Deborah H Kwon

Bio: Deborah H Kwon is an academic researcher from Cleveland Clinic. The author has contributed to research in topics: Medicine & Internal medicine. The author has an hindex of 23, co-authored 68 publications receiving 2106 citations. Previous affiliations of Deborah H Kwon include University of Colorado Denver.

Association between regional ventricular function and myocardial fibrosis in hypertrophic cardiomyopathy assessed by speckle tracking echocardiography and delayed hyperenhancement magnetic resonance imaging.

Abstract: The relationship among myocardial fibrosis, segmental strains, and hypertrophic cardiomyopathy (HCM) in patients with preserved left ventricular ejection fraction is not known. We evaluated this relationship in 39 consecutive patients with HCM with transthoracic echocardiography and delayed hyperenhancement magnetic resonance imaging 20 minutes after injection of 0.2 mmol/kg of gadolinium. Speckle tracking echocardiography was used to assess left ventricle strains. Fibrosis was determined semiautomatically with magnetic resonance imaging, using a 12-segment short-axis left ventricular model. Myocardial fibrosis was detected in 23 of 39 patients with HCM. The mean end-systolic longitudinal strain correlated with the number of fibrotic segments ( r = 0.47, P = .002) and total myocardial fibrosis ( r = 0.46, P = .003). Fibrosis and wall thickness were both multivariate predictors of lower segmental longitudinal strain ( P .003). Longitudinal, circumferential, and radial strains are decreased in patients with HCM even in the absence of fibrosis. Myocardial fibrosis is associated with depressed longitudinal strain in patients with HCM.

Extent of left ventricular scar predicts outcomes in ischemic cardiomyopathy patients with significantly reduced systolic function: a delayed hyperenhancement cardiac magnetic resonance study.

Abstract: Objectives The objective of the study was to determine whether the extent of left ventricular scar, measured with delayed hyperenhancement cardiac magnetic resonance (DHE-CMR), predicts survival in patients with ischemic cardiomyopathy (ICM) and severely reduced left ventricular ejection fraction (LVEF). Background Patients with ICM and reduced LVEF have poor survival. Such patients have a high myocardial scar burden. CMR is highly accurate in delineation of myocardial scar. Methods We studied 349 patients (76% men) with severe ICM (≥70% disease in ≥1 epicardial coronary, and mean LVEF of 24%) that underwent DHE-CMR (Siemens 1.5-T scanner, Erlangen, Germany), between 2003 and 2006. Scar (quantified as percentage of myocardium) was defined on DHE-MR images as an intensity >2 standard deviations above the viable myocardium. Transmurality score was semiquantitatively recorded in a 17-segment model as: 0 = no scar, 1 = 1% to 25% scar, 2 = 26% to 50%, 3 = 51% to 75%, and 4 = >75%. The LVEF, demographic data, risk factors, need for cardiac transplantation (CTx), and all-cause mortality were recorded. Results The mean age and follow-up were 65 ± 11 years and 2.6 ± 1.2 years (median 2.4 years [1.1, 3.5]), respectively. There were 56 events (51 deaths and 5 CTx). Mean scar percentage and transmurality score were higher in patients with events versus those without (39 ± 22 vs. 30 ± 20, p = 0.003, and 9.7 ± 5 vs. 7.8 ± 5, p = 0.004). On Cox proportional hazard survival analysis, quantified scar was greater than the median (30% of total myocardium), and female gender predicted events (relative risk 1.75 [95% Confidence Interval: 1.02 to 3.03] and relative risk 1.83 [95% Confidence Interval: 1.06 to 3.16], respectively, both p = 0.03). Conclusions In patients with ICM and severely reduced LVEF, a greater extent of myocardial scar, delineated by DHE-CMR is associated with increased mortality or the need for cardiac transplantation, potentially aiding further risk-stratification.

Association of myocardial fibrosis, electrocardiography and ventricular tachyarrhythmia in hypertrophic cardiomyopathy: a delayed contrast enhanced MRI study.

Abstract: Background Patients with hypertrophic cardiomyopathy (HCM) are predisposed to ventricular tachyarrhythmia (VT); likely due to myocardial fibrosis or disarray. Delayed hyperenhancement magnetic resonance imaging (DHE-MRI) accurately detects myocardial fibrosis (scar). We sought to determine the association between septal thickness, myocardial scar and VT. Methods Sixty-eight patients (mean age 44 years, 69% males) with documented HCM underwent cine MRI (Siemens Sonata or Avanto 1.5 T scanner, Erlangen, Germany) in short axis, 2, 3 and 4-chamber views and maximal interventricular septal thickness was recorded at end-diastole. Corresponding DHE-MR images (8–10 mm thick) were obtained, ∼20 min after injection of 0.2 mmol/kg of Gadolinium. Scar was determined semi-automatically (as % of total myocardium) using VPT software (Siemens) and defined as intensity >2 SD above viable myocardium in a 12 segment short-axis model at apex, mid LV and base. Presence of VT (documented on ambulatory ECG monitoring) and history of sudden death were recorded. Results One patient had a history of sudden death and 9 (13%) had VT on ambulatory ECG monitoring. On DHE-MRI, 39 (57%) patients had myocardial scar. Patients with VT had significantly higher scar %, compared to those without: 14% [6, 19] vs. 6% [0, 10], P = 0.01. On logistic regression, only the size of the scar was a significant predictor of VT (P = 0.03). Conclusions HCM subjects with VT have a higher % of myocardial scarring noted on DHE-MRI, independent of septal thickness or beta-blocker use.

Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study

Abstract: Summary Background Since December, 2019, Wuhan, China, has experienced an outbreak of coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Epidemiological and clinical characteristics of patients with COVID-19 have been reported but risk factors for mortality and a detailed clinical course of illness, including viral shedding, have not been well described. Methods In this retrospective, multicentre cohort study, we included all adult inpatients (≥18 years old) with laboratory-confirmed COVID-19 from Jinyintan Hospital and Wuhan Pulmonary Hospital (Wuhan, China) who had been discharged or had died by Jan 31, 2020. Demographic, clinical, treatment, and laboratory data, including serial samples for viral RNA detection, were extracted from electronic medical records and compared between survivors and non-survivors. We used univariable and multivariable logistic regression methods to explore the risk factors associated with in-hospital death. Findings 191 patients (135 from Jinyintan Hospital and 56 from Wuhan Pulmonary Hospital) were included in this study, of whom 137 were discharged and 54 died in hospital. 91 (48%) patients had a comorbidity, with hypertension being the most common (58 [30%] patients), followed by diabetes (36 [19%] patients) and coronary heart disease (15 [8%] patients). Multivariable regression showed increasing odds of in-hospital death associated with older age (odds ratio 1·10, 95% CI 1·03–1·17, per year increase; p=0·0043), higher Sequential Organ Failure Assessment (SOFA) score (5·65, 2·61–12·23; p Interpretation The potential risk factors of older age, high SOFA score, and d-dimer greater than 1 μg/mL could help clinicians to identify patients with poor prognosis at an early stage. Prolonged viral shedding provides the rationale for a strategy of isolation of infected patients and optimal antiviral interventions in the future. Funding Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences; National Science Grant for Distinguished Young Scholars; National Key Research and Development Program of China; The Beijing Science and Technology Project; and Major Projects of National Science and Technology on New Drug Creation and Development.

Recommendations for the Evaluation of Left Ventricular Diastolic Function by Echocardiography: An Update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging

Abstract: Recommendations for the Evaluation of Left Ventricular Diastolic Function by Echocardiography : An Update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging

2014 ESC Guidelines on diagnosis and management of hypertrophic cardiomyopathy The Task Force for the Diagnosis and Management of Hypertrophic Cardiomyopathy of the European Society of Cardiology (ESC)

