Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Chapter 11 Cardiology

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Composed almost entirely of muscle Two different pumps: –Pumps deoxygenated blood into the lungs to gather oxygen –Pumps oxygenated blood throughout the body Anatomy of The Heart

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Pericardium –Surrounds the heart like a sac Layers: –Epicardium – outer layer –Myocardium – middle layer –Endocardium – inner layer

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Chambers: sections through which blood is pumped –Right atrium (upper chamber) –Left atrium (upper chamber) –Right ventricle (lower chamber) –Left ventricle (lower chamber)

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Valves: open and close to maintain blood flow through the heart –Tricuspid valve – between right atrium and right ventricle –Mitral valve – between left atrium and left ventricle –Pulmonary valve – between the right ventricle and pulmonary artery –Aortic valve – between the left ventricle and the aorta Leaflets: prevent backflow of blood during heartbeat

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Arteries and Vessels –Arteries: carry blood away from the heart –Capillaries: feed tissues and collect waste –Venules: gather blood from the capillaries –Veins: carry blood back to the heart

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Coronary arteries: carry blood to the heart’s muscle tissue –Aorta: the main arterial line –Left coronary artery (LCA) –Right coronary artery (RCA) –Posterior descending artery (PDA)

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins –Left anterior descending artery (LAD) –Left circumflex artery (LCA) –Lesser vessels: Diagonal branches D1, D2 Obtuse marginal branches (OM1, OM2)

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Blood empties into vena cavae –Superior vena cava: carries blood from upper body to right atrium –Inferior vena cava: carries blood from lower body to right atrium Blood in right atrium empties into right ventricle Pumped by pulmonary artery to lungs Through left atrium and left ventricle Pumped into the aorta for circulation throughout the body Blood’s Path Through the Heart

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Cardiac Conduction –Provides the electric stimulus necessary for heart to beat Cardiac Cycle –The sequence of events in one heartbeat

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins –From the sinoatrial (SA) node, “the heart’s natural pacemaker” –To the AV node –To the bundle of His –To the left and right bundle branches –To the Purkinje fibers –To the ventricles and valves

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Heart rates –Normal heart rate: sinus rhythm –Arrhythmia: absence of heart rhythm –Dysrhythmia: abnormal heart rhythm

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Abnormal heart rates and rhythms –Bradycardia: slow heartbeat, less than 60 bpm –Tachycardia: fast heart rate, greater than 100 bpm –Atrial flutter: atrial rhythm is regular, but the rate is abnormally fast –Fibrillation: uncoordinated, irregular contraction of the heart muscle Atrial fibrillation Ventricular fibrillation

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins –Heart block: impaired conduction of the heart’s electrical impulses –Paroxysmal atrial tachycardia: a rapid heart rate that starts and stops suddenly and unpredictably –Premature atrial contraction: an extra heartbeat that originates from the atria before it should

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Blood Pressure –Measures the force of blood against artery walls –Sphygmomanometer: measures blood pressure –Indicated in terms of millimeters of mercury (mmHg)

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Signs of heart problems –Cyanosis: bluish tinge –Pallor: paleness –Edema: swelling of tissues –Diaphoresis: excessive sweating –Angina (angina pectoris): severe chest pain Common Cardiac Diseases and Treatments

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Hypertension –Primary hypertension: no identifiable cause –Secondary hypertension: another known cause Treatment: –Diuretics –Beta-blockers –ACE inhibitors –Calcium-channel blockers

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Coronary Artery Disease (CAD): narrowing arteries hinder blood supply to heart –Cause: plaques (atherosclerosis) –Symptoms: Angina pectoris (severe chest pain) Dyspnea (shortness of breath)

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins –Complications: PND, orthopnea –Treatment: Nitrates and other drug therapies Angioplasty (PTCA) Atherectomy Coronary artery bypass graft (CABG)

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Cardiomyopathy: impairment in structure and function of the myocardium –Dilated cardiomyopathy: enlargement of the heart chambers –Hypertrophic cardiomyopathy: overgrowth of heart muscle –Restrictive cardiomyopathy: ventricles stiffen and do not fill normally Treatment: –Drug therapy –Heart transplant

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Valvular Heart Disease: the heart’s ability to pump blood is impeded –Treatment: not usually required Pericarditis: inflammation of the pericardium –Treatment: Medications to reduce inflammation and pain Drainage of fluid

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Congenital Heart Disorders Atrial septal defect (ASD): “hole in the heart”, or in atrial septum –Treatment: hole usually closes on its own Ventricular septal defect (VSD): a hole in the ventricular septum –Treatment: hole usually closes on its own

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Patent Ductus Arteriosus –Ductus arteriosus remains open (patent) after birth –Treatment: condition will resolve alone or with corrective surgery Transposition of the Great Vessels –Location of aorta and pulmonary artery (great vessels) is switched –Treatment: arterial switch operation

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Tetralogy of Fallot –Too little oxygen in the blood, leading to cyanosis –Combination of four defects: VSD Pulmonary stenosis Displaced aorta Right ventricular hypertrophy –Treatment: surgery to increase blood flow and correct defects

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Blood Tests –Cardiac risk factor testing: evaluate risk of heart disease or stroke C-reactive protein (CRP) Homocysteine Lipoprotein (a) or Lp(a) Cholesterol particle test Diagnostic Studies and Procedures

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins –Lipid profile (total cholesterol, HDL and LDL) –Blood sugar (glucose) –B-type natriuretic peptide (BNP) –Cardiac enzyme studies

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Electrocardiogram (EKG/ECG) –Analyzes electrical activity of the heart –Produces graphic tracing of waveforms on paper strip –Deviation in shape or interval of waveforms indicates possible problem.

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Echocardiogram –Uses ultrasound to examine heart anatomy –Sound waves “echo” off cardiac structures –Provides image of beating heart on a computer screen.

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Cardiac Stress Test: evaluates the heart when heart is working –Measured using Bruce protocol –Expressed in metabolic equivalents (METS) –Nuclear scan thallium Camera records thallium received by the heart Shows problems with blood flow and pumping action

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Cardiac Catheterization and Angiography –Diagnose and treat heart disorders other than those involving coronary arteries –Radiopaque dye is inserted into coronary arteries to view images of the blood vessels as the heart pumps

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Multiple gated acquisition (MUGA) scan –Determines if the left and right ventricles are functioning properly –Diagnoses abnormalities in the heart wall

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins The Heart-Brain Insight