『Cardiology - Aortopathies』のカバーアート

Cardiology - Aortopathies

Cardiology - Aortopathies

無料で聴く

ポッドキャストの詳細を見る

このコンテンツについて

 Aortic Diseases: A Comprehensive BriefingDate: October 26, 2023Purpose: This briefing document provides a detailed overview of various aortic diseases, including chronic conditions like aneurysms and acute, life-threatening syndromes such as dissection and rupture. It consolidates key information on definitions, causes, risk factors, symptoms, diagnosis, surveillance, and treatment strategies, drawing from provided medical sources.1. Introduction to Aortic DiseasesAortic diseases encompass a spectrum of conditions affecting the aorta, the body's largest artery. These conditions range from chronic issues like thoracic and abdominal aortic aneurysms and aortic atheromas to acute, highly perilous events such as aortic dissection and aneurysm rupture. Prompt diagnosis, appropriate treatment, and vigilant surveillance are crucial for preventing disease progression, complications, and mortality.2. Thoracic Aortic Aneurysm (TAA)2.1. Definition and CharacteristicsTAA is defined as an increase in the thoracic aortic diameter greater than 50% relative to the expected or normal dimension, which varies by age, sex, and body type. TAAs can occur at the aortic root, ascending aorta, aortic arch, or descending aorta, most commonly affecting the root and ascending aorta, often linked to atherosclerosis.2.2. Causes and Risk FactorsCystic medial degeneration: The primary cause, involving weakening of the aortic wall due to loss of smooth muscle fibers and elastic fiber degeneration.Connective tissue disorders: Common in patients younger than 50 years, including Marfan syndrome, Ehlers-Danlos syndrome, and Loeys-Dietz syndrome.Bicuspid aortic valve: A significant risk factor, occurring in approximately 50% of affected individuals.Other risk factors: Hypertension, smoking, and advanced age.Other listed causes: Atherosclerosis, other genetic/congenital conditions (e.g., Turner syndrome, coarctation of the aorta), vasculitis (e.g., Takayasu arteritis, Giant cell arteritis), infectious causes (e.g., septic embolism, syphilis), and prior aortic injury or acute aortic syndrome.2.3. SymptomsTAAs are frequently asymptomatic and detected incidentally. When symptoms occur, they may include:Infrequent: Dysphagia (difficulty swallowing) and hoarseness due to compression of surrounding structures.Rupture: Severe chest pain, back pain, sudden shortness of breath, or sudden death.Associated with aortic regurgitation: Diastolic heart murmur, wide pulse pressure, or symptoms of heart failure.2.4. Diagnosis and SurveillanceScreening: Recommended only for patients with known genetic conditions predisposing to aortic aneurysms and dissections (e.g., Marfan syndrome, Ehlers-Danlos syndrome), or a family history of TAA or aortic dissection.Imaging Modalities (Table 36):Transthoracic echocardiography (TTE): Good for aortic root/proximal ascending aorta; no radiation/contrast. Limited visualization of distal ascending aorta, arch, and branches.Transesophageal echocardiography (TEE): Excellent visualization from root to descending aorta; no radiation/contrast. Invasive, operator dependent.CT angiography (CTA): Visualizes entire aorta and side branches; rapid; high sensitivity/specificity. Exposes patient to radiation and iodinated contrast.Magnetic resonance angiography (MRA): Visualizes entire aorta and side branches; high sensitivity/specificity; no radiation. Prolonged acquisition, contraindications (pacemakers, defibrillators, some kidney disease).Aortography: Provides exact information on size/shape of aortic lumen and side branches. Invasive, requires dye, potential for nephrotoxicity and worsening dissection. Poor for intramural hematoma.Measurement: Aortic diameter should be measured perpendicular to the long axis.Surveillance Frequency:3.5 to 4.4 cm diameter: Annual imaging.4.5 to 5.4 cm diameter: Imaging every 6 months.Marfan syndrome: Repeat assessment 6 months after initial diagnosis, then annually if stable.Rapid expansion (>0.5 cm/year) or approaching repair threshold: More frequent imaging.2.5. TreatmentMedical Therapy:For TAAs <5.0 cm.Aggressive blood pressure control: Goal <130/80 mm Hg.β-Blockers: Preferred antihypertensive agents; associated with reduced aneurysm growth, especially in Marfan syndrome.Losartan: Also associated with reduced aneurysm growth in Marfan syndrome.Surgical Repair: Warranted to prevent rupture, the leading cause of death in TAA patients.Degenerative ascending aortic aneurysm: >5.5 cm in diameter or rapid growth (≥0.5 cm/year or ≥0.3 cm/year over 2 years).Sporadic aneurysms: 5.0 cm or larger may be considered.Nonsyndromic hereditary TAA: ≥4.5 cm with high-risk family history; ≥5.0 cm without high-risk family history.Marfan syndrome/genetically mediated disorders: Lower threshold for elective repair (4.0-5.0 cm).Bicuspid aortic valve with ascending aortic aneurysm: >5.5 cm, or 5.0 cm if additional dissection risk factors or low operative risk.Concomitant cardiac surgery: Aortic repair should be ...
まだレビューはありません