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.

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.

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.

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.

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.

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.

[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.

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.

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.

Acetylsalicylic acid inhibits hepatitis C virus RNA and protein expression through cyclooxygenase 2 signaling pathways.

UNLABELLED: It has been reported that salicylates (sodium salicylate and aspirin) inhibit the replication of flaviviruses, such as Japanese encephalitis virus and dengue virus. Therefore, we considered it important to test whether acetylsalicylic acid (ASA) had anti-hepatitis C virus (HCV) activity. To this end, we examined the effects of ASA on viral replication and protein expression, using an HCV subgenomic replicon cell culture system. We incubated Huh7 replicon cells with 2-8 mM ASA for different times and measured HCV-RNA and protein levels by northern blot, real-time polymerase chain reaction, and western analysis, respectively. We found that ASA had a suppressive effect on HCV-RNA and protein levels (nearly 58%). ASA-dependent inhibition of HCV expression was not mediated by the 5'-internal ribosome entry site or 3'-untranslated regions, as determined by transfection assays using bicistronic constructs containing these regulatory regions. However, we found that HCV-induced cyclooxygenase 2 (COX-2) messenger RNA and protein levels and activity and these effects were down-regulated by ASA, possibly by a nuclear factor kappa B-independent mechanism. We also observed that the ASA-dependent inhibition of viral replication was due in part to inhibition of COX-2 and activation of p38 and mitogen-activated protein kinase/extracellular signal-regulated kinase kinase 1/2 (MEK1/2) mitogen-activated protein kinases (MAPKs). Inhibition of these kinases by SB203580 and U0126, respectively, and by short interfering RNA silencing of p38 and MEK1 MAPK prevented the antiviral effect of ASA. Taken together, our findings suggest that the anti-HCV effect of ASA in the Huh7 replicon cells is due to its inhibitory effect on COX-2 expression, which is mediated in part by the activation of MEK1/2/p38 MAPK. CONCLUSION: These findings suggest the possibility that ASA could be an excellent adjuvant in the treatment of chronic HCV infection.

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.

Genotyping of hepatitis C virus (HCV) in infected patients from Northeast Mexico.

UNLABELLED: Information about HCV genotypes in infected patients from different regions of Mexico is limited. OBJECTIVE: To determine the prevalence of HCV genotypes in a group of HCV infected patients who attended a third level Hospital in Northeast of Mexico. METHODS: Genotyping analysis was performed using the InnoLiPA-HCV genotype assay in 147 patients (65 males and 82 females, mean age 44 +/- 12 years) with positive anti-HCV antibodies and detectable HCV-RNA levels. RESULTS: Infected individuals were more likely to be female (56%). Histological data showed that 63% of the patients had chronic hepatitis, while the remainder presented cirrhosis (37%). The most frequent HCV genotype was 1 (73%). We found the following distribution: genotype 1 (2.7%), 1a (28.6%), 1b (37.4%), 1a/1b (4.1%), 2a (1.4%), 2b (8.8%), 2c (0.7%), 2a/2c (2.7%), 3 (2%), 3a (10.2%), 4 (0.7%) and 4c (0.7%). The most frequent associated risk factor was blood transfusion (72.5%). CONCLUSION: Prevalence of HCV genotypes in the Northeast of Mexico is similar to those reported previously in other Mexican regions and the most frequent risk factor continues being blood transfusion.

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.

Hepatitis C virus infection among HIV-1 infected individuals from northern Mexico.

AIMS: The prevalence of hepatitis C virus (HCV) infection, risk factors and HCV genotypes in 140 HIV-1 infected individuals from northern Mexico was determined. METHODS: Hepatitis C infection was confirmed by the detection of anti-HCV antibodies and HCV-RNA in sera, and genotyping was performed by the InnoLiPA-HCV genotype assay. RESULTS: Seventeen (12.1%) out of 140 HIV-infected individuals were found to be HCV-positive. Coinfected individuals were more likely to be male (87%). The most frequent genotype was 1a (41%), followed by 1b (29.4%), 2a/c (17.6%), 2b (5.9%) and 3 (5.9%). Serum transaminase concentrations (AST and ALT) were higher in coinfected patients. Among the risk factors for coinfection: sexual transmission was the most frequently observed (men who have sex with men (MSM); 64.7% and bisexual behavior; 64.7%) followed by intravenous drug users (IVDU) (53%). There was no association of the HCV genotypes with the age and risk factors for HIV-1 and HCV infection observed in the studied patients. CONCLUSION: The results suggest that the prevalence of HIV-1/HCV coinfection in Mexico is lower than in other American countries.

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.

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.

Frequency of protease and reverse transcriptase drug resistance mutations in naïve HIV-infected patients.

BACKGROUND: Infections with drug-resistant HIV viruses in naïve subjects may cause antiretroviral (ARV) treatment failure. The prevalence of ARV resistance mutations in HIV-1 transcripts of infected naïve patients from northeast Mexico was determined in this study. METHODS: RNA was extracted from plasma samples of 42 naïve individuals who were diagnosed between February 2001 and September 2003 as HIV-1 infected. Both protease (Pr) and reverse transcriptase (RT) were sequenced in 30 patients. In six samples only the RT segment was sequenced and in three samples only the protease segment was analyzed. RESULTS: One of 36 isolates (2.8%) had the M184V resistance mutation to nucleoside retrotranscriptase inhibitors. In the Pr segment, only minor mutations were detected in 27/33 isolates (81.8%). CONCLUSIONS: In this first study, prevalence of major mutations associated with ARV resistance in naïve patients in northeast Mexico is low compared to other countries, perhaps due to a low level of exposure of this population to ARV drugs.