Publications

2014
Matyal R, Sakamuri S, Huang T, Owais K, Parikh S, Khabbaz K, Wang A, Sellke F, Mahmood F. Oxidative stress and nerve function after cardiopulmonary bypass in patients with diabetes. Ann Thorac Surg. 2014;98 (5) :1635-43; discussion 1643-4.Abstract
BACKGROUND: Chronic hyperglycemia has been associated with increased oxidative stress in skeletal muscle and sympathetic nerve dysfunction. We investigated the effect of chronic hyperglycemia on the myocardium of patients with uncontrolled diabetes (UD) compared with patients with well-controlled diabetes (CD) and patients without diabetes (ND) after cardioplegic cardiopulmonary bypass (CP/CPB) with acute intraoperative glycemic control. METHODS: Atrial tissue and serum were collected from 47 patients (ND=18 with glycated hemoglobin [HbA1c] of 5.8±0.2; CD=8 with HbA1c of 6.1±0.1; with UD=21 with HbA1c=9.6±0.5) before and after CP/CPB for immunoblotting, protein oxidation assays, immunohistochemical evaluation, and microarray analysis. RESULTS: The uncontrolled group had increased total protein oxidation (p<0.05) and decreased levels of antioxidative enzyme manganese superoxide dismutase (MnSOD) (p<0.05) after CP/CPB compared with the controlled group. Collagen staining revealed increased fibrosis in patients with UD (p<0.05) compared with patients with CD and patients without diabetes. The uncontrolled group also showed a decrease in the neurogenic and angiogenic markers nerve growth factor (NGF) (p<0.05), neurotrophin (NT)-3 (p<0.05), and platelet-derived growth factor (PDGF)-β (p<0.05) compared with the other groups after CP/CPB. Atrial and serum microarray analysis showed increased oxidative stress and sympathetic nerve damage, increased fibrosis, and a decrease in angiogenesis in patients with UD (p<0.03) compared with patients without diabetes. CONCLUSIONS: CP/CPB led to higher oxidative stress in patients with UD before surgical intervention, even after normal glucose levels were maintained intraoperatively. Thus, controlled HbA1C in addition to acute intraoperative glucose control may be a more suitable end point for patients with diabetes undergoing cardiac operations.
Montealegre-Gallegos M, Pal A, Matyal R. Pro: Simulation training in transesophageal echocardiography. J Cardiothorac Vasc Anesth. 2014;28 (5) :1410-1.
Owais K, Pal A, Matyal R, Montealegre-Gallegos M, Khabbaz KR, Maslow A, Panzica P, Mahmood F. Three-dimensional printing of the mitral annulus using echocardiographic data: science fiction or in the operating room next door?. J Cardiothorac Vasc Anesth. 2014;28 (5) :1393-6.
Mahmood F. Training in echocardiography-top-down or a bottom-up approach?. J Am Soc Echocardiogr. 2014;27 (10) :18A-19A.
Owais K, Taylor CE, Jiang L, Khabbaz KR, Montealegre-Gallegos M, Matyal R, Gorman JH, Gorman RC, Mahmood F. Tricuspid annulus: a three-dimensional deconstruction and reconstruction. Ann Thorac Surg. 2014;98 (5) :1536-42.Abstract
BACKGROUND: Before clinical manifestation of regurgitation, the tricuspid annulus dilates and flattens when right ventricular dysfunction is potentially reversible. That makes the case for a prophylactic tricuspid annuloplasty even in the absence of significant tricuspid regurgitation. Owing to the appreciation of the favorable prognostic value of tricuspid annuloplasty, the geometry of the normal tricuspid annulus merits critical analysis. METHODS: Three-dimensional transesophageal echocardiographic data from 26 patients were analyzed using Image Arena (TomTec, Munich, Germany) software. Cartesian coordinate data from tricuspid annuli were exported to MATLAB (Mathworks, Natick, MA) for further processing. Annular metrics related to size, shape, and motion were computed. RESULTS: The tricuspid annulus demonstrated significant changes in area (p<0.01) and perimeter (p<0.03) during the cardiac cycle, with maximum values attained at end diastole. There was significant correlation between two- and three-dimensional area changes, indicating true expansion in the annulus. The anterolateral region of the annulus demonstrated the greatest dynamism (p<0.01), and the anteroseptal region showed the least. The anteroseptal region also displayed the most nonplanarity in the annulus. In addition, vertical translational motion was observed, with a mean distance of 11.3±3.7 mm between end systolic and end diastolic annular centroids. CONCLUSIONS: The tricuspid annulus is a dynamic, multiplanar structure with heterogeneous regional behavior. These characteristics should be taken into account for optimal annuloplasty device design and efficacy.
