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Dive into the research topics where Dylmitr Rittoo is active.

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Featured researches published by Dylmitr Rittoo.


Journal of The American Society of Echocardiography | 1994

A Prospective Study of Left Atrial Spontaneous Echo Contrast and Thrombus in 100 Consecutive Patients Referred for Balloon Dilation of the Mitral Valve

Dylmitr Rittoo; George R. Sutherland; Peter D. Currie; Ian R. Starkey; T R D Shaw

The aim of this study was to determine the clinical, echocardiographic, and hemodynamic predictors of left atrial spontaneous echo contrast (SEC) and thrombus, respectively, in patients referred for balloon dilation of the mitral valve and to establish the relationship between the two phenomena in this group of patients. One hundred consecutive patients (mean age 57 +/- 14 years) referred for mitral balloon (Inoue) dilation were studied prospectively with transthoracic and transesophageal (83 biplane and 17 single plane) echocardiography (TEE) combined with spectral and color Doppler modalities, immediately before the procedure. TEE was repeated within 24 hours of valvotomy in the first 55 patients. All patients also underwent comprehensive left- and right-sided heart catheterization. TEE was performed successfully in 96 patients. SEC was detected in all 65 patients in atrial fibrillation and in 14 (45%) of 31 patients in sinus rhythm. Patients with SEC were significantly older (61 +/- 13 vs 45 +/- 12 years; p < 0.001) and had larger left atrial volume (98 +/- 48 vs 64 +/- 24 ml; p < 0.001), higher mitral valve echocardiographic scores (7.4 +/- 3.2 vs 5.3 +/- 2.6; p = 0.016), lower cardiac output (3.5 +/- 1.1 versus 4.6 +/- 0.9 L/min; p < 0.001), lower peak systolic pulmonary vein flow velocity (SVm) (24 +/- 12 versus 45 +/- 11 cm/sec; p < 0.001), and correspondingly lower systolic velocity-time integral (4.0 +/- 2.6 vs 7.9 +/- 2.9 cm; p < 0.001) than had patients without SEC. There were no significant associations between SEC and either mitral valve area or anticoagulant therapy. SVm and atrial fibrillation were found to be independent predictors of SEC. In patients in sinus rhythm, SVm was the only independent predictor of SEC. After mitral balloon dilation, SEC disappeared in only two of 35 patients in atrial fibrillation and in five of eight patients in sinus rhythm. Significant mitral regurgitation occurred in the two patients in atrial fibrillation. TEE detected left atrial thrombus in 14 patients. Thrombus was significantly associated with age, mitral valve area, and the severity of SEC. The latter was found to be an independent predictor of thrombus. Two patients in sinus rhythm had evidence of left atrial mechanical dysfunction. Both patients had left atrial SEC and one had thrombus in the appendage. It is concluded that SEC in patients with severe mitral stenosis is dependent on left atrial systolic function and peak systolic pulmonary vein velocity. It is not related to mitral valve area or anticoagulant therapy.(ABSTRACT TRUNCATED AT 400 WORDS)


American Heart Journal | 1993

The comparative value of transesophageal and transthoracic echocardiography before and after percutaneous mitral balloon valvotomy: A prospective study

Dylmitr Rittoo; George R. Sutherland; Peter D. Currie; Ian R. Starkey; T R D Shaw

Transthoracic (TTE) and transesophageal echocardiography (TEE) were performed prospectively on 53 consecutive patients (mean age 59 +/- 14 years) immediately before and within 24 hours of mitral balloon valvotomy to compare the relative value of the two techniques. Biplane TEE was used in 38 patients and single-plane imaging was done in 11. All patients underwent left and right cardiac catheterization, left ventriculography, and coronary angiography. While TEE provided excellent images of the mitral valve in all patients, imaging planes were more limited than by TTE. Mitral valve morphology could be assessed satisfactorily by either technique. Echo scores derived from each showed good correlation (r = 0.90, p < 0.001). TEE transgastric longitudinal scanning provided superior detail of the subvalvar apparatus but only in 20 (53%) of 38 patients. Patients with good transgastric views had significantly smaller left atrial volumes than those without (58 +/- 22 vs 106 +/- 41 cm3, p < 0.001). Mitral valve orifice and the commissures were better assessed by TTE. Before valvotomy, mitral regurgitation (MR) graded by TEE and TTE color flow mapping was concordant with angiography in 80% and 81%, respectively. After valvotomy, TTE color flow mapping failed to detect MR in two of the three patients who developed severe MR. Two of these patients were examined by TEE, which demonstrated both the MR jets as well as leaflet tears. Thrombus was diagnosed in the left atrium in eight patients by TEE and in only one patient by TTE. Biplane TEE was required for accurate thrombus localization and for assessing its size and extent. Five patients with thrombus underwent balloon valvotomy without complications. Left-to-right atrial shunting was detected by TEE and TTE in 95% and 48% of patients, respectively. Flow convergence regions, from which quantitative flow information can be derived, were imaged by TEE only. TTE and TEE have complementary roles. However, TEE is essential for excluding thrombus in the left atrium before balloon valvotomy. After the procedure, TEE is recommended for the evaluation of patients with severe mitral regurgitation.


