General Rule in Writing Cardiac Diagnosis
When writing a cardiac diagnosis, you must follow a hierarchical structure: primary statements first, which can then be accompanied by modifiers and/or secondary statements, with secondary statements always requiring an accompanying primary statement. 1
Fundamental Structural Rules
The American Heart Association/American College of Cardiology provides explicit rules for diagnostic statement construction 1:
- Secondary statements must always be accompanied by a primary statement 1
- Modifiers must be accompanied by a primary statement 1
- A primary statement may stand alone, or be accompanied by modifiers, secondary statements, or both 1
- Each secondary statement can only accompany specific primary statements according to established pairing rules 1
- Each modifier can only accompany certain primary statements 1
Essential Diagnostic Components
For Heart Failure Diagnosis
Heart failure diagnosis requires BOTH typical symptoms (dyspnea, fatigue, peripheral edema) AND objective evidence of cardiac dysfunction, typically through echocardiography 1, 2, 3:
- Symptoms alone are insufficient - fatigue, dyspnea, and peripheral edema are not specific to heart failure 1, 2
- Objective cardiac dysfunction must be documented at rest 1, 2
- A normal ECG makes heart failure diagnosis unlikely (negative predictive value >90%) 1, 2
- Natriuretic peptides (BNP/NT-proBNP) provide high negative predictive value as a "rule out" test when clinical diagnosis is uncertain 2, 3
Classification by Ejection Fraction
Heart failure must be classified according to left ventricular ejection fraction (LVEF) 3:
- HFrEF (Heart Failure with Reduced EF): LVEF ≤40% 3
- HFmrEF (Heart Failure with Mildly Reduced EF): LVEF 41-49% 3
- HFpEF (Heart Failure with Preserved EF): LVEF ≥50% 3
- HFimpEF (Heart Failure with Improved EF): baseline LVEF ≤40%, ≥10-point increase, second measurement >40% 3
Staging System
Heart failure should be staged according to the revised classification 3:
- Stage A (At-risk): Risk factors present but no structural heart disease, symptoms, or elevated biomarkers 3
- Stage B (Pre-HF): Structural heart disease, abnormal cardiac function, or elevated natriuretic peptides WITHOUT current or prior symptoms 3
- Stage C (HF): Current or prior symptoms and/or signs caused by structural/functional cardiac abnormality 3
- Stage D (Advanced HF): Severe symptoms at rest, recurrent hospitalizations despite guideline-directed therapy, requiring advanced therapies 3
Functional Classification
Use NYHA functional class to classify symptom severity once heart failure is established 1, 4:
- Class I: Cardiac disease without limitation of physical activity; ordinary activity does not cause symptoms 1
- Class II: Slight limitation of physical activity; comfortable at rest, ordinary activity causes symptoms 1
- Class III: Marked limitation of physical activity; comfortable at rest, less than ordinary activity causes symptoms 1
- Class IV: Inability to carry on physical activity without discomfort; symptoms present at rest 1
Critical Diagnostic Pitfall
"Heart failure should never be the final diagnosis" - you must identify and document the underlying etiology and any exacerbating factors 1. The diagnosis is incomplete without specifying:
- The underlying cause (ischemic, hypertensive, valvular, etc.) 1
- The ejection fraction category 3
- The functional class 1, 4
- Any relevant secondary conditions or modifiers 1
Comparison Statements for Serial Diagnoses
When comparing serial cardiac diagnoses, use standardized comparison statements 1: