1. Assessing Mitral Valve Area and Orifice Geometry in Calcific Mitral Stenosis: A New Solution by Real-Time Three-Dimensional Echocardiography
- Author
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Thanh-Thao Ton-Nu, Kian Keong Poh, Lanqi Hua, Eleanor Morris, Sarah Chua, Judy Hung, John Chu, and Robert A. Levine
- Subjects
Male ,medicine.medical_specialty ,Echocardiography, Three-Dimensional ,Diastole ,Geometry ,Sensitivity and Specificity ,Article ,Mitral valve stenosis ,Computer Systems ,Internal medicine ,Mitral valve ,Image Interpretation, Computer-Assisted ,medicine ,Humans ,Mitral Valve Stenosis ,Radiology, Nuclear Medicine and imaging ,Aged ,business.industry ,Significant difference ,Calcinosis ,Reproducibility of Results ,Three dimensional echocardiography ,Organ Size ,medicine.disease ,medicine.anatomical_structure ,Calcific mitral stenosis ,Cardiology ,Mitral Valve ,Female ,Mitral valve area ,Cardiology and Cardiovascular Medicine ,business ,Body orifice - Abstract
Background Planimetry of mitral valve area (MVA) is difficult in calcific mitral stenosis (CaMS) in which limiting orifice is near the annulus, and unlike rheumatic mitral stenosis (RhMS), does not present an area for planimetry at the leaflet tips. Moreover, pressure half time (PHT)-derived MVA (MVA PHT ) has limitations in patients with CaMS in whom there are coexisting conditions that affect LV chamber compliance. We tested the hypothesis that real-time 3-dimensional echocardiography (RT3D) can guide measurement at the narrowest orifice in CaMS. Methods In 34 patients with CaMS, MVA by RT3D (MVA RT3D ) was obtained using a color-defined planimetry technique performed "en face" at the smallest annular orifice cross-section (diastolic maximum). MVA RT3D and MVA PHT were compared with an independent standard: MVA by continuity equation (MVA CEQ ). In a subgroup of 10 patients with CaMS or RhMS, the 3-dimensional shape of the stenotic mitral valve was examined, guided by color flow mapping. Results MVA PHT overestimated the mitral orifice area compared with MVA CEQ (2.01 ± 0.52 cm 2 vs 1.75 ± 0.46 cm 2 ; P = .037), whereas there was no significant difference in MVA RT3D and MVA CEQ (1.83 ± 0.52 cm 2 vs 1.75 ± 0.46 cm 2 , respectively, P = .61). MVA RT3D had a greater correlation with MVA CEQ than MVA PHT (R = 0.86 vs 0.59 MVA RT3D vs MVA PHT , respectively). There was better agreement between MVA by RT3D and MVA by continuity equation than MVA by PHT and MVA by continuity equation (difference in MVA: 0.23 ± 0.15 cm 2 vs 0.43 ± 0.29 cm 2 ; P RT3D − MVA CEQ vs MVA PHT − MVA CEQ, respectively). In CaMS, there was a tubular geometry to the valve shape. In contrast, RhMS had a doming funnel-shaped geometry. Conclusion RT3D provides an accurate measurement of MVA in CaMS. In contrast with the doming valve shape present in RhMS, the limiting anatomic orifice area occurs at the annulus in CaMS as measured by RT3D and reflects the effective orifice area as present in a tubular valve geometry.
- Published
- 2008