Inconsistent grading of severe aortic stenosis (small valve area but low gradient) is common even on invasive cardiac catheterization and is not fully explained by low stroke volume.
BACKGROUND: On echocardiography approximately one-third of patients with severe aortic valve stenosis based on aortic valve area (AVA or =30%. On invasive testing 85 patients (26%) demonstrated inconsistent (AVA40 mm Hg) with the remainder (28%) presenting with a calculated AVA> or =1 cm(2). Inconsistently graded patients were older (71 vs 67 years, p35 ml/m(2). CONCLUSION: In the framework of current guidelines inconsistent grading of aortic valve stenosis is common, extends to cardiac catheterisation and is only partially explained by low stroke volume despite apparently normal left ventricular systolic function.
Minners et al. (2010) studied this question.