Tapas Mondal

A wireless wearable ECG sensor for long-term applications

Ubiquitous vital signs sensing using wireless medical sensors are promising alternatives to conventional, in-hospital healthcare systems. In this work, a wearable ECG sensor is proposed. This sensor system combined an appropriate wireless protocol for data communication with capacitive ECG signal sensing and processing. The ANT protocol was used as a low-data-rate wireless module to reduce the power consumption and size of the sensor. Furthermore, capacitive ECG sensing is a simple technique that avoids direct contact with the skin and provides maximum convenience to the user. In our work, small capacitive electrodes were integrated into a cotton T-shirt together with a signal processing and transmitting board on a two-layer standard printed circuit board design technology. The entire system has small size, is thin, and has low power consumption compared to recent ECG monitoring systems. In addition, appropriate signal conditioning and processing were implemented to remove motion artifacts. The acquired ECG signals are comparable to ones obtained using conventional glued-on electrodes, and are easily read and interpreted by a cardiologist.

The anatomy and physiology of the sinoatrial node--a contemporary review.

The sinoatrial node is the primary pacemaker of the heart. Nodal dysfunction with aging, heart failure, atrial fibrillation, and even endurance athletic training can lead to a wide variety of pathological clinical syndromes. Recent work utilizing molecular markers to map the extent of the node, along with the delineation of a novel paranodal area intermediate in characteristics between the node and the surrounding atrial muscle, has shown that pacemaker tissue is more widely spread in the right atrium than previously appreciated. This can explain the phenomenon of a “wandering pacemaker” and concomitant changes in the P‐wave morphology. Extensive knowledge now exists regarding the molecular architecture of the node (in particular, the expression of ion channels) and how this relates to pacemaking. This review is an up‐to‐date summary of the current state of our appreciation of the above topics. (PACE 2010; 1392–1406)

Wearable Sensors for Remote Health Monitoring

Life expectancy in most countries has been increasing continually over the several few decades thanks to significant improvements in medicine, public health, as well as personal and environmental hygiene. However, increased life expectancy combined with falling birth rates are expected to engender a large aging demographic in the near future that would impose significant burdens on the socio-economic structure of these countries. Therefore, it is essential to develop cost-effective, easy-to-use systems for the sake of elderly healthcare and well-being. Remote health monitoring, based on non-invasive and wearable sensors, actuators and modern communication and information technologies offers an efficient and cost-effective solution that allows the elderly to continue to live in their comfortable home environment instead of expensive healthcare facilities. These systems will also allow healthcare personnel to monitor important physiological signs of their patients in real time, assess health conditions and provide feedback from distant facilities. In this paper, we have presented and compared several low-cost and non-invasive health and activity monitoring systems that were reported in recent years. A survey on textile-based sensors that can potentially be used in wearable systems is also presented. Finally, compatibility of several communication technologies as well as future perspectives and research challenges in remote monitoring systems will be discussed.

Impact of prenatal risk factors on congenital heart disease in the current era.

Background The healthcare burden related to congenital heart disease (CHD) is increasing with improving survival. We assessed changing trends in prenatal risk factors for CHD in the current era in a Canadian cohort. Methods and Results CHD patients <18 years old (n=2339) and controls without structural heart disease (n=199) were prospectively enrolled in an Ontario province‐wide biobank registry from 2008–2011. Family history, frequency of extra‐cardiac anomalies (ECAs), and antenatal risk factors were assessed. Temporal trends were analyzed and associations with CHD were measured using linear and logistic regression. Family history of CHD and frequency of major ECAs was higher in cases versus controls (P<0.001). Despite an increase in genetic testing in the recent era, only 9.5% of cases with CHD had a confirmed genetic diagnosis. Yield of genetic testing (ie, frequency of abnormal results) was higher in familial and syndromic cases. There was an increase in parental age at conception, maternal prepregnancy body mass index, maternal urinary tract infections, type 1 diabetes, and exposure to nonfertility medications during pregnancy from 1990–2011. Later year of birth, family history of CHD, presence of major ECAs, maternal smoking during pregnancy, and maternal medication exposure were associated with increased odds of CHD (P<0.05 for all). Advanced parental age was associated with increased odds of CHD caused by genetic abnormalities. Conclusions The increase in prenatal risk factors for CHD highlights the need for more rigorous ascertainment of genetic and environmental factors including gene‐environment interactions that contribute to CHD.

