Papers by Marti McCulloch
Journal of Ultrasound, 2014
Point of care ultrasound (POCUS) is a useful diagnostic tool in medicine. POCUS provides an easy ... more Point of care ultrasound (POCUS) is a useful diagnostic tool in medicine. POCUS provides an easy and reproducible method of diagnosis where conventional radiologic studies are unavailable. Telemedicine is also a great means of communication between educators and students throughout the world. Implementing POCUS with didactics and hands-on training, using portable ultrasound devices followed by telecommunication training, will impact the differential diagnosis and patient management in a rural community outside the United States. This is an observational prospective study implementing POCUS in Las Salinas, a small village in rural western Nicaragua. Ultrasound was used to confirm a diagnosis based on clinical exam, or uncover a new, previously unknown diagnosis. The primary endpoint was a change in patient management. International sonographic instructors conducted didactic and practical training of local practitioners in POCUS, subsequently followed by remote guidance and telecommunication for 3 months. A total of 132 patients underwent ultrasound examination. The most common presentation was for a prenatal exam (23.5 %), followed by abdominal pain (17 %). Of the 132 patients, 69 (52 %) were found to have a new diagnosis. Excluding pregnancy, 67 patients of 101 (66 %) were found to have a new diagnosis. A change in management occurred in a total of 64 (48 %) patients, and 62 (61 %) after excluding pregnancy. Implementing POCUS in rural Nicaragua led to a change in management in about half of the patients examined. With the appropriate training of clinicians, POCUS combined with telemedicine can positively impact patient care.
Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography, 2015
Journal of the American Society of Echocardiography, 2011
Clinical Cardiology, 2005
Adjunctive isometric exercise in the form of sustained submaximal handgrip (HG) is considered to ... more Adjunctive isometric exercise in the form of sustained submaximal handgrip (HG) is considered to increase the sensitivity of dobutamine stress echo (DSE) for detection of functionally significant coronary artery disease. The study was undertaken to quantify invasively the impact of HG in humans on hemodynamics and myocardial oxygen consumption (MVO2) during DSE. An invasive hemodynamic evaluation was performed during DSE and with addition of adjunctive HG in 11 subjects. Coronary sinus (CS) blood flow, right-sided and systemic pressures, oxygen saturations, and transthoracic two-dimensional echocardiography were obtained at each 3-min stage and after adding HG at peak DSE. Myocardial oxygen consumption was calculated by the Fick method and circumferential end-systolic wall stress (ESWS) by Mirsky's formula. At peak DSE, heart rate, left ventricular ejection fraction, CS flow, and MVO2 increased, whereas pulmonary capillary wedge pressure (PCWP) and circumferential end-systolic wall stress (ESWS) decreased from baseline. Compared with peak DSE, the addition of isometric HG at peak DSE caused an increase in PCWP (7 +/- 3 vs. 8.4 +/- 3 mmHg, p < 0.05), ESWS (112 +/- 25 x 103 vs. 125 +/- 32 x 103 dyne x s x cm2, p = 0.02), and CS flow (260 +/- 92 vs. 301 +/- 105 ml/min, p < 0.05). There was a minimal increase in left ventricular volumes, heart rate, and systolic blood pressure. The MVO2 increased from 29 +/- 8 ml/min at peak DSE to 31 +/- 9 ml/min with adjunctive HG (p = 0.03). Handgrip adjunctive to peak DSE results in a modest increase in MVO2, primarily by an increase in end-systolic wall stress.
Circulation, Jan 24, 2002
Journal of clinical ultrasound : JCU, 2003
Real-time 3-dimensional transthoracic echocardiography (RT-3D-TE) with real-time volume rendering... more Real-time 3-dimensional transthoracic echocardiography (RT-3D-TE) with real-time volume rendering (RTVR) offers multiple simultaneous views and spatial definition of intracardiac structures superior to that attainable by 2-dimensional transthoracic echocardiography (2D-TE). We hypothesized that RT-3D-TE would therefore improve identification of left ventricular apical thrombi (LVT). Patients were referred to our echocardiography laboratory over an 8-month period. Those diagnosed with a "suspicious" or "definite" LVT on the basis of 2D-TE images underwent RT-3D-TE on the same day. All 2D-TE, RT-3D-TE, and RTVR images were reviewed by 2 independent observers. RT-3D-TE findings were considered positive for LVT if LVT was visualized in both B-scan (apical orthogonal) and C-scan (short axis, with and without tilting angle) planes and on RTVR images, nondiagnostic (or suspicious) for LVT if it was not visualized in all planes, and negative for LVT if it was not visuali...
