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Bundle branch block
Pulseless electrical activity
Atrioventricular nodal reentrant tachycardia (AVNRT)
Premature atrial contraction
Long QT syndrome and Torsade de pointes
Premature ventricular contraction
Rheumatic heart disease
Atrial septal defect
Coarctation of the aorta
Patent ductus arteriosus
Ventricular septal defect
Hypoplastic left heart syndrome
Tetralogy of Fallot
Total anomalous pulmonary venous return
Transposition of the great vessels
Pericarditis and pericardial effusion
Aortic valve disease
Mitral valve disease
Pulmonary valve disease
Tricuspid valve disease
Coronary steal syndrome
Polycystic kidney disease
Renal artery stenosis
Peripheral artery disease
Subclavian steal syndrome
Superior mesenteric artery syndrome
Human herpesvirus 8 (Kaposi sarcoma)
Chronic venous insufficiency
Deep vein thrombosis
Acyanotic congenital heart defects: Pathology review
Aortic dissections and aneurysms: Pathology review
Atherosclerosis and arteriosclerosis: Pathology review
Cardiac and vascular tumors: Pathology review
Cardiomyopathies: Pathology review
Coronary artery disease: Pathology review
Cyanotic congenital heart defects: Pathology review
Dyslipidemias: Pathology review
Endocarditis: Pathology review
Heart blocks: Pathology review
Heart failure: Pathology review
Hypertension: Pathology review
Pericardial disease: Pathology review
Peripheral artery disease: Pathology review
Shock: Pathology review
Supraventricular arrhythmias: Pathology review
Valvular heart disease: Pathology review
Vasculitis: Pathology review
Ventricular arrhythmias: Pathology review
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Explaining Tetralogy of Fallot (1 of 5)
Tetralogy of Fallot (TOF)
tetralogy of Fallot as cause p. 302
Tetralogy of Fallot p. 302
20q10 syndromes p. 304
cyanosis caused by p. 733
fetal alcohol syndrome p. 304
lab findings in p. 729
outflow tract formation p. 285
thymic aplasia p. 114
Tetralogy of Fallot or TOF is a congenital heart condition where patients have four heart abnormalities.
Okay so now let’s go through these four findings in TOF one-by-one. The first abnormality is stenosis, or narrowing of the right ventricular outflow tract into the pulmonary artery. And this could either be narrowing of the valve itself, or narrowing of the infundibulum, the area right below the valve. Either way, this makes it harder for deoxygenated blood to get to the pulmonary circulation.
In response—and this also happens to be the second feature—the myocardium of the right ventricle hypertrophies, or gets really thick, in order to contract harder and push blood past the stenosis.
This causes their heart to look “boot-shaped” on an x-ray.
The third feature is that patients have a large ventricular septal defect, this gap between the ventricles that allows shunting of blood between them.
Now, in a patient with an isolated ventricular septal defect (meaning those that don’t have TOF), oxygenated blood is shunted from the left side to the right side because the pressure on the left is higher than the pressure on the right. For patients with TOF, though, the right ventricular outflow obstruction might block the normal blood flow so much that the pressure in the right ventricle has to be really high to get past it. Well the high right-sided pressures means that the left side of the heart actually becomes the path of least resistance and deoxygenated blood shunts from the right side to the left side.
The fourth and final feature is that the aorta overrides the ventricular septal defect. This one is super variable, sometimes the aorta’s way over here sitting on top of the septal defect and sometimes it’s more on the left ventricular side. Either way, if deoxygenated blood is shunted from right-to-left, then it flows over to the left ventricle and immediately out to the body.
Tetralogy of Fallot, or TOF, is a congenital disorder characterized by four heart abnormalities. There is stenosis in the right ventricular outflow tract, right ventricular hypertrophy, ventricular septal defect, and aortic override of the septal defect. These four defects cause oxygen-poor blood to flow from the right ventricle into the aorta, rather than being pumped to the lungs, which results in cyanosis. TOF is diagnosed with patient examination and health ultrasound, and treatment involves cardiac surgical repair, usually in the first year of life.
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