What is the best course of action for a patient with dyspnea (shortness of breath) on exertion and chest tightness, who is undergoing an EKG (electrocardiogram), chest X-ray, and Lexiscan (regadenoson) stress test, but refused to visit the emergency room (ER)?

Management of Dyspnea on Exertion with Chest Tightness in Outpatient Setting

Your planned outpatient workup with EKG, chest X-ray, and Lexiscan stress test is appropriate and sufficient to rule out serious cardiac pathology in this patient who refused emergency evaluation. 1, 2

Immediate Assessment Priority

The combination of dyspnea on exertion and chest tightness requires systematic evaluation to differentiate cardiac from pulmonary causes, as history and physical examination alone have only 59% sensitivity for cardiac disease despite 96% specificity. 3, 1 This means you cannot rely on clinical assessment alone to exclude serious pathology.

Key Clinical Distinctions to Document

• "Chest tightness" is relatively specific for bronchoconstriction and suggests asthma or reactive airway disease 1
• "Air hunger" would instead suggest restrictive lung mechanics or interstitial disease 1
• Document whether the patient has peripheral edema, orthopnea, or paroxysmal nocturnal dyspnea, though absence of edema does not exclude heart failure 1

Your Planned Diagnostic Workup

EKG (Appropriate First Step)

• Will detect ischemic changes, arrhythmias including atrial fibrillation, inappropriate sinus tachycardia, bradyarrhythmias, or chamber enlargement 1, 2
• 20% of patients with COPD entering rehabilitation programs have ischemic ECG changes, making this essential 3

Chest X-Ray (Appropriate Second Step)

• Identifies cardiomegaly, pulmonary congestion, pleural effusion, pneumonia, or masses 3, 1
• Critical caveat: Normal chest radiography does NOT exclude cardiac disease, particularly early heart failure or diastolic dysfunction 1, 2
• Bedside portable films have high inter-observer variability and reduced sensitivity for pulmonary embolism, pneumothorax, and pulmonary edema 4

Lexiscan Stress Test (Appropriate for Ischemia Evaluation)

• Stress echocardiography or pharmacologic stress testing characterizes cardiovascular causes of dyspnea including ischemia-induced systolic dysfunction 2
• Coronary artery disease is the most common cardiac cause when myocardial oxygen supply does not meet demand 1, 2
• Important safety warning: Regadenoson (Lexiscan) can rarely precipitate takotsubo cardiomyopathy presenting as acute heart failure with pulmonary edema requiring intubation 5

Additional Testing to Consider

Add BNP or NT-proBNP

• BNP <100 pg/mL or NT-proBNP <125 pg/mL effectively excludes heart failure 1
• This single blood test dramatically improves diagnostic accuracy and should be ordered alongside your initial workup 3, 1

Transthoracic Echocardiography

• Should be performed in ALL patients with dyspnea of suspected cardiac origin 3, 1, 2
• Assesses left ventricular systolic and diastolic function, valvular disease (aortic stenosis, mitral disease), right ventricular strain, and pericardial effusion 1, 2
• This is more definitive than stress testing alone for structural heart disease 2

When to Escalate Despite Outpatient Plan

Refer to Cardiology if:

• Stress test is positive for ischemia 1
• Echocardiography reveals valvular disease, reduced ejection fraction, or diastolic dysfunction 1
• BNP/NT-proBNP is significantly elevated 1
• Patient develops exertional syncope, pre-syncope, or worsening symptoms 3

Refer to Pulmonology if:

• Spirometry suggests obstructive or restrictive disease 1
• Chest X-ray shows interstitial changes or unexplained infiltrates 1
• Patient has unexplained hypoxemia 1

Consider Cardiopulmonary Exercise Testing if:

• Initial workup is unrevealing but symptoms persist 3, 6
• Multiple potential factors contribute to activity intolerance 3, 6
• Need to differentiate cardiac from pulmonary limitation or document deconditioning 6, 7

Critical Safety Considerations

Monitor the patient closely after the Lexiscan stress test, as rare cases of acute respiratory failure with pulmonary edema requiring intubation have been reported, presenting as takotsubo cardiomyopathy with severely reduced ejection fraction. 5 Ensure the patient has clear instructions to return immediately if dyspnea worsens acutely after the procedure.

The patient's refusal of ER evaluation is acceptable given your comprehensive outpatient plan, but document this refusal and ensure the patient understands warning signs requiring immediate emergency evaluation: chest pain at rest, severe dyspnea at rest, syncope, or palpitations with lightheadedness. 3