Adverse effect of unsp agents aff the cardiovasc sys, subs

This code signifies a patient experiencing an unintended and harmful reaction to an unknown substance, or a substance whose specific class is not documented, that primarily impacts the heart and blood vessels. This reaction is occurring during a follow-up visit for the initial adverse event.

Apply this code when a patient presents for ongoing management or evaluation of cardiovascular symptoms (e.g., arrhythmias, hypertension, hypotension) that are definitively linked to an adverse effect of an unidentifiable or unspecified drug, medication, or biological substance. This is appropriate for any encounter after the initial treatment of the adverse effect.

• Always strive for a more specific code if the agent causing the adverse effect is known.
• Ensure documentation clearly states the cardiovascular system is the primary system affected.
• Confirm the encounter is for follow-up care, not the initial presentation, to justify the "D" seventh character.