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KembaraXtra- Medicine- Aortic Stenosis
Aortic stenosis (AS) is a condition characterized by obstruction of left ventricular systolic outflow caused by thickening and calcification of the aortic valve, resulting in a significant pressure gradient between the left ventricle and the aorta. Symptoms typically develop when the aortic valve area decreases to less than 1.0 cm² (normal 3–4 cm²). Severe AS is defined by a valve area under 1.0 cm², a mean transvalvular gradient greater than 40 mm Hg, or a peak aortic jet velocity exceeding 4 m/s. Very severe AS is characterized by Doppler velocities greater than 5 m/s. Aortic stenosis is the most common valvular heart disease in adults in North America and Europe, with prevalence increasing markedly with age, particularly in individuals over 70 years.
Clinically, AS presents with a classic harsh, crescendo–decrescendo midsystolic murmur best heard at the base of the heart and radiating to the carotid arteries. Physical findings suggesting severe disease include diminished or absent second heart sound, slow-rising carotid pulse with delayed upstroke (pulsus parvus et tardus), presence of an S4, and paradoxical splitting of the second heart sound. Early symptoms include decreased exercise tolerance, exertional dyspnea, dizziness, or syncope, while later manifestations include angina, syncope, and congestive heart failure. The pathophysiology involves progressive narrowing of the valve, leading to increased left ventricular systolic pressure and concentric hypertrophy, which initially preserves cardiac output and ejection fraction. Over time, diastolic dysfunction and eventually systolic dysfunction develop, resulting in heart failure and high mortality if untreated. Approximately 20% of patients with severe AS develop acquired von Willebrand disease, which may cause gastrointestinal bleeding (Heyde syndrome) that often resolves after valve replacement.
The most common causes of AS include age-related idiopathic calcification of the aortic valve, which typically presents between ages 60 and 80 in developed countries, and rheumatic heart disease, which remains the leading cause worldwide and is characterized by commissural fusion. Congenital unicuspid or bicuspid aortic valves account for a significant proportion of cases, often presenting earlier in life. Less common causes include metabolic disorders such as Fabry disease, connective tissue and autoimmune diseases, radiation exposure, end-stage renal disease, and infective endocarditis.
Diagnosis is primarily established with echocardiography, which assesses valve anatomy, severity of stenosis, pressure gradients, valve area, left ventricular size, and function. Doppler echocardiography is essential for quantifying severity. Electrocardiography may show left ventricular hypertrophy or atrial enlargement, while chest radiography can reveal poststenotic dilation of the ascending aorta and valvular calcification. Cardiac catheterization is reserved for selected patients, particularly those undergoing valve replacement, to assess coronary artery disease or confirm invasive gradients. Computed tomography is crucial for anatomical assessment and planning transcatheter aortic valve replacement (TAVR). Exercise testing is recommended in asymptomatic patients with severe AS to uncover exertional symptoms or abnormal blood pressure responses.
Management of aortic stenosis is primarily surgical or transcatheter, as no medical therapy halts disease progression. Once symptoms develop, aortic valve replacement (AVR) is the definitive treatment, as symptomatic severe AS carries a mortality rate approaching 50% at two years without intervention. Medical management focuses on optimizing preload, maintaining sinus rhythm, cautious diuresis for volume overload, and controlling hypertension while avoiding excessive vasodilation. Balloon aortic valvuloplasty may be used as a temporary measure or bridge therapy in critically ill or nonoperative patients but is not a durable solution due to rapid restenosis.
Indications for AVR include all symptomatic patients with severe AS, asymptomatic patients with severe AS and left ventricular ejection fraction below 50%, and patients with severe AS undergoing other cardiac surgery. AVR may also be reasonable in asymptomatic patients with very severe AS, abnormal exercise testing, rapid disease progression, or low-flow/low-gradient severe AS when diagnostic criteria are met. The choice between surgical AVR (SAVR) and transcatheter AVR (TAVR) requires a multidisciplinary heart team approach and is based on patient age, life expectancy, surgical risk, valve anatomy, comorbidities, and patient preferences. In general, SAVR is favored in younger patients with long life expectancy, while TAVR is preferred in older patients, those with high surgical risk, or limited life expectancy.
Prognosis depends strongly on symptom status. Once symptoms appear, survival declines rapidly without valve replacement, with average survival of five years after angina onset, three years after syncope, and two years after heart failure develops. Regular follow-up with echocardiography is essential, even in asymptomatic patients, to monitor disease progression. Referral to cardiology and a heart valve team is recommended for all patients with severe AS, particularly those with symptoms, low-flow/low-gradient disease, or evidence of rapid progression. In patients with limited life expectancy or poor expected quality-of-life benefit from intervention, palliative care consultation plays a crucial role in shared decision-making and symptom management.
