HAHN Rebecca T.

Rebecca T. HAHN

Columbia College of Physicians and Surgeons, USA

キーワード :

Background: Aortic stenosis is the most common valvular disease of the elderly. The natural history of aortic stenosis （AS） has not changed however at least 30％ of patients with severe, symptomatic aortic stenosis are untreated.
Objective: Discuss the new echocardiography approaches to ventricular function in AS, and describe the echocardiographic predictors of outcome in AS with an approach to management of asymptomatic, severe AS.
Lecture Summary: Studies have suggested that the most common reason for denying surgery to symptomatic severe AS include low ejection fraction （EF）, neurologic dysfunction and advanced age. The assessment of risk and benefit to surgical intervention versus watchful waiting requires a full understanding of the evidence-based risk factors associated with worse survival. This lecture will attempt to answer the following questions: 1. Are there non-invasive tools that may better characterize ventricular structure and function （than EF）? 2. Are there predictors of symptom development and prognosis which may guide clinical decision-making?
Numerous echocardiographic predictors of symptoms have been identified including: aortic jet velocity （peak and rate of change）, transaortic gradient （mean and rate of change）, symptoms on exercise stress test. Traditional echocardiographic predictors of poor outcome include: aortic jet velocity （peak and rate of change）, valve calcification, aortic valve area, ventricular function （EF, strain and diastolic function）, assessment of ventriculo-arterial load, and stress testing. In addition LV end-diastolic volumes and left atrial volumes and the presence of “low stroke volume” predict poor outcomes.
Low-flow, low gradient aortic stenosis is a subgroup of patients with which may be difficult to diagnosis and risk assess. In the setting of normal EF, this phenomenon is considered “paradoxical” and a number of clinical scenarios may explain this patient subgroup. In the group with reduced ejection fraction, the use of dobutamine stress echocardiography has become standard procedure for determining true-severe AS from pseudo-severe AS. Newer parameters such as calcium score and projected valve area can also be used in this patient population to assess risk.


Summary: Figure 1 outlines the algorithm for approach to aortic stenosis using guidelines from the American College of Cardiology/American Heart Association and the European Society of Cardiology.