Sudden death can be seen in-

Ans. 'a' i.e., AS o The patients with Aortic stenosis are asymptomatic for a prolonged periods despite the obstruction and increased pressure load on the left ventricle.o The classic symptoms of Aortic stenosis areHeart failure, syncope andAnginaHowever, the classic symptoms reflect end stage diseaseo In general symptoms in patients with Aortic stenosis and normal left ventricualr systolic function rarely occur until the valve area is < 1.0 cm1, the jet velocity is over 4.0 m/s and the mean transvalvular gradient exceeds 40 mmHg.o In patients with known Aortic stenosis who are followed prospectively, the most common symptoms are decreased exercise tolerance and dyspnoea on exertion.o Once symptoms develop, even when mild, prompt surgical intervention is needed because average survivalwithout valve replacement is only two to three years with a high risk of sudden death.Sudden cardiac death in Aortic stenosiso Symptomatic severe Aortic stenosis is associated with a high risk of sudden cardiac death. Sudden cardiac death has been obser\>ed in 0-5% of adults with asymptomatic aortic stenosis and in 8-34% with symptomatic aortic stenosis.o The mechanism of sudden death has not been established.o Potential causes include an abnormal BezoldJariseh reflex with hypotension or bradyarryhthmia or malignant ventricular tachyarryhthmia.o However a relationship between NS IT and sudden death has not been established.o The risk of sudden death is reduced by valve replacement, so prompt valve replacement, is generally recommended for symptomatic Aortic stenosis.