Aortic stenosis (AS) is a condition characterized by obstruction of left ventricular systolic outflow caused by thickening and calcification of the aortic valve, resulting in a significant pressure gradient between the left ventricle and the aorta. Symptoms typically develop when the aortic valve area decreases to less than 1.0 cm² (normal 3–4 cm²). Severe AS is defined by a valve area under 1.0 cm², a mean transvalvular gradient greater than 40 mm Hg, or a peak aortic jet velocity exceeding 4 m/s. Very severe AS is characterized by Doppler velocities greater than 5 m/s. Aortic stenosis is the most common valvular heart disease in adults in North America and Europe, with prevalence increasing markedly with age, particularly in individuals over 70 years.
Clinically, AS presents with a classic harsh, crescendo–decrescendo midsystolic murmur best heard at the base of the heart and radiating to the carotid arteries. Physical findings suggesting severe disease include diminished or absent second heart sound, slow-rising carotid pulse with delayed upstroke (pulsus parvus et tardus), presence of an S4, and paradoxical splitting of the second heart sound. Early symptoms include decreased exercise tolerance, exertional dyspnea, dizziness, or syncope, while later manifestations include angina, syncope, and congestive heart failure. The pathophysiology involves progressive narrowing of the valve, leading to increased left ventricular systolic pressure and concentric hypertrophy, which initially preserves cardiac output and ejection fraction. Over time, diastolic dysfunction and eventually systolic dysfunction develop, resulting in heart failure and high mortality if untreated. Approximately 20% of patients with severe AS develop acquired von Willebrand disease, which may cause gastrointestinal bleeding (Heyde syndrome) that often resolves after valve replacement.
The most common causes of AS include age-related idiopathic calcification of the aortic valve, which typically presents between ages 60 and 80 in developed countries, and rheumatic heart disease, which remains the leading cause worldwide and is characterized by commissural fusion. Congenital unicuspid or bicuspid aortic valves account for a significant proportion of cases, often presenting earlier in life. Less common causes include metabolic disorders such as Fabry disease, connective tissue and autoimmune diseases, radiation exposure, end-stage renal disease, and infective endocarditis.
Diagnosis is primarily established with echocardiography, which assesses valve anatomy, severity of stenosis, pressure gradients, valve area, left ventricular size, and function. Doppler echocardiography is essential for quantifying severity. Electrocardiography may show left ventricular hypertrophy or atrial enlargement, while chest radiography can reveal poststenotic dilation of the ascending aorta and valvular calcification. Cardiac catheterization is reserved for selected patients, particularly those undergoing valve replacement, to assess coronary artery disease or confirm invasive gradients. Computed tomography is crucial for anatomical assessment and planning transcatheter aortic valve replacement (TAVR). Exercise testing is recommended in asymptomatic patients with severe AS to uncover exertional symptoms or abnormal blood pressure responses.
Management of aortic stenosis is primarily surgical or transcatheter, as no medical therapy halts disease progression. Once symptoms develop, aortic valve replacement (AVR) is the definitive treatment, as symptomatic severe AS carries a mortality rate approaching 50% at two years without intervention. Medical management focuses on optimizing preload, maintaining sinus rhythm, cautious diuresis for volume overload, and controlling hypertension while avoiding excessive vasodilation. Balloon aortic valvuloplasty may be used as a temporary measure or bridge therapy in critically ill or nonoperative patients but is not a durable solution due to rapid restenosis.
Indications for AVR include all symptomatic patients with severe AS, asymptomatic patients with severe AS and left ventricular ejection fraction below 50%, and patients with severe AS undergoing other cardiac surgery. AVR may also be reasonable in asymptomatic patients with very severe AS, abnormal exercise testing, rapid disease progression, or low-flow/low-gradient severe AS when diagnostic criteria are met. The choice between surgical AVR (SAVR) and transcatheter AVR (TAVR) requires a multidisciplinary heart team approach and is based on patient age, life expectancy, surgical risk, valve anatomy, comorbidities, and patient preferences. In general, SAVR is favored in younger patients with long life expectancy, while TAVR is preferred in older patients, those with high surgical risk, or limited life expectancy.
Prognosis depends strongly on symptom status. Once symptoms appear, survival declines rapidly without valve replacement, with average survival of five years after angina onset, three years after syncope, and two years after heart failure develops. Regular follow-up with echocardiography is essential, even in asymptomatic patients, to monitor disease progression. Referral to cardiology and a heart valve team is recommended for all patients with severe AS, particularly those with symptoms, low-flow/low-gradient disease, or evidence of rapid progression. In patients with limited life expectancy or poor expected quality-of-life benefit from intervention, palliative care consultation plays a crucial role in shared decision-making and symptom management.
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