Abstract: 2D : two-dimensional 99mTc-DPD : 99mTechnetium-3,3-diphosphono- 1,2-propanodi-carboxylic acid ACE : angiotensin-converting enzyme AF : atrial fibrillation AL : amyloid light chain AR : aortic regurgitation ARB : angiotensin receptor blocker ATTR : amyloidosis-transthyretin type AV : atrioventricular BiVAD : biventricular assist device BNP : brain natriuretic peptide BPM : Beats per minute CCS : Canadian Cardiovascular Society CFC : cardiofacialcutaneous CHA2DS2-VASc : Congestive Heart failure, hypertension, Age ≥75 (doubled), Diabetes, Stroke (doubled), Vascular disease, Age 65–74, and Sex (female) CMR : cardiac magnetic resonance CRT : cardiac resynchronization therapy CRT-D : cardiac resynchronization therapy-defibrillator CRT-P : Cardiac resynchronization therapy with a pacemaker CT : computed tomography DC : direct current DNA : deoxyribonucleic acid E/A : ratio of mitral peak velocity of early filling (E) to mitral peak velocity of late filling (A) E/e’ : ratio of early transmitral flow velocity (E) to early mitral annulus velocity (e’) EACTS : European Association for Cardio-Thoracic Surgery ECG : electrocardiogram EF : ejection fraction EPS : electrophysiological study ESC : European Society of Cardiology FDA : (US) Food and Drug Administration FHL1 : four and a half LIM domains 1 HAS-BLED : hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile INR, elderly (>65 years), drugs/alcohol concomitantly HCM : hypertrophic cardiomyopathy hs-cTnT : high sensitivity cardiac troponin T HTS : high throughput sequencing ICD : implantable cardioverter defibrillator ILR : implantable loop recorder INR : international normalized ratio IUD : intrauterine device LA : left atrium LAMP-2 : lysosome-associated membrane protein 2 LBBB : left bundle branch block LEOPARD : Lentigines, ECG abnormalities, Ocular hypertelorism, Pulmonary stenosis, Abnormal genitalia, Retardation of growth, and sensory-neural Deafness LGE : late gadolinium enhancement LV : left ventricular LVAD : left ventricular assist device LVH : left ventricular hypertrophy LVOTO : left ventricular outlow tract obstruction MADIT-RIT : Multicenter Automatic Defibrillator Implantation Trial—Reduce Inappropriate Therapy MAPK : mitogen activated protein kinase MELAS : mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes MERFF : myoclonic epilepsy with ragged red fibres MRA : mineralocorticoid receptor antagonist MYBPC3 : myosin-binding protein C, cardiac-type MYH7 : myosin-7 (s-myosin heavy chain) MYL3 : myosin light chain 3 NOAC : new oral anticoagulants NSVT : non-sustained ventricular tachycardia NT-proBNP : N-terminal pro brain natriuretic peptide NYHA : New York Heart Association OAC : oral anticoagulants o.d. : omni die (every day) PC-CMR : phase contrast cardiac magnetic resonance PDE5 : phosphodiesterase type 5 PET : positron emission tomography PRKAG2 : gamma-2 sub-unit of the adenosine monophosphate-activated protein kinase RAAS : renin angiotensin aldosterone system RV : right ventricular SAM : systolic anterior motion SCD : sudden cardiac death SAA : septal alcohol ablation S-ICD™ : Subcutaneous lead implantable cardioverter defibrillator SPECT : single photon emission computed tomography SSFP : steady-state free precession SVT : supraventricular tachycardia TOE : transoesophageal echocardiography TNNI3 : troponin I, cardiac muscle TNNT2 : troponin T, cardiac muscle TPM1 : tropomyosin alpha-1 chain TTE : transthoracic echocardiography TTR : transthyretin VF : ventricular fibrillation VKA : vitamin K antagonist VT : ventricular tachycardia WHO : World Health Organization Guidelines summarize and evaluate all available evidence at the time of the writing process, on a particular issue with the aim of assisting health professionals in selecting the best management strategies for an individual patient, with a given condition, taking into account the impact on outcome, as well as the risk-benefit-ratio of particular diagnostic or therapeutic means. Guidelines and recommendations should help the health professionals to make decisions in their daily practice. However, the final decisions concerning an individual patient must be made by the responsible health professional(s) in consultation with the patient and caregiver as appropriate. A great number of Guidelines have been issued in recent years by the European Society of Cardiology (ESC) as well as by other societies and organisations. Because of the impact on clinical practice, quality criteria for the development of guidelines have been established in order to make all decisions transparent to the user. The recommendations for formulating and issuing ESC Guidelines can be found on the ESC website (http://www.escardio.org/guidelines-surveys/esc-guidelines/about/Pages/rules-writing.aspx). ESC Guidelines represent the official position of the ESC on a given topic and are regularly updated. Members of this Task Force were selected by the ESC to represent professionals involved with the medical care of patients with this pathology. Selected experts in the field undertook a comprehensive review of the published evidence for management (including diagnosis, treatment, prevention and rehabilitation) of a given condition according to ESC Committee for Practice Guidelines (CPG) policy. A critical evaluation of diagnostic and therapeutic procedures was performed including assessment of the risk-benefit-ratio. Estimates of expected health outcomes for larger populations were included, where data exist. The level of evidence and the strength of recommendation of particular management options were weighed and graded according to predefined scales, as outlined in Tables 1 and 2 . The experts of …

Exercise Standards for Testing and Training A Scientific Statement From the American Heart Association

Abstract: The purpose of this report is to provide revised standards and guidelines for the exercise testing and training of individuals who are free from clinical manifestations of cardiovascular disease and those with known cardiovascular disease. These guidelines are intended for physicians, nurses, exercise physiologists, specialists, technologists, and other healthcare professionals involved in exercise testing and training of these populations. This report is in accord with the “Statement on Exercise” published by the American Heart Association (AHA).1 These guidelines are a revision of the 1995 standards of the AHA that addressed the issues of exercise testing and training.2 An update of background, scientific rationale, and selected references is provided, and current issues of practical importance in the clinical use of these standards are considered. These guidelines are in accord with the American College of Cardiology (ACC)/AHA Guidelines for Exercise Testing.3 ### The Cardiovascular Response to Exercise Exercise, a common physiological stress, can elicit cardiovascular abnormalities that are not present at rest, and it can be used to determine the adequacy of cardiac function. Because exercise is only one of many stresses to which humans can be exposed, it is more appropriate to call an exercise test exactly that and not a “stress test.” This is particularly relevant considering the increased use of nonexercise stress tests. ### Types of Exercise Three types of muscular contraction or exercise can be applied as a stress to the cardiovascular system: isometric (static), isotonic (dynamic or locomotory), and resistance (a combination of isometric and isotonic).4,5 Isotonic exercise, which is defined as a muscular contraction resulting in movement, primarily provides a volume load to the left ventricle, and the response is proportional to the size of the working muscle mass and the intensity of exercise. Isometric exercise is defined as a muscular contraction without movement (eg, handgrip) and imposes greater pressure than volume …