How to make a cardiac diagnosis?

Stepwise Approach to Cardiac Diagnosis

The most effective approach to cardiac diagnosis follows a structured four-step process beginning with a general clinical evaluation, followed by further cardiac examination, diagnostic testing, and finally treatment planning based on the European Society of Cardiology guidelines. 1

Step 1: Initial Clinical Evaluation

• Obtain a detailed history focusing on cardiac symptoms including chest pain characteristics (noting that only 10-25% of patients with chronic coronary syndrome present with classic anginal symptoms) 1, 2
• Evaluate for dyspnea (at rest, exertional, orthopnea, paroxysmal nocturnal dyspnea), fatigue, reduced exercise tolerance, peripheral edema, and syncope 2, 3
• Document cardiovascular risk factors (hypertension, diabetes, hyperlipidemia, smoking, family history) 2
• Perform physical examination with focus on cardiac aspects (displaced cardiac apex, third heart sound, jugular venous distention, peripheral edema) 3, 1
• Obtain a 12-lead resting ECG (mandatory in all patients) - a normal ECG makes heart failure very unlikely (negative predictive value >90%) 1, 2
• Order basic blood tests including complete blood count, electrolytes, renal function, liver function, glucose, lipid profile, and thyroid function 1, 2
• Consider chest X-ray, particularly when pulmonary symptoms are present 1, 2

Step 2: Further Cardiac Examination

• Perform echocardiography to assess cardiac structure and function - the preferred method to objectively document cardiac dysfunction 1
• Measure left ventricular ejection fraction to distinguish between systolic dysfunction and preserved systolic function 1
• Assess valvular function, cardiac filling characteristics through Doppler measurements, and chamber dimensions 1
• Consider B-type natriuretic peptide (BNP) or N-terminal pro-BNP testing when diagnosis remains uncertain - particularly useful as a "rule out" test due to high negative predictive value 1, 4

Step 3: Diagnostic Testing for Specific Conditions

For Suspected Coronary Artery Disease:

• For patients able to exercise with interpretable ECG: standard exercise ECG testing 1
• For patients able to exercise with uninterpretable ECG: exercise with nuclear MPI or echocardiography 1
• For patients unable to exercise: pharmacological stress with nuclear MPI, echocardiography, or CMR 1
• Consider coronary CT angiography as a first-line test in appropriate patients 1, 2

For Suspected Heart Failure:

• Echocardiography is essential to confirm diagnosis and determine type (systolic vs. diastolic) 1, 3
• Consider natriuretic peptide levels - particularly useful as a "rule out" test 1, 4
• Look for signs of congestion on chest X-ray (venous congestion, interstitial edema) 1, 3
• Consider exercise testing for prognostic stratification 1

For Suspected Pericardial Disease:

• First-level investigations: ECG, echocardiography, chest X-ray, blood tests including inflammatory markers 1
• Second-level investigations: CT, CMR, pericardiocentesis when indicated 1

Step 4: Advanced Testing When Indicated

• Holter/ambulatory ECG monitoring when arrhythmias are suspected 1
• Cardiac MRI for tissue characterization and viability assessment 1, 2
• Coronary angiography for patients with high-risk features, refractory symptoms, or when revascularization is being considered 1
• Invasive hemodynamic monitoring in acute or acutely decompensated heart failure not responding to initial treatment 1
• Consider myocardial biopsy in selected cases when specific cardiomyopathies are suspected 1

Common Pitfalls to Avoid

• Relying solely on typical symptoms - many patients with cardiac disease present atypically, especially women and elderly patients 2, 5
• Overlooking non-cardiac causes of symptoms like chest pain and dyspnea 1, 3
• Failing to recognize heart failure with preserved ejection fraction, which accounts for up to 40-50% of heart failure cases 3, 4
• Neglecting to evaluate for ischemic heart disease in patients with heart failure, given that coronary artery disease is the most common cause 3
• Missing cardiac disease in patients with obesity, as physical examination findings may be less apparent and BNP levels may be falsely low 4

Red Flags Requiring Immediate Attention

• Severe dyspnea at rest or with minimal exertion 6
• Respiratory rate >25 breaths per minute or oxygen saturation <90% despite oxygen therapy 6
• Hemodynamic instability (systolic BP <90 mmHg or significant drop from baseline) 6
• Signs of cardiogenic shock (confusion, cold clammy skin, weak pulse) 6
• Rapid weight gain (>2 kg/week) or sudden worsening of peripheral edema 6
• Chest pain accompanied by shortness of breath, especially if associated with sweating or nausea 6