66 research outputs found
Hypertrophic obstructive cardiomyopathy: alcohol septal ablation
Alcohol septal ablation (ASA) was introduced in 1994 as an alternative to septal myectomy for patients with hypertrophic obstructive cardiomyopathy and symptoms refractory to medical therapy. This procedure alleviates symptoms by producing a targeted, limited infarction of the upper interventricular septum, resulting in an increase in left ventricular outflow tract (LVOT) diameter, a decrease in LVOT gradient, and regression of the component of LV hypertrophy that is due to pressure overload. Clinical success, with improvement in symptoms and reduction in gradient, is achieved in the great majority of patients with either resting or provocable LVOT obstruction. The principal morbidity of the procedure is complete heart block, resulting in some patients in the requirement for a permanent pacemaker. The introduction of myocardial contrast echocardiography as a component of the ASA procedure has contributed to the induction of smaller myocardial infarctions with lower dosages of alcohol and, in turn, fewer complications. Non-randomized comparisons of septal ablation and septal myectomy have shown similar mortality rates and post-procedure New York Heart Association class for the two procedure
Inotropic effect of nicardipine in patients with heart failure: Assessment by left ventricular end-systolic pressure-volume analysis
AbstractNicardipine, a new dihydropyridine calcium channel blocker, has been investigated for the treatment of coronary artery disease and heart failure. To assess the inotropic effect of nicardipine in humans independent of its vasodilator effect, equihypotensive doses of intravenous nitroprusside (mean infusion rate 65 ± 13 μg/min) and nicardipine (mean dose 5.2 ± 0.4 mg) were administered to 15 patients with heart failure (New York Heart Association functional classes II to IV, radionuclide left ventricular ejection fraction 0.15 ± 0.02). Left ventricular micromanometer pressure and simultaneous radionuclide left ventricular volume were obtained at baseline, during nitroprusside infusion, during a second baseline period and during nicardipine infusion.Heart rate did not change significantly with either nitroprusside or nicardipine. Mean systemic arterial pressure decreased by an average of 21 mm Hg with both drugs. A greater decrease in left ventricular end-diastolic pressure occurred with nitroprusside (27 ± 2 to 14 ± 2 mm Hg, p < 0.01) than with nicardipine (27 ± 2 to 23 ± 3 mm Hg, p < 0.05), and pulmonary capillary wedge pressure decreased significantly only with nitroprusside. Cardiac index increased from 1.8 ± 0.1 to 2.1 ± 0.1 liters/min per m2(p < 0.05) with nitroprusside and to a greater extent from 1.7 ± 0.1 to 2.4 ± 0.1 liters/min per m2(p < 0.01) with nicardipine. Left ventricular ejection fraction increased with nicardipine (0.15 ± 0.01 to 0.19 ± 0.01, p < 0.01), but not with nitroprusside.Peak positive first derivative of left ventricular pressure (dP/dt) decreased by 9% with both agents. Left ventricular pressure-volume loops were constructed for 14 patients. In 12 patients, the left ventricular end-systolic pressure-volume relation was shifted rightward with nicardipine, indicating a negative inotropic effect, with no shift in the remaining 2 patients.Thus, nicardipine has a negative inotropic effect in patients with heart failure. Despite this effect, left ventricular ejection fraction and cardiac index increased with nicardipine. This overall improvement in ventricular systolic performance was due to a reduction in afterload
Coronary endothelial dysfunction in patients with acute-onset idiopathic dilated cardiomyopathy
AbstractObjectives. This study sought to determine whether coronary endothelial dysfunction exists in patients with acute-onset idiopathic dilated cardiomyopathy (DCM) and to explore its relation to recovery of left ventricular systolic function in this patient population.Background. Coronary endothelial dysfunction exists in chronic DCM, but its importance in the development and progression of ventricular dysfunction is not known. To address this issue we studied coronary endothelial function in patients with idiopathic DCM <6 months in duration and explored the relation between coronary endothelial function and subsequent changes in left ventricular ejection fraction (LVEF).Methods. Ten patients with