Journal of the American Society of Echocardiography, 2015
Point-of-care (POC) echocardiography may be helpful for mass triage, but such a strategy requires... more Point-of-care (POC) echocardiography may be helpful for mass triage, but such a strategy requires adequately trained sonographers at the remote site. The aim of this study was to test the feasibility of using a novel POC echocardiography training program for improving physicians' imaging skills during preanesthetic cardiac evaluations performed in a community camp organized for treating cataract blindness. Seventeen physicians were provided 6 hours of training in the use of POC echocardiography; nine were taught on site and eight were taught online through a transcontinental tele-echocardiography system. The trained physicians subsequently scanned elderly patients undergoing cataract surgery. The quality of images was graded, and agreement between local physicians' interpretations and Web-based interpretations by worldwide experts was compared. A total of 968 studies were performed, with 660 used for validating physicians' competence. Major cardiac abnormalities were seen in 136 patients (14.2%), with 32 (3.3%) deemed prohibitive to surgery in unmonitored settings. Although good-quality images were obtained more frequently by physicians trained on site rather than online (P = .03), there were no differences between the two groups in agreement with expert interpretations. The majority of physicians (70.6%) expressed satisfaction with the training (average Likert-type scale score, 4.24 of 5), with no difference seen between the two groups. The training resulted in significant improvements in self-perceived competence in all components of POC echocardiography (P < .001 for all). This study establishes the feasibility of using short-duration, one-on-one, personalized transcontinental tele-echocardiography education for wider dissemination of echocardiographic skills to local physicians in remote communities, essential for optimizing global cardiovascular health.
Ultrasound in Medicine & Biology, 2008
We describe the development of a cardiac flow model and imaging chamber to permit Doppler assessm... more We describe the development of a cardiac flow model and imaging chamber to permit Doppler assessment of complex and dynamic flow events. The model development included the creation of a circulatory loop with variable compliance and resistance; the creation of a secondary regurgitant circuit; and incorporation of an ultrasound imaging chamber to allow two-dimensional (2D) and three-dimensional (3D) Doppler characterization of both simple and complex models of valvular regurgitation. In all, we assessed eight different pulsatile regurgitant volumes through each of four rigid orifices differing in size and shape: 0.15 cm 2 circle, 0.4 cm 2 circle, 0.35 cm 2 slot and 0.4 cm 2 arc. The achieved mean (and range) hemodynamic measures were: peak trans-orifice pressure gradient 117 mm Hg (40 to 245 mm Hg), trans-orifice peak Doppler velocity 560 cm/s (307 to 793 cm/s), Doppler time-velocity integral 237 cm (111 to 362 cm), regurgitant volume 43 mL (11 to 84 mL) and orifice area 0.32 cm 2 (0.15 to 0.4 cm 2 ). The model was designed to optimize Doppler signal quality while reflecting anatomic structural relationships and flow events. The 2D color Doppler, 3D color Doppler and continuous wave Doppler quality was excellent whether the data were acquired from the imaging window parallel or perpendicular to the long-axis of flow. This model can be easily adapted to mimic other intracardiac flow pathology or assess future Doppler applications.
Journal of the American Society of Echocardiography, 2002
... RDCS; Alan Waggoner, RDCS; Sally Moos, RDCS; Sandra A. Witt, RDCS; Marti McCulloch, RDCS; Eri... more ... RDCS; Alan Waggoner, RDCS; Sally Moos, RDCS; Sandra A. Witt, RDCS; Marti McCulloch, RDCS; Eric Sisk, RDCS; Cris Gresser, RDCS; Jill Odabashian, RDCS; Susan Jasper, BSN, RN; Pam Burgess, RDCS; Dennis Carney, RCVT; Vickie Moore, RDCS; David Adams, RDCS. ...
Journal of the American Society of Echocardiography, 2007
Ultrasound technology has improved markedly in the past 10 to 15 years, prompting echocardiograph... more Ultrasound technology has improved markedly in the past 10 to 15 years, prompting echocardiographers to extend its use in studying cardiac structure and function. New ultrasound equipment and techniques offer superior image quality, greater accuracy, and expanding capabilities. As a result, more and improved imaging modalities are available for evaluating cardiac anatomy, ventricular function, blood flow velocity, and valvular diseases. Threedimensional (3D) echocardiography offers the ability to improve and expand the diagnostic capabilities of cardiac ultrasound. However, as with any emerging technology, the enthusiasm to embrace a new technique must be tempered by a critical appraisal of the evidence supporting its use. It is essential to assess the limitations as well as the unique capabilities it provides. Cardiac imaging should be safe, accurate, versatile, comprehensive, and cost-effective, while providing important clinical information. Criteria for appropriate utilization should be based on current evidence and updated as new information becomes available.
