Inadvertent Lead Placement In The Left Ventricle: A Case Report And Brief Review

Inadvertent lead placement in the left ventricle (LV) is an uncommon and often under-diagnosed complication of cardiac device implantation. Thromboembolic (TE) events are common and usually secondary to fibrosis or thrombus formation on or around the lead. Anticoagulation can prevent TE events. Percutaneous and surgical LV lead extractions have been performed successfully, but the risks of percutaneous lead removal are not well-defined. In this report, we describe a case of inadvertent LV lead placement and briefly review the contemporary literature.     

Factors associated with blood zinc,chromium, and lead concentrations in residents of the Nam Pong River in Thailand

This cross-sectional analytical study aimed to determine the blood levels of zinc (B-Zn), chromium (B-Cr), and lead (B-Pb) and to identify the factors influencing these levels in the blood of residents of the Nam Pong River. Quantitative data collection was utilized, and systematic random sampling was conducted to obtain 420 samples for measuring serum heavy metals, including B-Zn, B-Cr, and B-Pb. Multiple regression analysis was used to identify factors influencing the accumulation of heavy metals in the population, reported mean differences, 95% confidence intervals, and p values. The average levels of heavy metals were 74.38 ± 14.00 µg/dL (95% confidence interval [CI]: 73.03–75.72) for zinc, 0.28 ± 0.23 µg/L (95% CI: 0.26–0.30) for chromium, and 2.80 ± 1.60 µg/dL (95% CI: 2.64–2.95) for lead, which all were within normal limits. Factors influencing zinc levels included occupational exposure (batteries) (mean diff = 11.56; 95% CI: 1.81–21.32, p value = 0.02) and consumption of fish from the river exceeding 300 grams/meal or three times/week (mean diff = 4.68; 95% CI: 0.09–9.45, p value = 0.05). Factors influencing chromium levels included a history of past illness (mean diff = 0.19; 95% CI: 0.05–0.34, p value = 0.01) and dust/chemical exposure from industry (mean diff = 0.05; 95% CI: 0.00–0.11, p value = 0.05). Factors influencing lead concentrations included gender (mean diff = 1.82; 95% CI: 0.26–1.98, p value = 0.001), smoking (mean diff = 1.03; 95% CI: 0.60–1.45, p value < 0.001), and occupational exposure (garage) (mean diff = 1.11; 95% CI: 0.27–1.94, p value = 0.01).     

Action of lead on glutamate-activated chloride currents inHelix pomatia L. neurons

Summary 1. In molluscan neurons glutamate may, on different neurons, evoke either excitation or inhibition. We studied neurons ofHelix pomatia which have hyperpolarizing responses to glutamate and determined the effects of lead on these responses.2. In voltage clamp experiments, the reversal potentials of these glutamate responses indicate that they are due to a conductance increase to chloride ions. Further evidence for this conclusion was obtained by the demonstration that responses to glutamate remained unaffected in experiments with intracellular dialysis with K-free saline in the presence of Na- and K-free extracellular media. In these circumstances, there is effectively no other ion than chloride to carry the current. In isolated neurons the glutamate-evoked chloride current is concentration dependent between 25 and 2500 µM. The current rises over 200 msec and declines in the continued presence of glutamate over a period of about 3 sec.3. Lead (0.5–1.0 µM) potentiated the glutamate-evoked chloride current provided that the channels were not maximally activated. The potentiation was greater if lead was added 30–60 sec before glutamate application.4. These results suggest that potentiation of transmitter-evoked responses by lead must be considered as yet another possible site of action of lead on neurons, and thus this effect must be considered as a part of the mechanism responsible for the neurotoxicity of this heavy metal.     

A cataclasm due to spasm

We describe a 59-year-old patient presenting with ST-elevation acute coronary syndrome. Coronary angiography with intravascular ultrasound (IVUS) showed an important nonsignificant atherosclerotic lesion in the proximal left anterior descending artery (LAD) and presence of bridging in the mid-LAD. Our hypothesis was that focal spasm at this site was the cause of transmural ischaemia; therefore, treatment was given by performing a percutaneous coronary intervention (PCI) of the lesion. The patient remained symptom-free which confirmed our conclusion. The myocardial bridging had no clinical implications at this moment.     

