Upon examining a 46-year-old male smoker, you detect an irregularly irregular heart rhythm. What should you do?

The appropriate course of action in this scenario is to disqualify the individual and refer him to his primary medical doctor (PMD) or a cardiologist for further evaluation. An irregularly irregular heart rhythm, such as atrial fibrillation, can be indicative of underlying cardiac issues that may significantly impact the individual’s ability to safely operate a commercial vehicle.

Disqualification and referral for further evaluation ensure that the individual receives a comprehensive assessment of their cardiac health, which is crucial for determining any potential risks associated with driving. This approach emphasizes patient safety, as well as compliance with the Department of Transportation (DOT) regulations, which prioritize public safety by requiring that drivers do not have medical conditions that could impair their driving ability.

The other options may not adequately address the immediate need for safety and thorough medical evaluation of a potentially serious cardiac condition. It is essential to rule out significant issues before considering any form of certification, especially given the reported irregular heart rhythm and the individual's smoking status, which can further complicate cardiac health.