Mahmood F, Swaminathan M. Aortic stenosis and 3-dimensional echocardiography: the saga continues.. J Cardiothorac Vasc Anesth. 2013;27(1):192-3. doi:10.1053/j.jvca.2012.08.018
Publications
2013
Khabbaz K, Mahmood F, Shakil O, et al. Dynamic 3-dimensional echocardiographic assessment of mitral annular geometry in patients with functional mitral regurgitation.. Ann Thorac Surg. 2013;95(1):105-10. doi:10.1016/j.athoracsur.2012.08.078
BACKGROUND: Mitral valve (MV) annular dynamics have been well described in animal models of functional mitral regurgitation (FMR). Despite this, little if any data exist regarding the dynamic MV annular geometry in humans with FMR. In the current study we hypothesized that 3-dimensional (3D) echocardiography, in conjunction with commercially available software, could be used to quantify the dynamic changes in MV annular geometry associated with FMR.
METHODS: Intraoperative 3D transesophageal echocardiographic data obtained from 34 patients with FMR and 15 controls undergoing cardiac operations were dynamically analyzed for differences in mitral annular geometry with TomTec 4D MV Assessment 2.0 software (TomTec Imaging Systems GmbH, Munich, Germany).
RESULTS: In patients with FMR, the mean mitral annular area (14.6 cm(2) versus 9.6 cm(2)), circumference (14.1 cm versus 11.4 cm), anteroposterior (4.0 cm versus 3.0 cm) and anterolateral-posteromedial (4.3 cm versus 3.6 cm) diameters, tenting volume (6.2 mm(3) versus 3.5 mm(3)) and nonplanarity angle (NPA) (154 degrees ± 15 versus 136 degrees ± 11) were greater at all points during systole compared with controls (p 0.01). Vertical mitral annular displacement (5.8 mm versus 8.3 mm) was reduced in FMR compared with controls (p 0.01).
CONCLUSIONS: There are significant differences in dynamic mitral annular geometry between patients with FMR and those without. We were able to analyze these changes in a clinically feasible fashion. Ready availability of this information has the potential to aid comprehensive quantification of mitral annular function and possibly assist in both clinical decision making and annuloplasty ring selection.
Matyal R, Sakamuri S, Wang A, et al. Local infiltration of neuropeptide Y as a potential therapeutic agent against apoptosis and fibrosis in a swine model of hypercholesterolemia and chronic myocardial ischemia.. Eur J Pharmacol. 2013;718(1-3):261-70. doi:10.1016/j.ejphar.2013.08.023
While the angiogenic effects of Neuropeptide Y (NPY) in myocardial ischemia and hypercholesterolemia have been studied, its effects on altering oxidative stress, fibrosis and cell death are not known. We hypothesized that local infiltration of NPY in a swine model of chronic myocardial ischemia and hypercholesterolemia will induce nerve growth and cell survival, while reducing oxidative stress and fibrosis. Yorkshire mini-swine (n=15) were fed a high cholesterol diet for 5 weeks. Three weeks after surgical induction of focal myocardial ischemia, an osmotic pump was implanted, which delivered NPY (n=8, high cholesterol treated, HCT) or the vehicle (n=7, high cholesterol control, HCC) for 5 weeks. Then myocardium was harvested for analysis. Assessment of myocardial function and perfusion was made the last intervention. Immunoblotting demonstrated significantly decreased levels of MMP-9 (p=0.001) and TGF-β (p=0.05) and significantly increased levels of Ang-1 (p=0.002), MnSOD (p=0.006) and NGF (p=0.01) in HCT. Immunohistochemistry results revealed significantly decreased TUNEL staining (p=0.005) and GLUT4 translocation (p=0.004) in HCT. The functional data showed significantly improved blood flow reserve (p=0.02) and improved diastolic function -dP/dt (p=0.009) in the treated animals. Local infiltration of NPY results in positive remodeling in ischemic myocardium in the setting of hypercholesterolemia. By initiating angio and neurogenesis, NPY infiltration improves blood flow reserve and restoration of fatty acid metabolism. The associated increased cell survival and decreased fibrosis result in improved myocardial diastolic function. NPY may have a potential therapeutic role in patients with hypercholesterolemia associated coronary artery disease.
