Risk and Protective Factors for Sudden Cardiac Death: An Umbrella Review of Meta-Analyses

Arrhythmias and Sudden Cardiac Death

Ventricular tachyarrhythmias remain a major cause of sudden cardiac arrest (SCA) that leads to sudden cardiac death (SCD). Primary prevention strategies to prevent SCD include promoting a healthy lifestyle, following United States Preventive Service Task Force recommendations related to cardiovascular disease, and controlling comorbid conditions. For a patient experiencing SCA, early cardiopulmonary resuscitation and defibrillation should be performed. Implantable cardioverter defibrillators are more effective at secondary prevention compared with drug therapy but medications such as amiodarone, beta-blockers, and sotalol may be helpful adjuncts to reduce the risk of SCD or improve a patient's symptoms (eg, palpitations and inappropriate defibrillator shocks).

Anti-Arrhythmic Effects of Heart Failure Guideline-Directed Medical Therapy and Their Role in the Prevention of Sudden Cardiac Death: From Beta-Blockers to Sodium-Glucose Cotransporter 2 Inhibitors and Beyond

Sudden cardiac death (SCD) accounts for a substantial proportion of mortality in heart failure with reduced ejection fraction (HFrEF), frequently triggered by ventricular arrhythmias (VA). This review aims to analyze the pathophysiological mechanisms underlying VA and SCD in HFrEF and evaluate the effectiveness of guideline-directed medical therapy (GDMT) in reducing SCD. Beta-blockers, angiotensin receptor-neprilysin inhibitors, and mineralocorticoid receptor antagonists have shown significant efficacy in reducing SCD risk. While angiotensin-converting enzyme inhibitors and angiotensin receptor blockers exert beneficial impacts on the renin-angiotensin-aldosterone system, their direct role in SCD prevention remains less clear. Emerging treatments like sodium-glucose cotransporter 2 inhibitors show promise but necessitate further research for conclusive evidence. The favorable outcomes of those molecules on VA are notably attributable to sympathetic nervous system modulation, structural remodeling attenuation, and ion channel stabilization. A multidimensional pharmacological approach targeting those pathophysiological mechanisms offers a complete and synergy approach to reducing SCD risk, thereby highlighting the importance of optimizing GDMT for HFrEF. The current landscape of HFrEF pharmacotherapy is evolving, with ongoing research needed to clarify the full extent of the anti-arrhythmic benefits offered by both existing and new treatments.

Sudden Cardiac Death: An Update on Commotio Cordis

Sudden cardiac death (SCD) is one of the leading causes of cardiovascular mortality, and it is caused by a diverse array of conditions. Among these is commotio cordis, a relatively infrequent but still significant cause, often seen in young athletes involved in competitive or recreational sports. It is known to be caused by blunt trauma to the chest wall resulting in life-threatening arrhythmia (typically ventricular fibrillation). The current understanding pertains to blunt trauma to the precordium, with an outcome depending on factors such as the type of stimulus, the force of impact, the qualities of the projectile (shape, size, and density), the site of impact, and the timing of impact in relation to the cardiac cycle. In the management of commotio cordis, a history of preceding blunt chest trauma is usually encountered. Imaging is mostly unremarkable except for ECG, which may show malignant ventricular arrhythmias. Treatment is focused on emergent resuscitation with the advanced cardiac life support protocol algorithm, with extensive workup following the return of spontaneous circulation. In the absence of underlying cardiovascular pathologies, implantable cardiac defibrillator insertion is not beneficial, and patients can even resume physical activity if the workup is unremarkable. Proper follow-up is also key in the management and monitoring of re-entrant ventricular arrhythmias, which are amenable to ablative therapy. Prevention of this condition involves protecting the chest wall against blunt trauma, especially with the use of safety balls and chest protectors in certain high-risk sporting activities.  This study aims to elucidate the current epidemiology and clinical management of SCD with a particular focus on a rarely explored etiology, commotio cordis.

Sudden Cardiac Death in Young Individuals: A Current Review of Evaluation, Screening and Prevention

Sudden cardiac death (SCD) can affect all age groups, including young persons. While less common in the age < 35 population, the occurrence of SCD in the young raises concern, with multiple possible etiologies and often unanswered questions. While coronary artery disease is the leading cause in those > 35 years of age, the younger population faces a different subset of pathologies associated with SCD, including arrhythmias and cardiomyopathies. The tragic nature of SCD in the young entails that we explore and implement available screening methods for this population, and perform the necessary investigations such as electrocardiography (ECG) and echocardiography. In this review, we not only explore the vast etiology associated with SCD in those age < 35, but emphasize evaluation methods, who is at risk, and delve into screening of SCD in potential victims and their family members, in an attempt to prevent this traumatic event. Future research must work towards establishing preventative measures in order to reduce SCD, particularly unexplained SCD in the young.