Multi-input deep learning approach for Cardiovascular Disease diagnosis using Myocardial Perfusion Imaging and clinical data

PurposeAccurate detection and treatment of Coronary Artery Disease is mainly based on invasive Coronary Angiography, which could be avoided provided that a robust, non-invasive detection methodology emerged. Despite the progress of computational systems, this remains a challenging issue. The present research investigates Machine Learning and Deep Learning methods in competing with the medical experts' diagnostic yield. Although the highly accurate detection of Coronary Artery Disease, even from the experts, is presently implausible, developing Artificial Intelligence models to compete with the human eye and expertise is the first step towards a state-of-the-art Computer-Aided Diagnostic system.MethodsA set of 566 patient samples is analysed. The dataset contains Polar Maps derived from scintigraphic Myocardial Perfusion Imaging studies, clinical data, and Coronary Angiography results. The latter is considered as reference standard. For the classification of the medical images, the InceptionV3 Convolutional Neural Network is employed, while, for the categorical and continuous features, Neural Networks and Random Forest classifier are proposed.ResultsThe research suggests that an optimal strategy competing with the medical expert's accuracy involves a hybrid multi-input network composed of InceptionV3 and a Random Forest. This method matches the expert's accuracy, which is 79.15% in the particular dataset.ConclusionImage classification using deep learning methods can cooperate with clinical data classification methods to enhance the robustness of the predicting model, aiming to compete with the medical expert's ability to identify Coronary Artery Disease subjects, from a large scale patient dataset.     

Transport and Partitioning of Lead in Indian Mustard (Brassica juncea) and Wheat (Triticum aestivum)

Lead (Pb) contamination in soils is a serious concern because it can be taken up by crops and then transferred through the food chain, posing a potential risk to human health. Indian mustard (Brassica juncea) and wheat (Triticum aestivum) are important crop species known to accumulate heavy metals in their tissues. This study aimed at understanding the transport and accumulation of Pb in these two species and the risk associated with consumption of these foods, which would help us in mitigating accumulation of Pb in edible tissues. The plants were grown at different Pb concentrations for the entire life cycle, and the partitioning of the metal to different tissues was examined. The results showed that plant species differ widely in their ability to transport and accumulate Pb in different tissues. In B. juncea, there was significant accumulation of Pb in both siliques and seeds, whereas most of the Pb in wheat was concentrated in the vegetative tissues and less to the flag leaf and reproductive tissues. In both species, although seed Pb concentrations exceeded acceptable limits, dietary intake did not exceed acceptable limits in most treatments, indicating that more studies on Pb transport and redistribution in crop species is necessary.     

Correlation and Identification of Variable number of Tandem repeats of eNOS Gene in Coronary artery disease (CAD)

Endothelium-derived nitric oxide (NO) is synthesized from l-arginine by endothelial nitric oxide synthase (eNOS) encoded by the NOS3 gene on chromosome7. Since reduced NO synthesis has been implicated in the development of coronary atherosclerosis; polymorphisms of NOS gene might be associated with increased susceptibility to coronary artery disease (CAD). We therefore undertook this study to determine the association between the occurrence of CAD and eNOS4 b/a polymorphism in South Indian patients. We investigated the polymorphisms in the 27 base-pair tandem repeats in intron4 of the eNOS gene in 100 unrelated CAD patients with positive coronary angiograms and 100 age and sex matched control subjects without any history of symptomatic CAD. The eNOS gene intron4 b/a VNTR polymorphism was analyzed by polymerase chain reaction. The plasma lipids levels and other risk factors were also determined. The genotype frequencies for eNOS4b/b, eNOS4a/b and eNOS4a/a were 63, 26 and 11 per cent in CAD subjects, and 72, 20 and 8 per cent in control subjects, respectively. The genotype frequencies did not differ significantly between the two groups. The frequency of the a allele was 0.24 per cent in CAD subjects and 0.18 per cent in control subjects and no significant association was found between patients and control group (P = 0.57, Odds ratio = 3.62). Plasma lipids, glucose and creatinine levels were significantly increased in CAD group. The genotypic frequencies and the allele frequency did not differ significantly between the CAD patients and controls indicating that this polymorphism was not an independent risk factor for the development of CAD in South Indian patients.     

Azygos Vein Lead Implantation For High Defibrillation Thresholds In Implantable Cardioverter Defibrillator Placement

Evaluation of defibrillation threshold is a standard of care during implantation of implantable cardioverter defibrillator. High defibrillation thresholds are often encountered and pose a challenge to electrophysiologists to improve the defibrillation threshold. We describe a case series where defibrillation thresholds were improved after implanting a defibrillation lead in the azygos vein.