|LETTER TO THE EDITOR
|Year : 2018 | Volume
| Issue : 3 | Page : 197-198
Modified parameter of two-dimensional echocardiographic Wilkins score for assessment of rheumatic mitral valve stenosis
Wassam El Din Hadad El Shafey
Menoufia University Hospital, Shebien El Koom, Menoufia, Egypt
|Date of Web Publication||10-Dec-2018|
Dr. Wassam El Din Hadad El Shafey
Menoufia University Hospital, Shebien El Koom, Menoufia
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
El Shafey WE. Modified parameter of two-dimensional echocardiographic Wilkins score for assessment of rheumatic mitral valve stenosis. J Indian Acad Echocardiogr Cardiovasc Imaging 2018;2:197-8
|How to cite this URL:|
El Shafey WE. Modified parameter of two-dimensional echocardiographic Wilkins score for assessment of rheumatic mitral valve stenosis. J Indian Acad Echocardiogr Cardiovasc Imaging [serial online] 2018 [cited 2019 Jan 16];2:197-8. Available from: http://www.jiaecho.org/text.asp?2018/2/3/197/247022
| Introduction|| |
The mitral valve (MV) is the most commonly and severely affected (65%–70% of patients) by rheumatic process by stenosis and/or regurgitation. Percutaneous balloon mitral valvuloplasty (BMV) was introduced in 1984 by Inoue et al. for the treatment of selected patients with mitral stenosis (MS). BMV is a minimally invasive, nonsurgical procedure that has been established in several clinical studies to be a safe and effective therapeutic modality in selected patients with MS and is equivalent to or even better than surgical commissurotomy.
Unfavorable results of BMV are largely due to unfavorable morphology of the valve apparatus, particularly leaflets calcification and subvalvular apparatus involvement. A MV score has been proposed about two decades ago, based on morphologic assessment of MV apparatus by two-dimensional (2D) echocardiography to predict successful balloon dilation of the MV. Several other scores have been developed in the following years to more successfully predict balloon dilatation outcome.,
As regarding the subjective nature of the Wilkins score, for assessment of rheumatic MV stenosis by 2D echocardiography, I present a novel objective and quantitative echocardiographic parameter for precise selection of patient best treated by BMV in addition to Wilkins score, through measuring free 2D strain and strain rate of both papillary muscles of MV.
| Patients and Methodology|| |
- Patients with coronary artery disease (CAD) and apparent left ventricular (LV) wall motion abnormalities
- Patients with LV systolic dysfunction (ejection fraction % <50%)
- Patients with cardiac rhythm or conduction disturbances such as atrial fibrillation or artificial pacing
- Patients with concomitant moderate or severe mitral regurgitation, aortic stenosis, and aortic regurgitation.
Each person included in the study was subjected to
- Careful history taking and thorough physical examination
- Standard twelve-lead electrocardiogram: For assessment of cardiac rhythm and features suggesting chamber enlargement and CAD
- Basic echocardiographic measurement.
Patients were monitored through a single-lead electrocardiogram.
The left atrial diameter, LV end-systolic and end-diastolic diameters, LV fractional shortening percentage, the thickness of the interventricular septum, and the posterior wall were measured according to the recommendations of the American Society of Echocardiography.
The LV ejection fraction was calculated by Simpson's biplane method of disks. Conventional MS indices such as maximum MV pressure gradient and mean MV pressure gradient mean gradient (MG) were calculated. MV area (MVA) was measured by mitral orifice planimetry in parasternal short axis view and by the Doppler-derived pressure halftime method, and the average area was calculated by the mean value of two measurements. MS severity was calculated based on hemodynamic data, using MVA, MG, and pulmonary artery systolic pressure (PAP) as follows: mild MS (MVA >1.5 cm2, MG <5 mmHg, or PAP <30 mmHg), moderate MS (MVA 1.0–1.5 cm2, MG 5–10 mmHg, or PAP 30–50 mmHg), and severe MS (MVA <1.0 cm2, MG >10 mmHg, or PAP >50 mmHg). PAP was measured by adding 10 mmHg, considering the diameter of the inferior vena cava and level of its collapse resulting from respiration, to the value measured by evaluating the Bernoulli equation, which is simplified from tricuspid insufficiency velocities. The valvular insufficiency was evaluated by color flow Doppler imaging.
Measurement of the 2D strain and strain rate: 2D echocardiography images (transmit/receive 1.9/4.0 MHz) were obtained from LV apical LAX, 4C, and 2C views with frame rates of 50–90 frames/s. Digital data were stored and analyzed offline. LV endocardial surface was traced manually, and the speckle tracking width was modified so as to cover the whole LV wall thickness to obtain curves. Peak LV longitudinal systolic strain (LSS) and strain rate (LSSr) were calculated for apical LAX, 4C, and 2C views, and global LV systolic strain (GLSS) and strain rate (GLSSr) were calculated by averaging the three apical views. Longitudinal myocardial strain of papillary muscle PMs was evaluated using the free strain method from apical four chamber view for anterolateral PM (APM) and apical long-axis view for posteromedial PM (PPM).
Patients in whom PM views were visually clear in both systole and diastole were considered eligible for the assessment.
Free strain method enables the measurement of user-defined custom local velocities, displacement, and deformation using unlimited directional chords display technic. This workflow measures strain within the myocardial region, free of restraints on the location or direction of the measurements, which can be radial, longitudinal, and circumferential. Free strain is thought to be an easy, quick, and practical method of measuring myocardial deformation. This method may be particularly preferable in measuring the deformation of PMs since these structures are relatively separate from the LV myocardium and are not included in the commercially available LV strain models.
To measure the longitudinal strain by using the free strain method, a region of interest should be selected by clicking two points manually. The first point was selected from the base of the PM at its attachment zone to the LV wall. The second point was selected from the tip of the PM with special attention to keep a 3–5 mm distance from the chordae in order to avoid artifacts.
All STE acquisitions were performed at frame rates between 50–70 Hz frames per se cond. The average value of strain was taken from the three consecutive beats. The peak systolic values were recorded for global circumferential strain, GLS, and longitudinal S of APM and PPM.
All the echocardiographic studies were performed by one echocardiographer, and for intraobserver variability, a sample of 2D strain and strain rate measurements was randomly selected and examined by the same observer in two different days, and intraclass correlation coefficients for the same observer were calculated.
Rational for the study protocol
I supposed that the addition of 2D speckle tracking strain and strain rate parameters of both papillary muscles of the MV may increase the value of the traditional Wilkins score of rheumatic MV stenosis assessment especially in the area of gray zone where the Wilkins score is 9 to 11 over 16 as to precisely decide if the surgery is superior to the percutaneous BMV.
Hence, if the papillary muscle free strain and strain rate cutoff values were measured and decided where below those values might carry good indication for balloon valvuloplasty and values higher than these cutoff values may encourage toward surgery.
The rational for assessment of 2D speckle tracking-free strain and strain rate of both papillary muscles is that rheumatic affection of the papillary muscles and the underlying fibrosis that may affect the MV apparatus including subvalvular part could involve and extend toward both papillary muscles which subsequently hinder the free geometric changes and deformation during function of MV.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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