Syncope Unmasking ST-Elevation Myocardial Infarction and Undiagnosed Hypertrophic Cardiomyopathy in an Elderly Diabetic Male: A Case Report

Syncope in elderly patients with multiple co-morbidities constitutes a high-acuity, diagnostically complex emergency presentation. The present case report describes an 87-year-old male with known Type 2 Diabetes Mellitus (T2DM) on oral hypoglycaemic agents, anticoagulant therapy (apixaban) and diltiazem who presented at 07:15 hours with witnessed syncope followed by vomiting. On arrival the patient was critically ill: Glasgow Coma Scale (GCS) E1V1M1, Oxygen Saturation (SpO2 ) 80% on room air, heart rate 100 beats per minute and random blood glucose of 487 mg/dL. Emergency resuscitation included orotracheal intubation, insulin infusion, intravenous fluid therapy and empirical broad-spectrum antibiotics. A 12-lead Electrocardiogram (ECG) demonstrated inferior wall ST-elevation (leads II, III, aVF; 2 mm) and anterior ST-elevation (leads V3-V5; 4 mm) with tachycardia, evolving to ventricular premature complexes and Q-wave development on a repeat ECG 30 minutes later, establishing the diagnosis of acute ST-Elevation Myocardial Infarction (STEMI). Arterial Blood Gas (ABG) at intubation revealed severe mixed acidosis (potential of Hydrogen (pH) 7.01, partial pressure of Carbon Dioxide (pCO2 ) 61 mmHg, partial pressure of Oxygen (pO2 ) 91 mmHg, Bicarbonate (HCO3 ) 15 mmol/L, lactate 7.6 mmol/L), which corrected to near-normal by four hours post-intubation (pH 7.38, pCO2 38 mmHg, HCO3 22 mmol/L, lactate 1.6 mmol/L). Bedside echocardiography at admission identified previously unrecognised non-obstructive Hypertrophic Cardiomyopathy (HCM) with asymmetric septal hypertrophy, apical hypokinesia, Left Ventricular Ejection Fraction (LVEF) 45%, mild-to-moderate circumferential pericardial effusion (up to 1.0-1.2 cm) without tamponade, Grade I diastolic dysfunction, mitral annular calcification and mild aortosclerosis. Serial inflammatory markers (C-reactive protein 77.93 mg/L; procalcitonin 1.91 ng/mL) declined progressively with treatment. The patient was stabilised haemodynamically, extubated and discharged ambulatory, conscious and oriented. The present case illustrates the convergence of STEMI, undiagnosed HCM with pericardial effusion, a diabetic hyperglycaemic crisis and severe respiratory failure in a single elderly patient and underscores the role of simultaneous resuscitation, structured emergency investigation and point-of-care echocardiography in the modern Emergency Department.