventricular valves Semilunar valves Tricuspid valve (separates the right atria and right ventricle) Bicuspid or mitral valve (separates the left atria and left ventricle) Semilunar valves Pulmonary semilunar valve (opening of the pulmonary arteries) Aortic semilunar valve (opening of the aorta)

Physiology of the Heart Double pump Right heart Deoxygenated blood Left heart Oxygenated blood

Heart Rate and Cardiac Output Normal adult rate is between 72 and 80 beats per minute Cardiac output=stroke volume x heart rate Calculating the cardiac output Exercise increases cardiac output

Heart Sounds Valves make sounds when they close Called lubb dupp sounds Lubb Tricuspid and bicuspid valves (S1) Dupp Aortic and pulmonary valves (S2)

Conduction System Electrical impulses cause rhythmic beating of the heart Sinoatrial (SA) node or pacemaker Atrioventricular (AV) node Bundle of His Purkinje fibers

Figure 13-7 An electrical impulse from the SA node travels to the AV node and causes the ventricle to contract

ECG or EKG (1 of 2) The electrocardiogram is a device to record the electrical activity of the heart Systole Contraction Diastole Relaxation

ECG or EKG (2 of 2) Positive and negative deflection P, QRS, and T waves

Cardiovascular Technologists and Technicians Also known as ECG Technicians Assist Physicians in diagnosing and treating cardiac and peripheral vascular disease. Take electrocardiograms and the more skilled may do the Holter monitor and stress testing.

ECG Technicians Continued Education to prepare a technician for ECG, Holter, and stress testing is usually a one year certificate program. Job prospects are not very high for this profession since nurses and others may be trained to do procedures such as ECGs and stress testing.

Cardiology Technologists Specialize in cardiac catheterization procedures Training for cardiology technologists involves a two year program. Job prospect is very high for this profession. (Approx. 25% Increase between 2014 and 2024) Salary Range: $28,420- 87,170 California Annual Mean Wage $71, 230 https://www.bls.gov/oes/current/oes292031.htm

Effects of Aging Heart muscle fibers replaced by fibrous tissue Heart valves increase in thickness Cardiac output decreases Changes become more significant when elderly person becomes physically or mentally stressed

Prevention of Heart Disease Heart disease is the leading cause of death for both men and women in the US Coronary heart disease Risk factors Steps to lower risk or prevent heart disease Blood cholesterol levels and triglycerides

Diagnostic Tests – Noninvasive (1 of 2) Angiography Cardiac MRI Coronary calcium scoring/heart scan Echocardiography Electrocardiogram

Diagnostic Tests – Noninvasive (2 of 2) Exercise stress tests Holter monitor MUGA (multiple gated acquisition scan) Nuclear perfusion

Diagnostic Tests – Invasive Cardiac catheterization IVUS (intravascular coronary ultrasound) TEE

Diagnostic Tests – Blood Tests Arterial blood gases BNP Lipid panel C-reactive protein Cardiac Troponin T

Diseases of the Heart – Common Symptoms Arrhythmia Bradycardia Tachycardia Murmurs Mitral valve prolapse

Diseases of the Coronary Artery Coronary artery disease (CAD) Angina pectoris Myocardial infarction

Infectious Diseases of the Heart Pericarditis Myocarditis Endocarditis Rheumatic heart disease

Heart Failure (1 of 2) When the ventricles of the heart are unable to contract effectively and blood pools in the heart Symptoms depend on which ventricle fails

Heart Failure (2 of 2) Left ventricle failure Right ventricle failure Dyspnea (shortness of breath) Right ventricle failure Engorgement of organs, edema of the legs and feet, and ascites

Congestive Heart Failure Similar to heart failure Left-sided failure – pulmonary edema Right-sided failure – fluid buildup throughout body Treatment

EMT’s and Paramedics Respond to medical emergencies; they determine the nature and extent of the patient’s condition, determine if the patient has preexisting medical problems, provide emergency care and transport to a medical facility. May be registered at one of four levels by the National Registry of Emergency Medical Technicians: First Responder, EMT Basic, EMT- Intermediate, EMT- Paramedic.

EMT’s and Paramedics Continued Formal Training and Certification are needed in ALL states. Job outlook is good (Approx. 24% increase from 2014 to 2024) Salary Range: $20,860- 55,110 California Annual Mean Wage $ 37,410 https://www.bls.gov/oes/current/oes292041.htm

Rhythm/Conduction Defects Heart block First-degree block Second-degree block Third-degree block or complete heart block Premature contractions Atrial fibrillation PVCs Ventricular fibrillation

Types of Heart Surgery Angioplasty Cardiac stents Coronary bypass Transmyocardial laser revascularization

Heart Transplants Used as a last resort Histocompatibility Organ rejection

Medical Highlights Pacemaker Cardiac resynchronization therapy Defibrillator Heart pumps

How to Check a Patient’s Pulse There are four areas you can use to check for a patient’s pulse: carotid, brachial, radial and pedal The most common site is either the radial or carotid artery When taking a patient’s pulse you will take two fingers, most often your index and middle finger, and lightly place them over one of these areas

Pulse Continued For a more accurate number the ideal time to take a pulse is 30 seconds You will then take that number and multiply it by two to get the patient’s heart rate per minute Normal heart rate= 60-100 beats per minute

Time to Practice!

How to Take Blood Pressure https://www.youtube.com/watch?v=Gmic13mvsgo

LET’S PRACTICE!