Chapter 18 Alterations in Cardiac Function PDF

Chapter 18 Alterations in Cardiac Function Dr. Tashea S. Hillard, Associate Professor  ► Coronary heart disease (CHD): also called ischemic heart disease and coronary artery disease...

Chapter 18 Alterations in Cardiac Function Dr. Tashea S. Hillard, Associate Professor  ► Coronary heart disease (CHD): also called ischemic heart disease and coronary artery disease (CAD) ► Characterized by insufficient delivery of oxygenated blood to the myocardium caused by Coronary atherosclerotic coronary arteries (CAD) Heart ► Sequelae of CHD includes: Disease ► Angina pectoris ► Myocardial infarction ► Dysrhythmias ► Heart failure ► Sudden cardiac death Copyright © 2019, Elsevier Inc. All rights reserved. 2  Etiology of Coronary Heart Disease Coronary Heart Known risk factors: atherosclerosis, possible microcirculation abnormalities Disease (Cont.) Atherosclerosis causes narrowing of the arterial lumen that can lead to cardiac ischemia through thrombus coronary endothelial cell formation. vasospasm. dysfunction. Copyright © 2019, Elsevier Inc. All rights reserved. 3  Mechanisms of Coronary Atherosclerosis Lipids are transported via apoproteins. Coronary Heart Disease Lipoproteins associated with a greater risk of atherosclerosis (Cont.) High-density lipoproteins transport cholesterol from peripheral tissue back to the liver, clearing atheromatous plaque. Copyright © 2019, Elsevier Inc. All rights reserved. 4 Coronary Heart Disease (Cont.) Atherosclerotic plaque Endothelium becomes Mechanisms of Coronary formation initiated by injury to permeable and recruits Atherosclerosis coronary artery endothelium leukocytes. Oxidized lipids are damaging LDL insudation occurs with to endothelial and smooth oxidation by endothelial cells muscle cells, and stimulate and macrophages. recruitment of macrophages into the vessel. Copyright © 2019, Elsevier Inc. All rights reserved. 5 Copyright © 2013, 2010, 2005 by Saunders, an imprint of Elsevier Inc. 5  Mechanisms of Coronary Atherosclerosis ► Macrophages engulf the lipids; foam cells (lipid-filled macrophages) Coronary release inflammatory mediators and growth factors, attracting more Heart Disease leukocytes and stimulating smooth (Cont.) muscle proliferation. ► Excess lipid and debris accumulate within vessel wall and coalesce into lipid core. Copyright © 2019, Elsevier Inc. All rights reserved. 6 Copyright © 2013, 2010, 2005 by Saunders, an imprint of Elsevier Inc. 6  Mechanisms of Coronary Atherosclerosis Vulnerable plaques may rupture or Coronary become eroded, which stimulates clot formation on the plaque. Heart Disease large lipid core. Vulnerable plaques (Cont.) have thin cap. high shear stress. more collagen Stable plaques have and fibrin. stable cap. Copyright © 2019, Elsevier Inc. All rights reserved. 8 Copyright © 2013, 2010, 2005 by Saunders, an imprint of Elsevier Inc. 8  Mechanisms of Coronary Atherosclerosis ► Increased plaque vulnerability ► Active inflammation within the plaque ► Large lipid core with a thin cap ► Endothelial denudation (erosion) Coronary with superficial platelet adherence ► Fissured or ruptured cap Heart Disease ► Severe stenosis predisposing to (Cont.) high shear stress ► Lipid-lowering therapy: mainstay of treatment and prevention for atherosclerosis; also, stabilize the plaques, making them less prone to rupture Copyright © 2019, Elsevier Inc. All rights reserved. 9 Copyright © 2013, 2010, 2005 by Saunders, an imprint of Elsevier Inc. 9 Coronary Heart Disease (Cont.) Pathophysiology of Ischemia: oxygen supply Critical factors in meeting Ischemia insufficient to meet cellular demands for metabolic demands oxygen include: Rate of coronary perfusion Myocardial workload Copyright © 2019, Elsevier Inc. All rights reserved. 10  Pathophysiology of Ischemia Coronary perfusion can be altered by Coronary large, stable atherosclerotic plaque. Heart acute platelet aggregation and thrombosis. Disease vasospasm. (Cont.) failure of autoregulation by the microcirculation. poor perfusion pressure. Chronic occlusion of a coronary vessel: stable angina Copyright © 2019, Elsevier Inc. All rights reserved. 