Search results for "Cardiac"

Differential prognostic impact of type 2 diabetes mellitus in women and men with heart failure with preserved ejection fraction

2020

Introduction and objectives Type 2 diabetes mellitus (DM2) is a common comorbidity in patients with heart failure (HF) with preserved ejection fraction (HFpEF). Previous studies have shown that diabetic women are at higher risk of developing HF than men. However, the long-term prognosis of diabetic HFpEF patients by sex has not been extensively explored. In this study, we aimed to evaluate the differential impact of DM2 on all-cause mortality in men vs women with HFpEF after admission for acute HF. Methods We prospectively included 1019 consecutive HFpEF patients discharged after admission for acute HF in a single tertiary referral hospital. Multivariate Cox regression analysis was used to …

Overweight and obesity are associated with cardiac adverse structure remodeling in Chinese elderly with hypertension

2019

AbstractThere is limited information on the association of overweight and obesity with cardiac remodeling in elderly population. Therefore, we investigated whether overweight and obesity are associated with cardiac geometric structures and function in Chinese elderly. A total of 1183 hospitalized patients (aged 65–99 years) with primary hypertension were collected retrospectively in a cross-sectional study, and divided into underweight, normal weight, overweight and obesity patient groups according to their body mass index (BMI). Cardiac echocardiographic parameters were compared between the groups. BMI was 17.2 ± 1.2, 21.4 ± 1.2, 25.1 ± 1.2, 30.2 ± 2.6 kg/m2 in underweight, normal weight, …

Evaluation of nocturnal vs. morning measures of heart rate indices in young athletes

2022

Purpose The purpose of this study was to compare heart rate (HR) and heart rate variability in young endurance athletes during nocturnal sleep and in the morning; and to assess whether changes in these values are associated with changes in submaximal running (SRT) and counter-movement jump (CMJ) performance. Methods During a three-week period of similar training, eleven athletes (16 ± 1 years) determined daily HR and heart rate variability (RMSSD) during sleep utilizing a ballistocardiographic device (Emfit QS), as well as in the morning with a HR monitor (Polar V800). Aerobic fitness and power production were assessed employing SRT and CMJ test. Results Comparison of the average values fo…

Noncompaction of the Right Ventricle

2010

Noncompaction of the ventricular myocardium is a disease characterized by an increase of the ventricular trabecular meshwork caused by arrest of the normal endomyocardial morphogenesis (Figs. 1, 2, 3). In accordance with the normal human anatomy, the left ventricular wall is well compacted with a few thin trabeculae; on the contrary, the normal right ventricular wall is furrowed by many trabeculae (the trabecula of the marginal septum as well as other ones). For this reason, the term ‘‘noncompaction’’ usually refers to an exclusive or prevalent disease of the left ventricle [1–16]. Recently Song and Aragona et al. [1–3] reported two cases of isolated right-ventricular noncompaction. Accordi…

Spiral wave induced numerically using electrical stimulation and comparison with experimental results.

2010

Experiments in vitro on a Microelectrode Array (MEA) platform show that electrical stimulation can provoke the generation of spiral waves in cardiac tissue. Nevertheless, the conditions leading to this artificial fibrillation state remain unclear. In order to have a better understanding of this phenomenon, a numerical simulation study has been conducted. The results obtained with a two-dimensional FitzHugh-Nagumo model proved that it is possible to create spiral waves by adding a stimulation current under certain conditions, which are made explicit.

Titanate nanotubes: towards a novel and safer nanovector for cardiomyocytes.

2012

Actively contractile cardiomyocyte (CM) monolayer represents an interesting tool to study both cardiac diseases and injuries. However, this model is poorly transfectable with conventional agents. Consequently, there is a need to develop new carriers that could overcome this problem. Titanate nanotubes (TiONts) could be a potential candidate due to possibly higher cell uptake as a direct consequence of their shape. On the basis of this rationale, TiONts were assessed for their cytotoxicity and internalization pathways. Cytotoxicity was assessed for TiONts either functionalized with PEI or unfunctionalized and its spherical counterpart P25 TiO2. No cytotoxic effect was observed under TiONts, …

Flexible Magnetoresistive Sensors for Guiding Cardiac Catheters

2018

Cardiac catheterization is a procedure, in which a long thin tube that is called a “catheter” is inserted into the heart for diagnosis or treatment. Due to the excessive use of x-ray doses and contrast agents for orientation detection during the surgery, there is a need to find a better alternative. This paper presents magnetic tunnel junction sensors on flexible Si attached to the catheter tip for orientation detection during minimally invasive surgeries. Due to the small size of catheters, extreme minimization in terms of size, weight, thickness and power consumption is needed for any device implemented on it. The fabricated flexible magnetic tunnel junctions fulfill those requirements wi…

Investigation of the hemodynamic flow conditions and blood-induced stresses inside an abdominal aortic aneurysm by means of a SPH numerical model.

2019

The estimation of blood flow-induced loads occurring on the artery wall is affected by uncertainties hidden in the complex interaction of the pulsatile flow, the mechanical parameters of the artery, and the external support conditions. To circumvent these difficulties, a specific tool is developed by combining the aorta displacements measured by an electrocardiogram-gated-computed tomography angiography, with the blood velocity field computed by a smoothed particle hydrodynamics (SPH) numerical model. In the present work, the SPH model has been specifically adapted to the solution of the 3D Navier-Stokes equations inside a domain with boundaries of prescribed motion. Images of the abdominal…

Analysis of the effects of pulsed microwave on cardiac activity

1993

Abstract The exposure of isolated chick embryo hearts to 2.45 GHz pulse modulated microwaves has identified certain phenomena: (1) when the heartbeat was irregular, an appropriate pulse repetition rate caused regularization; (2) during regular beating, an increase of pulse repetition rate similarly increased the heartbeat frequency, until an irregular heartbeat appeared; (3) by applying microwaves, when an arrhythmia occurs, a regular beat appeared after a few seconds. Time correlation between the heartbeat and the modulating pulses revealed that regularization occurs when the modulation pulses, at a frequency close to the natural unperturbed heartbeat, were applied in the ventricular diast…

2006

Introduction The objective was to study the effects of a novel lung volume optimization procedure (LVOP) using highfrequency oscillatory ventilation (HFOV) upon gas exchange, the transpulmonary pressure (TPP), and hemodynamics in a porcine model of surfactant depletion. Methods With institutional review board approval, the hemodynamics, blood gas analysis, TPP, and pulmonary shunt fraction were obtained in six anesthetized pigs before and after saline lung lavage. Measurements were acquired during pressure-controlled ventilation (PCV) prior to and after lung damage, and during a LVOP with HFOV. The LVOP comprised a recruitment maneuver with a continuous distending pressure (CDP) of 45 mbar …