Publications by authors named "Jonathan F Plehn"

Background: Identification of a subclinical cardiomyopathy in pediatric patients with Friedreich's ataxia (FA) has not been well-described.

Methods: We performed echocardiography (Echo), cardiac magnetic resonance imaging (cMRI), and neurologic assessment in a cross-sectional analysis of 48 genetically confirmed FA subjects aged 9-17 years with moderate neurologic impairment but without a cardiovascular history. Echo- and cMRI-determined left ventricular mass were indexed (LVMI) to height in grams/m.

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Article Synopsis
  • There is limited evidence supporting the benefits of beta-blocker treatments, like bucindolol, for patients with heart failure and reduced left ventricular ejection fraction (HFREF) who also have atrial fibrillation (AF).
  • A post-hoc analysis of the Beta-blocker Evaluation of Survival Trial (BEST) indicated that bucindolol helped patients with AF reduce their resting heart rate to ≤ 80 beats per minute, which is linked to lower cardiovascular mortality and hospitalization rates.
  • Additionally, only patients with the β(1)389-Arg/Arg genotype showed significant reductions in all-cause mortality and heart failure hospitalizations with bucindolol treatment, highlighting genetic factors in treatment efficacy.
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Background: Pharmacogenetics involves complex interactions of gene products affecting pharmacodynamics and pharmacokinetics, but there is little information on the interaction of multiple genetic modifiers of drug response. Bucindolol is a β-blocker/sympatholytic agent whose efficacy is modulated by polymorphisms in the primary target (β(1) adrenergic receptor [AR] Arg389 Gly on cardiac myocytes) and a secondary target modifier (α(2C) AR Ins [wild-type (Wt)] 322-325 deletion [Del] on cardiac adrenergic neurons). The major allele homozygotes and minor allele carriers of each polymorphism are respectively associated with efficacy enhancement and loss, creating the possibility for genotype combination interactions that can be measured by clinical trial methodology.

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Background And Purpose: Chronic effects of hypertension may be observed in multiple end organs. Previous reports suggest that cardiovascular morphological features can mirror cerebral infarction. In this cross-sectional analysis of elderly subjects, we investigated the relationship of a comprehensive set of echocardiographic measures with cerebral infarction detected by MRI.

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Objective: To determine the exercise capacity of children and adolescents with Friedreich's Ataxia (FA) and to evaluate the effects of 6 months of idebenone treatment on exercise capacity.

Design: Exploratory endpoint in a randomized double-blind, placebo-controlled, phase II clinical trial designed to investigate the effects of idebenone on a biomarker of oxidative stress.

Setting: Exercise physiology laboratory in a single clinical research center.

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Exaggerated systolic blood pressure (BP) augmentation with exercise has been associated with impaired endothelial function and cardiovascular risk. However, previous studies were largely restricted to men, did not evaluate diastolic BP, and focused on peak exercise measures, which are influenced by effort and fitness level. The aim of this study was to determine the association of exercise BP responses with risk of incident cardiovascular disease (CVD).

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Purpose: In patients with systolic heart failure, the ability of cardiopulmonary exercise testing (CPX) variables to reflect pathophysiology is well established. The relationship between CPX and pathophysiology has, however, not been thoroughly investigated in patients with nonobstructive hypertrophic cardiomyopathy (NHCM). The objective of this study was to assess the ability of CPX variables to reflect resting hemodynamics in patients with nonobstructive hypertrophic cardiomyopathy NHCM.

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Unlabelled: The purpose of this study was to prospectively assess the effects of two adaptive postprocessing techniques on the evaluation of myocardial function with displacement-encoded magnetic resonance (MR) imaging, including sensitivity for abnormal wall motion, with two-dimensional echocardiography as the reference standard. Sixteen patients (11 men, five women; age range, 26-74 years) and 12 volunteers (six men, six women; age range, 29-53 years) underwent breath-hold MR imaging. Institutional review board approval and informed consent were obtained.

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The mechanisms underlying reduced exercise capacity in patients with nonobstructive hypertrophic cardiomyopathy (NHCM) could include perturbations of ventricular relaxation, diastolic compliance, or compensatory atrial systolic function. We hypothesized that a loss of atrial contractility in NHCM patients leads to reduced functional capacity. To test this hypothesis, we compared resting noninvasive left atrial ejection phase indices in 49 consecutive patients with NHCM (ages 36+/-10 years; 41% female) and normal left ventricular ejection fraction (mean, 68%+/-8%) with objective metabolic exercise parameters.

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Background: The left atrium is afterload sensitive, responding to immediate changes in left ventricular (LV) diastolic pressure, and left atrial volumetric remodeling has been reported in conditions associated with abnormal diastolic function. We examined the relationship between left atrial volumetric remodeling and objective measures of exercise capacity in patients with nonobstructive hypertrophic cardiomyopathy (HCM).

Methods: We compared LA volume indices, other 2-dimensional and Doppler echocardiographic parameters, invasive hemodynamic measures, and magnetic resonance imaging (MRI)-derived LV mass with exercise duration, maximal oxygen uptake (MV* O2), anaerobic threshold (AT), and ventilatory efficiency (VE/V* CO2 slope) in 43 patients with nonobstructive HCM.

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Objectives: The aim of this study was to determine echocardiographic predictors of outcome in patients with advanced heart failure (HF) due to severe left ventricular (LV) systolic dysfunction in the Beta-blocker Evaluation of Survival Trial (BEST).

Background: Previous studies indicate that echocardiographic measurements of LV size and function, mitral deceleration time, and mitral regurgitation (MR) predict adverse outcomes in HF. However, complete quantitative echocardiograms evaluating all of these parameters have not been reported in a prospective randomized clinical trial in the era of modern HF therapy.

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We sought to identify the clinical characteristics and outcomes of patients who had advanced heart failure and nonfatal myocardial infarction (MI) in the beta-Blocker Evaluation of Survival Trial (BEST) and to investigate whether bucindolol alters the risk of developing nonfatal MI. Of the 2,708 patients enrolled in the study, 142 had suspected MI and 69 had confirmed MI; there were 860 deaths overall. The rate of nonfatal MI in the BEST was low over the 4.

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Background: Mitral annular calcification (MAC) has been associated with adverse cardiovascular disease outcomes and stroke in longitudinal and community-based cohorts. Prospective data are limited on its association with atrial fibrillation (AF).

Methods: We examined the association between MAC and the long-term risk of AF over 16 years of follow-up in participants in the original cohort of the Framingham Heart Study who attended a routine examination between 1979 and 1981.

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Background: The prevalence of pulmonary hypertension in adults with sickle cell disease, the mechanism of its development, and its prospective prognostic significance are unknown.

Methods: We performed Doppler echocardiographic assessments of pulmonary-artery systolic pressure in 195 consecutive patients (82 men and 113 women; mean [+/-SD] age, 36+/-12 years). Pulmonary hypertension was prospectively defined as a tricuspid regurgitant jet velocity of at least 2.

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Acute massive pulmonary embolus (PE) when undiagnosed may lead to hemodynamic compromise and death. Echocardiography offers several clues to the diagnosis of PE. We describe how transesophageal echo was used in the diagnosis and management of two patients with this disorder.

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