An Automatic Method to Reduce Baseline Wander and Motion Artifacts on Ambulatory Electrocardiogram Signals

Today’s wearable medical devices are becoming popular because of their price and ease of use. Most wearable medical devices allow users to continuously collect and check their health data, such as electrocardiograms (ECG). Therefore, many of these devices have been used to monitor patients with potential heart pathology as they perform their daily activities. However, one major challenge of collecting heart data using mobile ECG is baseline wander and motion artifacts created by the patient’s daily activities, resulting in false diagnoses. This paper proposes a new algorithm that automatically removes the baseline wander and suppresses most motion artifacts in mobile ECG recordings. This algorithm clearly shows a significant improvement compared to the conventional noise removal method. Two signal quality metrics are used to compare a reference ECG with its noisy version: correlation coefficients and mean squared error. For both metrics, the experimental results demonstrate that the noisy signal filtered by our algorithm is improved by a factor of ten.

Postmortem fluorescence angiography of the explanted human heart

Within the scope of this technical report, the feasibility of indocyanine green (ICG) as a fluorescent agent for postmortem angiography of the heart is tested. The study included 4 deceased persons with no respective medical history of heart diseases. The basic patterns of findings in ICG fluorescence angiography associated with healthy hearts are presented. The method can easily be integrated into a workflow without restricting the macroscopic or histologic diagnostics. This paper represents the fundamental technical and analytical basis for upcoming studies concerning the possibilities and limitations of fluorescence angiography in the diagnosis of heart pathology.

Novel rhythm conversion approach in unsuccessful electric cardioversion of persistent atrial fibrillation

The average effectiveness of electrical cardioversion in persistent atrial fibrillation (AF) is considered about 90%. The success is limited by arrhythmia longevity, essential heart pathology, excessive body mass, concomitant deceases. A novel developed in Russia class III intravenous medication “Refralon” (4-nitro-N-(1RS)-1(4-fluorophenyl)-2-(1-ethylpiperidin-4-ethyl) benzamide hydrochloride) seems to be promising in sinus rhythm restoration in such patients. The aim of the study was to assess the effectiveness of a novel class III intravenous medication “Refralon” in conversion to sinus rhythm in patients with permanent AF in whom electrical cardioversion was unsuccessful. Materials and methods 19 patients were included: 16 male and 3 female aged from 45 to 68 years old (59,9±5,84 (M±SD)). Left atrial size was 47±3,2 × 59±2,8 mm, BMI 38,5±7,0 kg/m2, arrhythmia duration from 2 to 21 months (6,7±4,99). Refralon was injected according to the approved manual in ICU; heart rhythm and rate, blood pressure, SpO2 were monitored. Dynamic assessment of QT and QRS duration was performed. Results In 17 of 19 patients (89,4%) sinus rhythm was restored. In 7 patients (41%) sinus rhythm was restored before 10 min, in 4 patients (24%) before one hour, in 4 patients (24%) before two hours, in 2 patients (11%) before six hours. In two patients sinus rhythm was not restored. In both target dose was not infused due to non-sustained ventricular tachycardia in one case, and QT prolongation in another. Conclusion In a small pilot study Refralon was highly effective in patients with persistent atrial fibrillation when electrical cardioversion was ineffective. All the patients had significantly increased BMI. The results may suggest the indication for Refralon usage in obese patients. FUNDunding Acknowledgement Type of funding sources: None.

Sex differences in cardio-pulmonary pathology of SARS-CoV2 infected and Trypanosoma cruzi co-infected mice

Coronavirus disease-2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2; CoV2) is a deadly contagious infectious disease. For those who survived COVID-19, post-COVID cardiac damage poses a major threat for the progression of cardiomyopathy and heart failure. Currently, the number of COVID-related cases and deaths is increasing in Latin America, where a major COVID comorbidity is Chagas heart disease (caused by the parasite Trypanosoma cruzi). Here, we investigated the effect of T. cruzi infection on the pathogenesis and severity of CoV2 infection and, conversely, the effect of CoV2 infection on heart pathology during coinfection. We used transgenic human angiotensin-converting enzyme 2 (huACE2) mice infected with CoV2, T. cruzi, or coinfected with both in this study. Our study shows for the first time that white adipose tissue (WAT) serves as a reservoir for CoV2 and the persistence of CoV2 in WAT alters adipose tissue morphology and adipocyte physiology. Our data demonstrate a correlation between the loss of fat cells and the pulmonary adipogenic signaling and pathology in CoV2 infection. The viral load in the lungs is inversely proportional to the viral load in WAT, which differs between male and female mice. Our findings also suggest that adiponectin-PPAR signaling may differently regulate Chagas cardiomyopathy in coinfected males and females. We conclude that adipogenic signaling may play important roles in cardio-pulmonary pathogenesis during CoV2 infection and T. cruzi coinfection. The levels of adiponectin isomers differ between male and female mice during CoV2 infection and coinfection with T. cruzi, which may differently regulate inflammation, viral load, and pathology in the lungs of both the sexes. Our findings are in line with other clinical observations that reported that males are more susceptible to COVID-19 than females and suffer greater pulmonary damage.

