Aortic Regurgitant Orifice Area Research Articles

Preoperative Cardiac Computed Tomography Characteristics Associated with Recurrent Aortic Regurgitation after Aortic Valve Re-Implantation.

ObjectiveTo identify the preoperative cardiac computed tomography (CT) factors influencing postoperative recurrent aortic regurgitation (AR) in patients who underwent aortic valve repair with the re-implantation technique (David operation) due to AR.Materials and MethodsA total of 117 patients (age, 49.4 ± 15.6 years; 83 males) who underwent the David operation for AR were included in this retrospective study. Aortic root profiles including the aortic regurgitant orifice area (ARO) and the aortic cusp asymmetry ratio of the areas (ASRarea), which is defined as the maximum/minimum areas among the three cusp areas at the level of the commissures, were measured on preoperative cardiac CT scans. Clinical and CT findings were compared between a group with recurrent AR grade < 3 (no, trivial, or mild AR) and recurrent ≥ 3 + AR. To determine the optimal cut-off values of ASR and ARO, the receiver operating characteristic (ROC) curve was used. Cox regression analysis was used for the analysis of the factors affecting recurrent 3 + AR.ResultsPostoperatively, recurrent 3 + AR developed in 17 (14.5%) patients and occurred within a median of 268 days (interquartile range: 78–582 days). The cut-off ARO value for discriminating the patients with recurrent 3 + AR was > 24 mm2 (sensitivity, 76.5%; specificity 64.8%), and the area under the ROC curve (AUC) was 0.72. For ASRarea, the cut-off value was > 1.58 (sensitivity, 76.5%; specificity, 58.0%) and the AUC was 0.64. Multivariable Cox regression showed that ARO > 24 mm2 (hazard ratio = 3.79, p = 0.020) was a potential independent parameter for recurrent 3 + AR. ROC for the linear regression model showed that the AUC for both ARO and ASRarea was 0.73 (95% confidence interval, 0.64–0.81, p < 0.001).ConclusionARO and ASRarea detected on preoperative cardiac CT would be potentially helpful for identifying AR patients who may benefit from the David operation.

Validation de la reproductibilité de la mesure de la surface de l’orifice régurgitant par planimétrie dans l’insuffisance aortique : une étude préliminaire d’échocardiographie trans-œsophagienne tridimensionnelle

BackgroundAortic regurgitation is mainly evaluated by trans-thoracic echocardiography using multi-parametric qualitative and semi quantitative tools. All those parameters can fail to meet expectations, resulting in an imperfect diagnostic reliability and assessment of aortic regurgitation severity can be challenging. ObjectivesWe sought to evaluate feasibility and intra- and inter-observer reproducibility of aortic regurgitant orifice area measured by planimetry with tridimensional trans-esophageal echocardiography on patients with at least grade 2/4 aortic regurgitation. Patients and methodsConsecutive patients with at least grade 2/4 aortic regurgitation measured by trans-thoracic echocardiography and referred for trans-esophageal echocardiography for any reason were included. Planimetric reconstructions of regurgitant orifice area were studied and reproducibility indexes between senior and junior observers were calculated. ResultsTwenty-three patients were included in this study. Intra- and inter-observer reproducibility were excellent with an ICC of 0.95 [0.88–0.98], P<0.0001 and 0.91 [0.79–0.96], P<0.0001, respectively. Mean length of the measurement was 6.6±0.9min [CI95% 6.23–7.01]. ConclusionPlanimetric measurement of the aortic regurgitant orifice using tridimensional trans-esophageal echocardiography seems to be feasible and has great intra- and inter-observer reproducibility. Reconstruction durations were compatible with a daily use. There is a need now to investigate the reliability of this measurement as compared with the reference technique.

Quantification of Aortic Regurgitant Fraction and Volume with Multi-detector Computed Tomography: Comparison with Echocardiography

