What is the immediate management for a patient presenting with palpitations and shortness of breath (SOB)?

Immediate Management of Palpitations with Shortness of Breath

Patients presenting with palpitations and shortness of breath require immediate 12-lead ECG acquisition and interpretation to identify life-threatening arrhythmias, followed by continuous cardiac monitoring and assessment of hemodynamic stability. 1

Initial Assessment and Stabilization

Immediate Actions (Within Minutes of Presentation)

• Obtain a 12-lead ECG immediately at first medical contact to facilitate early diagnosis and triage—this is the gold standard for diagnosis and must be interpreted as soon as possible 1, 2, 3
• Initiate continuous ECG monitoring to detect life-threatening arrhythmias and allow prompt defibrillation if indicated 1
• Assess hemodynamic stability by checking blood pressure, mental status, and signs of shock or heart failure 1

Critical History Elements to Obtain Rapidly

• Symptom characteristics: sudden versus gradual onset, duration, associated chest pain, dizziness, near-syncope, or syncope 1
• Precipitating factors: exercise, emotional stress, caffeine, stimulants, or new medications 1
• Medication review: antiarrhythmics, QT-prolonging drugs, stimulants (including cocaine and amphetamines), supplements, or over-the-counter medications 1
• Past medical history: known heart disease (coronary, valvular, congenital), thyroid disease, electrolyte abnormalities, or previous arrhythmias 1, 4
• Family history: sudden cardiac death, cardiomyopathy, or inherited arrhythmia syndromes in first-degree relatives 1

Management Based on Hemodynamic Status

Hemodynamically Unstable Patients (Hypotension, Altered Mental Status, Shock)

• Perform immediate synchronized cardioversion for sustained ventricular tachycardia or supraventricular tachycardia causing hemodynamic instability 1
• Provide sedation immediately before cardioversion if the patient is conscious but hypotensive 1
• Start CPR with chest compressions if no pulse is definitively palpated within 10 seconds, performing cycles of 30 compressions and 2 breaths 1
• Use automated external defibrillator (AED) as soon as available for ventricular fibrillation or pulseless ventricular tachycardia 1

Hemodynamically Stable Patients with Suspected Supraventricular Tachycardia

• Attempt vagal maneuvers first (Valsalva maneuver with patient supine, bearing down for 10-30 seconds at 30-40 mm Hg pressure, or carotid sinus massage after confirming no bruit) 1, 5
• Administer IV adenosine 6 mg rapid push if vagal maneuvers fail—this terminates AVNRT in approximately 95% of cases 1, 5
• Give IV beta-blockers (metoprolol), diltiazem, or verapamil if adenosine is ineffective 1, 5
• Consider IV amiodarone if other measures fail, though this is less preferred initially 1

Patients with Wide-Complex Tachycardia

• Electrical cardioversion should be the first-line approach for hemodynamically stable patients with wide-complex tachycardia, as the differential includes ventricular tachycardia 1
• Administer IV procainamide or flecainide only in patients without severe heart failure or acute myocardial infarction 1
• Give IV amiodarone in patients with heart failure or suspected ischemia 1
• Avoid IV verapamil or beta-blockers in wide-complex tachycardia of uncertain etiology, as these can be dangerous if the rhythm is ventricular tachycardia 1

Specific Clinical Scenarios Requiring Immediate Recognition

Syncope with Documented or Suspected Ventricular Arrhythmia

• Hospitalize immediately for evaluation, monitoring, and management—this is a Class I recommendation 1
• Syncope with ventricular arrhythmia indicates high risk for sudden cardiac death and requires inpatient telemetry for 24-48 hours minimum 1

Thyroid Storm Presenting with Arrhythmia

• Consider thyroid storm in patients with palpitations, shortness of breath, diaphoresis, weight loss, and tachycardia (especially if heart rate >200 bpm) 4
• Initiate treatment immediately with IV hydrocortisone, methimazole, beta-blockers (metoprolol), and iodine drops if thyroid storm is suspected 4
• Avoid adenosine alone in patients with pre-excitation patterns (delta waves) on ECG, as this may precipitate ventricular fibrillation in Wolff-Parkinson-White syndrome 4

Atrial Fibrillation with Rapid Ventricular Response

• Assess for underlying precipitants: acute heart failure, valvular disease, hyperthyroidism, electrolyte abnormalities, or pulmonary disease 1, 6
• Initiate rate control with IV beta-blockers or calcium channel blockers unless contraindicated 1
• Consider anticoagulation based on CHA2DS2-VASc score, though immediate anticoagulation decisions depend on duration of arrhythmia 1

Diagnostic Workup After Stabilization

Essential Initial Testing

• Obtain basic laboratory studies: complete blood count, comprehensive metabolic panel (including potassium, magnesium, calcium), thyroid function tests, and troponin 1, 2
• Perform transthoracic echocardiography to assess for structural heart disease, valvular abnormalities, left ventricular function, and chamber sizes—this is usually appropriate for first assessment of patients with shortness of breath and palpitations 1
• Arrange ambulatory ECG monitoring if the arrhythmia is not captured on initial ECG: use 24-48 hour Holter monitoring for daily symptoms or two-week event recording for unpredictable palpitations 2, 3

High-Risk Features Requiring Hospitalization

• Admit patients with: documented ventricular arrhythmia, syncope or near-syncope, structural heart disease, family history of sudden cardiac death, or abnormal ECG findings suggesting inherited arrhythmia syndromes 1
• Maintain continuous telemetry monitoring until arrhythmic cause is ruled out or treated, typically 24-48 hours minimum 1

Common Pitfalls to Avoid

• Do not rely on symptom relief after nitroglycerin as a diagnostic maneuver—this can be misleading and is not recommended 1
• Do not assume palpitations correlate with arrhythmia—they are frequently reported during normal rhythm, and conversely, many patients with arrhythmias do not have palpitations 1, 7
• Do not dismiss symptoms in women—they tend to present with atypical symptoms and may receive reperfusion therapy less frequently despite equal benefit 1
• Do not use IV verapamil or diltiazem in patients with pre-excitation syndromes (Wolff-Parkinson-White), as this can precipitate ventricular fibrillation 1, 4
• Do not delay cardioversion in hemodynamically unstable patients while attempting pharmacologic conversion 1

Disposition Decisions

Patients Requiring Admission

• Documented ventricular arrhythmia or high suspicion for ventricular tachycardia 1
• Syncope or near-syncope associated with palpitations 1
• Hemodynamic instability at any point during evaluation 1
• Structural heart disease with new-onset arrhythmia 1
• Persistent symptoms despite treatment 2, 3

Patients Potentially Suitable for Outpatient Management

• Hemodynamically stable with benign arrhythmia (isolated premature atrial or ventricular contractions) 1, 3
• Normal ECG, normal physical examination, and no high-risk features 2, 3
• Symptoms clearly related to anxiety, caffeine, or other reversible non-cardiac causes after cardiac causes are excluded 7, 3
• However, arrange close follow-up and ambulatory monitoring even for apparently benign presentations, as up to 16% of patients have no identifiable cause initially 3