Second-Degree Type 2 Atrioventricular Block Requiring Permanent Cardiac Pacing in Patients on CDK4/6 Inhibitors: Report of Two Cases.

Introduction: A wide spectrum of cardiovascular (CV) toxicity is associated with anticancer treatment, and nearly all chemotherapeutic agents can elicit CV toxicity. Inhibitors of cyclin-dependent kinases 4/6 (CDK4/6Is) have become standard of care in the treatment of hormone receptor-positive, human epidermal growth factor receptor 2-negative metastatic breast cancer (MBC). CV side effects are uncommon with CDK4/6Is and only include QT prolongation, with a low incidence rate.

Bosentan and sildenafil in the treatment of HIV-associated pulmonary hypertension.

We present the case of an HIV/HCV-coinfected patient with HIV-related pulmonary hypertension (HRPH) who experienced a good clinical and functional response to bosentan, with a subsequent switch to oral sildenafil due to increased transaminase levels. Bosentan resulted less handy in this case, probably due to both side effects and co-morbidities.