<h3>Rationale and Objectives</h3> Evaluate quantification of the aortic regurgitant fraction and volume with computed tomography (CT). <h3>Materials and Methods</h3> Fifty-three patients with aortic regurgitation (AR) and 29 controls were examined with 64-multi-detector CT coronary angiography and transthoracic echocardiography (TTE). A dedicated software algorithm employing three-dimensional segmentation of left ventricle (LV) and right ventricle (RV) volumes and LV mass was applied. AR volume and fraction was calculated based on RV and LV stroke volumes (SV) and compared with echocardiography. The aortic regurgitant orifice area (ROA) was measured by CT. <h3>Results</h3> A good correlation of the AR fraction and AR volume determined by CT compared to echocardiography was found for mild, moderate, and severe AR with 14.2% ± 9, 28.8% ± 8, and 57.9% ± 9 (<i>r</i> = 0.95, <i>P</i> < .001) for AR fraction, and 15.7 mL ± 11.33 mL ± 14, and 98.9 mL ± 36 for AR volume (<i>r</i> = 0.92, <i>P</i> < .0001), respectively. CT correctly classified severity of AR in 93% of patients based of AR-fraction, and in 89% based on AR volume. The sensitivity and specificity of CT were 98% and specificity 90.3%. The specificity improved to 97%, if the ROA by CT was added as diagnostic criterion. <h3>Conclusion</h3> Aortic regurgitation fraction and volume can be accurately quantified from CT coronary angiography datasets. These parameters can assist clinical management, e.g. in case of pending cardiac surgery decision.

Planimetric Measurement of the Regurgitant Orifice Area Using Multidetector CT for Aortic Regurgitation: a Comparison with the Use of Echocardiography

ObjectiveThis study compared the area of the regurgitant orifice, as measured by the use of multidetector-row CT (MDCT), with the severity of aortic regurgitation (AR) as determined by the use of echocardiography for AR.Materials and MethodsIn this study, 45 AR patients underwent electrocardiography-gated 40-slice or 64-slice MDCT and transthoracic or transesophageal echocardiography. We reconstructed CT data sets during mid-systolic to enddiastolic phases in 10% steps (20% and 35-95% of the R-R interval), planimetrically measuring the abnormally opened aortic valve area during diastole on CT reformatted images and comparing the area of the aortic regurgitant orifice (ARO) so measured with the severity of AR, as determined by echocardiography.ResultsIn the 14 patients found to have mild AR, the ARO area was 0.18±0.13 cm2 (range, 0.04-0.54 cm2). In the 15 moderate AR patients, the ARO area was 0.36 ± 0.23 cm2 (range, 0.09-0.81 cm2). In the 16 severe AR patients, the ARO area was 1.00 ± 0.51 cm2 (range, 0.23-1.84 cm2). Receiver-operator characteristic curve analysis determined a sensitivity of 85% and a specificity of 82%, for a cutoff of 0.47 cm2, to distinguish severe AR from less than severe AR with the use of CT (area under the curve = 0.91; 95% confidence interval, 0.84-1.00; p < 0.001).ConclusionPlanimetric measurement of the ARO area using MDCT is useful for the quantitative evaluation of the severity of aortic regurgitation.

64-Slice Multidetector Computed Tomography (MDCT) for Detection of Aortic Regurgitation and Quantification of Severity

Recent advances in 64-slice multidetector computed tomography (MDCT) provide an opportunity to assess coronary artery disease, left ventricular function and, potentially, valvular heart disease. To determine the ability of 64-MDCT to both detect and to quantify the severity of aortic regurgitation (AR), as compared with transthoracic echocardiography (TTE). We evaluated a total of 64 patients (43 males, mean age 63+/-11 years), 30 with varying severities of AR as assessed by TTE and 34 matched controls. The severity of AR by TTE was determined using the vena contracta, the ratio of jet to left ventricular outflow tract (LVOT) height, and the ratio of the jet to LVOT cross-sectional area. AR by MDCT was defined as a lack of coaptation of the aortic valve leaflets in diastole and, if detected, the maximum anatomic aortic regurgitant orifice was determined. All 34 control patients without AR were correctly identified by MDCT. There were 14 patients with mild AR, 10 with moderate AR, and 6 with severe AR by TTE. Of these patients, MDCT correctly identified 21 patients with AR (sensitivity 70%, specificity 100%, positive predictive value [PPV] 100%, and negative predictive value [NPV] 79%). Anatomic regurgitant orifice area measured by MDCT correlated well with the TTE-derived vena contracta (r=0.79, P<0.001), ratio of jet to LVOT height (r=0.79, P<0.001), and ratio of jet to LVOT cross-sectional area (r=0.75, P<0.001). Direct planimetric measurement of the aortic valve anatomic regurgitant orifice area on 64-MDCT provides an accurate, noninvasive technique for detecting and quantifying AR.

Aortic regurgitation: quantitative methods by echocardiography.

