Person: Yeon, Susan B.
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Yeon
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Susan B.
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Yeon, Susan B.
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Publication Accuracy of Electrocardiographic Criteria for Atrial Enlargement: Validation with Cardiovascular Magnetic Resonance(BioMed Central, 2008) Tsao, Connie; Josephson, Mark; Hauser, Thomas; O'Halloran, Thomas; Agarwal, Anupam; Manning, Warren; Yeon, Susan B.Background: Anatomic atrial enlargement is associated with significant morbidity and mortality. However, atrial enlargement may not correlate with clinical measures such as electrocardiographic (ECG) criteria. Past studies correlating ECG criteria with anatomic measures mainly used inferior M-mode or two-dimensional echocardiographic data. We sought to determine the accuracy of the ECG to predict anatomic atrial enlargement as determined by volumetric cardiovascular magnetic resonance (CMR). Methods: ECG criteria for left (LAE) and right atrial enlargement (RAE) were compared to CMR atrial volume index measurements for 275 consecutive subjects referred for CMR (67% males, 51 \(\pm\) 14 years). ECG criteria for LAE and RAE were assessed by an expert observer blinded to CMR data. Atrial volume index was computed using the biplane area-length method. Results: The prevalence of CMR LAE and RAE was 28% and 11%, respectively, and by any ECG criteria was 82% and 5%, respectively. Though nonspecific, the presence of at least one ECG criteria for LAE was 90% sensitive for CMR LAE. The individual criteria P mitrale, P wave axis < \(30^\circ\), and negative P terminal force in V1 (NPTF-V1) > 0.04\(s{\cdot}mm\) were 88–99% specific although not sensitive for CMR LAE. ECG was insensitive but 96–100% specific for CMR RAE. Conclusion: The presence of at least one ECG criteria for LAE is sensitive but not specific for anatomic LAE. Individual criteria for LAE, including P mitrale, P wave axis < \(30^\circ\), or NPTF-V1 > 0.04\(s{\cdot}mm\) are highly specific, though not sensitive. ECG is highly specific but insensitive for RAE. Individual ECG P wave changes do not reliably both detect and predict anatomic atrial enlargement.Publication Circumferential myocardial strain in cardiomyopathy with and without left bundle branch block(BioMed Central, 2010) Han, Yuchi; Chan, Jonathan; Haber, Idith; Peters, Dana C; Zimetbaum, Peter; Manning, Warren; Yeon, Susan B.Background: Cardiac resynchronization therapy (CRT) has been shown to decrease mortality in 60-70% of advanced heart failure patients with left bundle branch block (LBBB) and QRS duration > 120 ms. There have been intense efforts to find reproducible non-invasive parameters to predict CRT response. We hypothesized that different left ventricular contraction patterns may exist in LBBB patients with depressed systolic function and applied tagged cardiovascular magnetic resonance (CMR) to assess circumferential strain in this population. Methods: We determined myocardial circumferential strain at the basal, mid, and apical ventricular level in 35 subjects (10 with ischemic cardiomyopathy, 15 with non-ischemic cardiomyopathy, and 10 healthy controls). Patterns of circumferential strain were analyzed. Time to peak systolic circumferential strain in each of the 6 segments in all three ventricular slices and the standard deviation of time to peak strain in the basal and mid ventricular slices were determined. Results: Dyskinesis of the anterior septum and the inferior septum in at least two ventricular levels was seen in 50% (5 out of 10) of LBBB patients while 30% had isolated dyskinesis of the anteroseptum, and 20% had no dyskinesis in any segments, similar to all of the non-LBBB patients and healthy controls. Peak circumferential strain shortening was significantly reduced in all cardiomyopathy patients at the mid-ventricular level (LBBB 9 ± 6%, non-LBBB 10 ± 4% vs. healthy 19 ± 4%; both p < 0.0001 compared to healthy), but was similar among the LBBB and non-LBBB groups (p = 0.20). The LBBB group had significantly greater dyssynchrony compared to the non-LBBB group and healthy controls assessed by opposing wall delays and 12-segment standard deviation (LBBB 164 ± 30 ms vs. non-LBBB 70 ± 17 ms (p < 0.0001), non-LBBB vs. healthy 65 ± 17 ms (p = 0.47)). Conclusions: Septal dyskinesis exists in some patients with LBBB. Myocardial circumferential strain analysis enables detailed characterization of contraction patterns, strengths, and timing in cardiomyopathy patients with and without LBBB.Publication A Systematic Approach to Performing a Comprehensive Transesophageal Echocardiogram. A Call to Order(BioMed Central, 2009) Kothavale, Avinash A; Yeon, Susan B.; Manning, WarrenBackground: While the order for a clinical transthoracic examination is fairly standardized, there is considerable variability between laboratories and even among physicians in the same laboratory with regard to the order for transesophageal echocardiograms (TEE). A systematic approach is desirable for more efficient use of physician and patient time, avoidance of inadvertent omission of important views, and to facilitate study review. Methods: We propose a standardized approach to TEE data acquisition in which cardiac structures are systematically identified and characterized at sequential positions and imaging planes to facilitate organized, efficient and comprehensive assessment. Results: Our approach to TEE study begins in the mid-esophagus with the imaging plane at 0°. Based on the specific indication for the TEE, a cardiac structure (e.g., mitral valve, left atrial appendage, or interatrial septum) is chosen as the primary focal point for a comprehensive, multiplane analysis. This structure is assessed in 20° – 30° increments as the imaging plane is advanced from 0° to 165°. Using the aortic valve as a reference point, pertinent cardiac structures are then assessed as the imaging plane is reduced to 135°, to 90°, to 40 – 60° and then back to 0°. The probe is then advanced into the stomach to obtain transgastric images at 0°, 90°, and 120°. Finally, the thoracic aorta and pulmonary artery are assessed as the probe is withdrawn from the body. Using this method, an organized and comprehensive TEE can be performed in 10 – 15 minutes. Conclusion: A standardized and systematic TEE approach is described for efficient and comprehensive TEE study.Publication The Scope of Medicare Reimbursement for New Medical Devices: Impact on Device Availability and the Standard of Care(1995) Yeon, Susan B.; Hutt, Peter BartonEvolving standards of care motivated by advances in medical technology alter the characteristics and costs of delivered health care. Faced with shifting reimbursement demands, the Health Care Financing Administration (HCFA) has promulgated regulations setting forth criteria and procedures for making coverage decisions about health care technology and setting prospective payment limits for health care services including those related to new technology. The effects of such regulations extend beyond the Medicare program due to the tendency of other health insurers to mirror HCFA coverage, the impact of Medicare payments on cross-subsidization and other effects of Medicare reimbursement decisions on the demand for and supply of health care. The principle statutory authority for rules limiting coverage of health care technology is Section 1862(a)( 1) of the Social Security Amendments of 1965 (codified in 42 U.S.C. § 1395y(a)( 1)) which provides that no Medicare payment shall be made for items or services, including medical devices, "which are not reasonable and necessary for the diagnosis or treatment of illness or injury or to improve the functioning of a malformed body member." In 1989 HCFA proposed a rule describing criteria and procedures for health care technology Medicare coverage decisions. The rule defines a reasonable and necessary service as one which is safe and effective, cost-effective, appropriate, and not experimental or investigational. A provision of the rule categorizes a medical device that has not been approved by the FDA as experimental or investigational and hence not reimbursible under the reasonable and necessary standard. In this paper I will (1) consider the legal force and implications of the provision excluding Medicare coverage of all unapproved medical devices, (2) discuss HCFA's recent efforts to investigate billing for investigational cardiac devices, (3) consider the impact of reimbursement for investigational device on device availability and (4) consider ways to reconcile prudent control of health care expenditures with expeditious promotion of high standards of health care.