Journal of the American Society of Echocardiography, 2009
Objective-The proximal isovelocity surface area (PISA) method is useful in the quantitation of ao... more Objective-The proximal isovelocity surface area (PISA) method is useful in the quantitation of aortic regurgitation (AR). We hypothesized that actual measurement of PISA provided with realtime 3-dimensional (3D) color Doppler yields more accurate regurgitant volumes than those estimated by 2-dimensional (2D) color Doppler PISA.
Journal of the American Society of Echocardiography, 2009
Journal of the American Society of Echocardiography, 2006
Color tissue Doppler (TD) measures mean myocardial velocities, whereas spectral TD measures peak ... more Color tissue Doppler (TD) measures mean myocardial velocities, whereas spectral TD measures peak velocities. Given that most data on left ventricular (LV) diastolic function used spectral TD, we investigated whether the differences in myocardial velocities between these modalities resulted in discrepancies in calculated E/Ea. Patients were imaged using an ultrasound machine. The systolic (Sa), early diastolic (Ea), and late diastolic (Aa) myocardial velocities by color and spectral TD were measured at basal and midsegments of the LV septal, lateral, inferior, and anterior walls in the apical views. The average of basal septal and lateral Ea was combined with the early transmitral diastolic velocity (E) to obtain E/Ea. In all, 31 patients were imaged, with a mean LV ejection fraction of 47.7% +/- 19.9. There were significant correlations between Sa, Ea, and Aa by color and spectral TD at all sites (R = 0.92, P < .001 for Ea at basal lateral wall) and between spectral and color E/Ea (R = 0.85, P < .001). Sa, Ea, and Aa were significantly lower by color TD than by spectral TD (basal septal color Ea = 3.0 +/- 2.0 cm/s vs 5.6 +/- 2.5 cm/s for spectral Ea, P < .001). Consequently, E/Ea by color TD was significantly higher than by spectral TD (22.3 +/- 15.3 vs 13.6 +/- 7.8, P < .001). Although significant correlations exist, myocardial velocities measured using color TD significantly underestimate velocities by spectral TD. Consequently, E/Ea by color TD significantly overestimates E/Ea using spectral TD, which could lead to errors in assessment of LV diastolic function.
Journal of the American Society of Echocardiography, 2011
Journal of the American Society of Echocardiography, 2011
Identification of mitral regurgitation (MR) mechanism and pathology are crucial for surgical repa... more Identification of mitral regurgitation (MR) mechanism and pathology are crucial for surgical repair. The aim of the present investigation was to evaluate the comparative accuracy of real-time three-dimensional (3D) transesophageal echocardiography (TEE) and transthoracic echocardiography (TTE) with two-dimensional (2D) TEE and TTE in diagnosing the mechanism of MR compared with the surgical standard. Forty patients referred for surgical mitral valve repair were studied; 2D and 3D echocardiography with both TTE and TEE were performed preoperatively. Two independent observers reviewed the studies for MR pathology, functional or organic. In organic disease, the presence and localization of leaflet prolapse and/or flail were noted. Surgical findings served as the gold standard. There was 100% agreement in identifying functional versus organic MR among all four modalities. Overall, 2D TTE, 2D TEE, and 3D TEE performed similarly in identifying a prolapse or a flail leaflet; 3D TEE had the best agreement in identifying anterior leaflet prolapse, and it also showed an advantage for segmental analysis. Three-dimensional TTE was less sensitive and less accurate in identifying flail segments. All modalities were equally reliable in identifying functional MR. Both 2D TEE and 3D TEE were comparable in diagnosing MR mechanism, while 3D TEE had the advantage of better localizing the disease. With current technology, 3D TTE was the least reliable in identifying valve pathology.
Journal of the American Society of Echocardiography, 2000
Education (ACCME) to sponsor continuing medical education for physicians. The ASE designated this... more Education (ACCME) to sponsor continuing medical education for physicians. The ASE designated this educational activity for 1 hour of Category 1 credit of the AMA Physicians' Recognition Award. The ASE adheres to ACCME Standards regarding industry support of continuing medical education. Disclosures of faculty and commercial sponsor relationships, if any, have been indicated.
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Papers by Marti McCulloch