11 Copyright © 2013, 2010, 2005 by Saunders, an imprint of Elsevier Inc. 11  Pathophysiology of Ischemia Coronary Acute occlusion: plaque disruption and thrombus Heart formation and results in unstable angina or MI Disease (Cont.) Myocardial ischemia may uncommonly be caused by low perfusion pressure coronary vasospasm. hypoxemia. from volume depletion or shock. Copyright © 2019, Elsevier Inc. All rights reserved. 12 Copyright © 2013, 2010, 2005 by Saunders, an imprint of Elsevier Inc. 12 Coronary Heart Disease (Cont.) Clinical Features and Management of Coronary Syndromes Chronic syndromes with slow progression because of chronic obstruction from stable atherosclerotic plaques Stable angina pectoris Ischemic cardiomyopathy Copyright © 2019, Elsevier Inc. All rights reserved. 13  Clinical Features and Management of Coronary Syndromes ► Acute coronary syndrome (ACS) associated with acute changes in plaque morphology and Coronary thrombosis; abrupt and can be Heart life-threatening ► Unstable angina Disease ► Myocardial infarction (Cont.) ► Any of the coronary heart syndromes may precipitate: sudden cardiac death and associated dysrhythmias. Copyright © 2019, Elsevier Inc. All rights reserved. 14 Copyright © 2013, 2010, 2005 by Saunders, an imprint of Elsevier Inc. 14  Angina Pectoris Burning, Coronary Chest pain associated with intermittent crushing, squeezing, myocardial ischemia choking, or Heart referred pain Disease (Cont.) May result in inefficient cardiac pumping with resultant pulmonary congestion and shortness of breath No permanent myocardial damage occurs. Copyright © 2019, Elsevier Inc. All rights reserved. 15  Angina Pectoris Three patterns Coronary Stable or typical angina Most common Heart Also called classic Characterized by stenotic Disease atherosclerotic coronary vessels Onset of anginal pain is generally (Cont.) predictable and elicited by similar stimuli each time. Relieved by rest and nitroglycerin Unstable or crescendo angina May progress to acute ischemia Copyright © 2019, Elsevier Inc. All rights reserved. 16  Angina Pectoris Three patterns Prinzmetal or variant angina Coronary Unpredictable attacks of anginal pain Onset of symptoms is unrelated to physical Heart or emotional exertion, heart rate, or other obvious causes of increased myocardial Disease oxygen demand. Characterized by vasospasms, atherosclerosis-induced hypercontractility, (Cont.) abnormal secretion of vasospastic chemicals by local mast cells, and abnormal calcium flux across vascular smooth muscle Responds well to treatment with calcium channel–blocking drugs Copyright © 2019, Elsevier Inc. All rights reserved. 17 Coronary Heart Disease (Cont.) Chest pain usually Plaque rupture with Acute Coronary more severe and acute thrombus Syndrome lasts longer than development typical angina Unstable ECG and MI—occlusion is angina—occlusion is biomarkers used for complete partial diagnosis Copyright © 2019, Elsevier Inc. All rights reserved. 18  Acute Coronary Syndrome Coronary Patients with chest pain and evidence of acute ischemia on the Heart electrocardiogram (ECG) (ST-segment elevation; STEMI) Disease Candidates for acute reperfusion therapy (Cont.) Patients presenting with symptoms of unstable angina and no ST elevation on the ECG (non-STEMI, NSTEMI) Candidates for antiplatelet drugs Copyright © 2019, Elsevier Inc. All rights reserved. 19 Coronary Heart Disease (Cont.) Acute Coronary Syndrome Acute occlusion causes a range of cellular events, depending on availability and adequacy of length of time that flow is relative workload. collateral blood flow. interrupted. Ultimate size of the infarcted tissue depends on the extent, duration, and severity of ischemia. Copyright © 2019, Elsevier Inc. All rights reserved. 20 Coronary Heart Disease (Cont.) After 18 to 24 hours: Acute Coronary area of infarction Syndrome becomes paler than surrounding tissues 5 to 7 days: turns At 1 to 2 weeks: yellowish and soft with necrotic tissue a rim of red vascular progressively connective tissue degraded and cleared away; infarcted myocardium weakened and By 6 weeks: necrotic susceptible to rupture tissue replaced by tough fibrous scar tissue Copyright © 2019, Elsevier Inc. All rights reserved. 21  Acute Coronary Syndrome Coronary Diagnosis Heart Signs and symptoms Electrocardiographic changes Disease Elevations of specific marker proteins in the blood Severe crushing, excruciating chest pain that (Cont.) may radiate to the arm, shoulder, jaw, or back Accompanied by nausea, vomiting, diaphoresis (sweating), shortness of breath Copyright © 2019, Elsevier Inc. All rights reserved. 22  ► Acute Coronary Syndrome ► Lasts more than 15 minutes and is not relieved by rest or nitroglycerin ► Asymptomatic MI: silent MI Coronary ► Women, the elderly, and Heart patients with diabetic Disease neuropathies ► (Cont.) Atypical symptoms, including fatigue, nausea, back pain, and abdominal discomfort ► ECG changes ► ST-segment elevation, large Q waves, and inverted T waves Copyright © 2019, Elsevier Inc. All rights reserved. 23  Acute Coronary Syndrome Coronary Serum marker changes Heart Myoglobin, troponin, lactate Disease dehydrogenase, and creatine kinase (Cont.) Increased CK-MB and troponin I and T Copyright © 2019, Elsevier Inc. All rights reserved. 25  Acute Coronary Syndrome Coronary Heart MI leads to drop in CO, triggering compensatory responses including Disease sympathetic activation. (Cont.) heart Sympathetic nervous rate. system activation leads contracti to increased lity. myocardial workload blood by increasing pressure. Copyright © 2019, Elsevier Inc. All rights reserved. 27 Copyright © 2013, 2010, 2005 by Saunders, an imprint of Elsevier Inc. 27  Acute Coronary Syndrome ► Overall prognosis for acute MI difficult to determine because of Coronary ► Of particular importance is how Heart quickly treatment is sought ► Disease Extent and location of the infarct ► Previous cardiovascular health (Cont.) ► Age ► Presence of other disease processes Copyright © 2019, Elsevier Inc. All rights reserved. 28 Copyright © 2013, 2010, 2005 by Saunders, an imprint of Elsevier Inc. 28  Acute Coronary Syndrome Treatment: Decreasing myocardial oxygen demand Coronary Sympathetic antagonists, rest, heart rate control, pain relief, afterload reduction Heart Increasing myocardial oxygen supply Thrombolysis, angioplasty, coronary Disease bypass grafting Monitoring and managing complications (Cont.) Early detection and management of dysrhythmias and conduction disorders; continuous ECG monitoring Copyright © 2019, Elsevier Inc. All rights reserved. 29 Copyright © 2013, 2010, 2005 by Saunders, an imprint of Elsevier Inc. 29  Sudden Cardiac Arrest Also called sudden cardiac death Coronary Heart Unexpected death from cardiac causes within 1 hour of symptom onset Disease Use of external defibrillators and CPR has increased survival. Lethal dysrhythmia (such as ventricular fibrillation) is usually the primary cause. Copyright © 2019, Elsevier Inc. All rights reserved. 30  Heart failure develops Chronic Ischemic insidiously because of Cardiomyopathy progressive ischemic myocardial damage. Coronary Appears to be a Heart Typically have history of consequence of slow, progressive apoptotic death of myocytes from chronic angina or MI Disease ischemia Scattered throughout the myocardium (Cont.) More common in older adults Prognosis: poor Copyright © 2019, Elsevier Inc. All rights reserved. 31  Endocardial and valvular structures may be damaged by Endocardial inflammation and scarring. and Valvular calcification. Disease congenital malformations. Cause altered hemodynamics of the heart and increase myocardial workload Copyright © 2019, Elsevier Inc. All rights reserved. 32  Stenosis: failure of the valve to open completely results in extra pressure work for the heart Endocardial Regurgitation (insufficiency): and Valvular inability of a valve to close Disease completely results in extra volume work for the heart (Cont.) Murmurs are common with valvular disorders. Copyright © 2019, Elsevier Inc. All rights reserved. 33  Mitral Stenosis Blood flow from left atrium to left ventricle impaired during ventricular diastole Endocardial and Valvular Increased pressure of the left atrium leads to atrial chamber enlargement and hypertrophy. Disease (Cont.) Can lead to chronic pulmonary hypertension, right ventricular hypertrophy, and right-sided heart failure Low-pitched, rumbling diastolic murmur; open snap; atrial dysrhythmias, atrial clots; exertional dyspnea Copyright © 2019, Elsevier Inc. All rights reserved. 34  Mitral Regurgitation Backflow of blood from the left ventricle Endocar to the left atrium during ventricular systole dial and Valvular Left atrium and ventricle dilate and hypertrophy cause by extra volume Disease (Cont.) May lead to left-sided heart failure High-pitched, pansystolic, blowing murmur; giant V waves; chronic weakness and fatigue Copyright © 2019, Elsevier Inc. All rights reserved. 35  ► Mitral Valve Prolapse ► Displacement (ballooning) of the mitral valve leaflets into the left atrium during ventricular systole Endocardial ► Women affected more than men and Valvular ► Typically asymptomatic Disease ► Midsystolic click or systolic murmur; palpitations; rhythm (Cont.) abnormalities; dizziness; fatigue; dyspnea; chest pain; or depression and anxiety Copyright © 2019, Elsevier Inc. All rights reserved. 36  ► Aortic Stenosis ► Predominant cause is age-related calcium deposits on the aortic cusps. Endocardial ► Results in obstruction of aortic and outflow from the left ventricle into the aorta during systole Valvular ► Left ventricle hypertrophy may Disease result in ischemia and left-sided (Cont.) heart failure. ► Crescendo-decrescendo murmur during ventricular systole with prominent S4; syncope; fatigue; angina Copyright © 2019, Elsevier Inc. All rights reserved. 37  Aortic Regurgitation Incompetent aortic valve allows blood to leak back Endocar from the aorta into the left ventricle during diastole. dial and Causes: abnormal aortic valve or aortic root dilation Valvular Disease Leads to left ventricle hypertrophy and dilation with eventual left-sided heart failure (Cont.) High-pitched blowing murmur during ventricular diastole; high systolic blood pressure; diastolic blood pressure usually low; palpitations Copyright © 2019, Elsevier Inc. All rights reserved. 38  Diseases of the Endocardium Rheumatic heart disease Endocar Acute inflammatory disease that follows infection with group A β-hemolytic dial and streptococci Damage is caused by immune attack on Valvular the individual’s own tissues. Antibodies against the streptococcal Disease antigens damage connective tissue in joints, heart, skin. (Cont.) Occurs mainly in children Fever; sore throat; joint inflammation; involuntary movements (Sydenham chorea); and a distinctive truncal rash Copyright © 2019, Elsevier Inc. All rights reserved. 39  Diseases of the Endocardium Infective endocarditis Endocar Invasion and colonization of endocardial structures by microorganisms with dial and resulting inflammation—vegetations Most common bacteria Valvular Streptococcus Staphylococcus Disease Acute infective endocarditis Prognosis poor (Cont.) Intravenous drug users susceptible Subacute infective endocarditis Predisposing risk factors typically present Copyright © 2019, Elsevier Inc. All rights reserved. 40  Myocarditis: inflammatory disorder of the heart muscle characterized by necrosis and degeneration of myocytes Clinical course: acute and stormy, with recovery or death from cardiac failure Myocardial occurring weeks to months after the onset of symptoms Diseases Cardiomyopathy may be genetic or acquired and is noninflammatory. Evolve more insidiously over years, with few symptoms until the heart slips into failure Copyright © 2019, Elsevier Inc. All rights reserved. 41  Myocarditis Characterized by inflammation, leukocyte infiltration, necrosis of cardiac muscle cells Myocardial Causes include microbial agents, Diseases immune-mediated diseases, physical agents (Cont.) Viral etiology most common Characterized by left ventricular dysfunction (“flabby” with patchy or diffuse necrotic lesions) and general dilation of all four chambers Copyright © 2019, Elsevier Inc. All rights reserved. 42  Cardiomyopathy Classified by cause or functional impairment Myocard ial Primary: dysfunction of unknown cause Diseases (Cont.) Secondary: known cause Dilated Functional Hypertrophic classifications Restrictive Copyright © 2019, Elsevier Inc. All rights reserved. 43  Dilated Cardiomyopathy Myocard Cardiac failure associated with dilation of one or both ventricular chambers ial Diseases Alcohol toxicity Pregnancy May be related Postviral (Cont.) to: myocarditis Genetic abnormality Slow progression of biventricular heart failure with low ejection fraction Copyright © 2019, Elsevier Inc. All rights reserved. 