RESUMEN
Sympathetic imbalance coupled with impairment of baroreceptor control is a key factor responsible for hemodynamic abnormalities in congestive heart failure. Vagal nerve stimulation (VNS) and baroreceptor activation therapy (BAT) are two novel interventions for the same. In this paper, we review the role of sympathovagal alterations in cardiac diseases like heart failure, arrhythmia, hypertension (HTN), etc. Studies like neural cardiac therapy for heart failure (NECTAR-HF), autonomic regulation therapy to enhance myocardial function and reduce progression of heart failure (ANTHEM-HF), and baroreflex activation therapy for heart failure (BEAT-HF), which comprise the history, efficacy, limitations, and current protocols, were extensively analyzed in contrast to one another. Vagal nerve stimulation reverses the reflex inhibition of cardiac vagal efferent activity, which is caused as a result of sympathetic overdrive during the course for heart failure. It has shown encouraging results in certain pre-clinical studies; however, there is also a possibility of serious cardiovascular adverse events if given in higher than the recommended dosage. Attenuated baroreflex sensitivity is attributed to cardiac arrhythmogenesis during heart failure. Baroreceptor activation therapy reverses this phenomenon. However, the surgical procedure for baroreceptor stimulation can have unwarranted complications, including worsening heart failure and hypertension. Considering the effectiveness of the given modalities and taking into account the inconclusive evidence of their adverse events, more clinical trials are needed for establishing the future prospects of these interventional approaches.
RESUMEN
Untreated myocardial infarction (MI) can potentially lead to many fatal complications which require immediate management. One of them is ventricular septal rupture (VSR) which necessitates the hemodynamic stabilization and closure of the septal rupture. Conventional treatment strategy involves surgical repair; however, percutaneous transcatheter repair using an occluder device is a promising upcoming approach. We conducted a detailed review of various published articles and examined the trends in incidence, risk factors, and pathophysiology of MI leading to VSR followed by an in-depth analysis of the various management strategies for the same. In the current clinical scenario, thrombolysis is an imperative management strategy that has been shown to decrease the occurrence of VSR by manifolds, more specifically in patients having ST-elevated MI. Delayed surgical closure remains the main treatment for post-infarction VSR. Other newer modalities, such as percutaneous closure devices and mechanical circulatory supports, are attractive alternative or complementary strategies to treat such patients, both postoperatively and perioperatively. However, earlier surgical repair in VSR increases the risk of mortality, and the optimal timing for VSR closure remains controversial. Despite surgical closure of VSR being the traditional treatment, it presents a considerably high operative risk. Although newer interventions such as percutaneous closure devices and mechanical circulatory supports provide impressive outcomes, their efficacy in high-risk patients remains inconclusive.