Symptom burden guiding invasive electrophysiological study in paroxysmal supraventricular tachycardia: The believe SVT registry.

BACKGROUND AND OBJECTIVE: Patients with palpitations clinically suggestive of paroxysmal supraventricular tachycardia (PSVT) are often managed conservatively until ECG-documentation of the tachycardia, leading to high impact on life quality and healthcare resource utilization. We evaluated results of electrophysiological study (EPS), and ablation when appropriate, among these patients, with special focus on gender differences in management. METHODS: BELIEVE SVT is a European multicenter, retrospective registry in tertiary hospitals performing EPS in patients with palpitations, without ECG-documentation of tachycardia or preexcitation, and considered highly suggestive of PSVT by a cardiologist or cardiac electrophysiologist. We analyzed clinical characteristics, results of EPS and ablation, complications, and clinical outcomes during follow-up. RESULTS: Six-hundred eighty patients from 20 centers were included. EPS showed sustained tachycardia in 60.9% of patients, and substrate potentially enabling AVNRT in 14.7%. No major/permanent complications occurred. Minor/transient complications were reported in 0.84% of patients undergoing diagnostic-only EPS and 1.8% when followed by ablation. During a 3.4-year follow-up, 76.2% of patients remained free of palpitations recurrence. Ablation (OR: 0.34, P < .01) and male gender (OR: 0.58, P = .01) predicted no recurrence. Despite a higher female proportion among patients with recurrence, (77.2% vs 63.5% among those asymptomatic during follow-up, P < .01), 73% of women in this study reported no recurrence of palpitations after EPS. CONCLUSIONS: EPS and ablation are safe and effective in preventing recurrence of nondocumented palpitations clinically suggestive of PSVT. Despite a lower efficacy, this strategy is also highly effective among women and warrants no gender differences in management.

Compatibility of a novel temperature-controlled, irrigated radiofrequency catheter with ultra-high-density mapping.

Background: Compatibility of DiamondTemp (DT) radiofrequency (RF) catheter with the Rhythmia mapping system has not been manufacturer-reported nor its tracking accuracy reported. Methods: Consecutive patients undergoing macroreentrant atrial tachycardia ablation guided by Rhythmia and ablated using DT were prospectively enrolled. Following catheter configuration, ablation lines were performed and remapped to measure the RF tag to effective-ablation-line-center (RFT-ALC) distance. Results: Among 20 consecutive patients (54 maps), 40 ablation lines were evaluated. Overall, the RFT-ALC distance was 3.88 ± 2.95 mm, and the operator assessment of accuracy was high. No complications occurred. Conclusion: The use of DT catheter guided by the Rhythmia mapping system is feasible and accurate.

Systematic Workflow and Electrogram guidance to reduce X-ray Exposure Time during cryoballoon ablation of atrial fibrillation: the SWEET-Cryo strategy.

AIMS: Cryoballoon pulmonary vein isolation (CB-PVI) offers similar efficacy to point-by-point radiofrequency PVI for patients with atrial fibrillation (AF), but generally with higher X-ray exposure. Strategies aimed at reducing fluoroscopy mostly rely on other costly imaging techniques, limiting their applicability. We designed a Systematic Workflow and Electrogram guidance to reduce X-ray Exposure Time during CB-PVI (SWEET-Cryo) strategy and analysed its impact on fluoroscopy use and acute procedural and clinical outcomes. METHODS AND RESULTS: We enrolled 100 patients with paroxysmal or persistent AF undergoing CB-PVI by two operators with different levels of expertise. Patients treated with the SWEET-Cryo strategy (prospective cohort; n = 50) or conventional fluoroscopy (retrospective control cohort; n = 50) were compared. When applied by the senior operator, the SWEET-Cryo strategy significantly reduced the mean fluoroscopy time (FT) (2.6 ± 1.25 vs. 20.3 ± 10.8 min) and mean dose area product (DAP) (5.1 ± 3.8 vs. 35.3 ± 22.3 Gy cm2) compared with those of the control group, respectively (P < 0.001). Significant reductions in FT (6.4 ± 2.5 min vs. 32.5 ± 10.05) and DAP (13.9 ± 7.7 vs. 92.3 ± 63.8) were also achieved by the less experienced operator (P < 0.001). No difference was observed in acute and long-term complications or freedom from AF between fluoroscopy strategies during a 33-month median follow-up. Mean FT was maintained below 3 min in randomly selected cases performed during the follow-up period. CONCLUSION: In contrast to conventional protocols and regardless of the operator's experience, the optimized SWEET-Cryo strategy dramatically reduced fluoroscopy exposure during CB-PVI. The efficacy, safety, or added costs of the ablation procedure were not compromised.

