Size and motion of the mitral valve annulus in man. I. A two-dimensional echocardiographic method and findings in normal subjects.

Abstract

SUMMARY Using wide-angle, phased-array, two-dimensional echocardiography, mitral leaflets and their annular attachments were recorded from a view close to the standard apical four-chamber view. The transducer was rotated and recordings were made at 300 rotational intervals around the circumference of the mitral valve annulus. To reconstruct the annulus, diameters (or chords) from each rotational interval were arranged around a reference point. This was done for 12 times during the cardiac cycle. Annular areas were planimetered and circumferences measured. Correlation was good for areas reconstructed and measured by the same observer on separate occasions (r = 0.963) and by two different observers (r = 0.987). In 11 normal subjects the annular area index (area divided by body surface area) increased during diastole to a maximum of 3.8 ± 0.7 cm2/m2 (mean ± SD) in late diastole. There was presystolic followed by systolic narrowing to a minimum in midsystole. The mean reduction in area was 26 3%. The maximal annular circumference was 9.3 ± 0.9 cm and the mean reduction in circumference was 13 3%. The overall motion pattern was similar to that reported in experimental studies in the dog. Mitral annular reconstruction may provide new information about normal and abnormal function of the mitral valve apparatus.IN EXPERIMENTAL STUDIES and in human subjects on cardiopulmonary bypass, the size of the mitral valve annulus has been reported to change during the cardiac cycle.'-" There has been no technique available to measure mitral annular areas during the cardiac cycle in human subjects. Little is known of the size and motion of the mitral annulus in intact man, although important observations relating to its size have been made at autopsy.6-'0 Study of the mitral valve annulus may provide new insights into the overall function of the mitral valve apparatus in health and disease.We used a two-dimensional echocardiographic technique to reconstruct the mitral valve annulus so that its area could be measured at different times during the cardiac cycle to examine phasic changes. tape using a Sanyo cassette recorder. The images could be redisplayed in real-time, slow motion or as single frames. Still frames were recorded on 90-mm film during real-time studies and are used as illustrations in this paper. Mounted on the echocardiographic transducer was an inclinometer,"' a circular, fluid-filled chamber containing an air bubble that allows measurement of 300 transducer rotational intervals.Our method was designed to reconstruct the mitral valve annulus at 12 times during the cardiac cycle from diameters and chords measured at 300 rotational intervals. The transducer was held at the left ventricular apical impulse and the beam was directed toward the left atrium and the mitral valve leaflets to identify their annular hinge points. A view close to the standard apical four-chamber view was usually the initial plane of examination. Additional planes were obtained at 300 rotational intervals. Six planes were used to provide chords o...

The relationship of mitral annular shape to the diagnosis of mitral valve prolapse.

“…The mitral anulus in these patients was studied in a series of views obtained by rotation about the cardiac apex in a mnanner similar to that described by Ormiston et al 12 This procedure was used because the three-dimensional configuration of the mitral anulus cannot be discerned in any single tomographic view available with conventional scanning techniques. The mitral valve was initially examined in the apical four-chamber view, which includes the apex and displays a full excursion of both the mitral and tricuspid leaflets.…”

Relation of pulmonary vein to mitral flow velocities by transesophageal Doppler echocardiography. Effect of different loading conditions.

“…This indicates that downward movement of the mitral valve annulus also contributes to systolic forward flow. 1 13 During left ventricular contraction, the annulus moves toward the apex in a rightward direction,23 25 causing an increase in the left atrial area. This left atrial area increase results in a drop in left atrial pressure with a subsequent increase in flow from the pulmonary veins into the left atrium.…”

Morphological and Morphometrical Analysis of Mitral Valve Annulus of Heart in Human Adult Cadavers

“…The mean average value are in wide array of comparison with the studies of Gerda et al [11], Shahim Akthar et al [12], Rusted et al [13], Tetsura Sakai et al [14], Cheichi et al [15] using cadaveric hearts, Du Plessis and Merchand, [16], A.K. Datta et al [17] using fresh hearts and Ormiston,et al [18] (9.3 ± 0.9 cm) by 2D echocardiographic method who reported a higher range in both the sexes with fresh heart specimens, but significantly lesser than findings of McAlpine [19] using hearts in diastolic state perfusion method and higher with the findings of Andrade, Tinois, Vieira et al [20], However, the maximum percentage of annular circumference is in the range of 9 -9.99 cm which can be deliberately said as the no. of specimens used for the current study is much higher than with the earlier reports.…”

“…Out of 60 hearts, the annular circumference is maximum in the range 9-9.99cm seen in 17 hearts (28.3%) and the lowest is in the range of 5-5.99cm seen in 1 heart (1.67%). 9 Shahim Akthar Cheema [12] 10 Tetsura Sakai [14] 11 Patil, Mehta, Prajapati [7] 12 R C Brock [9] 13 Louis A Du Plessis [16] 14 Bernadine H Bulkley [10] 15 A.K.Datta [17] 16 Andrade Tinois Vieira [20] 17 M. Kavimani [8] 18 Omriston et al [18] …”