acute-onset idiopathic DCM (duration of heart failure symptoms 2.0 ± 0.4 months [mean ± SEM]) and 11 control patients with normal left ventricular function underwent assessment of coronary endothelial function during intracoronary administration of the endothelium-dependent vasodilator acetylcholine and the endothelium-independent vasodilator adenosine. Coronary cross-sectional area (CSA) was determined by quantitative coronary angiography and coronary blood flow (CBF) by the product of coronary CSA and CBF velocity measured by an intracoronary Doppler catheter. Patients with DCM underwent assessment of left ventricular function before and several months after the study.Results. Acetylcholine infusion produced no change in coronary CSA in control patients but significant epicardial constriction in patients with DCM (−36 ± 11%, p < 0.01). These changes were associated with increases in CBF in control patients (+118 ± 49%, p < 0.01) but no change in patients with DCM. Infusion of adenosine produced increases in coronary caliber and blood flow in both groups. Follow-up assessment of left ventricular function was obtained in nine patients with DCM 7.0 ± 1.7 months after initial study, at which time LVEF had improved by ≥0.10 in four patients. Multiple linear regression revealed a positive correlation between both the coronary CSA (r2 = 0.57, p < 0.05) and CBF (r2 = 0.68, p < 0.01) response to acetylcholine and the subsequent improvement in LVEF.Conclusions. Coronary endothelial dysfunction exists at both the microvascular and the epicardial level in patients with acute-onset idiopathic DCM. The preservation of coronary endothelial function in this population is associated with subsequent improvement in left ventricular function
Associations Between Brain Structure and Connectivity in Infants and Exposure to Selective Serotonin Reuptake Inhibitors During Pregnancy
Importance Selective serotonin reuptake inhibitor (SSRI) use among pregnant women is increasing, yet the association between prenatal SSRI exposure and fetal neurodevelopment is poorly understood. Animal studies show that perinatal SSRI exposure alters limbic circuitry and produces anxiety and depressive-like behaviors after adolescence, but literature on prenatal SSRI exposure in humans is limited and mixed.
Objective To examine associations between prenatal SSRI exposure and brain development using structural and diffusion magnetic resonance imaging (MRI).
Design, Setting, and Participants A cohort study conducted at Columbia University Medical Center and New York State Psychiatric Institute included 98 infants: 16 with in utero SSRI exposure, 21 with in utero untreated maternal depression exposure, and 61 healthy controls. Data were collected between January 6, 2011, and October 25, 2016.
Exposures Selective serotonin reuptake inhibitors and untreated maternal depression.
Main Outcomes and Measures Gray matter volume estimates using structural MRI with voxel-based morphometry and white matter structural connectivity (connectome) using diffusion MRI with probabilistic tractography.
Results The sample included 98 mother (31 [32%] white, 26 [27%] Hispanic/Latina, 26 [27%] black/African American, 15 [15%] other) and infant (46 [47%] boys, 52 [53%] girls) dyads. Mean (SD) age of the infants at the time of the scan was 3.43 (1.50) weeks. Voxel-based morphometry showed significant gray matter volume expansion in the right amygdala (Cohen d = 0.65; 95% CI, 0.06-1.23) and right insula (Cohen d = 0.86; 95% CI, 0.26-1.14) in SSRI-exposed infants compared with both healthy controls and infants exposed to untreated maternal depression (P < .05; whole-brain correction). In connectome-level analysis of white matter structural connectivity, the SSRI group showed a significant increase in connectivity between the right amygdala and the right insula with a large effect size (Cohen d = 0.99; 95% CI, 0.40-1.57) compared with healthy controls and untreated depression (P < .05; whole connectome correction).
Conclusions and Relevance Our findings suggest that prenatal SSRI exposure has an association with fetal brain development, particularly in brain regions critical to emotional processing. The study highlights the need for further research on the potential long-term behavioral and psychological outcomes of these neurodevelopmental changes
Genomic epidemiology of syphilis in England: a population-based study.
