ECG (? acute coronary syndrome, long QT interval)

Chest X-ray (? pulmonary oedema, pneumothorax, rib fracture)

Echocardiography (? structural heart disease, right and left ventricular size and systolic function, pericardial effusion)

Arterial blood gases and pH

Plasma sodium, potassium, calcium and magnesium

Plasma urea and creatinine

Blood glucose

Plasma troponin