Mahmood F, Shakil O, Mahmood B, Chaudhry M, Matyal R, Khabbaz K. Mitral annulus: an intraoperative echocardiographic perspective.. J Cardiothorac Vasc Anesth. 2013;27(6):1355-63. doi:10.1053/j.jvca.2013.02.008
Warraich H, Matyal R, Bergman R, et al. Impact of aortic valve replacement for aortic stenosis on dynamic mitral annular motion and geometry.. Am J Cardiol. 2013;112(9):1445-9. doi:10.1016/j.amjcard.2013.06.013
The impact of aortic valve replacement (AVR) on the dynamic geometry and motion of the mitral annulus remains unknown. We analyzed the effects of AVR on the dynamic geometry and motion of the mitral annulus. We used 3-dimensional transesophageal echocardiography to analyze 39 consecutive patients undergoing elective surgical AVR for aortic stenosis. Intraoperative 3-dimensional transesophageal echocardiography was performed immediately before and after AVR. Volumetric data sets were analyzed using a software package capable of dynamically tracking the mitral annulus and leaflets during the entire systolic ejection phase. After AVR, there were significant decreases (p 0.01) in annular dimensions such as anteroposterior (3.5 ± 0.1 vs 3.2 ± 0.1 cm), anterolateral-posteromedial (3.7 ± 0.1 vs 3.5 ± 0.1 cm), and commissural diameters (3.7 ± 0.1 vs 3.3 ± 0.1 cm), as well as annular circumference (12.0 ± 0.30 vs 11.1 ± 0.2 cm) and 3-dimensional mitral annular area (mean 10.9 ± 0.6 vs 9.3 ± 0.3 cm(3)). Vertical mitral annular displacement was also reduced (6.2 ± 3.1 vs 4.3 ± 2.2 mm). Mitral annular nonplanarity angle (154 ± 1.5° vs 161 ± 1.6°) and aorto-mitral angle (133 ± 3.3° vs 142 ± 2.0°) were both increased after AVR, suggesting reduced nonplanar shape of the mitral annulus and reduced aorto-mitral flexion. In conclusion, these data demonstrate that mitral annular size is reduced immediately after AVR and that the dynamic motion of the mitral annulus is restricted. These findings may have important clinical implications for patients undergoing AVR with concurrent mitral regurgitation.
Jainandunsing J, Mahmood F, Matyal R, et al. Impact of three-dimensional echocardiography on classification of the severity of aortic stenosis.. Ann Thorac Surg. 2013;96(4):1343-8. doi:10.1016/j.athoracsur.2013.05.018
BACKGROUND: Owing to its elliptical shape, the left ventricle outflow tract (LVOT) area is underestimated by two-dimensional (2D) diameter-based calculations which assume a circular shape. This results in overestimation of aortic stenosis (AS) by the continuity equation. In cases of moderate to severe AS, this overestimation can affect intraoperative clinical decision making (expectant management versus replacement). The purpose of this intraoperative study was to compare the aortic valve area calculated by 2D diameter based and three-dimensional (3D) derived LVOT area via transesophageal echocardiography (TEE) and its impact on severity of AS.
METHODS: The LVOT area was calculated using intraoperative 2D and 3D TEE data from patients undergoing aortic valve replacement (AVR) and coronary artery bypass graft (CABG) surgery using the 2D diameter (RADIUS), 3D planimetry (PLANE), and 3D biplane (π·x·y) measurement (ELLIPSE) methods. For each method, the LVOT area was used to determine the aortic valve area by the continuity equation and the severity of AS categorized as mild, moderate, or severe.
