Permanent Complete Heart Block: A Rare Complication of Influenza Infection

The cardiovascular complications of viral illnesses are often underestimated in clinical practice. The influenza virus, one of the most prevalent viral infections, has been associated with a wide spectrum of arrhythmias that are typically transient and self-resolving. We present the case of a 60-year-old female with no prior cardiac comorbidities who developed a complete heart block after an influenza infection. She presented to the clinic with flu-like symptoms and was found to have a complete heart block with a junctional escape rhythm. Polymerase chain reaction testing subsequently confirmed an influenza A infection. She was initially placed on a temporary pacemaker. However, a permanent dual-chamber pacemaker was implanted as bradycardia persisted. Later follow-ups in the cardiology clinic showed that the patient remained dependent on the pacemaker. While there are a few descriptions of influenza-induced transient atrioventricular block, cases of influenza-induced permanent complete heart block are extremely rare, particularly in the absence of severe myocardial inflammation.

An Uncommon Case of Myocarditis Secondary to Durvalumab Plus Tremelimumab

Tumor immunotherapy is an important clinical strategy for the treatment of various solid and hematological malignancies, and its use is on the rise. Immune checkpoint inhibitors (ICIs) are immunotherapies that boost anticancer immune responses by targeting receptors on the surface of T-lymphocytes. Two important ICIs are anti-programmed death ligand-1 (anti-PD-L1) monoclonal antibodies and anti-cytotoxic T-lymphocyte-associated antigen-4 (anti-CTLA-4) monoclonal antibodies. Tremelimumab (anti-CTLA-4) and durvalumab (anti-PD-L1) have been shown to be effective monotherapies. However, their combination has demonstrated effective and encouraging antitumor activity with manageable safety in patients with unresectable hepatocellular carcinoma. We present the case of an 80-year-old male with hepatocellular carcinoma who had undergone drug-eluting bead transarterial chemoembolization (DEB-TACE) on three occasions and had been started on a combination of ICIs, durvalumab, and tremelimumab. He subsequently developed various immune-related adverse effects in different organ systems, including hepatic and cardiovascular complications. Appropriate treatment was administered, but ultimately, he passed away. We aim to discuss the initial evaluation for suspected immune-related adverse events, specifically those related to myocarditis and its various manifestations, prognosis, and treatment.