Exercise-Induced Sustained Ventricular Tachycardia without Structural Heart Disease: A Case Report.

BACKGROUND Exercise-induced ventricular tachycardia (VT) has been widely reported in patients with preexisting structural heart disease or underlying ischemia and is attributed to reentry tachycardia and abnormal automaticity. However, studies regarding exercise-induced VT in individuals without evident structural heart disease are still limited. CASE REPORT A 51-year-old woman came to our practice for a treadmill stress echocardiogram. The patient experienced only mild chest discomfort and was otherwise asymptomatic. Cardiovascular risk factors were significant only for obesity and positive family history of coronary artery disease in the mother. During the exercise stress test, the patient developed wide complex VT with multiple capture beats accompanied by nausea and dizziness, which lasted approximately 2 minutes before resolving spontaneously. Subsequent evaluation with magnetic resonance imaging, transthoracic echocardiography, and coronary angiography revealed an absence of apparent structural heart disease. CONCLUSIONS Exercise-induced VT in the absence of structural heart disease, although rare, can pose a life-threatening event and requires different considerations for management. The benefits of currently available therapeutic options have yet to be elucidated for this subset of patients. Thus, we assert that there is a need for further investigation on the approach of exercise-induced VT in patients without structural heart disease.

The Reproductive Journey in the Genomic Era: From Preconception to Childhood.

It is estimated that around 10-15% of the population have problems achieving a pregnancy. Assisted reproduction techniques implemented and enforced by personalized genomic medicine have paved the way for millions of infertile patients to become parents. Nevertheless, having a baby is just the first challenge to overcome in the reproductive journey, the most important is to obtain a healthy baby free of any genetic condition that can be prevented. Prevention of congenital anomalies throughout the lifespan of the patient must be a global health priority. Congenital disorders can be defined as structural or functional anomalies that occur during intrauterine life and can be identified prenatally, at birth, or sometimes may only be detected later during childhood. It is considered a frequent group of disorders, affecting 3-6% of the population, and one of the leading causes of morbidity and mortality. Congenital anomalies can represent up to 30-50% of infant mortality in developed countries. Genetics plays a substantial role in the pathogenesis of congenital anomalies. This becomes especially important in some ethnic communities or populations where the incidence and levels of consanguinity are higher. The impact of genetic disorders during childhood is high, representing 20-30% of all infant deaths and 11.1% of pediatric hospital admissions. With these data, obtaining a precise genetic diagnosis is one of the main aspects of a preventive medicine approach in developed countries. The field of reproductive health has changed dramatically from traditional non-molecular visual microscope-based techniques (i.e., fluorescence in situ hybridization (FISH) or G-banding karyotype), to the latest molecular high-throughput techniques such as next-generation sequencing (NGS). Genome-wide technologies are applied along the different stages of the reproductive health lifecycle from preconception carrier screening and pre-implantation genetic testing, to prenatal and postnatal testing. The aim of this paper is to assess the new horizon opened by technologies such as next-generation sequencing (NGS), in new strategies, as a genomic precision diagnostic tool to understand the mechanisms underlying genetic conditions during the "reproductive journey".

Identification and Characterization of Extracellular Vesicles and Its DNA Cargo Secreted During Murine Embryo Development.

Extracellular vesicles (EVs) are known to transport DNA, but their implications in embryonic implantation are unknown. The aim of this study was to investigate EVs production and secretion by preimplantation embryos and assess their DNA cargo. Murine oocytes and embryos were obtained from six- to eight-week-old females, cultured until E4.5 and analyzed using transmission electron microscopy to examine EVs production. EVs were isolated from E4.5-day conditioned media and quantified by nanoparticle tracking analysis, characterized by immunogold, and their DNA cargo sequenced. Multivesicular bodies were observed in murine oocytes and preimplantation embryos together with the secretion of EVs to the blastocoel cavity and blastocyst spent medium. Embryo-derived EVs showed variable electron-densities and sizes (20-500 nm) and total concentrations of 1.74 × 107 ± 2.60 × 106 particles/mL. Embryo secreted EVs were positive for CD63 and ARF6. DNA cargo sequencing demonstrated no differences in DNA between apoptotic bodies or smaller EVs, although they showed significant gene enrichment compared to control medium. The analysis of sequences uniquely mapping the murine genome revealed that DNA contained in EVs showed higher representation of embryo genome than vesicle-free DNA. Murine blastocysts secrete EVs containing genome-wide sequences of DNA to the medium, reinforcing the relevance of studying these vesicles and their cargo in the preimplantation moment, where secreted DNA may help the assessment of the embryo previous to implantation.