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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The orifice area was non-invasively assessed in 19 patients with mitral or mitral and tricuspid stenosis by combined cross-sectional and Doppler echocardiography. Stroke volume was calculated as the product of aortic or pulmonic cross-sectional area and the time velocity integral of the flow across that valve, and the stenotic valve area was obtained as the stroke volume divided by the time velocity integral of the stenotic valve. In addition, the mitral valve area was estimated by the pressure half-time method of Hatle et al. The non-invasive determinations were compared with those calculated by the Gorlin formula at cardiac catheterization. The valve area obtained by combined cross-sectional and Doppler echocardiography showed a close correlation with the Gorlin area, r = 0.90, SEE = 0.13 cm2, n = 20. In contrast, the valve area estimated by the pressure half-time method showed only a moderate correlation with the Gorlin area, r = 0.68, SEE = 0.38 cm2, n = 18, and estimates by this method tended to significantly overestimate the Gorlin area. In conclusion, non-invasive valve area determinations based on combined cross-sectional and Doppler echocardiography can be used to accurately quantify the severity of the lesion in patients with atrioventricular valve stenosis, while determinations by the pressure half-time method may show errors of a magnitude that limits its clinical applicability.
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PMID:Doppler echocardiographic assessment of the valve area in patients with atrioventricular valve stenosis by application of the continuity equation. 272 84

Seventeen consecutive patients undergoing bidirectional cavopulmonary anastomosis (BDCPA) using normothermic, noncardioplegic, cardiopulmonary bypass were studied preoperatively and early postoperatively (12.2 days) using transthoracic echocardiographic techniques. The purpose of the study was to assess the changes in left ventricular mechanics associated with the change in blood flow related to the BDCPA. Of the 17 patients, pulmonary atresia and tricuspid stenosis was present in 7, tricuspid atresia in 6, double inlet left ventricle in 3, and severe pulmonic stenosis with straddling of the tricuspid valve in 1. All other forms of single ventricle type anatomy and other patients undergoing BDCPA were excluded for the purposes of this study. The mean left ventricular end-diastolic volume index fell from 120 mL/m2 to 91.1 mL/m2 (p < 0.05). Similarly the left ventricular end-systolic volume index fell from 55.8 mL/m2 to 42.3 mL/m2, respectively (p < 0.05). The stroke volume index also fell from 64.5 mL/m2 to 48.8 mL/m2. Left ventricular ejection fraction was preserved and was unchanged in every patient. It was concluded that BDCPA, performed as described above, preserves left ventricular function and that the systolic and diastolic volumes as well as the stroke volume are significantly decreased as evidence of improvement of left ventricular mechanics. The continued use of the BDCPA either as a definitive procedure or as a staged procedure in preparation for total cavopulmonary connection is therefore endorsed.
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PMID:Enhancement of ventricular mechanics following bidirectional superior cavopulmonary anastomosis in patients with single ventricle. 777 75

The right ventricle in patients with severe outflow obstruction or atresia and a small tricuspid valve often remains too hypoplastic even after optimal palliation to tolerate biventricular repair with closure of the atrial septal defect. In these patients, nonpulsatile cavopulmonary (Glenn) anastomosis has traditionally facilitated biventricular repair. In 1989, Billingsley and associates reported the addition of a bidirectional cavopulmonary anastomosis to the definitive biventricular repair in patients with hypoplastic right ventricle, pulmonary atresia, and intact ventricular septum. The atrial septal defect was left open with an adjustable snare for later closure. We report five patients with hypoplastic right ventricle (mean diastolic volume 48.4%, mean stroke volume 40.2% of predicted value) who had the atrial septal defect closed at the time of the biventricular repair. Four patients, who had the bidirectional cavopulmonary anastomosis supplementing the biventricular repair, had no evidence of excessive right atrial or superior vena cava hypertension postoperatively. One patient, who had atypical tetralogy of Fallot with tricuspid stenosis, developed recurrent pericardial tamponade and marked hepatomegaly following conventional tetralogy repair with closure of the atrial septal defect. These complications were controlled with the addition of bidirectional cavopulmonary anastomosis 2 months later. Postoperative hemodynamic or Doppler studies in these patients revealed pulsatile flow in the entire pulmonary artery system, including the artery distal to the Glenn anastomosis. This modification of biventricular repair allows primary closure of the atrial septal defect and provides pulsatile arterial flow in the entire pulmonary artery, even when the right ventricle is significantly hypoplastic.
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PMID:Biventricular repair of hypoplastic right ventricle assisted by pulsatile bidirectional cavopulmonary anastomosis. 841 91

Authors report the results of prospective and longitudinal study. The aims of this study were to evaluate among 35 patients, prevalence, diagnosis and treatment aspects of tricuspid stenosis (TS), as well as evolution and pronostical factors. The prevalence of TS was about 4.2%. The main clinical signs were: dyspnoea (94.2%), jugular veinus pulses (42.8%), superior cave syndrom (68.8%), diastolic rumble (74.3%). ECG showed sinus rhythm (51.4%), a right atrial hypertrophy (48.5%). Echocardiography showed tricuspid leaflets thickened (82.8%), a right atrial hypertrophy (48.5%), a mean gradient between right atrial and right ventricle: 8.6 +/- 3.14 mmHg (65.7%) and mean tricuspid area about 1.41 +/- 0.83 cm2 (continuous equation); about 1.74 +/- 1.29 cm2 (Hatle formula) and 1.11 0.84 cm2 (simplified Hatle formula). Aetiology was only rheumatic fever. After a follow-up of 8.53 +/- 6.06 months, the mortality rate was 28.5%. Complications were irreducible heart failure (24 cases), liver failure (2 cases) and stroke (3 cases). Factors associated with mortality were: severity of tricuspid stenosis and pulmonary hypertension, importance of dyspnea and heart failure (p < 0.041).
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PMID:[Tricuspid valve stenosis. A prospective study of 35 cases]. 1578 15

Two-dimensional echocardiography (2DE) with color Doppler has been the standard tool for assessing valvular heart disease. However, this requires conceptualizing three-dimensional (3D) valvular anatomy from individual 2D slices, which is inadequate for complex valvular abnormalities. Similarly, Doppler-based methods are inherently limited by several assumptions and are influenced by hemodynamics and concomitant valvular disease. 3DE has improved both morphological and functional assessment of valvular heart disease. It provides additional morphological information, which leads to better understanding of the mechanism of valvular dysfunction and surgical planning. 3D planimetry has proven to be accurate in the evaluation of valvular stenosis. This direct assessment eliminates measurement errors and could potentially serve as new gold standard. The continuity equation for aortic stenosis can be simplified by directly measuring left ventricular outflow tract area and stroke volume. In patients with valvular regurgitation, vena contracta area can be directly measured by using 3D color Doppler which is more accurate than the standard 2D methods. By applying hemi-elliptical formula or directly measuring isovelocity surface area, 3DE has significantly improved the accuracy in regurgitant severity assessment. This is particularly useful in patients with eccentric jets. 3DE has an advantage over 2DE in assessment of tricuspid valve due to its complex geometry. Direct planimetry of orifice area in tricuspid stenosis, or vena contracta area in tricuspid regurgitation are promising although validation studies are needed before they can be applied for clinical decision making. 3DE has not been widely studied in pulmonic valve disease but preliminary data indicate that it is feasible.
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PMID:Three-dimensional echocardiography in valvular heart disease. 2318 93