Adenosine-induced ventricular fibrillation in a patient with supraventricular tachycardia

Adenosine is frequently used for paroxysmal supraventricular tachycardia (PSVT) treatment in the emergency department (ED). Atrial and ventricular pro-arrhythmic effects of adenosine were described in the literature, but ventricular fibrillation (VF) secondary to adenosine administration was rarely reported (with an incidence of < 1%). Reported herein is the first case of a 72-year-old female patient who developed VF hemodynamic collapse after an intravenous administration of adenosine for PSVT treatment. She had no known pre-excitation or accessory pathway, nor any underlying structural heart disease or prolonged QT syndrome. Raising awareness of this potential life-threatening pro-arrhythmic effect of adenosine is important, given its frequent use for PSVT treatment in the ED.

Medical Care for Patients with Substance Use Disorders

Primary care clinicians commonly encounter patients with substance use disorders and can provide effective treatment for their problems. Many of the medical complications associated with drug use are due to the use of needles; these include transmission of HIV and hepatitis C, soft tissue infections, and endocarditis. Harm reduction strategies reduce the harms associated with drug use without targeting use itself; these include syringe distribution, safe consumption facilities, naloxone distribution, and pre-exposure HIV prophylaxis. Patients on opioid agonist treatment may develop a number of problems, including hypogonadism, constipation, and psychomotor impairment; those on methadone may develop prolonged QT syndrome. Other issues include drug interactions, treatment of acute pain, and perioperative care. Treating pain in patients with substance use disorder can be complicated; for many, especially those with opioid use disorder, treatment with buprenorphine or enrollment in methadone maintenance is the best option.

Corticosteroids for Posttransplant Immune Reconstitution Syndrome in Cryptococcus gattii Meningoencephalitis: Case Report and Literature Review

Cryptococcus gattii represents an emerging fungal pathogen of immunocompromised and immunocompetent hosts in the United States. To our knowledge, this is the first case of posttransplant immune reconstitution syndrome due to C. gattii meningoencephalitis successfully treated with corticosteroids. We also report successful maintenance phase treatment with isavuconazole, a novel triazole, following fluconazole-induced prolonged QT syndrome.

Exercise-Induced Syncope in a Sedentary Woman

Vasovagal (neurocardiogenic) syncope, a subtype of reflex syncope, has many well-known triggers. However, we found no previous report of vasovagal exercise-induced syncope in a sedentary person. We present the case of a 35-year-old sedentary woman who experienced vasovagal syncope as she underwent an exercise stress test. Results of evaluations, including resting and stress electrocardiography and echocardiography, were normal. Her presentation is highly unusual: syncope has typically not been associated with exercise except in young athletes, people with structural heart abnormalities, or people with a prolonged QT syndrome. To our knowledge, this is the first report of vasovagal syncope associated with exercise in a sedentary patient who had normal cardiac and electrophysiologic function. We suggest possible physiologic mechanisms and diagnostic strategies.