What is the treatment for a 37-year-old female presenting with dyspnea (shortness of breath) on exertion, palpitations, dizziness, and diaphoresis?

Diagnostic Workup and Treatment for a 37-Year-Old Female with Exertional Dyspnea, Palpitations, Dizziness, and Diaphoresis

This patient requires immediate vital signs assessment, ECG, and echocardiography to rule out cardiac arrhythmias, structural heart disease, or cardiomyopathy, as palpitations with dizziness represent potentially serious cardiac pathology that demands urgent evaluation. 1, 2

Immediate Assessment

• Measure oxygen saturation via pulse oximetry, respiratory rate, pulse rate, blood pressure, and temperature immediately 1, 2
• Obtain a 12-lead ECG on presentation, which is the gold standard for diagnosing arrhythmias causing palpitations 3
• Continue pulse oximetry monitoring until the patient is stable 1

Palpitations accompanied by dizziness are considered potentially serious and warrant aggressive investigation for cardiac arrhythmias including supraventricular tachycardia, atrial fibrillation, premature ventricular contractions, or ventricular tachycardia. 4, 5, 3

Critical Differential Diagnoses to Consider

Cardiac Arrhythmias (Most Concerning)

• Supraventricular tachycardia can cause exercise-induced breathlessness in young adults and presents with palpitations, dizziness, and diaphoresis 4
• Complete heart block can manifest as shortness of breath, dyspnea on exertion, syncope, dizziness, or fatigue in young adults 4
• Any arrhythmia including sinus tachycardia, atrial fibrillation, premature ventricular contractions, or ventricular tachycardia can cause palpitations 5

Structural Heart Disease

• Hypertrophic cardiomyopathy is well known to cause sudden death and presents with dyspnea and chest pain that improve with beta-blockers 4
• Hypertrophic cardiomyopathy causes exertional breathlessness through LV outflow tract obstruction, restrictive physiology, or dyssynchronous contraction at fast heart rates 6
• Mitral valve prolapse can cause palpitations in this age group 5

Other Cardiac Causes

• Congestive heart failure can present with dyspnea on exertion, though less common in this age group 4
• Pericarditis can cause palpitations 5

Essential Diagnostic Testing

Initial Laboratory Work

• Brain natriuretic peptide (BNP) levels to help exclude heart failure 1, 7
• Thyroid function tests, as hyperthyroidism can cause palpitations, diaphoresis, and exertional dyspnea 5
• Complete blood count to assess for anemia 4
• Blood glucose to evaluate for hypoglycemia 5

Imaging Studies

• Transthoracic echocardiography (TTE) is the primary imaging modality and is mandated when cardiac cause is suspected to confirm or exclude diagnosis, quantify chamber volumes, assess systolic and diastolic function, and identify structural abnormalities including hypertrophic cardiomyopathy, valvular disease, or cardiomyopathies. 1, 7
• Chest X-ray to assess for cardiomegaly or pulmonary pathology 1, 7

Ambulatory Monitoring

• If the etiology cannot be determined from history, physical examination, resting ECG, and echocardiography, ambulatory ECG monitoring is indicated 5
• For unpredictable or non-daily palpitations, an initial two-week course of continuous closed-loop event recording is indicated 5
• For daily palpitations, Holter monitoring for 24-48 hours may be appropriate 5, 3

Advanced Testing if Initial Workup Inconclusive

• Cardiopulmonary exercise testing (CPET) is the definitive test to distinguish between cardiac, pulmonary, vascular, and deconditioning causes when initial evaluation is inconclusive. 1, 7
• Key CPET parameters include peak VO2 (percent-predicted) to assess functional capacity, VE/VCO2 slope and PETCO2 to identify ventilation-perfusion abnormalities, and peak exercise VE/MVV ratio to assess ventilatory limitation 1

Treatment Approach Based on Diagnosis

If Cardiac Arrhythmia Identified

• Patients with palpitations accompanied by dizziness, excessive fatigue, or chest pains should receive adequate acute care aiming to stabilize their condition before referring to a higher level of care. 3
• Specific antiarrhythmic therapy depends on the type of arrhythmia identified on ECG or monitoring 3

If Hypertrophic Cardiomyopathy Diagnosed

• Beta-blockers are the first-line treatment as patients with hypertrophic cardiomyopathy can have dyspnea and chest pain that improve with beta-blockers 4
• Metoprolol can be used, though caution is needed as beta-blockers can cause bradycardia, heart block, and cardiac arrest; monitor heart rate and rhythm closely 8
• Avoid abrupt discontinuation of beta-blocker therapy, particularly in patients with coronary artery disease, as severe exacerbation of angina, myocardial infarction, and ventricular arrhythmias have been reported 8

If Supraventricular Tachycardia

• Adenosine may be used for acute termination, though it carries risks including cardiac arrest, ventricular arrhythmias, AV block, bronchoconstriction, and hypotension 9
• Avoid adenosine in patients with symptoms or signs of acute myocardial ischemia, unstable angina, or cardiovascular instability 9

If Non-Cardiac Cause Identified

• Treat hyperthyroidism if present 5
• Address hypoglycemia if identified 5
• Manage anxiety if determined to be the primary cause 5

Critical Pitfalls to Avoid

• Do not dismiss palpitations with dizziness as benign anxiety without thorough cardiac evaluation, as these symptoms indicate potentially serious arrhythmias or structural heart disease. 4, 5, 3
• Do not assume the diagnosis without ECG documentation of the arrhythmia during symptoms 5, 3
• In young women, do not overlook cardiac causes as women are at risk for underdiagnosis of cardiac pathology 2
• Do not abruptly discontinue beta-blocker therapy if initiated, as this can precipitate severe cardiac events 8
• Do not use adenosine without appropriate resuscitative measures immediately available 9
• Recognize that up to 16% of patients with palpitations may have no identifiable cause despite thorough evaluation 5