Search results for "Heart Ventricle"
showing 10 items of 163 documents
European Clinical Experience with a Dual Chamber Single Pass Sensing and Pacing Defibrillation Lead
2002
Dual chamber ICDs are increasingly implanted nowadays, mainly to improve discrimination between supraventricular and ventricular arrhythmias but also to maintain AV synchrony in patients with bradycardia. The aim of this study was to investigate a new single pass right ventricular defibrillation lead capable of true bipolar sensing and pacing in the right atrium and integrated bipolar sensing and pacing in the right ventricle. The performance of the lead was evaluated in 57 patients (age 61 +/- 12 years; New York Heart Association 1.9 +/- 0.6, left ventricular ejection fraction 0.38 +/- 0.15) at implant, at prehospital discharge, and during a 1-year follow-up. Sensing and pacing behavior of…
No evidence of adverse cardiac remodeling in former elite endurance athletes
2016
Background: The impact of high exercise loads on a previously healthy heart remains controversial. We examined the consequences of decades of strenuous endurance exercise at the highest competition level on heart dimensions and volumes as well as on serum biomarkers of cardiac fibrosis/remodeling. Methods and results: We compared echocardiographic measurements and serum biomarkers of cardiac fibrosis/remodeling [troponin I, galectin-3, matrix metallopeptidase-2 and -9, N-terminal pro-brain natriuretic peptide, carboxy-terminal propeptide of type I procollagen, and soluble suppressor of tumorigenicity-2 (sST-2)/interleukin(IL)-1R4] in 53 male athletes [11 former professional ('elite') and 42…
Isolated RV diverticulum: diagnosis by cardiac magnetic resonance and 3D TEE
2014
A 16-year-old male was referred to our hospital because of exertional chest pain. There was no personal or family history of any cardiovascular disease. Findings on physical examination and vital signs were normal. An ECG showed a right bundle superoanterior zonal block pattern with low potentials in frontal plane and intraventricular conduction delay (QRS Complex 120 msg) with pseudo-epsilon wave in V1 …
GAS CHROMATOGRAPHIC ESTIMATION OF ACETYLCHOLINE IN THE RABBIT HEART USING A NITROGEN SELECTIVE DETECTOR
1973
The distribution of ACh in the rabbit heart was investigated by a modified gas chromatographic estimation method. ACh was extracted with perchloric acid, precipitated as reineckate and demethylated with sodium benzenethiolate. The tertiary amines derived from ACh and other choline esters were concentrated by a microdistillation procedure. Gas chromatography was performed using a nitrogen selective detector. In the range of concentrations between 0.4 and 2.5 nmol ACh per tissue sample the coefficient of variation was 5.2 per cent. The recovery of ACh added to heart extracts was 101 per cent. Evidence for the identity of the choline ester isolated from rabbit hearts and authentic ACh was obta…
Downregulation and Nuclear Relocation of MLP During the Progression of Right Ventricular Hypertrophy Induced by Chronic Pressure Overload
2000
Abstract The cardiac LIM domain protein MLP plays a crucial role in the architecture and mechanical function of cardiac myocytes. Mice lacking the MLP gene develop cardiac hypertrophy, dilated cardiopathy and heart failure. We investigated whether downregulation of MLP is induced by pressure overload and contributes to the physiopathology of cardiac hypertrophy and failure. We studied this mechanism in rat right ventricles submitted to pulmonary arterial hypertension, because it is known that this ventricle is very vulnerable to the deleterious effects of pressure overload. During the progression of cardiac hypertrophy to failure over a 31 days period there was a dramatic decrease by 50% of…
Effect of aging and hypertension on β-myosin heavy chain in heart of spontaneously hypertensive rats
2001
During aging rat myocardium undergoes structural changes characterized by a shift in the synthesis of myosin heavy chain (MHC) from V1 isoform, composed of two alpha-MHC, to V3 isoform, composed of two beta-MHC. In rat, besides ageing, cardiac hypertrophy as adaptive response to a superimposed pressure load (such as hypertension) is characterized by predominance of V3 myosin isoform. The aim of our study was to evaluate the expression of beta-MHC in right (RV) and left (LV) ventricles of spontaneously hypertensive rats (SHRs), a well defined animal model of hypertension, in relation to aging. We used very young (8-week old) and young (15-week old) SHRs and age-matched normotensive Harlan Sp…
Expression of thyroid hormone receptor isoforms in the hypertrophic heart of spontaneously hypertensive rats
2001
Thyroid hormones (THs) enhance MHC alpha gene- and repress MHC beta gene-transcription in the heart, by interacting with specific nuclear receptors (TRs), that bind to regulatory sequences localized upstream of basal promoter of myosin heavy chain (MHC) genes. The overall effects of THs include an increase in V1- and a decrease in V3-myosin isozyme concentration in the heart. Myosin V1 contains two MHC alpha chains and has a higher ATPase activity than V3 isoform, which contains two beta chains. Previous studies on papillary muscles of spontaneously hypertensive rats (SHRs) showed that heart hypertrophy is accompanied by a shift from alpha to beta MHC accumulation. The present study was aim…
Evaluation of left ventricular mass on cadmium-zinc-telluride imaging: Validation against cardiac magnetic resonance
2017
Background. Single-photon emission computed tomography has shown relevant limitations in the quantification of left ventricular (LV) mass. We sought to compare the estimates of LV mass on Cadmium-Zinc-Telluride (CZT) myocardial perfusion imaging (MPI) as compared to cardiac magnetic resonance (CMR). Methods and results. Twenty-five patients underwent MPI on a CZT camera and CMR on a 1.5 T scanner within 12 ± 3 weeks. LV mass was quantified on CZT images using two softwares: 4D-MSPECT (4DM) and Emory Cardiac Toolbox (ECTb). LV mass by CMR was quantified using MASS software (Medis, Leiden, The Netherlands). LV mass values obtained with 4DM and ECTb were highly reproducible [intraclass correla…
Echocardiographic reference ranges for normal left ventricular 2D strain: results from the EACVI NORRE study
2017
International audience; Aims - To obtain the normal ranges for 2D echocardiographic (2DE) measurements of left ventricular (LV) strain from a large group of healthy volunteers accounting for age and gender. Methods and results - A total of 549 (mean age: 45.6 ± 13.3 years) healthy subjects were enrolled at 22 collaborating institutions of the Normal Reference Ranges for Echocardiography (NORRE) study. 2DE data sets have been analysed with a vendor-independent software package allowing homogeneous measurements irrespective of the echocardiographic equipment used to acquire the data sets. The lowest expected values of LV strains and twist calculated as ± 1.96 standard deviations from the mean…
Echocardiographic reference ranges for normal cardiac chamber size: Results from the NORRE study
2014
AimsAvailability of normative reference values for cardiac chamber quantitation is a prerequisite for accurate clinical application of echocardiography. In this study, we report normal reference ranges for cardiac chambers size obtained in a large group of healthy volunteers accounting for gender and age. Echocardiographic data were acquired using state-of-the-art cardiac ultrasound equipment following chamber quantitation protocols approved by the European Association of Cardiovascular Imaging.MethodsA total of 734 (mean age: 45.8 ± 13.3 years) healthy volunteers (320 men and 414 women) were enrolled at 22 collaborating institutions of the Normal Reference Ranges for Echocardiography (NORR…