Association between mortality and cardiovascular diseases in the vulnerable Mexican population: A cross-sectional retrospective study of the COVID-19 pandemic.

Cardiovascular diseases (CVDs) continue to be the leading cause of death worldwide. Over the past couple of years and with the surge of the COVID-19 pandemic, mortality from CVDs has been slightly overshadowed by those due to COVID-19, although it was during the peak of the pandemic. In the present study, patients with CVDs (CVDs; n = 41,883) were analyzed to determine which comorbidities had the largest impact on overall patient mortality due to their association with both diseases (n = 3,637). Obesity, hypertension, and diabetes worsen health in patients diagnosed positive for COVID-19. Hence, they were included in the overview of all patients with CVD. Our findings showed that 1,697 deaths were attributable to diabetes (p < 0.001) and 987 deaths to obesity (p < 0.001). Lastly, 2,499 deaths were attributable to hypertension (p < 0.001). Using logistic regression modeling, we found that diabetes (OR: 1.744, p < 0.001) and hypertension (OR: 2.179, p < 0.001) significantly affected the mortality rate of patients. Hence, having a CVD diagnosis, with hypertension and/or diabetes, seems to increase the likelihood of complications, leading to death in patients diagnosed positive for COVID-19.

Arritmias ventriculares en el síndrome de takotsubo: cuestión de sexo / Sex-related risk of arrhythmia in takotsubo syndrome

Resumen El síndrome de takotsubo, también conocido como miocardiopatía de estrés, representa un difícil reto diagnóstico, pues en muchos casos su presentación es superponible al infarto de miocardio por ruptura de placa; el diagnóstico definitivo se basa en la ausencia de lesiones culpables en la coronariografía. La fisiopatología de la enfermedad no está por completo establecida, y tiene un pronóstico generalmente benigno. Sin embargo, existe un porcentaje no despreciable de pacientes que sufren complicaciones graves, entre las que destacan las arritmias malignas tipo taquicardia ventricular polimórfica por prolongación del intervalo QT. A pesar de que el síndrome de takotsubo afecta principalmente a las mujeres, quienes por otra parte también suelen tener intervalos QT más prolongados en condiciones basales, la muerte súbita de origen arrítmico aparece con mayor frecuencia en los hombres que sufren esta enfermedad. Se presentan dos casos de ensanchamiento extremo del intervalo QT corregido en pacientes con takotsubo que tuvieron desenlaces diferentes. El propósito de este trabajo es destacar y revisar las diferencias electrocardiográficas y pronósticas relacionadas con el sexo de los sujetos que desarrollan esta controvertida enfermedad.

Abstract Takotsubo syndrome, also known as stress cardiomyopathy, is a difficult diagnostic challenge as, in many cases, its presentation can overlap with that of myocardial infarction due to plaque rupture. The definitive diagnosis is based on the lack of culprit lesions on coronariography. The pathophysiology of the disease has not been completely ascertained, and it has a generally benign prognosis. However, a not inconsiderable percentage of patients experience serious complications, notably malignant arrhythmias like polymorphic ventricular tachycardia due to a prolonged QT interval. Despite takotsubo syndrome affecting mainly women who, furthermore, generally have longer basal QT intervals, sudden death due to arrhythmias is more common in men with this disease. Two cases are presented of extremely prolonged corrected QT intervals in patients with takotsubo, with different outcomes. The purpose of this paper is to highlight and review the electrocardiographic and prognostic differences related to the gender of the individuals who develop this controversial disease.

