Feature Papers from Hearts Editorial Board Members

Adult congenital heart disease (ACHD) represents a significant portion of congenital anomalies, and with improved treatments leading to an increased life expectancy, its prevalence has been increasing over the past few decades. Nonetheless, a considerable number of patients with ACHD require cardiac rhythm management devices during their lifetime. Traditionally, transvenous pacemaker placement has been the standard mode of treatment for these patients. However, some patients with ACHD have anatomical barriers that obscure this mode of treatment. Leadless pacing systems (LPSs) have changed the field of pacing. Currently, two different LPSs are available. In a real-world setting, implanting an LPS in patients after tricuspid valve (TV) surgery seems to be a straightforward procedure with a low risk of complications, with patients showing no valvular dysfunction after the intervention. LPS implantation is an option to avoid device-related complications in patients with previous TV surgery. Moreover, it has been demonstrated that even the jugular approach seems as safe as the femoral approach and could be considered an alternative implantation method for LPSs. The Aveir VR leadless pacemaker is a helix LPS with unique features, such as its capacity as a dual-chamber leadless pacemaker, the ability to map electrical parameters before releasing the device, and its possibility of being retrievable. Hereby, we present the case of Ebstein’s anomaly, atrial septal defect closure, and previous TV surgery with symptomatic intermittent advanced atrioventricular block. This case illustrates that a transjugular approach for LPSs is also feasible in patients with ACHD. Full article

Cardiac arrest remains a leading cause of death worldwide and is a global health crisis. First described in the medical literature in the 18th century, modern cardiopulmonary resuscitation (CPR) with closed chest compressions has remained the standard of care since 1960. Despite exponential advances in basic science research and technological innovations, cardiac arrest survival remains a dismal 10%. The standard of care closed chest compressions provide only 20–30% of baseline cardiac output to the body. Have modern therapies plateaued in effectiveness? This article reviews the history of cardiac arrest, its therapies, and opportunities for future treatments. Through an exploration into the history of CPR and breakthroughs in its treatment paradigms, modern-day researchers and providers may find further inspiration to combat the cardiac arrest public health crisis. Full article

Background: Recent studies have suggested an increased risk of acute myocardial infarction (AMI) following daylight saving time (DST) transitions in cohorts of American and European patients. We aim to validate this finding in a Canadian population. Methods: We performed a retrospective cohort study of patients admitted to the Hôpital du Sacré-Coeur de Montréal with a diagnosis of AMI requiring a coronary angiogram from 28 February 2016 to 3 December 2022. The transition period was defined as two weeks following DST, while the control periods were two weeks before and two weeks after the transition period. Patients aged 18 years or older were included. The primary endpoint was the incidence rate ratio (IRR) of AMI following DST transitions while the secondary endpoint was infarct size by biomarkers. A subgroup analysis compared the pre-COVID-19 period (2016–2019) to the post-COVID-19 period (2020–2022). Results: A total of 1058 patients were included (362 in the transition group and 696 in the control group). The baseline clinical characteristics were comparable between both groups. The rate of AMI per day following the DST transitions was 1.85 compared to 1.78 during control periods. The DST transitions were not associated with an increase in AMI (IRR = 1.04, 95% CI 0.91–1.18, p = 0.56) nor with infarct size. In the subgroup analysis, DST was associated with a significant increase in the incidence of AMI only in the pre-COVID-19 period, with a rate of 2.04 AMI per day in the transition group compared to 1.71 in the control group (IRR = 1.19, 95% CI 1.01–1.41, p = 0.041). In contrast, there was a significant increase in the size of AMI following DST in the post-COVID-19 period subgroup, with a creatine phosphokinase-MB (CK-MB) concentration of 137 ± 229 µg/L compared to 93 ± 142 µg/L (p = 0.013). Conclusions: In this Canadian cohort, there was a significant increase in the incidence of AMI in the pre-COVID-19 period, and infarct sizes were significantly larger following the DST transitions in the post-COVID-19 period. No significant associations emerged when pre- and post-COVID-19 periods were pooled. Full article

Cardiorenal syndrome (CRS) is a life-threatening disorder that involves a complex interplay between the two organs. Managing this multifaceted syndrome is challenging in the hospital and requires a multidisciplinary approach to tackle the many manifestations and complications. There is no universally accepted algorithm to treat patients, and therapeutic options vary from one patient to another. The mainstays of therapy involve the stabilization of hemodynamics, decongestion using diuretics or renal replacement therapy, improvement of cardiac output with inotropes, and goal-directed medical treatment with renin–angiotensin–aldosterone system inhibitors, beta-blockers, and other medications. Mechanical circulatory support is another viable option in the armamentarium of agents that improve symptoms in select patients. Full article

Germline mutations in Breast cancer susceptibility genes 1 and 2 (BRCA1 and BRCA2) cause breast, ovarian, and other cancers, and the chemotherapeutic drug doxorubicin (Dox) is widely used to treat these cancers. However, Dox use is limited by the latent induction of severe cardiotoxicity known as Dox-induced cardiomyopathy, for which there are no specific treatments currently available. Dox is administered into the systemic circulation, where it readily translocates into sub-cellular compartments and disrupts the integrity of DNA. Accumulating evidence indicates that oxidative stress, DNA damage, inflammation, and apoptosis all play a central role in Dox-induced cardiomyopathy. The BRCA1 and BRCA2 proteins are distinct as they perform crucial yet separate roles in the homologous recombination repair of DNA double-strand breaks, thereby maintaining genomic integrity. Additionally, both BRCA1 and BRCA2 mitigate oxidative stress and apoptosis in both cardiomyocytes and endothelial cells. Accordingly, BRCA1 and BRCA2 are essential regulators of pathways that are central to the development of cardiomyopathy induced by Doxorubicin. Despite extensive investigations, there exists a gap in knowledge about the role of BRCA1 and BRCA2 in Doxorubicin-induced cardiomyopathy. Here, we review the previous findings and associations about the expected role and associated mechanisms of BRCA1 and 2 in Dox-induced cardiomyopathy and future perspectives. Full article

An unroofed coronary sinus is a malformation that leads to a shunt between the coronary sinus and the left atrium. In our case, the shunt led to the formation of a gigantic left atrial aneurysm compressing the left atrium on transesophageal echocardiography. During surgery, a myxoma was incidentally discovered. Full article