BACKGROUND: Syphilis is a sexually transmitted bacterial infection caused by Treponema pallidum subspecies pallidum. Since 2012, syphilis rates have risen dramatically in many high-income countries, including England. Although this increase in syphilis prevalence is known to be associated with high-risk sexual activity in gay, bisexual, and other men who have sex with men (GBMSM), cases are rising in heterosexual men and women. The transmission dynamics within and between sexual networks of GBMSM and heterosexual people are not well understood. We aimed to investigate if whole genome sequencing could be used to supplement or enhance epidemiological insights around syphilis transmission. METHODS: We linked national patient demographic, geospatial, and behavioural metadata to whole T pallidum genome sequences previously generated from patient samples collected from across England between Jan 1, 2012, and Oct 31, 2018, and performed detailed phylogenomic analyses. FINDINGS: Of 497 English samples submitted for sequencing, we recovered 240 genomes (198 from the UK Health Security Agency reference laboratory and 42 from other laboratories). Three duplicate samples (same patient and collection date) were included in the main phylogenies, but removed from further analyses of English populations, leaving 237 genomes. 220 (92·8%) of 237 samples were from men, nine (3·8%) were from women, and eight (3·4%) were of unknown gender. Samples were mostly from London (n=118 [49·8%]), followed by southeast England (n=29 [12·2%]), northeast England (n=24 [10·1%]), and southwest England (n=15 [6·3%]). 180 (76·0%) of 237 genomes came from GBMSM, compared with 25 (10·5%) from those identifying as men who have sex with women, 15 (6·3%) from men with unrecorded sexual orientation, nine (3·8%) from those identifying as women who have sex with men, and eight (3·4%) from people of unknown gender and sexual orientation. Phylogenomic analysis and clustering revealed two dominant T pallidum sublineages in England. Sublineage 1 was found throughout England and across all patient groups, whereas sublineage 14 occurred predominantly in GBMSM older than 34 years and was absent from samples sequenced from the north of England. These different spatiotemporal trends, linked to demography or behaviour in the dominant sublineages, suggest they represent different sexual networks. By focusing on different regions of England we were able to distinguish a local heterosexual transmission cluster from a background of transmission in GBMSM. INTERPRETATION: These findings show that, despite extremely close genetic relationships between T pallidum genomes globally, genomics can still be used to identify putative transmission clusters for epidemiological follow-up. This could be of value for deconvoluting putative outbreaks and for informing public health interventions. FUNDING: Wellcome funding to the Sanger Institute, UK Research and Innovation, National Institute for Health and Care Research, European and Developing Countries Clinical Trials Partnership, and UK Health Security Agency
Global phylogeny of Treponema pallidum lineages reveals recent expansion and spread of contemporary syphilis.
Funder: Queensland GovernmentSyphilis, which is caused by the sexually transmitted bacterium Treponema pallidum subsp. pallidum, has an estimated 6.3 million cases worldwide per annum. In the past ten years, the incidence of syphilis has increased by more than 150% in some high-income countries, but the evolution and epidemiology of the epidemic are poorly understood. To characterize the global population structure of T. pallidum, we assembled a geographically and temporally diverse collection of 726 genomes from 626 clinical and 100 laboratory samples collected in 23 countries. We applied phylogenetic analyses and clustering, and found that the global syphilis population comprises just two deeply branching lineages, Nichols and SS14. Both lineages are currently circulating in 12 of the 23 countries sampled. We subdivided T. p. pallidum into 17 distinct sublineages to provide further phylodynamic resolution. Importantly, two Nichols sublineages have expanded clonally across 9 countries contemporaneously with SS14. Moreover, pairwise genome analyses revealed examples of isolates collected within the last 20 years from 14 different countries that had genetically identical core genomes, which might indicate frequent exchange through international transmission. It is striking that most samples collected before 1983 are phylogenetically distinct from more recently isolated sublineages. Using Bayesian temporal analysis, we detected a population bottleneck occurring during the late 1990s, followed by rapid population expansion in the 2000s that was driven by the dominant T. pallidum sublineages circulating today. This expansion may be linked to changing epidemiology, immune evasion or fitness under antimicrobial selection pressure, since many of the contemporary syphilis lineages we have characterized are resistant to macrolides
Phase 2 study of aficamten in patients with obstructive hypertrophic cardiomyopathy
Background:
Left ventricular outflow tract (LVOT) obstruction is a major determinant of heart failure symptoms in obstructive hypertrophic cardiomyopathy (oHCM). Aficamten, a next-in-class cardiac myosin inhibitor, may lower gradients and improve symptoms in these patients.
Objectives:
This study aims to evaluate the safety and efficacy of aficamten in patients with oHCM.
Methods:
Patients with oHCM and LVOT gradients ≥30 mm Hg at rest or ≥50 mm Hg with Valsalva were randomized 2:1 to receive aficamten (n = 28) or placebo (n = 13) in 2 dose-finding cohorts. Doses were titrated based on gradients and ejection fraction (EF). Safety and changes in gradient, EF, New York Heart Association functional class, and cardiac biomarkers were assessed over a 10-week treatment period and after a 2-week washout.
Results:
From baseline to 10 weeks, aficamten reduced gradients at rest (mean difference: −40 ± 27 mm Hg, and −43 ± 37 mm Hg in Cohorts 1 and 2, P = 0.0003 and P = 0.0004 vs placebo, respectively) and with Valsalva (−36 ± 27 mm Hg and −53 ± 44 mm Hg, P = 0.001 and <0.0001 vs placebo, respectively). There were modest reductions in EF (−6% ± 7.5% and −12% ± 5.9%, P = 0.007 and P < 0.0001 vs placebo, respectively). Symptomatic improvement in ≥1 New York Heart Association functional class was observed in 31% on placebo, and 43% and 64% on aficamten in Cohorts 1 and 2, respectively (nonsignificant). With aficamten, N-terminal pro–B-type natriuretic peptide was reduced (62% relative to placebo, P = 0.0002). There were no treatment interruptions and adverse events were similar between treatment arms.
Conclusions:
Aficamten resulted in substantial reductions in LVOT gradients with most patients experiencing improvement in biomarkers and symptoms. These results highlight the potential of sarcomere-targeted therapy for treatment of oHCM
Efficacy and safety of aficamten in symptomatic non-obstructive hypertrophic cardiomyopathy: results from the REDWOOD-HCM trial, cohort 4
Background
This open-label phase 2 trial evaluated the safety and efficacy of aficamten in patients with nonobstructive hypertrophic cardiomyopathy (nHCM).
Methods
Patients with symptomatic nHCM (left ventricular outflow tract obstruction gradient ≤ 30 mmHg, left ventricular ejection fraction [LVEF] ≥ 60%, N-terminal pro-B-type natriuretic peptide [NT-proBNP] > 300 pg/mL) received aficamten 5–15 mg once daily (doses adjusted according to echocardiographic LVEF) for 10 weeks.
Results
We enrolled 41 patients (mean ± SD age 56 ± 16 years; 59% female). At Week 10, 22 (55%) patients experienced an improvement of ≥ 1 New York Heart Association class; 11 (29%) became asymptomatic. Clinically relevant improvements in Kansas City Cardiomyopathy Questionnaire Clinical Summary Scores occurred in 22 (55%) patients. Symptom relief was paralleled by reductions in NT-proBNP levels (56%; P < 0.001) and high-sensitivity cardiac troponin I (22%; P < 0.005). Modest reductions in LVEF (mean ± SD) of −5.4% ± 10 to 64.6% ± 9.1 were observed. Three (8%) patients had asymptomatic reduction in LVEF < 50% (range: 41%–48%), all returning to normal after 2 weeks of washout. One patient with prior history of aborted sudden cardiac death experienced a fatal arrhythmia during the study.
Conclusions
Aficamten administration for symptomatic nHCM was generally safe and was associated with improvements in heart failure symptoms and cardiac biomarkers
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Myogenic influences on the electrical auditory brainstem response (EABR) in humans
Two cases demonstrating the effects of myogenic artifact on the electrical auditory brainstem response (EABR) when using a promontory stimulation site are presented. Intensity‐response functions were obtained in the unparalyzed condition, then repeated after infusion of a neuromuscular paralyzing agent. In both cases, the myogenic response was observed at lower stimulus intensities than the EABR components. As intensity increased, the myogenic responses grew at extremely rapid rates and made any subsequent identification of auditory responses virtually impossible. To alleviate the adverse influence of myogenic components, general anesthesia and a paralyzing agent must be incorporated into the test protocol when acquiring the EABR using a promontory site of stimulation
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