Complete interatrial block in a left-atrial dependent atrioventricular node.

INTRODUCTION: A middle-age woman underwent an electrophysiologic study due to recurrent atypical atrial flutter. METHODS AND RESULT: Radiofrequency ablation of cavotricuspid isthmus and anterior mitral line was performed. During energy delivery on the anterior left atrial wall, interatrial dissociation and complete block of the sinus impulse to the atrioventricular (AV) node was observed. AV node activation became dependent on a subsidiary left atrial rhythm. CONCLUSION: Anatomical location of intra and inter-atrial connections must be taken into account when performing extensive ablation procedures, specially in cases with prior cardiac surgeries.

Seroprevalence of Anti-SARS-CoV-2 Antibodies in Blood Donors from Nuevo Leon State, Mexico, during 2020: A Retrospective Cross-Sectional Evaluation.

The progression and distribution of the SARS-CoV-2 pandemic are continuously changing over time and can be traced by blood donors' serological survey. Here, we investigated the seroprevalence of anti-SARS-CoV-2 antibodies in blood donors in Nuevo Leon, Mexico during 2020 as a strategy for the rapid evaluation of the spread of SARS-CoV-2 and asymptomatic case detection. We collected residual plasma samples from blood donors who attended two regional donation centers from January to December of 2020 to identify changes in anti-SARS-CoV-2 IgG prevalence. Plasma samples were analyzed on the Abbott Architect instrument using the commercial Abbott SARS-CoV-2 IgG chemiluminescent assay. We found a total of 99 reactive samples from 2068 analyzed plasma samples, resulting in a raw prevalence of 4.87%. Donors aged 18-49 years were more likely to be seropositive compared to those aged >50 years (p < 0.001). Weekly seroprevalence increased from 1.8% during the early pandemic stage to 27.59% by the end of the year. Prevalence was 1.46-fold higher in females compared to males. Case geographical mapping showed that Monterrey city recorded the majority of SARS-CoV-2 cases. These results show that there is a growing trend of seroprevalence over time associated with asymptomatic infection that is unnoticed under the current epidemiological surveillance protocols.

Decline in influenza cases in Mexico after the implementation of public health measures for COVID-19.

Mexico took swift action and has strictly followed mitigation measures to prevent the spread of coronavirus disease, COVID-19. In this study we compared influenza activity indicators in our country after the implementation of public health measures for COVID-19. We compared indicators of influenza activity in 2020 before and after public health measures were taken to reduce COVID-19 with the corresponding indicators from three preceding years and the immediate one, and the potential decrease in seasonal influenza cases/deaths. Nationwide surveillance data revealed a drastic decline in influenza diagnosis in outpatient clinics and public hospitals, influenza positivity rates of clinical specimens, and confirmed severe cases during the following 10 weeks of 2020 as lockdown activities and control measures were established compared with the same period of 2019. Our results suggest that the measures taken for COVID-19 were effective in reducing the spread of other viral respiratory diseases as influenza in our country.

Parent's Perspective towards Child COVID-19 Vaccination: An Online Cross-Sectional Study in Mexico.

COVID-19 vaccination programs continue in child populations. Thus, parents' attitude towards COVID-19 vaccination of their children is crucial for these strategies to succeed. The present study derives from the application of an online COVID-19 Vaccine Acceptance & Hesitancy Questionnaire (COV-AHQ) in which we measure parent's hesitancy towards children's vaccination (section 4 of the COV-AHQ) and other significant factors. A logistic regression analysis with backward stepwise method was used to quantify the associations between factors and parent's hesitancy. According to the correlation analysis, the most representative factors predicting vaccine hesitancy/acceptance were positive attitude towards vaccination, parents believing that the COVID-19 vaccine will enhance the economic situation of the country, parents actively researching information, having the willingness to obtain the COVID-19 vaccine themselves, and the possibility of their children developing adverse effects. Our findings also showed that parents are highly interested in having their children vaccinated. Nonetheless, parents expressed high levels of concern involving their children in developing adverse effects from the vaccine. In addition, obtaining influenza immunization prompted interest in obtaining the COVID-19 vaccine, and younger-aged parents are much more concerned with having their children vaccinated. Therefore, in order to ensure successful vaccination programs, policymakers and health authorities should design strategies to gain confidence and provide security amongst the population, including giving continuous information about the benefits of vaccination and presenting the frequency of side effects to bring parents on board with vaccinating their children.

