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Background: The Gorlin equation is the reference method for the assessment of aortic valve area in aortic stenosis and is calculated using a constant, called the coefficient of contraction, which is empirically assumed to be 1. This coefficient is the ratio of effective aortic area to anatomic aortic area, and a value of 1 indicates that both are the same. The purpose of this study was to estimate the actual coefficient of contraction in patients with aortic stenosis and to evaluate its impact on aortic area as calculated by the Gorlin equation. Methods: We studied 17 patients with moderate to severe aortic stenosis. Effective aortic area was calculated using the continuity equation. Anatomic aortic area was obtained by planimetry with transesophageal echocardiography. Aortic valve area by the Gorlin equation was calculated from echocardiography data. The coefficient of contraction was derived as above. Results: The coefficient of contraction was inversely related to the pressure recovery. Effective area was correlated with anatomic area (r = 0.86, P < 0.01) but there was a high mean difference (0.22 ± 0.14 cm 2 ). Aortic area by the Gorlin equation was not correlated with anatomic area, but the correlation became significant when the Gorlin equation was corrected for coefficient of contraction and pressure recovery. Conclusions: Using a coefficient of contraction of 1 in the Gorlin equation gives a poor correlation with anatomic area. Using the calculated coefficient of contraction for each patient and the mean gradient for pressure recovery improves the correlation with anatomic area. These facts could be taken in account when Gorlin equation is considered as the reference method.

Muscle fiber disarray (MFD) has been described as the histologic feature of hypertrophic cardiomyopathy (HC), but it was also found in normal and other abnormal conditions. Its distribution related to the topography of the myocardium has not been described. In this paper, the incidence of MFD in hearts free from HC, the frequency of the histologic disorganization and the affected muscles involved were studied at autopsy. 29 hearts with acute myocardial infarction and 1 with suppurated myocarditis were employed. Macroslides containing the point of maximum septal enlargement were selected for histological examination. The areas of MFD were measured by a polar planimeter and correlated with the involved wall, the total slice area, parietal widths and involved muscles. 27 patients (90%) presented with MFD; hypertrophic ventricular walls were observed in 10, 8 of which had MFD. The remaining 20 patients with nonhypertrophic ventricular walls had MFD in 19 instances. There was septal posterior involvement in 26 cases (p < 0.0005). 12 patients (44.4%) had only one wall involved. Only 1 patient presented more than 5 % of MFD in regard to the total area. The septal wall was the most affected (p < 0.0005). The most commonly affected muscle was the deep-sinospiral, either alone or combined with other muscles (p < 0.01). Greater MFD was found (23/30) in patients with septum/posterior wall ratio < 1.3 cm. It is concluded that MFD may affect up to 10% of the septum in patients free from HC, and that secondary hypertrophy is not a prerequisite for MFD. The splitting of the superficial and deep fibers as observed at the anterior and posterior septum and the change of the course of two nearby muscular groups may explain these findings. Thus, a high probability exists of finding MFD at the septal and right ventricular level in patients who do not have HC and are studied by endomyocardial biopsy.

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Background Studies of ejection dynamics in severe aortic stenosis and prosthetic valve obstruction had demonstrated a delay in aortic valve opening. Purpose The aim of this study was to compare and evaluate ejection dynamics and valve kinetics in patients with severe aortic stenosis with preserved ejection fraction with normal and low flow. Methods 83 patients (age average 68±11 years) with severe aortic stenosis (aortic valve area &lt;1cm2) and preserved ejection fraction (≥50%) were studied with Doppler echocardiography and included prospectively. The ratio of aortic valve area measured at mid-deceleration and mid-acceleration (Md/Ma) were calculated using velocity of left ventricular outflow tract and aortic transvalvular velocity in continuity equation as an index of valvular kinetics. A ratio of Md/Ma &gt;1 indicate delay in opening of aortic valve. Assessment of ejection dynamics was evaluated with acceleration time (AT), ejection time (ET) and the ratio AT/ET estimated from aortic Doppler velocities profiles. Aortic flow was calculated as stroke volume/ET. According to stroke volume index and mean gradient patients were classified in 3 groups: normal-flow, low-gradient (NFLG) 25 patients, low-flow, low-gradient (LFLG) 28 patients and normal-flow, high-gradient (HG) 30 patients. Analysis of the variance and coefficient of correlation “r” were used for statistical evaluation. A p value &lt;0.05 was considered significant. Results There was no significant difference among the 3 groups with regard to ratio Md/Ma: NFLG 1.29±0.38, LFLG 1.22±0.26 and HG 1.23±0.45, NS. No difference was found in AT in the 3 groups, but ET was shorter in LFLG (310±30 ms) in comparison with NFLG (345±32 ms) and HG (361±31 ms), p&lt;0.01. Ratio AT/ET occurred in early systole in NFLG (0.27±0.07) compared with LFLG (0.32±0.07) and HG (0.39±0.07), p&lt;0.01. As expected, flow was decreased in LFLG (163±20 ml/s, p&lt;0.001) compared with NFLG (217±13 ml/s) and HG (233±44 ml/s). There was no correlation among AT/ET and aortic flow or stroke volume index. Conclusions There were not differences among the groups with regard to kinetic of the valve evaluated by mean of ratio Md/Ma. According to ratio AT/ET, aortic valve takes less time to open in NFLG compared with LFLG and HG independent of aortic flow suggesting a different ejection dynamics pattern in this group. Funding Acknowledgement Type of funding source: None

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Introduction: In patients with severe aortic stenosis (AS), low-gradient, low-flow, and preserved ejection fraction (EF) (≥ 50%) (LG/LFp) the decrease in stroke volume index (Svi) could be due to diminished contractility. The aim of this study was to analyze if low Svi in patients withLG/LFp is related to a decrease in contractility. Methods: Thirty patients with LF/LGp and 63 normal subjects were studied with Doppler echocardiography. The level of contractility (LC) was assessed by mean of midwall shortening fraction (mSF) -end-systolic stress relationship. Relative wall thickness (RWT) and aortic valve area (AVA) were calculated. Results: LC was diminished in 40% of LF/LGp patients. By bivariate analysis LC correlated with RWT and mSF. Svi correlated with AVA but not with LC. In multiple linear regression, RWT and mSF were predictors independents of LC. About Svi, AVA was the only predictor independent variable. Conclusion: Decreased contractility was present in 40% of LF/LGp patients despite preserved EF. LC had correlation with mSF and EPR. Low Svi appears to be related to AS severity rather than low contractility.