How to Write a Cardiac Diagnosis
A cardiac diagnosis should be structured to include: (1) the specific cardiac syndrome with functional classification, (2) left ventricular ejection fraction with quantified measurements, (3) underlying etiology, and (4) relevant comorbidities that impact prognosis and treatment.
Essential Components of the Diagnosis
Primary Cardiac Syndrome Classification
Specify the type of heart failure based on ejection fraction: HFrEF (heart failure with reduced ejection fraction, LVEF ≤40%), HFpEF (heart failure with preserved ejection fraction, LVEF ≥50%), or HFmrEF (heart failure with mid-range ejection fraction, LVEF 41-49%) 1, 2.
Include NYHA functional class (I-IV) to quantify symptom severity, as this classification has been used to select patients in treatment trials and determines which therapies are indicated 1.
For stable angina, classify chest pain as typical angina (substernal chest discomfort provoked by exertion/emotion, relieved by rest/nitroglycerin), atypical angina (two of three characteristics), or noncardiac chest pain (one or none of the characteristics) 1.
Quantified Structural and Functional Assessment
State the numerical LVEF obtained from comprehensive 2-dimensional echocardiography with Doppler flow studies, as this is the single most useful diagnostic test 1.
Document ventricular dimensions and/or volumes, wall thickness, chamber geometry, and regional wall motion abnormalities 1.
Specify right ventricular size and systolic performance, atrial dimensions/volumes, and valve function including severity of mitral and tricuspid regurgitation 1.
Include noninvasive hemodynamic data such as mitral valve inflow pattern, pulmonary venous inflow pattern, mitral annular velocity (for LV filling characteristics), and tricuspid regurgitant gradient with inferior vena cava assessment (for pulmonary artery pressure estimation) 1.
Underlying Etiology
Identify the structural abnormality causing the cardiac syndrome: ischemic heart disease (with documentation of coronary anatomy if known), valvular disease, hypertensive heart disease, diabetic cardiomyopathy, or other specific etiologies 1, 3.
For ischemic etiology, cardiac MRI should be used to assess for myocardial scarring 1.
Document prior myocardial infarction with location if applicable, as this affects prognosis and device therapy eligibility 1.
Critical Comorbidities
List diabetes mellitus explicitly, as it is a particularly important risk factor that increases the risk of heart failure 2- to 4-fold and worsens prognosis 1, 4.
Document hypertension with current control status, as it is both a precipitating factor and requires specific management in heart failure 1.
Include renal function (eGFR and serum creatinine), as this impacts medication dosing and prognosis 1.
Note atrial fibrillation if present, as it is common in patients with diabetes and heart failure, increases mortality, and requires anticoagulation 1.
Diagnostic Algorithm for Heart Failure
Step 1: Confirm Clinical Syndrome
Three conditions must be satisfied for HFrEF diagnosis: (1) symptoms typical of HF (dyspnea, fatigue, ankle swelling), (2) signs typical of HF (elevated jugular venous pressure, pulmonary rales, peripheral edema, third heart sound), and (3) reduced LVEF 1, 3.
Four conditions must be satisfied for HFpEF diagnosis: (1) symptoms typical of HF, (2) signs typical of HF, (3) normal or only mildly reduced LVEF with non-dilated LV, and (4) relevant structural heart disease (LV hypertrophy/LA enlargement) and/or diastolic dysfunction 1.
Note that signs may not be present in early stages or in patients treated with diuretics 1.
Step 2: Obtain Diagnostic Testing
Perform resting ECG in all patients, though >50% with chronic stable angina have normal results 1.
Order transthoracic echocardiography as the initial evaluation for all suspected heart failure patients 1.
Measure BNP or NT-proBNP levels, as systolic heart failure is unlikely when B-type natriuretic peptide level is normal 3.
Obtain chest radiography to assess for venous congestion, interstitial edema, or cardiac enlargement 1, 3.
Step 3: Risk Stratification for Stable Angina
Estimate pretest probability of CAD based on age, sex, and chest pain characteristics (typical vs. atypical vs. noncardiac) 1.
Adjust probability upward for presence of diabetes, hyperlipidemia, smoking, hypertension, family history of premature CAD, or postmenopausal status in women 1.
Perform exercise ECG using Bruce protocol and Duke treadmill score for risk stratification in patients with intermediate to high probability of CAD who can exercise and are not taking digoxin 1.
Measure left ventricular function by resting echocardiography in patients with history of MI, pathologic Q waves, symptoms/signs of heart failure, or complex ventricular arrhythmias, as decreased ejection fraction is the strongest predictor of long-term survival 1.
Example Diagnostic Statements
For Heart Failure with Reduced Ejection Fraction:
"Heart failure with reduced ejection fraction (LVEF 28% by echocardiography), NYHA functional class III, ischemic etiology with prior anterior wall myocardial infarction, complicated by type 2 diabetes mellitus and hypertension."
For Stable Angina:
"Chronic stable angina, Canadian Cardiovascular Society class II, with high probability of coronary artery disease based on typical anginal symptoms in 65-year-old male with diabetes and hypertension, LVEF 55% by echocardiography."
For Heart Failure with Preserved Ejection Fraction:
"Heart failure with preserved ejection fraction (LVEF 58% by echocardiography), NYHA functional class II, with left ventricular hypertrophy (interventricular septal thickness 14 mm) and left atrial enlargement (LA volume index 42 mL/m²), grade II diastolic dysfunction, hypertensive etiology, complicated by type 2 diabetes mellitus and atrial fibrillation."
Common Pitfalls to Avoid
Do not use vague terminology like "congestive heart failure" without specifying ejection fraction category, as treatment differs substantially between HFrEF and HFpEF 1.
Do not omit functional classification, as NYHA class determines eligibility for device therapies (ICD, CRT) and specific medications 1.
Do not fail to quantify LVEF numerically, as specific thresholds (≤35%, ≤40%) determine treatment recommendations 1.
Do not overlook precipitating factors for heart failure decompensation, including acute coronary syndrome, arrhythmias, uncontrolled hypertension, medication non-adherence, or infections 1, 5.
Do not forget to assess for conditions that precipitate "functional" angina, including hyperthyroidism, anemia, hypoxemia, aortic stenosis, or severe uncontrolled hypertension 1.