44 Myocardial Diseases (Cont.) Septum may be Thickened, affected, leading to Hypertrophic hyperkinetic idiopathic Cardiomyopathy ventricular muscle hypertrophic subaortic mass stenosis. Genetic abnormality: Clinical course is Asymptomatic or autosomal dominant variable, typically slow dyspnea and angina pattern progression. Copyright © 2019, Elsevier Inc. All rights reserved. 45  Restrictive Cardiomyopathy Rarest form of cardiomyopathy Myocard Stiff, fibrotic, rigid, noncompliant ventricle ial with impaired diastolic filling Diseases Most commonly associated with amyloidosis (Cont.) Decreased cardiac output and left-sided heart failure can result. Exercise intolerance, dyspnea, and weakness Copyright © 2019, Elsevier Inc. All rights reserved. 46  ► Typically sequelae of other disorders such as: Pericardial ► Systemic infection ► Trauma Diseases ► Metabolic derangement ► Neoplasia Copyright © 2019, Elsevier Inc. All rights reserved. 47  Pericardial Effusion Pericardial Accumulation of Diseases noninflammatory fluid in the pericardial sac (Cont.) Serous Composition of Serosanguineous usual fluids Purulent Blood Copyright © 2019, Elsevier Inc. All rights reserved. 48  Cardiac Tamponade When fluid accumulation in the pericardial sac is large/sudden it can lead to external compression of the heart chambers such that filling is impaired. Pericardial Diseases Manifestations include: (Cont.) Reduced stroke volume Compensatory increases in heart rate Pulsus paradoxus Hypotension, distended neck veins and muffled heart sounds―called Beck’s triad Treatment: pericardiocentesis Copyright © 2019, Elsevier Inc. All rights reserved. 49  Pericarditis Pericardial Acute or chronic inflammation Diseases of the pericardium (Cont.) Chronic pericarditis: healed stage of the acute form that results in chronic pericardial dysfunction Copyright © 2019, Elsevier Inc. All rights reserved. 50 Copyright © 2013, 2010, 2005 by Saunders, an imprint of Elsevier Inc. 50  Acute Pericarditis Most cases idiopathic and Pericardial presumed viral Diseases (Cont.) Uncomplicated form resolves spontaneously. Typically presents as chest pain; fever, leukocytosis, malaise, and tachycardia; friction rub Copyright © 2019, Elsevier Inc. All rights reserved. 51  Chronic Pericarditis Two principal forms: Adhesive Pericardial mediastinopericarditis—pericard ial sac is destroyed and the Diseases external aspect of the heart (Cont.) adheres to surrounding mediastinal structures Constrictive pericarditis—pericardial sac becomes dense, nonelastic, fibrous, and scarred Copyright © 2019, Elsevier Inc. All rights reserved. 52  Abnormality of the heart that is present from birth. Congenital Heart Diseases Different congenital heart anomalies result in two primary pathologic processes: Shunting of blood Obstruction to blood through abnormal flow because of pathways in the heart or abnormal narrowing great vessels Copyright © 2019, Elsevier Inc. All rights reserved. 53  Embryologic Development Congenital Heart defects commonly Heart associated with these abnormalities: Diseases Development of atrial septum (Cont.) Development of the ventricular septum Division of the main outflow tract (truncus arteriosus) into the pulmonic and aortic arteries Development of the valves Copyright © 2019, Elsevier Inc. All rights reserved. 54 Congenital Heart Diseases (Cont.) Etiology and Incidence of Congenital Heart Disease Congenital heart disease is the most common heart disorder in children. Maternal rubella during first trimester of pregnancy May be attributed to Exposure to cardiac teratogens Genetic influences Copyright © 2019, Elsevier Inc. All rights reserved. 55  Pathophysiology of Congenital Heart Disease Congeni tal Heart Result in two primary pathologies Diseases Shunt: abnormal path of blood flow through the heart or great vessels (Cont.) Right to left: cyanotic Left to right: acyanotic Obstruction: interference with blood flow because of abnormal narrowing leading to increased workload of affected chamber Acyanotic Copyright © 2019, Elsevier Inc. All rights reserved. 56  Acyanotic Congenital Defects Congeni tal Heart Disorders that result in left-to-right shunting of blood or obstruction to Diseases flow are generally acyanotic (Cont.) These disorders include: Pulmonary Atrial septal Ventricular Patent ductus Coarctation of and aortic defect septal defect arteriosus the aorta Stenosis or atresia Copyright © 2019, Elsevier Inc. All rights reserved. 