What is the appropriate evaluation and management for a 21-year-old female with orthopnea and palpitations?

Differential Diagnosis and Evaluation for a 21-Year-Old Female with Orthopnea and Palpitations

Most Likely Differential Diagnoses

In a young patient presenting with acute orthopnea (1 night) and chronic palpitations (years), the primary concerns are supraventricular arrhythmias with acute heart failure, structural cardiac abnormalities (particularly congenital lesions like cor triatriatum or mitral valve prolapse), and less commonly, acute valvular dysfunction. 1

High-Priority Cardiac Causes:

• Supraventricular tachycardia (SVT) with acute decompensation: Chronic palpitations suggest paroxysmal arrhythmia; acute orthopnea indicates new-onset heart failure or pulmonary congestion 1, 2
• Atrial fibrillation with rapid ventricular response: Can cause both chronic palpitations and acute heart failure symptoms 1, 2
• Structural heart disease with arrhythmia: Including mitral valve prolapse (common in young females), congenital lesions (cor triatriatum), or cardiomyopathy 1, 3
• Wolff-Parkinson-White syndrome: Pre-excitation with paroxysmal tachycardia can present with years of palpitations and acute decompensation 1

Secondary Considerations:

• Acute valvular dysfunction: Though rare, spontaneous aortic or mitral valve pathology can present with acute orthopnea 4
• Thyroid disease: Hyperthyroidism causing atrial arrhythmias with high-output heart failure 1
• Anxiety/panic disorder: Can cause chronic palpitations but would not explain true orthopnea 1

Immediate Evaluation Protocol

History Elements to Elicit:

Critical symptom characterization 1:

• Orthopnea specifics: Ability to lie flat, number of pillows required, presence of paroxysmal nocturnal dyspnea 1
• Palpitation characteristics: Regular vs irregular, sudden onset/offset (suggests SVT), gradual onset (suggests sinus tachycardia), skipped beats (suggests premature contractions) 1, 2
• Associated symptoms: Syncope, near-syncope, chest pain, dyspnea on exertion, edema 1
• Precipitating factors: Exercise, emotional stress, caffeine, alcohol, stimulant use 1

Essential past medical and family history 1:

• Congenital heart disease, prior cardiac evaluation
• Medications (including over-the-counter stimulants, QT-prolonging drugs)
• Family history of sudden cardiac death, cardiomyopathy, arrhythmias, or channelopathies in first-degree relatives
• Thyroid disease, electrolyte abnormalities

Physical Examination Priorities:

Hemodynamic assessment 1:

• Heart rate, blood pressure (including orthostatic vitals), respiratory rate
• Jugular venous pressure elevation (suggests heart failure)
• Presence of S3 gallop, murmurs (particularly mitral regurgitation or click)
• Pulmonary rales (indicates pulmonary congestion) 1
• Peripheral edema

Specific findings to assess 1:

• Irregular pulse (atrial fibrillation)
• Irregular cannon A waves (ventricular tachycardia)
• Mid-systolic click with late systolic murmur (mitral valve prolapse)

Diagnostic Testing Algorithm

Immediate Testing (Emergency Department/Acute Setting):

12-lead ECG is mandatory 1, 2:

• Look for pre-excitation (delta waves suggesting WPW syndrome)
• QT prolongation (risk for torsades de pointes)
• Evidence of atrial fibrillation, SVT, or ventricular arrhythmias
• Signs of chamber enlargement or ischemia

Laboratory evaluation 1:

• Thyroid-stimulating hormone (TSH)
• Electrolytes (potassium, magnesium, calcium)
• Complete blood count
• Troponin (if chest pain present)
• B-type natriuretic peptide (BNP) to assess for heart failure

Transthoracic echocardiography should be performed urgently 1, 2:

• Assess for structural heart disease (congenital abnormalities, valve disease, cardiomyopathy)
• Evaluate left ventricular function and chamber sizes
• Look for mitral valve prolapse, cor triatriatum, or other congenital lesions 3

Rhythm Monitoring Strategy:

If palpitations are not captured on initial ECG 2, 5, 6:

• 48-hour ambulatory ECG (Holter) monitoring is first-line for frequent symptoms 2
• Event recorder or wearable loop recorder for less frequent episodes 1, 2
• Patient should be instructed to activate recorder during symptomatic episodes

Management Approach

Acute Management (If Hemodynamically Unstable):

Hospitalization is mandatory for patients with syncope, near-syncope, or acute heart failure symptoms 1:

• Continuous cardiac monitoring
• Intravenous access
• Oxygen therapy if hypoxic
• Diuretics if pulmonary congestion present (orthopnea suggests elevated pulmonary capillary wedge pressure) 1

If arrhythmia documented with hemodynamic compromise 1, 2:

• Immediate cardioversion for unstable SVT or atrial fibrillation with rapid ventricular response
• Beta-blockers or calcium channel blockers for rate control if hemodynamically stable

Definitive Management Based on Diagnosis:

For documented SVT 1, 2:

• Vagal maneuvers as first-line acute treatment
• Adenosine for acute termination
• Beta-blockers for chronic management
• Referral to electrophysiology for catheter ablation (curative in >90% of cases)

For WPW syndrome 1:

• All patients require electrophysiology referral due to risk of sudden death
• Avoid AV nodal blocking agents (digoxin, verapamil, diltiazem) in atrial fibrillation with WPW
• Catheter ablation is definitive treatment

For mitral valve prolapse with palpitations 1:

• Beta-blockers (metoprolol 25-100 mg daily) for symptom control
• Aspirin 75-325 mg daily if neurological symptoms present
• Avoid stimulants (caffeine, alcohol, cigarettes)
• Endocarditis prophylaxis NOT routinely recommended unless significant regurgitation

For structural heart disease 1, 2:

• Guideline-directed medical therapy for heart failure (ACE inhibitors, beta-blockers, diuretics)
• Surgical correction if congenital lesion identified (e.g., cor triatriatum) 3

Indications for Urgent Cardiology/Electrophysiology Referral

Immediate referral required for 1, 2:

• Pre-excitation on ECG (WPW syndrome)
• Syncope or near-syncope with palpitations
• Documented sustained ventricular arrhythmia
• Structural heart disease on echocardiography
• Severe symptoms (dyspnea, chest pain) during palpitations
• Family history of sudden cardiac death

Critical Pitfalls to Avoid

Do not dismiss palpitations as anxiety in a young patient with acute orthopnea—this combination suggests organic cardiac disease until proven otherwise 1

Do not rely solely on symptom severity to gauge risk—ventricular arrhythmias can present with minimal symptoms while benign premature contractions can be highly symptomatic 1

Do not use AV nodal blocking agents (verapamil, diltiazem, digoxin) in patients with pre-excitation and atrial fibrillation, as this can precipitate ventricular fibrillation 1

Do not discharge without rhythm documentation if the patient has had syncope or near-syncope—these patients require hospitalization and monitoring 1

Orthopnea in a 21-year-old is never normal—this mandates echocardiography to exclude structural heart disease, even if initial ECG is normal 1, 2