Acute on chronic diastolic (congestive) heart failure

This code signifies a sudden worsening of pre-existing, long-term diastolic heart failure. It indicates that the heart's ability to relax and fill with blood has acutely deteriorated in a patient already suffering from chronic heart failure primarily due to impaired ventricular relaxation.

Use this code when documentation clearly indicates a patient with a history of chronic diastolic heart failure presents with an acute exacerbation of symptoms such as increased dyspnea, edema, or fatigue. Supporting documentation should specify "acute on chronic" and "diastolic" or "preserved ejection fraction" (HFpEF).

• Ensure documentation explicitly states "acute on chronic" and "diastolic" or "HFpEF" to differentiate from systolic or unspecified types.
• Do not use this code if the heart failure is solely acute or solely chronic without the "acute on chronic" component.
• Always sequence this code as the principal diagnosis when it is the primary reason for the encounter, followed by codes for any associated conditions or complications.