Genetic determinants of right-ventricular remodeling after tetralogy of Fallot repair.

Background:Hypoxia-inducible factor (HIF1A) regulates the myocardial response to hypoxia and hemodynamic load. We investigated the association of HIF1A variants with right-ventricular (RV) remodeling after tetralogy of Fallot (TOF) repair.Methods:Children with TOF were genotyped for three single-nucleotide polymorphisms in HIF1A. Genotypes were analyzed for association with RV myocardial protein expression and fibrosis at complete repair (n = 42) and RV dilation, fractional area change, and freedom from pulmonary valve/conduit replacement on follow-up.Results:In 180 TOF patients, mean age at repair was 1.0 ± 0.8 y with follow-up at 9.0 ± 3.5 y; 82% had moderate to severe pulmonary insufficiency. Freedom from RV reinterventions at 5, 10, and 15 y was 92, 84, and 67%, respectively. Patients with more functioning HIF1A alleles had higher transforming growth factor β1 expression and more fibrosis at initial repair as compared with controls (P < 0.05). During follow-up, patients with more functioning HIF1A alleles showed less RV dilation, better preservation of RV function, and greater freedom from RV reinterventions (P < 0.05). This was confirmed in a replication cohort of 69 patients.Conclusion:In children who have had TOF repair, a lower number of functioning HIF1A alleles was associated with RV dilation and dysfunction, suggesting that hypoxia adaptation in unrepaired TOF may influence RV phenotype after repair.

Management of myocardial infarction in children with Kawasaki disease.

Kawasaki disease is an acute, systemic vasculitis of unknown cause affecting mainly neonates (infants) and young children. Despite treatment during the acute phase with intravenous immunoglobulin and aspirin, up to 5% of those affected will develop coronary aneurysms, predisposing them to thrombotic complications that could result in myocardial infarction and/or death. There are treatment protocols in place for the management of myocardial infarction in adults, but the practical nature of medication is unclear in children. To date, there are no clinical trials or specific recommendations on the dosing of thrombolytic therapy for the treatment of myocardial infarction in Kawasaki pediatric patients. However, there are reports of the use of thrombolytic agents, including streptokinase, urokinase and tissue plasminogen activator, as well as the monoclonal platelet glycoprotein (GP)IIb/IIIa receptor inhibitor, abciximab, that have been used to treat myocardial infarction in children with Kawasaki disease. The outcomes in these reports are varied. This review provides a summary of the available data on the management of children with Kawasaki disease suffering from myocardial infarction or thrombotic complications that can potentially lead to myocardial infarction.

Prenatally diagnosed mosaic trisomy 22 in a fetus with left ventricular non-compaction cardiomyopathy.

Jia-Chi Wang,* Linda Dang, Tapas Kumar Mondal, and Aneal Khan Cytogenetics Laboratory, Hamilton Regional Laboratory Medicine Program, Hamilton Health Sciences, Hamilton, Canada Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada Department of Medical Genetics, University of Calgary, Alberta Children’s Hospital, Calgary, Alberta, Canada

Exome sequencing identifies rare variants in multiple genes in atrioventricular septal defect

