What is the appropriate diagnosis and management for a 50-year-old male presenting with dyspnea (shortness of breath) on exertion without edema?

Dyspnea on Exertion in a 50-Year-Old Male Without Edema

This patient requires immediate evaluation for cardiac causes, particularly coronary artery disease and heart failure with preserved ejection fraction (HFpEF), as these are the most common life-threatening etiologies in this age group presenting with exertional dyspnea. 1, 2

Initial Diagnostic Approach

First-Line Testing (Perform Immediately)

• Chest radiography to identify cardiomegaly, pulmonary congestion, pleural effusion, pneumonia, or masses 3, 2
• Electrocardiography to detect ischemic changes, arrhythmias (atrial fibrillation, inappropriate sinus tachycardia), or chamber enlargement 3, 1, 2
• Transthoracic echocardiography (rated 9/9 "usually appropriate" by ACR) to assess left ventricular systolic and diastolic function, valvular disease (aortic stenosis, mitral regurgitation), right ventricular strain, and pericardial effusion 3, 1
• B-type natriuretic peptide (BNP) or NT-proBNP measurement: BNP <100 pg/mL or NT-proBNP <125 pg/mL effectively excludes heart failure 3, 1, 2
• Complete blood count to assess for anemia 2, 4
• Basic metabolic panel to evaluate for renal dysfunction and electrolyte abnormalities 2, 4
• Spirometry to identify obstructive (asthma, COPD) or restrictive patterns 2, 4
• Pulse oximetry to assess for hypoxemia 5, 2

Critical Clinical Examination Findings to Assess

• Jugular venous distention suggests elevated right heart pressures from heart failure or pulmonary hypertension 4
• Cardiac auscultation for S3 gallop (heart failure), murmurs (valvular disease), or irregular rhythm (atrial fibrillation) 3, 1
• Lung auscultation for decreased breath sounds (COPD, pleural effusion), wheezing (asthma, COPD), or bibasilar crackles (heart failure, interstitial lung disease) 2, 4
• Digital clubbing suggests interstitial lung disease, pulmonary veno-occlusive disease, or chronic hypoxemia 3, 4
• Tachycardia >120 bpm is a Framingham criterion for heart failure 3

Most Likely Cardiac Diagnoses in This Population

Coronary Artery Disease

• Most common cardiac cause of dyspnea when myocardial oxygen supply does not meet demand 1, 2
• If clinical suspicion exists, proceed to stress echocardiography (uniquely positioned to characterize ischemia-induced systolic dysfunction) or coronary CT angiography 3, 1, 2
• Invasive coronary angiography remains the gold standard when revascularization is being considered 1

Heart Failure with Preserved Ejection Fraction (HFpEF)

• Primary care clinicians must recognize HFpEF as a potential diagnosis in persons with dyspnea and exertional intolerance 3
• Patients describe "air hunger" and "inability to get a deep breath" due to restrictive mechanics and elevated filling pressures 3, 2
• Diagnostic criteria require: EF ≥50%, elevated natriuretic peptides (BNP >35 pg/mL ambulatory or >100 pg/mL hospitalized; NT-proBNP >125 pg/mL ambulatory or >300 pg/mL hospitalized), and objective evidence of structural/functional cardiac abnormality 3
• Pitfall: Lower natriuretic peptide levels relative to HFrEF for given elevation in left ventricular end-diastolic pressure, especially with higher BMI 3

Valvular Heart Disease

• Aortic stenosis may be present even in younger patients with congenital bicuspid aortic valve 1
• Mitral valve disease (stenosis or regurgitation) causes elevated left atrial pressures and pulmonary congestion 1, 2
• Echocardiography is diagnostic 3, 1

Arrhythmias

• Atrial fibrillation causes dyspnea through rapid ventricular response, loss of atrial kick, or tachycardia-induced cardiomyopathy 1
• Inappropriate sinus tachycardia and bradyarrhythmias (sick sinus syndrome) may present primarily with dyspnea 1

Most Likely Pulmonary Diagnoses

Chronic Obstructive Pulmonary Disease (COPD)

• Consider in patients with smoking history presenting with increased dyspnea 2
• Spirometry shows obstructive pattern (FEV1/FVC <0.70) 4, 6
• Pitfall: Severe emphysema can present with minimal spirometry impairment but severe DLCO impairment due to ventilation/perfusion mismatch 7

Asthma

• Patients describe "chest tightness" specifically related to bronchoconstriction 2
• Spirometry shows reversible obstruction 4

Interstitial Lung Disease

• Presents with progressive dyspnea, dry cough, and bibasilar crackles 2
• Patients describe "air hunger" due to restrictive mechanics 2
• DLCO is characteristically reduced 4, 7

Second-Line Testing (If First-Line Inconclusive)

• Formal pulmonary function testing to characterize obstructive or restrictive patterns and assess diffusing capacity (DLCO) 2, 4
• Cardiac MRI for cardiomyopathies, myocarditis, or infiltrative diseases when echocardiography is inconclusive 3, 1, 2
• CT chest with IV contrast (rated 7/9 "usually appropriate") to diagnose suspected pulmonary causes including interstitial lung disease or pulmonary embolism 3, 4
• Cardiopulmonary exercise testing to differentiate cardiac from pulmonary limitation and identify exercise-induced bronchoconstriction, deconditioning, or dysfunctional breathing 3

Critical Diagnostic Pitfalls to Avoid

• History and physical examination alone have high specificity (96%) but low sensitivity (59%) for cardiac causes—do not rely on clinical assessment alone 3, 1, 2
• Normal chest radiography does not exclude cardiac disease, particularly early heart failure or diastolic dysfunction 1, 2
• "Chest tightness" is relatively specific for bronchoconstriction (asthma, COPD), while "air hunger" suggests restrictive mechanics (heart failure, pulmonary fibrosis) 2
• Absence of edema does not exclude heart failure—many patients with HFpEF or early heart failure present without peripheral edema 3
• Etiology is multifactorial in one-third of patients—consider multiple contributing diagnoses 4

When to Refer

• Cardiology referral is warranted to exclude alternative diagnoses, optimize guideline-directed medical therapy, and identify clinical trial eligibility 3
• Pulmonology referral if interstitial lung disease, pulmonary hypertension, or unexplained hypoxemia is suspected 2
• Specialty referral to multidisciplinary dyspnea clinic when diagnosis remains elusive after initial workup 2