Imaging of low-gradient severe aortic stenosis

Area of Science:

• Cardiology
• Echocardiography
• Valvular Heart Disease

Background:

• Severe aortic stenosis (AS) typically presents with high flow and gradient.
• A subset of patients exhibit low-flow, low-gradient severe AS (LGSAS), complicating assessment.
• Recent identification of LGSAS with preserved left ventricular (LV) function in elderly, hypertensive patients with specific LV characteristics.

Purpose of the Study:

• To review the current understanding of low-flow, low-gradient severe AS (LGSAS).
• To highlight the role of cardiac imaging in hemodynamic classification and management decisions for LGSAS.
• To discuss the distinction between pseudo-AS and true LGSAS with contractile reserve.

Main Methods:

• Review of existing literature on low-flow, low-gradient severe AS.
• Emphasis on the diagnostic utility of dobutamine echocardiography.
• Discussion of imaging findings in LGSAS patients with preserved LV function.

Main Results:

• Dobutamine echocardiography is crucial for differentiating pseudo-AS from true LGSAS.
• True LGSAS with contractile reserve may benefit from surgical intervention.
• Specific patient profiles (elderly, hypertensive, small LV cavity, concentric hypertrophy) are associated with LGSAS and preserved LV function.

Conclusions:

• Accurate hemodynamic classification of LGSAS is essential for appropriate patient management.
• Cardiac imaging, particularly echocardiography, is vital for guiding therapeutic strategies in LGSAS.
• Understanding LGSAS nuances, including preserved LV function variants, improves patient outcomes.