Accelerating the Mdx Heart Histo-Pathology through Physical Exercise

Chronic cardiac muscle inflammation and fibrosis are key features of Duchenne Muscular Dystrophy (DMD). Around 90% of 18-year-old patients already show signs of DMD-related cardiomyopathy, and cardiac failure is rising as the main cause of death among DMD patients. The evaluation of novel therapies for the treatment of dystrophic heart problems depends on the availability of animal models that closely mirror the human pathology. The widely used DMD animal model, the mdx mouse, presents a milder cardiac pathology compared to humans, with a late onset, which precludes large-scale and reliable studies. In this study, we used an exercise protocol to accelerate and worsen the cardiac pathology in mdx mice. The mice were subjected to a 1 h-long running session on a treadmill, at moderate speed, twice a week for 8 weeks. We demonstrate that subjecting young mdx mice (4-week-old) to “endurance” exercise accelerates heart pathology progression, as shown by early fibrosis deposition, increases necrosis and inflammation, and reduces heart function compared to controls. We believe that our exercised mdx model represents an easily reproducible and useful tool to study the molecular and cellular networks involved in dystrophic heart alterations, as well as to evaluate novel therapeutic strategies aimed at ameliorating dystrophic heart pathology.

Gain-of-function cardiomyopathic mutations in RBM20 rewire splicing regulation and re-distribute ribonucleoprotein aggregates within processing bodies

RNA binding motif protein 20 (RBM20) is a key regulator of alternative splicing in the heart, and its mutation leads to malignant dilated cardiomyopathy (DCM). To understand the mechanism of RBM20-associated DCM, we engineered isogenic human induced pluripotent stem cells (iPSCs) with heterozygous or homozygous DCM-associated missense mutations in RBM20 (R636S) as well as RBM20 knockout (KO) iPSCs. iPSC-derived engineered heart tissues made from these cell lines recapitulated contractile dysfunction of RBM20-associated DCM and revealed greater dysfunction with missense mutations than KO. Analysis of RBM20 RNA binding by eCLIP revealed a gain-of-function preference of mutant RBM20 for 3′ UTR sequences that are shared with amyotrophic lateral sclerosis (ALS) and processing-body associated RNA binding proteins (FUS, DDX6). Deep RNA sequencing revealed that the RBM20 R636S mutant has unique gene, splicing, polyadenylation and circular RNA defects that differ from RBM20 KO, impacting distinct cardiac signaling pathways. Splicing defects specific to KO or R636S mutations were supported by data from R636S gene-edited pig hearts and eCLIP. Super-resolution microscopy verified that mutant RBM20 maintains limited nuclear localization potential; rather, the mutant protein associates with cytoplasmic processing bodies (DDX6) under basal conditions, and with stress granules (G3BP1) following acute stress. Taken together, our results highlight a novel pathogenic mechanism in cardiac disease through splicing-dependent and -independent pathways that are likely to mediate differential contractile phenotypes and stress-associated heart pathology.

