Area and gradient mismatch: The discordance of a small valve area and low gradients

Laura M. Franey, Steven J. Lester, Frances O. Wood, Amr E. Abbas

Research output: Chapter in Book/Report/Conference proceedingChapter


While the clinical severity of aortic stenosis (AS) is based largely on symptoms, indications for surgical aortic valve replacement (SAVR) and/or transcutaneous (TAVR) rely upon calculated estimates of the hemodynamic significance and degree of valvular stenosis. Severe AS is defined as an aortic valve area (AVA) <1.0 cm2 or indexed AVA <0.6 cm2/m2, mean trans-valvular pressure gradient (ΔP) >40 mmHg, and/or peak trans-aortic velocity >4 m/s by Doppler echocardiography. Whether the above conditions must be met individually or collectively remains unclear. As noted, area/gradient match occurs when both the AVA and ΔP fall within the severe range. This may occur regardless of the presence of normal or abnormal ejection fraction and regardless of the presence or absence of low flow (defined as a stroke volume index on echocardiography <35 ml/m2). However, the AVA may be in the severe range, while the gradient may be in the non-severe range. This has been referred to as area/gradient mismatch and will be discussed further in this chapter.

Original languageEnglish (US)
Title of host publicationAortic Stenosis
Subtitle of host publicationCase-Based Diagnosis and Therapy
PublisherSpringer-Verlag London Ltd
Number of pages12
ISBN (Electronic)9781447152422
ISBN (Print)9781447152415
StatePublished - Jan 1 2015


  • Aortic stenosis severity
  • Area/gradient match
  • Low flow area-gradient mismatch
  • Surgical aortic valve replacement (SAVR)
  • Transcutaneous aortic valve replacement (TAVR)

ASJC Scopus subject areas

  • General Medicine
  • General Biochemistry, Genetics and Molecular Biology


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