Quantification of aortic regurgitation (AR) is a common and difficult clinical problem. The severity of regurgitation has traditionally been estimated with the use of contrast aortography, which is impractical as a screening tool or for serial examinations. In the past two decades, Doppler echocardiography has emerged as an important tool in the quantification of AR. Pulsed Doppler mapping of the depth of the regurgitant jet into the left ventricle was one of the initial echocardiographic methods used for this purpose. The slope and pressure (or velocity) half-time of continuous-wave Doppler profiles of regurgitant jets are also useful. These Doppler techniques may be used to determine the regurgitant volume or regurgitant fraction in patients with AR. The use of color Doppler to measure the height (or cross-sectional area) of the regurgitant jet relative to the height (cross-sectional area) of the left ventricular outflow tract is both sensitive and specific in the quantification of AR. More recently, the continuity principle has been used to determine the effective aortic regurgitant orifice area, which increases as AR becomes more severe. Although this is a promising tool, calculation of this value is not yet common practice in most echocardiography laboratories. Although no single echocardiographic technique is without limitations, all have some validity, and it is reasonable to use a combination of them to obtain a composite estimate of the severity of AR.

Evaluation of effective aortic regurgitant orifice area and its effect on aortic regurgitant volume with Doppler echocardiography.

The authors measured the aortic regurgitant orifice area (ROA) using Doppler echocardiography and attempted to clarify how important the ROA is in determining the regurgitant volume (RV) in 22 patients with chronic aortic regurgitation (AR). The RV was calculated from the difference between the left ventricular ejection flow volume and transmitral inflow volume as measured by Doppler echocardiography. The ROA was obtained by two methods: RV/time velocity integral of AR jet measured by continuous wave Doppler (calculation method) and manual tracing of minimum cross-sectional area of short-axis color Doppler. The RV ranged from 10 to 90 mL/beat and the ROA by calculation method was from 0.05 to 0.35 cm2, which showed a strong correlation (r = 0.93, p < 0.001). The time velocity integral of aortic regurgitant jet showed a poor correlation with the RV (r = 0.45, p < 0.05). The values of ROA by the two methods showed a good correlation (r = 0.93, p < 0.001). Thus, the authors conclude that the ROA is a basic determinant of the RV in AR and that color Doppler can be employed to precisely assess the ROA.

Lack of Dynamic Change in Effective Aortic Regurgitant Orifice Area Measured by Direct Flow Convergence Surface Area From 3D Flow Images: A Chronic Animal Study

Lack of Dynamic Change in Effective Aortic Regurgitant Orifice Area Measured by Direct Flow Convergence Surface Area From 3D Flow Images: A Chronic Animal Study

Lack of dynamic change in effective aortic regurgitant orifice area measured by direct flow convergence surface area from 3D flow images: a chronic animal study

Lack of dynamic change in effective aortic regurgitant orifice area measured by direct flow convergence surface area from 3D flow images: a chronic animal study

Quantifying aortic regurgitation by using the color Doppler-imaged vena contracta: a chronic animal model study.

The aim of the present study was to evaluate the accuracy of determining aortic effective regurgitant orifice area (EROA) and aortic regurgitant volume by using the color Doppler-imaged vena contracta (CDVC). Twenty-nine hemodynamically different states were obtained pharmacologically in eight sheep with surgically induced aortic regurgitation. Instantaneous regurgitant flow rates (RFRs) were obtained with aortic and pulmonary electromagnetic flowmeters (EFMs), and aortic EROAs were determined from EFM RFRs divided by continuous wave Doppler velocities. Color Doppler-derived EROAs were estimated by measuring the maximal diameters of the CDVC. Peak and mean RFRs and regurgitant volumes per beat were calculated from vena contracta area continuous wave diastolic Doppler velocity curves. Peak EFM-derived RFRs varied from 1.8 to 13.6 (6.3+/-3.2) L/min (range [mean+/-SD]), mean RFRs varied from 0.7 to 4.9 (2.7+/-1.3) L/min, regurgitant volumes per beat varied from 7.0 to 48.0 (26.9+/-12.2) mL/beat, and the regurgitant fractions varied from 23% to 78% (55+/-16%). EROAs determined by using CDVC measurements correlated well with reference EROAs obtained by using the EFM method (r=.91, SEE=0.07 cm2). Excellent correlations and agreements between peak and mean RFR and regurgitant volumes per beat as determined by Doppler echocardiography and EFM were also demonstrated (r=.95 to .96). Our study indicates that the CDVC method can be used to quantify both aortic EROAs and regurgitant flow rates.