Screening for Pulmonary Hypertension in Systemic Sclerosis—A Primer for Cardio-Rheumatology Clinics

Systemic sclerosis (SSc) is a rare disease, with unfavorable clinical course and prognosis, characterized by progressive multisystemic involvement. SSc associated pulmonary hypertension (SSc-PAH) and interstitial lung disease (ILD) are the most important factors for morbi-mortality in these patients, being responsible for more than 60% of total deaths. Though pulmonary arterial hypertension (PAH) is the dominant subtype seen in SSc, PH secondary to ILD, left-heart pathology, and pulmonary veno-occlusive disease (PVOD) are also possible occurrences. Initial evaluation of a SSc case is complex and should be performed with a multidisciplinary approach. Early detection of SSc-PAH is imperative, given the fact that new and effective medications are available and early treatment was shown to improve outcomes. Therefore, screening algorithms must be used adequately and in a cost-effective manner. Sensitivity and negative predictive value (NPV) are the most important performance measures in a screening test. Several algorithms were developed in the last decade (e.g., DETECT and ASIG) and demonstrated higher efficiency when compared to older algorithms. The present manuscript details the risk factors for SSc-PAH and includes a critical description of current detection algorithms, as a primer for clinicians working in the field of cardio-rheumatology.

Galectin-Receptor Interactions Regulates Cardiac Pathology Caused by Trichinella spiralis Infection

The parasitic nematode Trichinella spiralis causes trichinellosis, a serious food-borne parasitic zoonosis worldwide. Infection with T. spiralis may also cause myocarditis. In the present study, we used mouse models to assess the impact of blockage of galectin-receptor interactions by α-lactose on cardiac immunopathology during acute T. spiralis experimental infection. Our data demonstrated that, after T. spiralis infection, blockage of galectin-receptor interactions resulted in cardiac dysfunction detected by transthoracic conventional echocardiography, and increased serum Gal-3 level, a biomarker of myocardial damage. In addition, there were increased eosinophil number in peripheral blood, and increased eosinophil infiltration in the heart and spleen tissues accompanied with increased mRNA levels of eosinophil granule proteins (including eosinophil cationic protein (ECP) and eosinophil peroxidase (EPO)) and IL-5 in these organs; increased cardiac fibrosis accompanied with increased Gal-3 and collagen 1 expressions in the hearts of mice with blockage of galectin-receptor interactions after T. spiralis infection. Correlation analysis showed that significant positive correlations existed between the mRNA levels of Gal-3 and ECP/EPO/eosinophil major basic protein/IL-5/CCL11/CCR3/α-SMA/collagen 1 in the hearts of both T. spiralis-infected mice and T. spiralis-infected mice with blockage of galectin-receptor interactions. Our data suggest that galectin-receptor interactions play a pivotal role during acute T. spiralis infection, and lack of galectin-receptor interactions upregulates Gal-3 which, in turn, leads to elevated heart eosinophil recruitment, exacerbated heart pathology and fibrosis, and heart functional damage.

Piscine Orthoreovirus (PRV)-3, but Not PRV-2, Cross-Protects against PRV-1 and Heart and Skeletal Muscle Inflammation in Atlantic Salmon

Heart and skeletal muscle inflammation (HSMI), caused by infection with Piscine orthoreovirus-1 (PRV-1), is a common disease in farmed Atlantic salmon (Salmo salar). Both an inactivated whole virus vaccine and a DNA vaccine have previously been tested experimentally against HSMI and demonstrated to give partial but not full protection. To understand the mechanisms involved in protection against HSMI and evaluate the potential of live attenuated vaccine strategies, we set up a cross-protection experiment using PRV genotypes not associated with disease development in Atlantic salmon. The three known genotypes of PRV differ in their preference of salmonid host species. The main target species for PRV-1 is Atlantic salmon. Coho salmon (Oncorhynchus kisutch) is the target species for PRV-2, where the infection may induce erythrocytic inclusion body syndrome (EIBS). PRV-3 is associated with heart pathology and anemia in rainbow trout, but brown trout (S. trutta) is the likely natural main host species. Here, we tested if primary infection with PRV-2 or PRV-3 in Atlantic salmon could induce protection against secondary PRV-1 infection, in comparison with an adjuvanted, inactivated PRV-1 vaccine. Viral kinetics, production of cross-reactive antibodies, and protection against HSMI were studied. PRV-3, and to a low extent PRV-2, induced antibodies cross-reacting with the PRV-1 σ1 protein, whereas no specific antibodies were detected after vaccination with inactivated PRV-1. Ten weeks after immunization, the fish were challenged through cohabitation with PRV-1-infected shedder fish. A primary PRV-3 infection completely blocked PRV-1 infection, while PRV-2 only reduced PRV-1 infection levels and the severity of HSMI pathology in a few individuals. This study indicates that infection with non-pathogenic, replicating PRV could be a future strategy to protect farmed salmon from HSMI.