What is the appropriate emergency evaluation and management for a patient presenting with tachycardia, headache, abdominal pain, dyspnea, and a sense of panic?

Emergency Evaluation and Management of Tachycardia with Headache, Abdominal Pain, Dyspnea, and Panic

This constellation of symptoms demands immediate assessment for life-threatening acute coronary syndrome, pulmonary embolism, or aortic dissection before attributing symptoms to panic disorder, as misdiagnosis of cardiac ischemia as anxiety occurs in 54% of patients, particularly women. 1

Immediate Stabilization (Within 10 Minutes)

• Obtain a 12-lead ECG within 10 minutes of arrival to identify ST-segment elevation myocardial infarction, as this is the single most critical time-sensitive intervention. 1
• Attach continuous cardiac monitoring, establish IV access, and measure oxygen saturation immediately. 2, 3
• Provide supplemental oxygen only if SaO₂ is below 90%, as routine oxygen in normoxic patients may worsen myocardial injury. 1
• Measure high-sensitivity troponin as soon as possible after presentation. 1

Assess Hemodynamic Stability

If the patient exhibits altered mental status, severe chest pain, acute heart failure signs, hypotension, or shock, proceed directly to synchronized cardioversion without waiting for diagnostic workup. 2

• Unstable patients require immediate intervention; do not delay for complete diagnostic evaluation. 2
• For stable patients, proceed with systematic evaluation below. 2

Critical Diagnostic Considerations

Heart Rate Threshold

• A heart rate ≥150 bpm indicates a primary arrhythmia requiring immediate workup rather than a secondary physiologic response. 3
• Below 150 bpm, search aggressively for reversible triggers: fever, dehydration, anemia, pain, hyperthyroidism, medications (albuterol), caffeine, or illicit stimulants. 4

Life-Threatening Differential Diagnosis

Acute Coronary Syndrome:

• Chest discomfort occurs in 79% of men and 74% of women with ACS, but 40% of men and 48% of women present with atypical symptoms including dyspnea, headache, and abdominal pain. 5
• Headache, anxiety, and abdominal pain are recognized prodromal and acute symptoms of cardiac ischemia and predict adverse cardiac events. 6
• Tachycardia, dyspnea, diaphoresis, and tachypnea are characteristic physical findings in ACS. 1
• Cardiac cephalgia (headache as the primary manifestation of cardiac ischemia) should be suspected in older patients with atherosclerotic risk factors presenting with recent-onset headache. 7

Pulmonary Embolism:

• Tachycardia and dyspnea occur in more than 90% of PE patients; pleuritic pain (which may be perceived as abdominal pain if diaphragmatic irritation occurs) is common. 1
• Accentuated P2 heart sound may be present on examination. 1

Aortic Dissection:

• Sudden onset of severe chest or back pain with pulse differential suggests dissection, though pulse differential has only 30% sensitivity. 1
• Abdominal pain may indicate extension into mesenteric vessels. 1

Distinguishing SVT from Panic Disorder

• 67% of patients with unrecognized supraventricular tachycardia fulfill criteria for panic disorder, and physicians incorrectly attribute SVT symptoms to panic/anxiety in 54% of cases, with women disproportionately mislabeled. 1
• True SVT typically has abrupt onset and termination, whereas anxiety-related tachycardia has gradual onset and offset. 1
• "Neck pounding" or "shirt flapping" sensations suggest AVNRT due to cannon a-waves from atrial contraction against a closed tricuspid valve. 1
• Polyuria following an episode strongly suggests AVNRT due to elevated atrial natriuretic peptide. 1

Diagnostic Algorithm for Stable Patients

Step 1: ECG Interpretation

• ST-segment elevation → immediate cardiology consultation for primary PCI within 120 minutes. 1, 5
• ST-segment depression, T-wave inversion, or both → NSTE-ACS; measure serial troponins and pursue early invasive strategy within 24-48 hours if high-risk features present. 5
• Pre-excitation pattern (delta wave) → urgent electrophysiology referral even if symptoms minimal, due to sudden death risk. 4, 2
• Regular narrow-complex tachycardia → likely AVNRT or AVRT; consider vagal maneuvers if stable. 1

Step 2: Troponin and Risk Stratification

• High-sensitivity troponin is the preferred test to distinguish NSTEMI from unstable angina. 5
• For high-risk NSTE-ACS patients without contraindications, invasive coronary angiography within 24-48 hours reduces mortality from 6.5% to 4.9%. 5

Step 3: Imaging if Diagnosis Uncertain

• Echocardiography improves diagnostic accuracy and reduces inappropriate discharge in doubtful chest pain cases. 8
• CT angiography ("triple rule-out") can simultaneously assess for ACS, PE, and aortic dissection when diagnosis remains unclear after initial evaluation. 9

Management of Anxiety Component

• Do not administer benzodiazepines until life-threatening cardiac causes are excluded, as sedation may mask evolving symptoms and delay recognition of deterioration. 10
• Once cardiac causes are ruled out and SVT is confirmed, mild tranquilizers (benzodiazepines) may be considered for anxiety. 1
• Lorazepam carries risks of respiratory depression, especially when combined with opioids or other CNS depressants; use cautiously and monitor closely. 10

Common Pitfalls to Avoid

• Never attribute tachycardia, dyspnea, and chest discomfort to panic disorder without obtaining ECG and troponin, particularly in women and patients over 30 years old. 1
• Never delay transfer from office to emergency department for troponin measurement; transport immediately if ACS suspected. 1
• Never use AV nodal blocking agents if pre-excitation is present on ECG, as this can precipitate ventricular fibrillation in atrial fibrillation with accessory pathway conduction. 2
• Do not assume normal troponin and ECG exclude ACS; among inappropriately discharged patients with cardiac events, 7/8 had normal troponin and 7/8 had normal ECG. 8

Disposition Decisions

Admit for:

• Any troponin elevation, ischemic ECG changes, or high-risk features (age >65, known CAD, diabetes, renal insufficiency, hemodynamic instability). 5
• Suspected PE or aortic dissection requiring definitive imaging. 1
• Documented sustained SVT requiring rate/rhythm control or ablation consideration. 1

Discharge with urgent cardiology follow-up if:

• Normal serial troponins, non-ischemic ECG, low-risk clinical features, and alternative diagnosis established. 1
• Provide event recorder or Holter monitor for palpitation documentation if SVT suspected but not captured. 4