Persistent second-degree atrioventricular block following adenosine infusion for nuclear stress testing.

The agents used for nuclear stress testing (NST) including adenosine, dobutamine, and dipyridamole, are generally well tolerated and the incidence of serious complications associated with their use in NST is relatively low. Adenosine possesses a potent inhibitory effect on the atrioventricular (AV) node and may induce a transient conduction defect which could result in first-, second-, or third-degree heart block in some patients. The use of the potent AV nodal blocker adenosine for nuclear stress testing in patients with evidence of underlying conduction system disease may result in serious complications.

Exertional rhabdomyolysis and renal failure in patients with sickle cell trait: is it time to change our approach?

Based upon numerous reported cases and despite widespread beliefs to the contrary, sickle cell trait (SCT) may be deemed a quantifiable risk factor in certain subsets of patients. As a result of common misconceptions regarding SCT, most individuals with the condition are generally not informed regarding the possible consequences of certain activities such as venturing to high altitudes or participating in overly exertional physical activities. Acute exertional rhabdomyolysis is a potentially serious clinical illness and is caused by skeletal muscle injury resulting in the release of myoglobin and other cellular contents, including creatine kinase, into the circulatory system.