CHAPTER 14. PERFORMING AN ELECTROCARDIOGRAM (ECG)
Augustus Desiré Waller (1856–1922), working at St Mary’s Hospital in Paddington, London, produced the first electrocardiogram (ECG) recording in a human subject in 1887 using a Lippmann capillary electrometer attached to a projector. This projected the resultant trace onto a photographic plate that was moved by a toy train. Interestingly he saw little practical application for this, and it was not until Willem Einthoven (1860–1927) in Leiden used a string galvanometer rather than a capillary electrometer, which increased sensitivity, that the ECG became more usable. Einthoven went on to describe the tracing in terms of P, Q, R, S and T waves, and associated changes with some cardiac disorders. He was eventually rewarded with a Nobel Prize in 1924.
INTRODUCTION
The ECG is the basic investigation for diagnosing acute cardiac disorders. This procedure is normally undertaken by nursing staff but you need to be familiar with the process since positioning of the electrode leads will affect the accuracy of the ECG obtained.
INDICATIONS
• Suspected or confirmed acute coronary syndrome.
• Chest pain (of any nature).
• Shortness of breath (of any nature).
• Suspected arrhythmias.
• Collapse.
• Electrolyte abnormalities (particularly potassium).
• Suspected or confirmed bacterial endocarditis (to monitor for progressive lengthening of the PR interval).
• Pre-operative work-up.