57 Congenital Heart Diseases (Cont.) ATRIAL MAJORITY OF LONG-TERM ATRIAL SEPTAL INCREASE IN SEPTAL DEFECTS OCCUR PULMONARY DEFECT AT THE LOCATION BLOOD FLOW OF THE FORAMEN MAY EVENTUALLY OVALE. LEAD TO PULMONARY HYPERTENSION, RIGHT VENTRICULAR HYPERTROPHY, AND REVERSAL TO A RIGHT-TO-LEFT Copyright © 2019, Elsevier Inc. All rights reserved. SHUNT. 58  Ventricular Septal Defect Congeni Most common congenital cardiac anomaly tal Heart Diseases Typically located in the membranous (Cont.) septum, near the bundle of His Increase in pulmonary blood flow can result in pulmonary hypertension, right ventricular hypertrophy, and reversal of the shunt. Copyright © 2019, Elsevier Inc. All rights reserved. 59 Congenital Heart Diseases (Cont.) Conditions that cause Supposed to close low blood oxygen Patent Ductus after birth but does tension may Arteriosus not contribute to continued patency. Continued patency Results in pulmonary No clinical identified by harsh, hypertension and can significance in early grinding systolic lead to right-sided life murmur or thrill heart failure Copyright © 2019, Elsevier Inc. All rights reserved. 60  Coarctation of the Aorta Narrowing or stricture of the aorta that impedes blood flow Congenital Commonly located just before or after the ductus arteriosus Heart Diseases Preductal coarctation usually more severe and (Cont.) associated with other anomalies Upper extremities typically have an elevated blood pressure; lower extremities have weak pulses and low blood pressure. Usually accompanied by systolic murmurs and ventricular hypertrophy Copyright © 2019, Elsevier Inc. All rights reserved. 61  Pulmonary Stenosis or Atresia Congenital Heart Pulmonary atresia—blood must enter the lungs by traveling through a septal opening and a Diseases patent ductus arteriosus (Cont.) Pulmonary stenosis—usually because of abnormal fusion of the valvular cusps and can lead to right ventricular hypertrophy Copyright © 2019, Elsevier Inc. All rights reserved. 62  ► Aortic Stenosis or Atresia ► Aortic atresias: not compatible with survival Congenital ► Aortic stenosis: involve the Heart valvular cusps or the Diseases subvalvular fibrous ring and results in high left ventricular (Cont.) afterload with left ventricular hypertrophy ► Prominent systolic murmur Copyright © 2019, Elsevier Inc. All rights reserved. 63  Cyanotic Congenital Defects Congenital Disorders that result in right-to-left Heart shunting of blood result in cyanosis. Diseases (Cont.) These disorders include: Transposition Tetralogy of Truncus Tricuspid of the great Fallot arteriosus atresia arteries Copyright © 2019, Elsevier Inc. All rights reserved. 64  Tetralogy of Fallot Four defining features Congeni Ventricular septal defect tal Heart Aorta positioned above the ventricular septal opening Pulmonary stenosis that obstructs right Diseases ventricular outflow Right ventricular hypertrophy (Cont.) Severity related to degree of pulmonary stenosis Live into adulthood Copyright © 2019, Elsevier Inc. All rights reserved. 65  Transposition of the Great Arteries Aorta arises from the right ventricle and the pulmonary artery arises from the left ventricle. Congenital Results in two separate, noncommunicating circulations Heart Diseases Incompatible with life unless mixing of blood occurs through other defects. Treatment of choice: corrective surgery in which the aorta and pulmonary arteries are cut from the heart and sewn to the opposite ventricular outflow tract Copyright © 2019, Elsevier Inc. All rights reserved. 66  Truncus Arteriosus Failure of the pulmonary artery and aorta to separate results in formation of one large vessel that receives blood from both the right and left ventricles. Congenital Heart Results in systemic cyanosis Diseases (Cont.) High pulmonary blood flow may cause pulmonary hypertension and right ventricular hypertrophy. Surgery required for survival Copyright © 2019, Elsevier Inc. All rights reserved. 67  Tricuspid Atresia Usually associated with underdevelopment of the right ventricle and an atrial septal defect Congenital Allows blood to bypass right ventricle Heart Diseases A patent ductus arteriosus is required to perfuse (Cont.) lungs. Cyanosis present at birth, mortality high Surgery required for survival Copyright © 2019, Elsevier Inc. All rights reserved. 68