Purpose:The genetic etiology of atrioventricular septal defect (AVSD) is unknown in 40% cases. Conventional sequencing and arrays have identified the etiology in only a minority of nonsyndromic individuals with AVSD.Methods:Whole-exome sequencing was performed in 81 unrelated probands with AVSD to identify potentially causal variants in a comprehensive set of 112 genes with strong biological relevance to AVSD.Results:A significant enrichment of rare and rare damaging variants was identified in the gene set, compared with controls (odds ratio (OR): 1.52; 95% confidence interval (CI): 1.35–1.71; P = 4.8 × 10−11). The enrichment was specific to AVSD probands, compared with a cohort without AVSD with tetralogy of Fallot (OR: 2.25; 95% CI: 1.84–2.76; P = 2.2 × 10−16). Six genes (NIPBL, CHD7, CEP152, BMPR1a, ZFPM2, and MDM4) were enriched for rare variants in AVSD compared with controls, including three syndrome-associated genes (NIPBL, CHD7, and CEP152). The findings were confirmed in a replication cohort of 81 AVSD probands.Conclusion:Mutations in genes with strong biological relevance to AVSD, including syndrome-associated genes, can contribute to AVSD, even in those with isolated heart disease. The identification of a gene set associated with AVSD will facilitate targeted genetic screening in this cohort.Genet Med 18 2, 189–198.

Thrombosis and thromboembolic complications in fontan patients: a literature review.

Hemodynamic fluctuations and thromboembolic complications are significant areas of concern during the postoperative management of patients with univentricular hearts. The objective of this study is to review the incidence and risk factors associated with thrombosis and thromboembolic complications following total cavopulmonary anastomosis, the third stage of the palliative surgical procedure. A literature search of published evidence was conducted on OvidSP MEDLINE(R) and Embase followed by paired title, abstract, and full-text screening based on specific inclusion criteria. High risks of thromboembolic outcomes were identified across studies, with variable incidences between 3% and 20%, high mortality rates up to 38%, and an inverse relationship with prophylaxis treatment administration. Several risk factors for thrombotic complications, including chronic systemic venous hypertension, protein-losing enteropathy, passive blood flow, atrial arrhythmias, conduit stenosis, prosthetic material use, coagulation factor abnormalities, and several patient characteristics were identified. Based on these findings, a prophylactic anticoagulation algorithm has been proposed.

Development and validation of a generic scale for use in transition programmes to measure self-management skills in adolescents with chronic health conditions: the TRANSITION-Q

AIM To develop a generic self-management skills scale for use with adolescents diagnosed with a chronic health condition who are aged 12 to 18 years. BACKGROUND There is a lack of methodologically sound scales for healthcare teams to use to measure self-management skills in adolescents with chronic conditions transitioning to adult care. METHODS Adolescents aged 12 to 18 years with a broad range of chronic health conditions, including neurodevelopmental conditions, were recruited from May to August 2013 from nine outpatient clinics at McMaster Childrens Hospital (Canada). Thirty-two participated in a cognitive interview, and 337 completed a questionnaire booklet. Interviews were used to develop the TRANSITION-Q. Rasch measurement theory (RMT) analysis was used to identify items that represent the best indicators of self-management skills. Traditional psychometric tests of measurement performance were also conducted. RESULTS The response rate was 92% (32/32 cognitive; 337/371 field test). RMT analysis resulted in a 14-item scale with three response options. The overall fit of the observed data to that expected by the Rasch model was non-significant, providing support that this new scale measured a unidimensional construct. Other tests supported the scale as scientifically sound, e.g. Person Separation Index = 0.82; good item fit statistics; no differential item function by age or gender; low residual correlations between items; Cronbachs alpha = 0.85; test-retest reliability = 0.90; and tests of construct validity that showed, as hypothesized, fewer skills in younger participants and in participants who required assistance to complete the scale. Finally, participants who agreed they are ready to transfer to adult healthcare reported higher TRANSITION-Q scores than did participants who disagreed. CONCLUSIONS The TRANSITION-Q is a short, clinically meaningful and psychometrically sound scale. This generic scale can be used in research and in paediatric and adolescent clinics to help evaluate readiness for transition.