RESULTS: A total of 66 patients completed the study. The RADIUS method (3.5 ± 0.9 cm(2)) underestimated LVOT area by 21% (p 0.05) compared with the PLANE method (4.1 ± 0.1 cm(2)) and by 18% (p 0.05) compared with the ELLIPSE method (4.0 ± 0.9 cm(2)). There was no significant difference between the two 3D methods, namely, PLANE and ELLIPSE. Seven AVR patients (18%) and 1 CABG surgery patient (6%) who had originally been classified as severe AS by the 2D method were reclassified as moderate AS by the 3D methods (p 0.001).
CONCLUSIONS: Three-dimensional echocardiography has the potential to impact surgical decision making in cases of moderate to severe AS.
Shakil O, Majid A, Gangadharan S, Mahmood F. Repair of a full-thickness tracheal tear using cardiopulmonary bypass.. J Bronchology Interv Pulmonol. 2013;20(3):290-2. doi:10.1097/LBR.0b013e31829ddbb3
Mahmood F, Kim H, Chaudary B, et al. Tricuspid annular geometry: a three-dimensional transesophageal echocardiographic study.. J Cardiothorac Vasc Anesth. 2013;27(4):639-46. doi:10.1053/j.jvca.2012.12.014
OBJECTIVE: To demonstrate the clinical feasibility of accurately measuring tricuspid annular area by 3-dimensional (3D) transesophageal echocardiography (TEE) and to assess the geometric differences based on the presence of tricuspid regurgitation (TR). Also, the shape of the tricuspid annulus was compared with previous descriptions in the literature.
DESIGN: Prospective.
SETTING: Tertiary care university hospital.
INTERVENTIONS: Three-dimensional TEE.
PARTICIPANTS: Patients undergoing cardiac surgery.
MEASUREMENTS AND MAIN RESULTS: Volumetric data sets from 20 patients were acquired by 3D TEE and prospectively analyzed. Comparisons in annular geometry were made between groups based on the presence of TR. The QLab (Philips Medical Systems, Andover, MA) software package was used to calculate tricuspid annular area by both linear elliptical dimensions and planimetry. Further analyses were performed in the 4D Cardio-View (TomTec Corporation GmBH, Munich, Germany) and MATLAB (Natick, MA) software environments to accurately assess annular shape. It was found that patients with greater TR had an eccentrically dilated annulus with a larger annular area. Also, the area as measured by the linear ellipse method was overestimated as compared to the planimetry method. Furthermore, the irregular saddle-shaped geometry of the tricuspid annulus was confirmed through the mathematic model developed by the authors.
CONCLUSIONS: Three-dimensional TEE can be used to measure the tricuspid annular area in a clinically feasible fashion, with an eccentric dilation seen in patients with TR. The tricuspid annulus shape is complex, with annular high and low points, and annular area calculation based on linear measurements significantly overestimates 3D planimetered area.
Shakil O, Mahmood B, Matyal R, Jainandunsing J, Mitchell J, Mahmood F. Simulation training in echocardiography: the evolution of metrics.. J Cardiothorac Vasc Anesth. 2013;27(5):1034-40. doi:10.1053/j.jvca.2012.10.021
Matyal R, Wang A, Mahmood F. Percutaneous ventricular septal defect closure with Amplatzer devices resulting in severe tricuspid regurgitation.. Catheter Cardiovasc Interv. 2013;82(6):E817-20. doi:10.1002/ccd.24803
While percutaneous intervention is an alternative for patients who are not surgical candidates, the rate of morbidity and mortality is comparable to open repair. Appending the reported complications associated with percutaneous intervention (device mal-positioning, dislodgement, and entrapment in the sub-valvular apparatus), we report mechanical damage to the tricuspid valve (TV). Percutaneous closure with an Amplatzer septal occluder device was attempted on three patients who developed a ventricular septal defects (VSD) after myocardial infarction. In all three cases, damage to the tricuspid leaflet was noted post-procedure. The accompanying severe tricuspid regurgitation led to right ventricular failure, even in the patients where the VSD was considered successfully occluded. Despite successful deployment of the Amplatzer device, complications with catheter manipulation may still arise. Damage to the TV can occur during percutaneous VSD closure with Amplatzer device. Periprocedure TEE monitoring can detect damage to the tricuspid leaflets.
