Emerging Technologies in Cardiac Pacing From Leadless Pacers to Stem Cells.

Modern pacemakers can sense and pace multiple chambers of the heart. These pacemakers have different modes and features to optimize atrioventricular synchrony and promote intrinsic conduction. Despite recent advancements, current pacemakers have several drawbacks that limit their feasibility. In this review article, we discuss several of these limitations and detail several emerging technologies in cardiac pacing aimed to solve some of these limitations. We present several technological advancements in cardiac pacing, including the use of leadless pacemakers, physiologic pacing, battery improvements, and bioartificial pacemakers. More research still needs to be done in testing the safety and efficacy of these new developments.

CRISPR-Cas9 Applications in Cardiovascular Disease.

The CRISPR-Cas9 system is an economical and accessible gene-editing technology first discovered as a naturally occurring bacterial immune system. Since its fairly recent discovery, CRISPR-Cas9 system's efficiency and simplicity have been successfully used to edit genomes of living organisms in many fields, working in vitro and in vivo in germline and somatic cells to knock-out harmful mutated genes or in some cases working to knock-in a beneficial gene. A current application of the gene-editing system works against specific mutations that cause certain cardiovascular diseases. However, there are current technical limitations as well as ethical dilemmas in introducing gene-editing to humans. Here, we explore highlights on the current state of research of the CRISPR-Cas9 system through the lens of cardiovascular disease and examine potential untouched applications of the system in the field of cardiology.

Is Exercise Helpful or Harmful in Dealing With Specific Arrhythmia.

Exercise is universally known to benefit health by lowering risk for cardiovascular disease and mortality. However, in patients with pre-existing cardiac conditions, including channelopathies, cardiomyopathies and coronary artery disease, exercise can cause sudden cardiac death (SCD). In this review, we explore exercise related risks and current recommendations for specific conditions. The risk of myocardial infarction (MI) during strenuous exercise in asymptomatic individuals with coronary artery disease is decreased with habitual exercise, especially if they have a normal ejection fraction and no ischemia. Furthermore, cardiac rehabilitation has been shown to be beneficial in heart failure. On the other hand, surgery is recommended for certain anomalous coronaries prior to engaging in vigorous activity. In addition, both exercise-induced disease progression and SCD in arrhythmogenic cardiomyopathy restrict ability to engage in competitive sports, as is the case in hypertrophic cardiomyopathy. Other diseases, like myocarditis only cause temporary risk for SCD. Previously considered benign, common conditions like early repolarization do increase SCD risk. Finally, certain gear including thicker chest protectors for athletes engaging in sports with hard, small spherical objects decrease risk of commotio cordis. While significant advances have been achieved in diagnosing and treating previously unrecognized conditions that predispose to sudden cardiac death, more research is needed to further tailor recommendations to allow beneficial exercise in those with rarer conditions that are under-represented in large systemic studies.