Spin-polarized atomic hydrogen : devices and phenomena

+118hlm.;24c

Borderline Q-waves in individuals without overt cardiovascular disease: relations with adiposity, subclinical atherosclerosis and vascular stiffness

Background: Characteristics and risk factors associated with electrocardiographic borderline Q-waves are not fully elucidated, especially in individuals without overt cardiovascular disease (CVD). Also, the relation of isolated and non-isolated borderline Q-waves with subclinical atherosclerosis and vascular stiffness is unknown. Methods and results: We included 5746 Netherlands Epidemiology of Obesity study participants without overt CVD. Participants were divided in three groups: no Q-waves (93.7%), isolated (4.6%) and non-isolated borderline Q-waves (1.7%). Borderline Q-waves were defined as Minnesota Codes 1.2.x and 1.3.x and non-isolated as ≥1 of abnormal QRS axis, left ventricular hypertrophy or ST/T abnormalities. Several characteristics and measures of body fat were assessed. Vascular stiffness was assessed by pulse wave velocity (PWV) and subclinical atherosclerosis by carotid intima-media thickness (cIMT). Percentage of men, alcohol intake, blood pressure and fasting glucose concentrations were, compared with no Q-waves, higher in the isolated and highest in the non-isolated borderline Q-wave group. Isolated borderline Q-waves were associated with higher body mass index (difference compared with no Q-waves: 1.0 kg/m2; 95%CI: 0.3–1.7; p-value: 0.006), waist circumference (3.4 cm; 1.0–5.8; 0.005), and visceral adipose tissue (21.9 cm2; 7.4–36.3; 0.003) and differences were even larger for non-isolated borderline Q-waves. Compared with no Q-waves, non-isolated borderline Q-waves were associated with higher PWV (1.2 m/s; 0.4–2.0; 0.004) and cIMT (23.4 μm; 3.0–43.8; 0.024), whereas isolated borderline Q-waves were not. Conclusion: Cardiovascular risk factors and measures of body fat, especially abdominal adiposity, were higher in participants with isolated borderline Q-waves, compared with no Q-waves, and highest in the non-isolated borderline Q-wave group. Non-isolated borderline Q-waves were associated with subclinical atherosclerosis and vascular stiffness. Future studies should investigate potential added value of borderline Q-waves in CVD prediction

Validation of infarct size and location from the ECG by inverse body surface mapping

This paper describes the incorporation of body surface mapping algorithms to detect the position and size of acute myocardial infarctions using standard 12 lead ECG recording. The results are compared with the results from cardiac MRI scan analysis. In case patient specific volume conductor models are used, the position of the infarction could be accurately determined. When generalized patient volume conductor models were examined, the estimation of the infarct position became significantly less accurate. The calculations of the size of the infarctions need further improvement

Estimating infarct severity from the ECG using a realistic heart model

The early phase of myocardial infarction is accompanied by changes in the ST segment of the ECG. This makes the ST segment the clinical marker for the detection of acute myocardial infarction. The determination of the infarct severity, location and size of the myocardial tissue at risk will support clinical decision making. In this study we used an inverse procedure to estimate the location and size of the infarcted heart region. The method estimates the local transmembrane amplitude based on the ECG amplitude near the J-point of the standard 12 leads signals using a patient specific volume conductor model. For the 5 available patient cases the positions as well as the size of the estimated infarct region were in accordance with results based on MRI

Changes in frequency of premature complexes and heart rate variability related to shift work

OBJECTIVES To investigate whether an increased risk of cardiovascular disease might be caused by increased arrhythmogeneity and by unfavourable changes in autonomic cardiac control the changes in the occurrence of premature complexes (PVCs) and in heart rate variability (HRV) were studied in subjects who started to work in shifts. METHODS1 Year changes in frequency of PVCs and HRV were measured in 49 shift workers and 22 control subjects working in daytime. All respondents were starting in a new job in integrated circuit or waste incinerator plants. RESULTSThe incidence of PVC increased significantly in shift workers over the 1 year follow up, compared with daytime workers. The frequency of ventricular extrasystoles increased in 48.9 f the shift workers, and in 27.3 f the daytime workers. The Spearman correlation coefficient between the number of nights worked and the change in PVCs was 0.33 (p=0.004). A small non-significant unfavourable change in HRV was found in both the shift and daytime workers. CONCLUSIONSA change in arrhythmogeneity, but not in cardiac autonomic control, might explain the increased risk of cardiovascular disease in shift worker

Normal values of the ventricular gradient and QRS-T angle, derived from the pediatric electrocardiogram

Cardiolog

Effect of Aging on Left Atrial Compliance and Electromechanical Properties in Subjects Without Structural Heart Disease

Cardiolog

Multi-ancestry GWAS of the electrocardiographic PR interval identifies 202 loci underlying cardiac conduction

The electrocardiographic PR interval reflects atrioventricular conduction, and is associated with conduction abnormalities, pacemaker implantation, atrial fibrillation (AF), and cardiovascular mortality. Here we report a multi-ancestry (N = 293,051) genome-wide association meta-analysis for the PR interval, discovering 202 loci of which 141 have not previously been reported. Variants at identified loci increase the percentage of heritability explained, from 33.5% to 62.6%. We observe enrichment for cardiac muscle developmental/contractile and cytoskeletal genes, highlighting key regulation processes for atrioventricular conduction. Additionally, 8 loci not previously reported harbor genes underlying inherited arrhythmic syndromes and/or cardiomyopathies suggesting a role for these genes in cardiovascular pathology in the general population. We show that polygenic predisposition to PR interval duration is an endophenotype for cardiovascular disease, including distal conduction disease, AF, and atrioventricular pre-excitation. These findings advance our understanding of the polygenic basis of cardiac conduction, and the genetic relationship between PR interval duration and cardiovascular disease

Observation of cyclotron-resonance in the photoconductivity of two-dimensional electrons

Contains fulltext : 115610.pdf (publisher's version ) (Open Access