Journal of the American Society of Echocardiography
Original articleMitral Annulus Size Links Ventricular Dilatation to Functional Mitral Regurgitation
Section snippets
Methods
We analyzed the data of the consecutive canines with tachycardia-induced cardiomyopathy that were included in various experimental heart failure treatment protocols from January 2001 to July 2002.8, 9, 10, 11 All data were collected in a prospective manner. All animals received humane care in compliance with the “Guide for the Care and Use of Laboratory Animals” prepared by the Institute of Laboratory Animal Resources, National Research Council, and published by the National Academy Press
Results
Table 1 shows hemodynamic and echocardiographic parameters associated with dilated cardiomyopathy induction. Although echocardiography data at baseline and after cardiomyopathy induction were acquired with the animal in conscious and anesthetized state, respectively, the dramatic change of parameters can still be appreciated. Interestingly, the only parameter that was not changed was LV long-axis length in diastole. MR was detected by color Doppler mapping in 42/53 studies. If MR was present,
Discussion
In this study, we have shown that the amount of functional MR observed in the presence of global LV dilation is coupled to mitral annular dilation. Interestingly, MR showed no consistent association with mitral leaflet deformation or PM tethering. However, mitral annular dilation showed correlation with these previously described features of functional MR, which may indicate that they all relate to the same underlying process, with mitral annulus area a most easily quantified feature. Finally,
References (26)
- et al.
Overestimation of severity of ischemic/functional mitral regurgitation by color Doppler jet area
Am J Cardiol
(1994) - et al.
The mechanism of decrease in dynamic mitral regurgitation during heart failure treatmentimportance of reduction in the regurgitant orifice size
J Am Coll Cardiol
(1998) - et al.
Determinants of pulmonary hypertension in left ventricular dysfunction
J Am Coll Cardiol
(1997) - et al.
Device-based change in left ventricular shapea new concept for the treatment of dilated cardiomyopathy
J Thorac Cardiovasc Surg
(2001) - et al.
Induction and maintenance of an experimental model of severe cardiomyopathy with a novel protocol of rapid ventricular pacing
J Thorac Cardiovasc Surg
(2002) - et al.
The Coapsys device to treat functional mitral regurgitationin vivo long-term canine study
J Thorac Cardiovasc Surg
(2004) - et al.
Echocardiographic assessment of regional ventricular function after device-based change of left ventricular shape
J Am Soc Echocardiogr
(2004) - et al.
Isolated annular dilation does not usually cause important functional mitral regurgitationcomparison between patients with lone atrial fibrillation and those with idiopathic or ischemic cardiomyopathy
J Am Coll Cardiol
(2002) - et al.
Beta-blockade therapy in chronic heart failurediastolic function and mitral regurgitation improvement by carvedilol
Am Heart J
(2000) - et al.
Ventricular remodeling and mitral valve modifications in dilated cardiomyopathynew insights from anatomic study
J Thorac Cardiovasc Surg
(2002)
Does the intertrigonal distance dilate? Never say never
J Thorac Cardiovasc Surg
Tachycardia-induced cardiomyopathy in the ovine heartmitral annular dynamic three-dimensional geometry
J Thorac Cardiovasc Surg
Geometric changes of mitral annulus assessed by real-time 3D echocardiographybecoming enlarged and less non-planar in the antero-posterior direction during systole in proportion to global left ventricular systolic function
J Am Soc Echocardiogr
Cited by (23)
Functional Mitral Regurgitation: Imaging Insights, Clinical Outcomes and Surgical Principles
2017, Progress in Cardiovascular DiseasesMitral annulus segmentation from four-dimensional ultrasound using a valve state predictor and constrained optical flow
2012, Medical Image AnalysisCitation Excerpt :It is typically viewed in the clinical setting using four-dimensional (3D + time) ultrasound (4DUS), as ultrasound is inexpensive, portable, and non-ionizing. The shape and motion of the annulus are used in a number of applications, most commonly for pathology diagnosis, as it has been shown that the there is a strong correlation of annular shape and motion to several pathologies (Levine et al., 1989; Herregods et al., 1997; Flachskampf et al., 2000; Kaplan et al., 2000; Ahmad et al., 2004; Kaji et al., 2005; Popovic et al., 2005; Daimon et al., 2008; Alkadhi et al., 2009; Bothe et al., 2008). It is also used as boundary conditions for mitral valve models (Kunzelman et al., 1993; Einstein et al., 2005; Lim et al., 2005; Votta et al., 2008; Hammer et al., 2008a,b), to assess valve function (Salgo et al., 2002; Jimenez et al., 2003), for surgical planning (Fabricius et al., 2004), and for implant design (Ferrazzi et al., 2009).
