Severe substernal chest pain for 2 hours with radiation to the left arm and jaw, associated with profuse diaphoresis and nausea.
This is a 58-year-old male with a background history of hypertension, type 2 diabetes mellitus, and hyperlipidaemia who presents to the emergency department with a 2-hour history of severe, 9/10 intensity, pressure-like chest pain localised substernally. The pain began abruptly at rest at approximately 14:30 and radiates to the left arm and jaw.
The pain is associated with profuse diaphoresis, nausea, and one episode of non-bloody vomiting. The patient reports no dyspnoea, no palpitations, and no pre-syncopal symptoms. There is no pleuritic component, no positional variation, and no relief with antacids.
The patient has never experienced this type of pain before. He denies recent travel, prolonged immobility, or lower limb swelling. He has not taken any nitrates prior to arrival. His regular medications were taken this morning. He has a 30 pack-year smoking history (10 cigarettes/day, ongoing) and drinks alcohol occasionally. His father died of a myocardial infarction at age 62.
Current Medications:
Allergies: No known drug allergies. No known food allergies.
Social History: Lives with family and has good home supports. Current smoker — 10 cigarettes/day, 30 pack-years. Alcohol: occasional, less than 14 units/week.
| Parameter | Value | Reference Range | Status |
|---|---|---|---|
| Blood Pressure (Systolic/Diastolic) | 88 / 60 mmHg | 90–140 / 60–90 mmHg | ⬇ Hypotensive |
| Heart Rate | 112 bpm | 60–100 bpm | ⬆ Tachycardia |
| Respiratory Rate | 22 breaths/min | 12–20 breaths/min | ⬆ Elevated |
| Oxygen Saturation (SpO₂) — room air | 94% | ≥96% | ⬇ Low |
| Temperature | 37.1°C | 36.5–37.5°C | Normal |
| Glasgow Coma Scale | 15 / 15 | 15 | Normal |
| Capillary Refill Time | 3 seconds | <2 seconds | ⬆ Prolonged |
General: Diaphoretic, pale, and in obvious discomfort. Alert and oriented to person, place, and time. Appears acutely unwell.
Cardiovascular: Jugular venous pressure elevated at approximately 4cm above the sternal angle. Heart sounds S1 + S2 present, no murmurs, no added sounds. Peripheral pulses palpable but weak bilaterally. Capillary refill 3 seconds peripherally. No peripheral oedema.
Respiratory: Respiratory rate 22/min. Air entry bilaterally. Fine bibasal crepitations present, right greater than left. No wheeze. Dull to percussion at right base. No use of accessory muscles.
Abdomen: Soft, non-distended, non-tender. No organomegaly. Bowel sounds present and normal. No renal angle tenderness.
Neurological: GCS 15/15. Pupils equal and reactive 3mm bilaterally. No focal neurological deficits. Cranial nerves grossly intact.
Skin / Peripheries: Pallor and diaphoresis. No rash, no jaundice, no cyanosis.
12-Lead ECG:
Laboratory Results:
| Investigation | Result | Reference Range |
|---|---|---|
| Troponin I (high-sensitivity) | 2400 ng/L ⬆ | <40 ng/L |
| CK-MB | 48 U/L ⬆ | <25 U/L |
| BNP (B-type Natriuretic Peptide) | 520 pg/mL ⬆ | <100 pg/mL |
| Haemoglobin | 13.8 g/dL | 13.5–17.5 g/dL |
| White Blood Cells | 11.2 × 10⁹/L | 4.0–11.0 × 10⁹/L |
| Platelets | 224 × 10⁹/L | 150–400 × 10⁹/L |
| Sodium | 138 mmol/L | 135–145 mmol/L |
| Potassium | 4.1 mmol/L | 3.5–5.0 mmol/L |
| Creatinine | 98 µmol/L | 62–106 µmol/L |
| eGFR | 72 mL/min/1.73m² | ≥60 mL/min/1.73m² |
| Glucose (random) | 9.4 mmol/L ⬆ | 4.0–7.8 mmol/L |
| HbA1c | 7.8% ⬆ | <7.0% (diabetic target) |
| Total Cholesterol | 5.9 mmol/L ⬆ | <5.2 mmol/L |
| LDL Cholesterol | 3.8 mmol/L ⬆ | <2.0 mmol/L (high-risk target) |
| INR | 1.1 | 0.8–1.2 |
| Lactate | 2.8 mmol/L ⬆ | <2.0 mmol/L |
| Arterial pH | 7.31 ⬇ | 7.35–7.45 |
Chest X-Ray (Portable AP): Mild cardiomegaly. Pulmonary vascular congestion with upper lobe diversion. Small right pleural effusion. No pneumothorax. No mediastinal widening.
Bedside Echocardiogram (Emergency): Inferior and inferolateral wall hypokinesia. Estimated ejection fraction 40%. No pericardial effusion. No obvious valvular pathology on this limited study. Right ventricle appears mildly dilated — formal right-sided assessment pending.
Primary Diagnosis: Inferior ST-Elevation Myocardial Infarction (STEMI) complicated by cardiogenic shock. Most likely culprit vessel: Right Coronary Artery (RCA) based on inferior lead involvement.
Differential Diagnosis:
ST elevation in leads II, III, aVF with reciprocal depression in I and aVL is the hallmark ECG pattern of inferior STEMI. Elevated troponin I (60× upper limit of normal) and inferior wall hypokinesia on bedside echo confirm ongoing myocardial injury. Cardiogenic shock (SBP 88, elevated lactate 2.8, BNP 520) indicates significant haemodynamic compromise. Right ventricular involvement must be excluded with right-sided leads before initiating fluid therapy.
Severe chest pain with radiation to the jaw raises dissection in the differential. However, the pain character is pressure-like rather than tearing, there is no pulse deficit, no limb ischaemia, and no mediastinal widening on CXR. The ECG and troponin pattern is more consistent with primary ACS. Dissection is lower probability but cannot be fully excluded without CT aortogram if clinical doubt persists after ECG correlation.
Haemodynamic instability and low SpO₂ are consistent with massive PE. However, the patient has no PE risk factors (no recent travel, immobility, or DVT history), the ECG shows inferior ST elevation rather than right heart strain or S1Q3T3 pattern, and the troponin rise matches ACS kinetics. Bedside echo shows inferior wall hypokinesia rather than RV dilation as the dominant finding. PE is considered unlikely.
The presence of ≥1mm ST elevation in two contiguous inferior leads, combined with the degree of troponin elevation, meets full STEMI criteria. NSTEMI is excluded by the ECG findings.