Swaminathan M, Mahmood F. When i do a TEE, am I ready for what comes next?. J Cardiothorac Vasc Anesth. 2014;28 (4) :1178.
Mahmood F, Owais K, Montealegre-Gallegos M, Matyal R, Panzica P, Maslow A, Khabbaz KR. Echocardiography derived three-dimensional printing of normal and abnormal mitral annuli. Ann Card Anaesth. 2014;17 (4) :279-83.Abstract
AIMS AND OBJECTIVES: The objective of this study was to assess the clinical feasibility of using echocardiographic data to generate three-dimensional models of normal and pathologic mitral valve annuli before and after repair procedures. MATERIALS AND METHODS: High-resolution transesophageal echocardiographic data from five patients was analyzed to delineate and track the mitral annulus (MA) using Tom Tec Image-Arena software. Coordinates representing the annulus were imported into Solidworks software for constructing solid models. These solid models were converted to stereolithographic (STL) file format and three-dimensionally printed by a commercially available Maker Bot Replicator 2 three-dimensional printer. Total time from image acquisition to printing was approximately 30 min. RESULTS: Models created were highly reflective of known geometry, shape and size of normal and pathologic mitral annuli. Post-repair models also closely resembled shapes of the rings they were implanted with. Compared to echocardiographic images of annuli seen on a computer screen, physical models were able to convey clinical information more comprehensively, making them helpful in appreciating pathology, as well as post-repair changes. CONCLUSIONS: Three-dimensional printing of the MA is possible and clinically feasible using routinely obtained echocardiographic images. Given the short turn-around time and the lack of need for additional imaging, a technique we describe here has the potential for rapid integration into clinical practice to assist with surgical education, planning and decision-making.
Montealegre-Gallegos M, Mahmood F. Intraoperative transesophageal echocardiography: Monere to Decidere. J Cardiothorac Vasc Anesth. 2014;28 (6) :1700-1.
Bardia A, Montealegre-Gallegos M, Mahmood F, Owais K, Pal A, Matyal R. Left atrial size: an underappreciated perioperative cardiac risk factor. J Cardiothorac Vasc Anesth. 2014;28 (6) :1624-32.
Li Z, Roussakis E, Koolen PGL, Ibrahim AMS, Kim K, Rose LF, Wu J, Nichols AJ, Baek Y, Birngruber R, et al. Non-invasive transdermal two-dimensional mapping of cutaneous oxygenation with a rapid-drying liquid bandage. Biomed Opt Express. 2014;5 (11) :3748-64.Abstract
Oxygen plays an important role in wound healing, as it is essential to biological functions such as cell proliferation, immune responses and collagen synthesis. Poor oxygenation is directly associated with the development of chronic ischemic wounds, which affect more than 6 million people each year in the United States alone at an estimated cost of $25 billion. Knowledge of oxygenation status is also important in the management of burns and skin grafts, as well as in a wide range of skin conditions. Despite the importance of the clinical determination of tissue oxygenation, there is a lack of rapid, user-friendly and quantitative diagnostic tools that allow for non-disruptive, continuous monitoring of oxygen content across large areas of skin and wounds to guide care and therapeutic decisions. In this work, we describe a sensitive, colorimetric, oxygen-sensing paint-on bandage for two-dimensional mapping of tissue oxygenation in skin, burns, and skin grafts. By embedding both an oxygen-sensing porphyrin-dendrimer phosphor and a reference dye in a liquid bandage matrix, we have created a liquid bandage that can be painted onto the skin surface and dries into a thin film that adheres tightly to the skin or wound topology. When captured by a camera-based imaging device, the oxygen-dependent phosphorescence emission of the bandage can be used to quantify and map both the pO2 and oxygen consumption of the underlying tissue. In this proof-of-principle study, we first demonstrate our system on a rat ischemic limb model to show its capabilities in sensing tissue ischemia. It is then tested on both ex vivo and in vivo porcine burn models to monitor the progression of burn injuries. Lastly, the bandage is applied to an in vivo porcine graft model for monitoring the integration of full- and partial-thickness skin grafts.
