Radiation-associated Arrhythmias: Putative Pathophysiological Mechanisms, Prevalence, Screening and Management Strategies

Cardiac Complications of Radiation Therapy

Radiation therapy is a critical component in managing many malignancies by improving local control and survival. The benefits of radiation may come at the expense of unintended radiation injury to the surrounding normal tissues, with the heart being one of the most affected organs in thoracic radiation treatments. As cancer survivors live longer, radiation-induced cardiotoxicity (RICT) is now increasingly recognized. In this review, we highlight the spectrum and pathophysiology of RICT. We summarize contemporary recommendations for risk stratification, screening, prevention, and management of RICT. We briefly highlight novel applications for radiation to treat some cardiac conditions such as resistant arrhythmias.

A Primer on the Evolving Subspecialty of Onco-Electrophysiology

Cardio-oncology has become a well-established subspecialty because of the growing burden of cardiovascular diseases in oncology patients, resulting from the cardiac toxicities of cancer therapies and the coexistence of both conditions in the same population. As with other cardiovascular conditions, cardiac arrhythmias have emerged as an important concern in patients with cancer. However, the management of arrhythmias is more complicated in these patients because of complex interactions between oncotherapeutics and arrhythmia-treatment strategies. Similarly, patients with cardiac implantable electronic devices (CIEDs) require cancer treatment strategies that involve radiation therapy require specific management strategies. Thus, there is a need for a specific mechanistic understanding of electrophysiological abnormalities, arrhythmia, and device management in oncology patients, especially given the expanding range of oncologic therapies and radiation strategies. This increasingly prevalent clinical challenge requires new expertise that expands on a yearly basis. This narrative review deals with this recent expansion and addresses key areas of onco-electrophysiology, including the mechanistic basis of common electrocardiographic changes, diagnosis, and management of arrhythmias attributable to oncotherapeutics and the care of patients with arrhythmias who require oncologic therapies, especially patients with devices and drug interactions leading to arrhythmias as seen by cardiac physicians dealing with oncology patients. In addition, it reviews evolving management strategies and protocols for patients with implantable devices, especially if urgent radiation is needed. This review aims to bridge the recent knowledge growth in arrhythmia care for patients with cancer and highlight the evolution of onco-electrophysiology as a subspeciality.

Radiation-associated cardiovascular disease in patients with cancer: current insights from a cardio-oncologist

Radiation-associated cardiovascular disease (RACD), a complex disease characterized with pericarditis, myocardial damage, valvular heart diseases, heart failure, vasculopathy and ischemic heart disease, has a generally poor prognosis. While RACD may be acute, it often manifests in the late years or even decades following radiation exposure to the chest. With an increasing number of cancer survivors, RACD is likely to become an important issue in cardio-oncology. This review discusses pre-radiation therapy (RT) preparation, peri-RT patient management and long follow-up planning post-RT from a cardiology perspective. Additionally, a novel technique of stereotactic radiotherapy, which has been applied for the treatment of intractable cardiac arrhythmias, is presented. Appropriate patient examination and management during and after RT are essential to support patients undergoing cancer treatment to improve long life expectancy. A multidisciplinary team is needed to determine how to manage patients who receive RT to reduce RACD, to detect early phases of RACD and to provide the best treatment for RACD. Recent studies increasingly report advances in diagnosis using new equipment that has the potential to detect early phases of RACD, along with growing evidence for the optimal treatment for RACD. This review provides an overview of recent studies and guidelines to report on the latest findings, and to identify unresolved issues surrounding RACD that require validation in future studies.

Cardiac Arrhythmias in Patients Treated for Lung Cancer: A Review

Cardio-oncology currently faces one of the greatest challenges in the field of health care. The main goal of this discipline is to ensure that patients treated for cancer do not suffer or die from cardiovascular disease. The number of studies on the mechanisms of heart injury during cancer treatment is constantly increasing. However, there is insufficient data on heart rhythm disorders that may result from this treatment. This issue seems to be particularly important in patients with lung cancer, in whom anticancer therapy, especially radiotherapy, may contribute to the onset of cardiac arrhythmias. The observed relationship between cardiac dosimetry and radiotherapy-induced cardiotoxicity in lung cancer treatment may explain the increased mortality from cardiovascular causes in patients after chest irradiation. Further research is essential to elucidate the role of cardiac arrhythmias in this context. Conversely, recent reports have highlighted the application of stereotactic arrhythmia radioablation (STAR) in the treatment of ventricular tachycardia. This review of available studies on the epidemiology, pathogenesis, diagnosis, and treatment of arrhythmias in patients treated for lung cancer aims to draw attention to the need for regular cardiological monitoring in this group of patients. Improving cardiac care for patients with lung cancer has the potential to enhance their overall therapeutic outcomes.