Propranolol syrup to tablets change triggers electrical storm in Jervell-Lange-Nielsen syndrome.

A 10-year-old girl with genetically confirmed Jervell-Lange-Nielsen syndrome treated with beta-blocker and developed electrical storm after changing propranolol syrup to tablets. Jervell-Lange-Nielsen is characterised by long QT and congenital sensorineural deafness, with high risk of malignant arrhythmias at early ages. Gastric involvement and achlorhydria may be present, with subsequent alteration of medication bioavailability which can trigger severe arrhythmic complications.

Genetic Variability of Chikungunya Virus in Southern Mexico.

Chikungunya virus (CHIKV) is a mosquito-borne alphavirus that causes Chikungunya fever. CHIKV entered Mexico through the state of Chiapas in October 2014. To fully understand the Chikungunya fever outbreak that occurred in southern Chiapas during 2015, we evaluated 22 PCR-confirmed CHIKV-positive patients, identified CHIKV genetic variability, reconstructed viral dispersal, and assessed possible viral mutations. Viruses were isolated and E2, 6K, and E1 genes were sequenced. We applied phylogenetic and phylogeographic approaches, modeled mutations, and estimated selective pressure. Different CHIKV strains circulated in Chiapas during summer 2015. Three isolates grouped themselves in a well-supported clade. Estimates show that the outbreak started in Ciudad Hidalgo and posteriorly dispersed towards Tapachula and neighboring municipalities. We found six non-synonymous mutations in our isolates. Two mutations occurred in one isolate and the remaining mutations occurred in single isolates. Mutations E2 T116I and E2 K221R changed the protein surface in contact with the host cell receptors. We could not find positive selected sites in our CHIKV sequences from southern Chiapas. This is the first viral phylogeographic reconstruction in Mexico characterizing the CHIKV outbreak in southern Chiapas.

Molecular and Clinical Characterization of Chikungunya Virus Infections in Southeast Mexico.

Chikungunya fever is an arthropod-borne infection caused by Chikungunya virus (CHIKV). Even though clinical features of Chikungunya fever in the Mexican population have been described before, there is no detailed information. The aim of this study was to perform a full description of the clinical features in confirmed Chikungunya-infected patients and describe the molecular epidemiology of CHIKV. We evaluated febrile patients who sought medical assistance in Tapachula, Chiapas, Mexico, from June through July 2015. Infection was confirmed with molecular and serological methods. Viruses were isolated and the E1 gene was sequenced. Phylogeny reconstruction was inferred using maximum-likelihood and maximum clade credibility approaches. We studied 52 patients with confirmed CHIKV infection. They were more likely to have wrist, metacarpophalangeal, and knee arthralgia. Two combinations of clinical features were obtained to differentiate between Chikungunya fever and acute undifferentiated febrile illness. We obtained 10 CHIKV E1 sequences that grouped with the Asian lineage. Seven strains diverged from the formerly reported. Patients infected with the divergent CHIKV strains showed a broader spectrum of clinical manifestations. We defined the complete clinical features of Chikungunya fever in patients from Southeastern Mexico. Our results demonstrate co-circulation of different CHIKV strains in the state of Chiapas.

A case report of small bowel perforation secondary to cytomegalovirus related immune reconstitution inflammatory syndrome in an AIDS patient.

Non-traumatic small bowel perforation is rare in adults but carries a high morbidity and mortality. The diagnosis is made on clinical suspicion, and the most common causes in developing countries are infectious diseases, being cytomegalovirus infection in immunocompromised patients the main etiology. We describe a patient with a recently diagnosed advanced stage HIV infection and an intestinal perforation associated with cytomegalovirus immune reconstitution inflammatory syndrome after highly active antiretroviral therapy initiation.