2013
Maslow A, Mahmood F, Singh A, Dobrillovic N, Poppas A. Problems with excess mitral leaflet after repair: possible issues during repair and preservation of the posterior leaflet. J Cardiothorac Vasc Anesth. 2013;27 (1) :92-7.
Matyal R, Wang A, Mahmood B, Khabbaz K, Mahmood F. A woman with a history of stroke and a mass in the aorta. J Cardiothorac Vasc Anesth. 2013;27 (1) :197-8.
Jainandunsing JS, Matyal R, Shahul SS, Wang A, Woltersom B, Mahmood F. 3-dimensional right ventricular volume assessment. J Cardiothorac Vasc Anesth. 2013;27 (2) :367-75.Abstract
PURPOSE: The purpose of this review was to evaluate new computer software available for 3-dimensional right ventricular (RV) volume estimation. DESCRIPTION: Based on 2-dimensional echocardiography, various algorithms have been used for RV volume estimation. These are complex, time-consuming techniques and are prone to significant error. The current clinical paradigm of RV volume assessment is based on the visual quantitative assessment of chamber size and the use of tricuspid annular and RV internal diameters as a surrogate measure of RV volume. Hence, there is a need for a practical method for the intraoperative assessment of RV volume. EVALUATION: The evaluation consists of an objective review of the capabilities of this software and its potential application in the operating room. The authors also performed a detailed review of the potential limitations and possible improvements. CONCLUSIONS: This new software has the potential to be incorporated into the existing workflow environment of the ultrasound systems in the future, making it clinically feasible to perform perioperative RV volume analysis.
Shakil O, Jainandunsing JS, Ilic R, Matyal R, Mahmood F. Ischemic mitral regurgitation: an intraoperative echocardiographic perspective. J Cardiothorac Vasc Anesth. 2013;27 (3) :573-85.
Bergman R, Mahmood F. Anesthesiologists and transesophageal echocardiography: echocardiographers or echocardiologists?. J Cardiothorac Vasc Anesth. 2013;27 (3) :627.
Mahmood F, Swaminathan M. Aortic stenosis and 3-dimensional echocardiography: the saga continues. J Cardiothorac Vasc Anesth. 2013;27 (1) :192-3.
Khabbaz KR, Mahmood F, Shakil O, Warraich HJ, Gorman JH, Gorman RC, Matyal R, Panzica P, Hess PE. Dynamic 3-dimensional echocardiographic assessment of mitral annular geometry in patients with functional mitral regurgitation. Ann Thorac Surg. 2013;95 (1) :105-10.Abstract
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.
Govindan S, Hayward G, Mahmood F, Subramaniam B. Echocardiographic quantification of mitral valvular response to myocardial revascularization. Ann Card Anaesth. 2013;16 (1) :23-7.Abstract
AIMS AND OBJECTIVES: Mild and/or moderate ischemic mitral regurgitation (IMR) may resolve after isolated coronary artery bypass grafting (CABG). It has been shown that the loss of saddle shape of the mitral valve is associated with IMR and is determined by an increase in the nonplanarity angle (NPA). The aim of this prospective, observational study was to test the hypothesis that NPA might decrease immediately after CABG alone in patients with mild to moderate IMR. MATERIALS AND METHODS: This prospective, observational study was conducted in an academic, tertiary care hospital. Twenty patients underwent 2D and 3D transoesophageal echocardiography (TEE) and mitral valve assessment before and immediately after the CABG. NPA, circularity index, and other geometric variables were obtained. They were compared using paired t test. The SPSS (Version 15.0, Chicago, IL, USA) was used for statistical analysis. P <0.05 was considered significant. RESULTS: The NPA was similar in the pre- and post-bypass periods (148° ± 15°, 148° ± 19°, P = 0.88). Circularity index (0.93 ± 0.13, 0.97 ± 0.11, P = 0.41) also was similar. CONCLUSIONS: There was no change in the mitral valve NPA with revascularization alone in patients with mild or moderate IMR. Mitral valve does not change its planarity (NPA) with revascularization alone in patients with IMR.
Bergman R, Shakil O, Mahmood B, Matyal R. Major surgery, hemodynamic instability, and a left atrial appendage clot: what to do?. J Cardiothorac Vasc Anesth. 2013;27 (3) :625-6.
Mahmood F, Shakil O, Gerstle JR, Matyal R. Percutaneous closure of an atrial septal defect and 3-dimensional echocardiography. J Cardiothorac Vasc Anesth. 2013;27 (2) :400-1.

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