Part 1: Initial Presentation & History
Mr. John Doe, a 55-year-old male, presents to the Emergency Department with a chief complaint of "chest pain" for the past 12 hours. He describes it as a dull ache, constantly present, located sub-sternally, not radiating, and not significantly worsened by exertion. He denies shortness of breath, palpitations, diaphoresis, nausea, or vomiting.
Past Medical History: Hypertension (controlled on medication), Type 2 Diabetes Mellitus (controlled on medication), dyslipidemia. No known Coronary Artery Disease (CAD). No prior Myocardial Infarction (MI) or cardiac procedures.
Social History: Smoked 1 pack/day for 30 years (quit 5 years ago), occasional alcohol use. No illicit drug use. Works as an accountant.
Current Medications: Lisinopril 20mg daily, Metformin 1000mg BID, Atorvastatin 40mg daily.
Allergies: No known drug allergies (NKDA).
Initial Vital Signs:
- BP: 145/88 mmHg
- HR: 82 bpm
- RR: 16 breaths/min
- Temp: 98.6°F (oral)
- O2 Sat: 98% on room air
Based on the initial presentation and history, list 3-5 conditions in your differential diagnosis for Mr. Doe's chest pain and briefly explain your reasoning for each, considering both cardiac and non-cardiac causes.
Part 2: Initial Workup
Initial 12-lead EKG Findings:
- Rhythm: Sinus rhythm
- Rate: 78 bpm
- Intervals: Normal PR interval, QRS duration, and QT interval.
- ST/T wave changes: No significant ST-segment elevation or depression. No pathological Q waves. T-waves are upright in all leads. Non-specific T-wave flattening in leads V4-V6.
- Axis: Normal axis.
Initial Lab Results:
- Cardiac Enzymes:
- Troponin I: <0.01 ng/mL (Normal: <0.04 ng/mL) - initial, 0 hr
- CK-MB: 1.2 ng/mL (Normal: <3.6 ng/mL)
- BNP: 55 pg/mL (Normal: <100 pg/mL)
- D-dimer: 0.35 ug/mL FEU (Normal: <0.50 ug/mL FEU)
- Complete Blood Count (CBC) with differential:
- WBC: 9.8 x /uL (Normal: 4.5-11.0)
- Hb: 14.2 g/dL (Normal: 13.5-17.5)
- Plt: 250 x /uL (Normal: 150-450)
- Complete Metabolic Panel (CMP):
- Na: 138 mEq/L (Normal: 135-145)
- K: 4.1 mEq/L (Normal: 3.5-5.0)
- Cr: 1.0 mg/dL (Normal: 0.6-1.2)
- Glucose: 125 mg/dL (Normal: 70-100)
- LFTs: Within Normal Limits (WNL) (AST, ALT, Alk Phos, Tbili)
- Lactate: 1.0 mmol/L (Normal: <2.0 mmol/L)
Analyze the EKG and lab results provided. How do these findings alter your initial differential diagnosis? Which conditions become more or less likely, and why? Provide specific values or EKG descriptors to support your reasoning.
Part 3: Further History & Physical Exam
Further History Elicited: Upon further questioning, Mr. Doe admits the pain occasionally feels "sharp" when taking a deep breath or lying flat, and it feels slightly better when leaning forward. He denies recent fever, chills, cough, or symptoms of a viral illness. He also denies any associated lightheadedness, syncope, or vomiting.
Physical Exam Findings:
- General: Alert, oriented, appears comfortable at rest.
- Cardiac: Jugular Venous Pressure (JVP) not elevated. S1, S2 audible. No S3 or S4. A faint, triphasic pericardial friction rub is appreciated best over the left sternal border in expiration with the patient leaning forward. No murmurs. Peripheral pulses 2+ and symmetric.
- Pulmonary: Lungs clear to auscultation bilaterally. No crackles, wheezes, or rhonchi. Respiration unlabored.
- Abdominal: Soft, non-tender, non-distended. Normal bowel sounds.
- Extremities: No edema. No calf tenderness or cords.
Based on all information presented so far (initial presentation, EKG, labs, and the newly elicited history and physical exam findings), identify the top 2-3 most critical, life-threatening conditions to immediately rule out. What specific diagnostic tests or imaging would you order next to help differentiate between these, and what are you specifically looking for with each?
Synthesize all provided information (history, physical exam, EKG, labs, and inferring potential results of imagined ordered tests like an echocardiogram showing a small pericardial effusion with no wall motion abnormalities and normal global function, and serial troponins remaining normal) to state the single most likely diagnosis. Provide a detailed justification, referencing specific positive and negative data points from the case that support your conclusion and rule out alternatives.
Briefly outline the immediate, critical management steps (medications, procedures, consultations) for acute pericarditis, assuming it is confirmed.