Atrioventricular block, second degree

This code signifies a type of heart block where electrical impulses from the atria are intermittently blocked from reaching the ventricles, leading to some P waves not being followed by a QRS complex. It represents a partial disruption in the electrical conduction pathway between the upper and lower chambers of the heart.

Use this code when documentation explicitly states "second-degree AV block" or specifies Mobitz Type I (Wenckebach) or Mobitz Type II. This diagnosis is typically made based on electrocardiogram (ECG) findings demonstrating characteristic patterns of dropped QRS complexes.

• Differentiate between Mobitz Type I and Type II if specified; both fall under this code.
• Do not confuse with first-degree AV block (prolonged PR interval) or third-degree (complete) AV block.
• Code any underlying cause of the AV block, such as myocardial infarction or drug toxicity, as a secondary diagnosis.