The anti­dengue virus properties of statins may be associated with alterations in the cellular antiviral profile expression.

Dengue virus (DENV) susceptibility to cholesterol depleting treatments has been previously reported. There are numerous questions regarding how DENV seizes cellular machinery and cholesterol to improve viral production and the effect of cholesterol sequestering agents on the cellular antiviral response. The aim of the present study was to evaluate the mechanisms involved in the negative regulation of DENV replication induced by agents that diminish intracellular cholesterol levels. Cholesterol synthesis was pharmacologically (fluvastatin, atorvastatin, lovastatin, pravastatin and simvastatin treatment) and genetically (HMGCR­RNAi) inhibited, in uninfected and DENV2­infected hepatoma Huh­7 cells. The cholesterol levels, DENV titer and cellular antiviral expression profile were evaluated. A reduction in the DENV titer, measured as plaque forming units, was observed in DENV­infected cells following 48 h treatment with 10 µM fluvastatin, 10 µM atorvastatin, 20 µM lovastatin and 20 µM simvastatin, which achieved 70, 70, 65 and 55% DENV2 inhibition, respectively, compared with the untreated cells. In addition, the cytopathic effect was reduced in the statin­treated DENV­infected cells. Statins simultaneously reduced cholesterol levels at 48 h, with the exception of DENV2 infected cells. Genetic inhibition of cholesterol synthesis was performed using RNA interference for 3­hydroxy­3­methylglutaryl­CoA reductase (HMGCR­siRNA), which indicated a slight reduction in DENV2 titer at 48 h post­infection, however, with no significant reduction in cholesterol levels. In addition, DENV2 infection was observed to augment the intracellular cholesterol levels in all experimental conditions. Comparison between the cellular antiviral response triggered by DENV2 infection, statin treatment and HMGCR­siRNA in infected, uninfected, treated and untreated Huh7 cells, showed different expression profiles for the antiviral genes evaluated. All downregulating cholesterol agents evaluated reduced the expression of genes associated with cellular immune and pro­inflammatory responses. These results indicate that statin-mediated downregulation of DENV2 infectious particles number is independent of cholesterol levels and it is partially mediated by the modulation of the cellular antiviral profile.

Chronic rhino-orbito-cerebral mucormycosis: A case report and review of the literature.

Mucormycosis is a life-threatening disease, were rhinocerebral infection is most commonly seen in the clinical setting. Chronic mucormycosis is a rare presentation that exhibits a challenging diagnosis. We describe the case of a 47 year old diabetic man with complains of left zygomatic arch swelling of 3 months evolution. He had received previous antibiotic treatment without improvement. Biopsy of maxillary sinus revealed the presence of non-septated, 90° angle branched hyphae compatible with zygomicetes. The patient was treated with surgical debridement and amphotericin B until there was no evidence of fungi in the tissue by biopsy. We reviewed chronic rhino-orbito-cerebral mucormycosis from 1964-2014 and 22 cases were found, being this the second case of chronic mucormycosis reported in Mexico. A quarter of the cases were seen in immunocompetent hosts. As only 20% of the causal agent can be isolated by culture, the diagnosis is mainly made by biopsy. Besides treatment with amphotericin B, posaconazole as alternative, and control of the underlying comorbidities, surgical debridement represents the corner stone therapy. We recommend at least 36 month follow-up, due to the 13% risk of recurrence. A chronic presentation has a general survival rate of approximately 83%.

[First case of HIV-1 subtype C infection in Mexico]. / Infección por VIH-1 subtipo C. Primer caso informado en México.

We herein report the first case of HIV-1 subtype C described in Mexico, which was detected in a South African patient who died in Mexico of an AIDS-related non-Hodgkin lymphoma. Although HIV-1 subtype B is the predominant virus circulating in Mexico, the case reported highlights the importance of molecular monitoring of the spreading of HIV-1 subtypes.