Another multidisciplinary look at ischemic mitral regurgitation
2011, Seminars in Thoracic and Cardiovascular SurgeryCitation Excerpt :Although annular dilation may affect coaptation depth if subvalvular geometry remains constant, it is septal-lateral annular enlargement that exhausts mitral leaflet redundancy resulting in MR by decreasing leaflet coaptation length (ie, the length of leaflet apposition at the coaptation line).54 Similar observations were reported by Popović and colleagues42 in their echocardiographic assessment of FMR in a canine model of tachycardia induced cardiomyopathy. Tethering of both leaflets has also been observed echocardiographically in patients with IMR.27,58
Effects and mechanisms of left ventricular false tendons on functional mitral regurgitation in patients with severe cardiomyopathy
2009, Journal of Thoracic and Cardiovascular SurgeryCitation Excerpt :Rather, the pathophysiology of functional MR is related to the subvalvular apparatus. Prior studies of the relationship of mitral annular dilation have shown that although the mitral valve annulus dilates symmetrically in both ischemic and nonischemic cardiomyopathies, MD does not correlate with MR severity or cause of cardiomyopathy.8,9,21 CD and CA are emerging diagnostic and prognostic parameters linking functional MR to mitral subvalvular deformation and leaflet tenting.5,6,22
Simultaneous Right Atrioventricular Pacing: A Novel Model to Study Atrial Remodeling and Fibrillation in the Setting of Heart Failure
2008, Journal of Cardiac FailureCitation Excerpt :None of our dogs died unexpectedly before completion of the pacing protocol, but is occasionally encountered in the RV pacing models.27 RV pacing results in severe left ventricular dysfunction, accompanied by mitral regurgitation due in part to mitral annulus enlargement.16,28 In contrast, the profound alterations in left atrial size and function in SAVP are associated with less severe LV dysfunction than in RV pacing.
The year in echocardiography
2006, Journal of the American College of CardiologyCitation Excerpt :Enlargement of the right ventricular outflow tract (RVOT) (generally in the absence of global RV enlargement) was present in 100% of probands with an RVOT diameter of >30 mm in 89% (sensitivity 89% and specificity 86%). The most frequent morphologic abnormality was trabecular derangement (54%), followed by a hyperreflective moderator band in 34% and sacculations in 17% (34); 2) identified a new locus at 13q31.3-q32.1 for the genetic defect in a family mitral valve prolapse (35); 3) expanded our understanding of the pathophysiology of ischemic mitral regurgitation by demonstrating that papillary muscle dysfunction “per se” decreased tethering and MR (36,37); 4) revalidated the importance of vegetation size >10 mm and mobility in predicting embolic complications in infectious endocarditis (38); and 5) identified the multivariate clinical (age >50 years, female gender, pre-operative AF, and concomitant coronary artery bypass grafting) and echocardiographic (LA diameter ≥46 mm) predictors of overall mortality in patients with hypertrophic obstructive cardiomyopathy after surgical myectomy (39). While all cardiac imaging modalities continue to improve, echocardiography provides unique clinical information that is readily available at the bedside, in the invasive laboratory, and in the operating room.