Aortic stenosis and autonomic dysfunction: co-conspirators in syncope.

Autonomic dysfunction and aortic stenosis share several clinical characteristics, including, in severe cases, syncope. Both illnesses tend to manifest later in life, and most cases are idiopathic in origin. In a short period of 4 weeks, the authors noted that three patients out of 36 referrals for autonomic dysfunction also had histories of aortic valve replacement due to stenosis. In each case, similar presenting symptoms of fatigue, light-headedness, and syncope were attributed to aortic stenosis without mention of autonomic failure as a possible contributor. The authors propose that patients for whom symptoms of aortic valve stenosis are not relieved by surgical intervention may have concomitant autonomic dysfunction contributing significantly to their symptoms. Furthermore, the two conditions may comprise a dangerous combination, aortic stenosis causing physical obstruction of ventricular outflow, and autonomic dysfunction causing decreased venous return and insufficient cardiac filling. It may be beneficial for patients with aortic stenosis who present with syncope to be considered for possible autonomic dysfunction to address both potential pathophysiologies contributing to the syncope.