Congenital Heart Disease PDF

9/27/2023 Congenital heart disease • Abnormalities of heart or greater vessels that are present at birth: 1% of live births • Causes: congenital infection (rubella virus), genetic factors • Divided into 3 major groups • Malformations causing left to right shunt • Malformations causing right to left...

9/27/2023 Congenital heart disease • Abnormalities of heart or greater vessels that are present at birth: 1% of live births • Causes: congenital infection (rubella virus), genetic factors • Divided into 3 major groups • Malformations causing left to right shunt • Malformations causing right to left shunt • Malformations causing obstruction • Shunt is an abnormal communication between chambers or blood vessels • Obstructive congenital heart disease are developmental anomalies that obstruct vascular flow by narrowing chambers, valves or major blood vessels • Atresia is a complete obstruction 1 Congenital heart disease • Left to right shunt: septal defects & patent ductus arteriosus • Most common congenital cardiac defects • Initially cause left to right shunt due to low pressures in pulmonary circulation and right side of heart • Increase pulmonary blood flow result in right ventricular hypertrophy 2 PDA is most common. From aorta to pulmonary shunt. Septal defect are VSD and ASD Congenital heart disease • Left to right shunt • With time pulmonary hypertension and right ventricular hypertrophy can cause a reverse flow and cause cyanosis • Atrial Septal Defects • Failure of closure of foramen ovale after birth • Patent Ductus Arteriosus • Permits blood flow from aorta (bypassing lungs) to pulmonary artery during intrauterine life 3 1 9/27/2023 Congenital heart disease • Left to right shunt In septal defects , eventually (any septal effects at trial or V), you will see sinus is (blue discoloration of the skin which happens more in the right side shunting but eventually will be seen in both sides) only if patient survives for such a long period of time. • Ventricular Septal Defects Should not be an opening Left ventricle 4 It is the left side because left side ventricular wall wil be thicker.. also the aorta is present and you can tell its the aorta because you can see the bicuspid valves of the aorta Congenital heart disease • Right to left shunt • Cyanosis because pulmonary circulation is bypassed and poorly oxygenated blood enters systemic circulation • Tetralogie de Fallot Cyanosis • Most common form • Ventricular Septal Defects (VSD) • Obstruction to right ventricular outflow tract • Aorta that overrides the VSD • Right ventricular hypertrophy 5 Congenital heart disease • Right to left shunt • Cyanosis because pulmonary circulation is bypassed and poorly oxygenated blood enters systemic circulation Main category of • Tetralogie de Fallot the right to left shunt • Most common form • Ventricular Septal Defects (VSD) • Obstruction to right ventricular outflow tract • Aorta that overrides the VSD • Right ventricular hypertrophy 6 4 things which are happening which results in the right to left shunt: Ventricular septal defect right to left shunt Obstruction to RV outflow tract, the pulmonary artery carries to RV but it has stenosis and obstruction, maybe the artery is not well developed (narrowing) Aorta that overrides VSD which means: aorta should take blood from LV but in this condition because of morphology blood goes from RV directly to Aorta. RV hypertrophy. RV does most of the work so it gets Hypertrophy. 2 9/27/2023 Shows that there is a ventricular septal defect 7 Stenotic pulmonary artery Obstruction due to stenosis. Stenosis means narrowing. Thick RV 8 Diseases of the heart • Heart failure aka congestive heart failure (CHF) – heart is no longer able to pump blood at rates that meet the requirements of metabolizing tissues • Forward failure‐ inadequate cardiac output Inadequate cardiac output more on the oxygenated side (left ventricle • Backward failure‐increased congestion of venous circulation • Can affect predominantly left side or right side, or both sides of heart 9 3 9/27/2023 Left‐sided heart failure • Most common causes: • Ischemic Heart Disease, Coronary vessels usually affected • systemic hypertension, • mitral or aortic valve disease, • primary diseases of myocardium Embolism, thrombosis, hyperlipidemia, atherosclerosis causes of coronoary obstruction. Essentially myocardial infarction occurs 10 Ischemic heart disease • Myocardial infarction: Morphology Necrosis and fibrosis ( fibrotic tissue is always pale and white) (End result of ischemic heart disease) somewhere upstream there was an obstruction of coronary 11 Ischemic heart disease • Myocardial infarction: Morphology • • • • Myocardial fibers very thin hypereosinophilic Some nuclei very condensed or karyolitic Loss of/separation of myocardial fibers Necrosis Subacute inflammation • more macrophages and more lymphocytes and some neutrophils • Acute inflammation Fibrosis • Lots of neutrophils indicative of the acute inflammation • Eventually will be fibrosis (toluedine stain or trichromatic stain which also gives purple coloration but mainly for blue) Collagen is all blue coloration 12 4 9/27/2023 Left‐sided heart failure What can cause LSHF: • Morphology: hypertrophy, dilation, fibrosis, atrial thrombi • Extracardiac lesions: pulmonary congestion and edema • Dyspnea (breathlessness), cardiomegaly, tachycardia, a third heart sound, and fine rales at lung bases produced by respirations through edematous alveoli This is dilated cardiomyopathy Rales due to edema in lungs DCM could be caused by any of these: • • • 13 • • • • Infections, such as HIV and Lyme disease. Autoimmune disease, such as polymyositis. Alcohol abuse, cocaine use, exposure to heavy metals, and certain chemotherapy drugs. Thyroid disease. Diabetes. High blood pressure. Irregular heart rhythms. 