two cusps at the aortic valve instead of the usual three) and rheumatic aortic stenosis (now rare in the West). Obstruction at the level of the aortic valve causes increased pressure within the heart's left ventricle. This can lead to hypertrophy and ultimately dysfunction of the heart. While x-ray and ECG might indicate aortic stenosis, echocardiography is the diagnostic procedure of choice. US findings also help in grading the severity of the disease. In cases of symptomatic severe aortic stenosis, AVR is warranted. In cases of asymptomatic but severe aortic stenosis, more factors should be taken into consideration. Aortic regurgitation, on the other hand, has many causes: degeneration of the cusps, endocarditis, bicuspid aortic valve, aortic root dilatation, trauma, connective tissue disorders such as Marfan syndrome or Ehlers-Danlos lead to imperfect closure of the valve during diastole, hence the blood is returning from the aorta towards the left ventricle of the heart. Acute aortic regurgitation (caused by endocarditis, aortic dissection or trauma) ends up in pulmonary edema, because of the acute increase in left ventricle (LVEDP) that does not have time to adjust to the regurgitation. Chronic regurgitation, by contrast, gives the heart time to change shape, resulting in eccentric hypertrophy, which has disastrous effects on the myocardium. Ultrasound is here also the best diagnostic mobility, either it is transthoracic or transesophageal. Indications for surgery Guidelines for aortic valve replacement As long-term data on the survival and quality of life of people following valve replacement have become available, evidence-based guidelines for aortic valve replacement have been developed. These help healthcare professionals decide when aortic valve replacement is the best option for a patient. Two widely accepted sets of guidelines used by surgeons and cardiologists are the American Heart Association and American College of Cardiology Guidelines for the Management of Patients with Valvular Heart Disease, and the European Society of Cardiology and the European Association for Cardio‑Thoracic Surgery Guidelines for the management of valvular heart disease. Aortic stenosis Aortic stenosis is treated with aortic valve replacement in order to avoid angina, syncope, or congestive heart failure. Individuals with severe aortic stenosis are candidates for aortic valve replacement once they develop symptoms or when their heart function is impacted. Some people with asymptomatic aortic stenosis may also be candidates for aortic valve replacement, especially if symptoms appear during exercise testing. Patients with moderate aortic valve stenosis who need another type of cardiac