Clues Pointing TO This Diagnosis

Recurrent unexpected panic attacks — discrete episodes of intense fear
Palpitations — racing heart — chest tightness — classic cardiac mimics
Shortness of breath — paresthesias — dizziness — during attack
Attacks peak within minutes — typically resolve within 20 to 30 minutes
At least one attack followed by persistent concern about future attacks — anticipatory anxiety
Avoidance behavior — shrinking world
Normal cardiac workup — ECG — troponin — echo
Multiple episodes in different settings — not situationally bound
Responds to CBT — SSRIs — benzodiazepines short term only

Why It's NOT the Similar Diseases

NOT acute MI or ACS — always rule out first — ECG and troponin distinguish. ACS causes persistent chest pressure — radiation to arm or jaw — diaphoresis — ECG changes — troponin elevation. Lisa's cardiac workup is completely normal.
NOT pheochromocytoma — pheo causes episodic hypertension with the classic triad — headache — palpitations — diaphoresis — elevated plasma metanephrines or urine catecholamines. Lisa has normal blood pressure between attacks — normal labs.
NOT hyperthyroidism — hyperthyroidism causes weight loss — heat intolerance — persistent tachycardia — tremor. Lisa's thyroid labs are normal — symptoms are episodic not persistent.
NOT hypoglycemia — hypoglycemia causes symptoms that resolve immediately with glucose — blood glucose low during attack. Lisa's glucose is normal.
NOT cardiac arrhythmia — arrhythmia causes episodic palpitations but Holter monitor shows abnormal rhythm during symptoms. Lisa's Holter is normal during attacks.

Differential Diagnosis List

Acute MI — ruled out by normal ECG — normal troponin — episodic nature
Pheochromocytoma — ruled out by normal blood pressure between episodes — normal plasma metanephrines
Hyperthyroidism — ruled out by normal TSH and free T4
Hypoglycemia — ruled out by normal glucose during attacks
Cardiac arrhythmia — ruled out by normal Holter monitor during symptomatic episodes

Key Distinguishing Test

ECG — rules out arrhythmia and ischemia during attack. Troponin — rules out ACS. TSH and free T4 — rules out hyperthyroidism. Plasma metanephrines — rules out pheochromocytoma. Holter monitor — rules out arrhythmia. Fasting glucose — rules out hypoglycemia. Diagnosis of panic disorder is clinical after ruling out medical causes.

Board Note

📝 DSM-5 PANIC DISORDER CRITERIA: Recurrent unexpected panic attacks PLUS at least one month of persistent concern about future attacks or their consequences OR significant maladaptive behavior change — avoidance. Panic attacks involve at least 4 of 13 symptoms — palpitations — sweating — trembling — shortness of breath — choking — chest pain — nausea — dizziness — derealization — fear of losing control — fear of dying — paresthesias — chills or hot flushes. First-line treatment is CBT — specifically panic-focused CBT — remission rates above 80%. SSRIs and SNRIs are first-line pharmacotherapy. Benzodiazepines are short-term only — risk of dependence. Beta blockers are NOT first-line for panic disorder. ACS must always be excluded first — missing an MI in a panic presentation is one of the most dangerous diagnostic errors in medicine.

“Lisa’s Story”