Effective Regurgitant Orifice Area by the Color Doppler Flow Convergence Method for Evaluating the Severity of Chronic Aortic Regurgitation

The aim of the present study was to evaluate dynamic changes in aortic regurgitant (AR) orifice area with the use of calibrated electromagnetic (EM) flowmeters and to validate a color Doppler flow convergence (FC) method for evaluating effective AR orifice area and regurgitant volume. In 6 sheep, 8 to 20 weeks after surgically induced AR, 22 hemodynamically different states were studied. Instantaneous regurgitant flow rates were obtained by aortic and pulmonary EM flowmeters balanced against each other. Instantaneous AR orifice areas were determined by dividing these actual AR flow rates by the corresponding continuous wave velocities (over 25 to 40 points during each diastole) matched for each steady state. Echo studies were performed to obtain maximal aliasing distances of the FC in a low range (0.20 to 0.32 m/s) and a high range (0.70 to 0.89 m/s) of aliasing velocities; the corresponding maximal AR flow rates were calculated using the hemispheric flow convergence assumption for the FC isovelocity surface. AR orifice areas were derived by dividing the maximal flow rates by the maximal continuous wave Doppler velocities. AR orifice sizes obtained with the use of EM flowmeters showed little change during diastole. Maximal and time-averaged AR orifice areas during diastole obtained by EM flowmeters ranged from 0.06 to 0.44 cm2 (mean, 0.24 +/- 0.11 cm2) and from 0.05 to 0.43 cm2 (mean, 0.21 +/- 0.06 cm2), respectively. Maximal AR orifice areas by FC using low aliasing velocities overestimated reference EM orifice areas; however, at high AV, FC predicted the reference areas more reliably (0.25 +/- 0.16 cm2, r = .82, difference = 0.04 +/- 0.07 cm2). The product of the maximal orifice area obtained by the FC method using high AV and the velocity time integral of the regurgitant orifice velocity showed good agreement with regurgitant volumes per beat (r = .81, difference = 0.9 +/- 7.9 mL/beat). This study, using strictly quantified AR volume, demonstrated little change in AR orifice size during diastole. When high aliasing velocities are chosen, the FC method can be useful for determining effective AR orifice size and regurgitant volume.

Dynamic nature of the aortic regurgitant orifice area during diastole in patients with chronic aortic regurgitation.

The effective aortic regurgitant orifice area varies with aortic pressure in animal models of acute aortic regurgitation. The purpose of this study was to determine whether the aortic regurgitant orifice area changes during diastole in patients with chronic aortic regurgitation. Two-dimensional and Doppler echocardiography were performed immediately before and after magnetic resonance velocity mapping using a cine phase contrast sequence in 17 patients with chronic aortic regurgitation. ECG-gated continuous-wave Doppler velocity time integrals and magnetic resonance flow rates were measured 16 times per cardiac cycle. The mean aortic regurgitant orifice area (centimeters squared) was calculated by the continuity equation. The regurgitant orifice area was also determined for each diastolic acquisition interval. Changes in the regurgitant orifice area during diastole were modeled using an asymptotic exponential decay model to determine the static and dynamic components of the orifice. The regurgitant orifice area increased directly with regurgitant fraction (y[cm2] = 0.0072[cm2/%]*x[%]-0.0409[cm2]; r = .86, P < .0001). In 15 of 17 (88%) patients, the regurgitant orifice area decreased during diastole. The dynamic component of the regurgitant orifice area decreased with increasing regurgitant fraction (y[%] = -0.98x[%]+96.9[%]; r = -.90, P < .0001). There were no significant differences in heart rate, systolic or diastolic blood pressures, or continuous-wave Doppler velocity time integrals measured before or after the magnetic resonance examination. The effective regurgitant orifice area decreases during diastole in patients with chronic aortic regurgitation. This phenomenon should be considered when evaluating aortic regurgitant severity.

Influence of aortic pressure on effective regurgitant orifice area in aortic regurgitation.

