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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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Renal nutcracker syndrome is when the left renal vein, which drains blood from the left kidney, gets squeezed between two large arteries: the superior mesenteric artery and abdominal aorta. It’s kind of like the renal vein is the nut and the two arteries are the nutcracker.
Now, blood heading toward the lower body exits the left ventricle, swoops around the aortic arch, and then flows downward through the descending aorta, a large, muscular blood vessel about as thick as a thumb. The descending aorta runs along the back of the abdominal wall next to the spine, where it’s called the abdominal aorta, until it splits into the common iliac arteries. The abdominal aorta gives rise to many smaller arteries, including three unpaired arteries: the celiac artery, the superior mesenteric artery, and the inferior mesenteric artery. All three of these arteries branch off the anterior wall and supply blood to the digestive tract.
The renal vein carries blood returning from the kidney to the heart, passing between the aorta and the superior mesenteric artery. The angle formed between these two vessels is called the aortomesenteric angle. It’s usually around 45 degrees, with the renal vein cushioned by a bit of fat in the mesentery. If that aortomesenteric angle is reduced, the arteries begin to pinch the left renal vein like a nutcracker, preventing blood from returning back to the heart. This leads to a backup of blood in the left kidney, causing renal hypertension. Over time, the high pressures can cause small breaks in the renal blood vessels, and a bit of blood can even get into the urine. Also, because the left testicular vein drains into the left renal vein, blood can end up pooling in the left testicle as well.
Nutcracker syndrome is a condition in which the left renal vein is squeezed between the superior mesenteric artery and the aorta, due to a narrow aortomesenteric angle. This results in increased pressure in the left renal vein, which can lead to hematuria and flank pain as well as a left-sided varicocele in people with testicles.
Nutcracker syndrome is diagnosed with imaging tests such as ultrasound or CT scan. The treatment may simply be weight gain, because as the mesenteric fat pad gets fatter, it widens the aortomesenteric angle, thus relieving the compression on the left renal vein. Sometimes surgery is the best treatment option to relieve the compression on the left renal vein.
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