Circulation | 1993

Quantification of left-to-right atrial shunting and defect size after balloon mitral commissurotomy using biplane transesophageal echocardiography, color flow Doppler mapping, and the principle of proximal flow convergence.

Dylmitr Rittoo; George R. Sutherland; T R D Shaw

BackgroundThe flow convergence region (FCR), a zone of progressive laminar velocity acceleration, can be imaged by color Doppler proximal to stenotic and regurgitant orifices. Theoretically, FCR proximal to a discrete circular and planar orifice consists of concentric hemispheric shells of equal and accelerating velocities centered at the orifice. According to the continuity principle, flow rate across any of these isovelocity surfaces equals flow rate through the orifice. The aim of this study was to investigate whether these principles could be applied to quantify left-to-right shunting and the size of atrial septal defects after balloon mitral commissurotomy. Methods and ResultsBiplane transesophageal echocardiography (TEE) with color flow imaging was performed on 36 consecutive patients (mean age, 57


American Journal of Cardiology | 1993

Role of transesophageal echocardiography in diagnosis and management of central pulmonary artery thromboembolism

Dylmitr Rittoo; George R. Sutherland; Leslie Samuel; Andrew D. Flapan; T R D Shaw

16 years; range, 14-78 years) immediately before and within 24 hours of balloon (Inoue, N=33; Mansfield, N=3) mitral commissurotomy. Left-to-right atrial shunting was detected by TEE in 33 patients (92%) and by oximetry in 11 patients (31%). The radius r of FCR was measured from the first aliasing limit, at a Nyquist velocity reduced to 11 cm/sec by zero-shifting, to the orifice in the atrial septum. FCR was assumed to be hemispherical. Hence, flow rate (Q) was calculated as 2


Journal of The American Society of Echocardiography | 1994

Posterior Left Ventricular Pseudoaneurysm After Aortic Valve Replacement in a Patient With Rheumatoid Arthritis: Diagnosis by Transesophageal Echocardiography

Dylmitr Rittoo; George R. Sutherland

r2 Vr, where Vr is the velocity at a radial distance r. The velocity profile of transatrial flow was assessed by means of high pulse repetition frequency, from which the maximum flow velocity (Vp) and the velocity-time integral (VTI) were obtained. The flow area of the atrial septal defect was calculated as Q., the maximal flow rate, divided by Vp. Hence, shunt flow was calculated as flow area XVTIxheart rate. FCR was analyzed in two orthogonal planes. Mean Qm. (38.1 & 26.5 versus 5.3


Journal of The American Society of Echocardiography | 1997

Detection of a small left atrial myxoma: value and limitations of four imaging modalities

Dylmitr Rittoo; Lawrence Cotter

2.7 mL/sec), flow area (22.1


The Cardiology | 1998

A Prospective Echocardiographic Study of the Effects of Balloon Mitral Commissurotomy on Pre-Existing Mitral Regurgitation in Patients with Mitral Stenosis

Dylmitr Rittoo; George R. Sutherland; T R D Shaw

11.2 versus 4.4


The Cardiology | 1997

Transseptal Mitral Balloon Valvotomy in Patients with Atrial Septal Aneurysms

Dylmitr Rittoo; George R. Sutherland; T R D Shaw

2.0 mm2), and shunt flow (1,590


The Lancet | 1992

Complications of "ecstasy" misuse

DevB. Rittoo; Dylmitr Rittoo; Simon J. Ellis; AndrewJ. Larner

1,070 versus 200


Journal of The American Society of Echocardiography | 1999

Recurrent Prosthetic Valve Thrombosis: Importance of Prolonged Doppler Echocardiography Examination for Diagnosis

Dylmitr Rittoo; Helen Buckley; Lawrence Cotter

130 mL/min) on transverse plane imaging were all significantly higher in patients with shunts detected by oximetry than in those without. Similar results were obtained from longitudinal plane imaging. Q. correlated well with oximetric shunt flow (r=0.89-0.94, p<0.001) and shunt ratio (r=0.91-0.94, p<0.001). Flow area correlated closely (r=0.93-0.94, p<0.001) with area determined by direct measurement from two-dimensional echocardiography. Shunt flow determined by FCR also correlated closely (r=0.94-0.98, p<0.001) with that determined by oximetry and that derived from two-dimensional echocardiography and pulsed Doppler (r=0.96, p<0.001). ConclusionsThe flow convergence region imaged by TEE color flow mapping provides new and accurate quantitative information on atrial shunt flow and defect size after balloon mitral valvotomy. It is a quick, reliable, and fairly simple method that can be readily incorporated into routine clinical practice.

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George R. Sutherland

Katholieke Universiteit Leuven

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T R D Shaw

Western General Hospital

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Ian R. Starkey

Western General Hospital

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DevB. Rittoo

University of Manchester

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Leslie Samuel

Aberdeen Royal Infirmary

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