The regurgitant volume in aortic regurgitation is determined by the diastolic filling period, the pressure gradient between the left ventricle and aorta, and the hemodynamic size of the regurgitant orifice area. To test the hypothesis that the aortic regurgitant orifice area is related to aortic pressure and aortic root size, 16 fresh calf heart and aorta specimens were studied in vitro using a continuous-flow system over a range of aortic pressures. Regurgitant orifice areas were calculated as the ratio of flow divided by peak velocity through the valve measured by image-guided continuous-wave Doppler, and aortic root areas were measured by two-dimensional echocardiography. When the defect was created at the edge of the noncoronary leaflet (n = 10), regurgitant orifice area gradually increased 51 +/- 33% when aortic pressure was increased from approximately 40 to 152 cm of water (29.6 to 112.5 mm Hg) (p less than 0.0001). Similarly, the aortic root size increased 82 +/- 29% when the defect was created at the leaflet edge (p less than 0.0001). In contrast, when defects were created at the center of the noncoronary leaflet (n = 6), only a small increase in regurgitant orifice area (9 +/- 7%) was observed with increasing pressure (p = 0.043). The aortic root area remained strongly pressure dependent in specimens with defects at leaflet centers (p less than 0.0001). The aortic regurgitant orifice area is dependent on both aortic pressure and the nature of the defect in the valve. Because not all regurgitant aortic valves are alike, further study of the nature of the regurgitant orifice area in humans may allow identification of patients who would benefit most from aggressive pharmacological therapy.

Load dependence of the effective regurgitant orifice area in a sheep model of aortic regurgitation

Treatment of patients with aortic regurgitation with vasodilators reduces regurgitant volume, ventricular dilation and left ventricular mass. Although these effects are presumably due to afterload reduction, it is also possible that the aortic regurgitant orifice area is not constant. To test the latter hypothesis, aortic regurgitation was created in 10 open chest sheep by partial resection of the noncoronary leaflet under direct visualization. Regurgitant flow was measured with an aortic supravalvular electromagnetic probe; aortic and left ventricular pressures were measured with catheter-tipped micromanometer pressure transducers.The effective regurgitant orifice area was calculated by a modification of the continuity equation in a manner similar to the Gorlin equation. The regurgitant orifice area was measured three times: after aortic regurgitation was created, after mean arterial pressure was increased by 15 to 25 mm Hg with intravenous dopamine and after mean arterial pressure was reduced by 15 to 25 mm Hg with intravenous sodium nitroprusside. Comparison of regurgitant volumes and areas obtained after creation of aortic regurgitation and at the conclusion of the experiment in the absence of dopamine or sodium nitroprusside demonstrated no significant change over time.Dopamine administration was associated with an 86 ± 81% increase in regurgitant volume (p < 0.01) and a 38 ± 44% increase in regurgitant orifice area (p < 0.01). Sodium nitroprusside administration resulted in a 51 ± 14% decrease in regurgitant volume (p < 0.001) and a 28 ± 21% reduction in regurgitant orifice area (p = 0.007).In this model of acute aortic regurgitation, the effective regurgitant orifice area was altered by increasing or decreasing the aortic transvalvular pressure gradient. This dynamic nature of the regurgitant orifice area may be secondary to changes in aortic root geometry at various aortic pressures. Reduction of this area may be one of the mechanisms of the beneficial effect of afterload reduction in patients with aortic regurgitation, particularly when the elasticity of the aortic valve apparatus has not been impaired by fibrosis or calcification.

Effective aortic regurgitant orifice area: Description of a method based on the conservation of mass

The natural history of aortic regurgitation is incompletely understood in part because of the lack of a simple method to estimate the defect size. A method of determining the effective regurgitant orifice area that combines Doppler catheter and Doppler echocardiographic techniques and is based on the principle of conservation of mass (the continuity equation) is described. To validate the application of the Doppler catheter system for measuring regurgitant supravalvular diastolic flow, an in vitro model of retrograde aortic flow was used. These studies indicated that measurements of supravalvular retrograde velocity with the Doppler catheter accurately reflect retrograde diastolic velocity when the aorta is <4.8 cm in diameter.Twenty-three patients undergoing cardiac catheterization were studied; 20 of these patients had aortic regurgitation. Retrograde supravalvular diastolic velocity was determined from a Doppler catheter positioned above the aortic valve. The effective regurgitant orifice area was calculated with use of the Doppler catheterderived regurgitant volume and mean transvalvular diastolic velocity as determined by either catheterization or continuous wave Doppler echocardiography. The catheterization-derived regurgitant orifice area increased with the angiographic grade of aortic regurgitation as follows: 1+ (0.04 to 0.10 cm2), 2+ (0.15 to 0.49 cm2), 3+ (0.29 to 1.11 cm2) and 4+ (1.24 to 1.33 cm2).By combining Doppler catheter, echocardiographic and cardiac catheterization techniques, the effective aortic regurgitant orifice area may be estimated; this hydrodynamic area correlates with grading by supravalvular aortography. Calculation of this area provides a quantitative alternative to aortography for estimating the severity of aortic regurgitation but should be used with caution in patients with a markedly dilated aorta.