14 Right‐sided heart failure • Most common cause is left ventricular failure, with associated pulmonary congestion and elevation in pulmonary and arterial pressure Thickening of the walls • Other causes: pulmonary hypertensive diseases, pulmonary valvular disease • Right ventricular hypertrophy and dilation • Pulmonary congestion and left ventricular hypertrophy are present or absent • Systemic and portal venous congestion, with hepatic and splenic enlargement, peripheral edema, pleural effusion, and ascites in vessels in hypertensive diseases 15 5 9/27/2023 Valvular heart disease • Stenosis is the failure of a valve to open completely, obstructing forward flow • Insufficiency results from failure of a valve to close completely, allowing reversed flow (regurgitation) • Abnormal flow through diseased valves produce abnormal heart sounds called murmurs • Rheumatic Valvular Disease • Immune mediated inflammatory disease (HS II‐ antibody mediated) that occurs a few weeks after group A streptococcal infection • M protein of certain strep strains induce antibodies that cross‐ react with self glycoproteins in the heart and other tissues • Acute rheumatic heart disease > inflammation of the valves, myocardium or pericardium • Chronic form> scarring of valves resulting in permanent dysfunction 16 Vegetative endocarditis, bacterial infection of valves. A group Streptococcus 17 18 Immune triggered, could be any antigen to trigger antibody antigen complex formation. 6 9/27/2023 Valvular heart disease • Rheumatic Valvular Disease 19 Valvular heart disease • Rheumatic Valvular Disease Acute> insuficiency Shrunken valve Chronic> stenosis 20 Cardiomyopathies • Cardiomyopathies are heart muscle diseases attributable to intrinsic myocardial dysfunction • Genetic disorders: muscular dystrophies • Inflammatory disorders (myocarditis) • Idiopathic • Cardiomyopathies divided into three morphological groups • Dilated cardiomyopathy • Hypertrophic cardiomyopathy • Restrictive cardiomyopathy 21 Restrictive: Walls of heart cannot contract or relax properly. Could be calcium, iron, potassium defect 7 9/27/2023 22 Dilated leads to systolic dysfunction Hypertrophic and restrictive leads to diastolic dysfunction Hypertrophic Dilated Normal 23 Cardiomyopathies • Myocarditis: • Inflammation is the cause not the response to myocardial degeneration and necrosis • Infectious diseases: • Coxsackievirus (human), parvovirus (dogs) >T Cell mediated immunity against infected myocytes • Borrelia burgdorferi (Lyme) • Trypanosoma cruzi • Immune mediated: • rheumatic fever • drug hypersensitivity (methyl dopamine), toxic substances (hairy vetch) 24 8 9/27/2023 Cardiomyopathies • Myocarditis: morphology Lymphocytic Hypersensitivity Just lymphocytes and is a hypersensitivity reaction Giant cell Eosinophils Trypanosomal Eosinophils are commonly associated with allergic and parasitic infections Organisms reside in the myocardial fibers but cause inflammation a lot Giant macrophages within the myocardium, multinucleated. 25 Cardiomyopathies • Dilated Cardiomyopathy (DCM) : • Congestive cardiomyopathy Same thing as dilated CM • Most common cause of cardiomyopathy • Progressive cardiac dilation and contractile (systolic) Progressive cardiac dilation. dysfunction, with or without concurrent hypertrophy • Genetic (X‐linked muscular dystrophy), • Toxic exposure (alcohol, doxorubicin), • Myocarditis, • Pregnancy associated physiological changes. 26 Alcohol, Myocarditis, Pregnancy, Genetic muscular dystrophy, Cardiomyopathies • Dilated Cardiomyopathy (DCM) : Collagen fibers Long term DCM. 27 Collagen fibers should not be present in this much. Why? Because the contractility of the myocardiocytes will decrease because of that much collagen 9 9/27/2023 28 Cells more thickened, and nucleus is karyomegalic and mayo fibers haphazardly arranged Hypertrophic Cardiomyopathy. We know its hypertrophic because cells are more thickened and the sarcoplasmn is thickened and the nucleus is karyomegalic Haphazardly arranged myofibers Left side intra ventricular system. 29 Tumors • Benign tumors – Hemangioma‐ increase numbers of normal or abnormal vessels filled with blood Originate from blood vessels, form abnormal vascular system, localized and can form in skin, heart, blood vessels Originates in the lymph system only, and wont see red blood cells, only white blood cells, will look white colored grossly – Lymphangioma‐ lymphatic analogue of hemangiomas – Glomangioma‐ arise from modified SMCs of glomus body, a Smooth muscle cells of glomus body present in the heart. You just need to remember that they are arteriovenous structure involved in thermoregulation modified smooth muscle cells and basically these are the glomus body is structure involved in – Bacilliary angiomatosis‐ opportunistic infection in thermoregulation. There neoplasia in the heart can be called glomangioma immunocompromised persons that manifests as vascular proliferations Junction between neoplasia and inflammation 30 10 9/27/2023 Tumors of blood vessels Capillary variant Cavernous variant 31 • Intermediate grade (low grade malignant tumors) – Kaposi Sarcoma – common in AIDS patients, presents with red to purple skin plaques – Hemangioendothelioma • Malignant Tumors – Angiosarcoma – malignant endothelial neoplasms – Hemangiopericytoma – rare tumors derived from pericytes‐ myofibroblast like cells that are normally arranged around capillaries and venules – Hemangiosarcoma 32 11