How Can You Tell if You Have White Mold or Efflorescence? First, look at the type of material on which you see the white substance. If you see it on anything other than concrete or masonry, itâs mold. Second, spray the substance with a little water in a spray bottle and simply wipe it with a rag.
Thus, as shown in electrophysiologic studies, PR interval prolongation (ie, first-degree AV block) may be due to conduction delay within the right atrium, the AVN, the His-Purkinje system, or a combination of these. Overall, dysfunction at the AVN is much more common than dysfunction at the His-Purkinje system.
QT prolongation, a surrogate marker for the risk of developing TdP, is an established side effect of Class I and Class III anti-arrhythmic medicines. It is also a rare side effect of a wide range of non-cardiac medicines including some antibiotics, antihistamines, opioid analgesics and complementary medicines.