00:00 / 00:00
Bundle branch block
Pulseless electrical activity
Atrioventricular nodal reentrant tachycardia (AVNRT)
Premature atrial contraction
Long QT syndrome and Torsade de pointes
Premature ventricular contraction
Coronary steal syndrome
Coarctation of the aorta
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
Pulmonary valve disease
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0 / 1 complete
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carcinoid syndrome p. 359
systolic ejection murmur in p. 297
wide splitting in p. 296
The pulmonary valve is typically made up of three leaflets, the anterior, the left, and the right, and it opens during systole to allow blood to be ejected to the lungs. During diastole, it closes to allow the heart to fill with blood and get ready for another systole. If the pulmonary valve doesn’t open all the way, it makes it harder for the heart to pump blood out to the lungs, and this is called pulmonary stenosis. If the pulmonary valve doesn’t close all the way, then blood leaks back into the right ventricle, and this is called pulmonary valve regurgitation or pulmonary insufficiency.
Pulmonary valve stenosis is often congenital, meaning that at birth, the leaflets are irregularly shaped or not fully developed. Pulmonic valve stenosis is often associated with congenital heart conditions like Tetralogy of Fallot, which affects all four chamber of the heart, as well as a genetic condition called Noonan's syndrome. In other cases, pulmonary valve stenosis can be caused by mechanical stress over time, which damages endothelial cells around the valves. This damage causes fibrosis and calcification, which harden the valve and make it more difficult for the valve to open all the way.
Because pulmonary valve stenosis makes it harder for the valve to open when the right ventricle tries to eject blood, the valve resists for a second before finally snapping open, and this causes a characteristic “ejection click.” Because the blood has to flow through a narrow opening, we get increased turbulence, which creates a noise called a murmur. This murmur gets louder as more blood flows past the opening, and then it gets quieter as the amount of blood flowing through the valve decreases because There’s less in the ventricle. This sound is described as a crescendo-decrescendo murmur.
Since it’s more difficult to open this hardened valve and push blood past it, the right ventricle has to generate really high pressures. To achieve those pressures it thickens its muscles, and this is called concentric right ventricular hypertrophy. This happens because new sarcomeres are added in parallel to the existing ones. However, even though you have this bulked up ventricle, the heart still might struggle to get enough blood through the narrowed opening and the lungs. Ultimately, that means that blood gets backed up, and so the person can develop right-sided heart failure. A final, different complication of pulmonic valve stenosis is called microangiopathic hemolytic anemia, and it’s the damage caused to red blood cells as they’re forced through the smaller valve. This splits them into smaller fragments called schistocytes, which leads them to get peed out and to hemoglobinuria, or hemoglobin in the urine.
Pulmonary valve diseases include pulmonary valve stenosis, which is associated with congenital heart conditions like Tetralogy of Fallot. It results in the pulmonary valve not opening fully and has a characteristic crescendo-decrescendo murmur on auscultation. Over time, it can lead to right-sided heart failure and signs of cyanosis but can be treated with balloon valvuloplasty.
There is also pulmonary valve regurgitation, which results in blood flowing backward into the right ventricle, and it is characterized by a diastolic-decrescendo murmur. It's usually asymptomatic, but over time it can also lead to right-sided heart failure. Pulmonary valve regurgitation can be treated with valve replacement.
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