What is the most common paper speed used for an ECG?

The most common paper speed used for an electrocardiogram (ECG) is 25 mm/sec. This speed is standardized for clinical use and provides an optimal balance between detail and readability. At this speed, the PQRST waveforms — the graphical representation of the heart's electrical activity — are clearly visible and easily interpreted by healthcare professionals.

Using 25 mm/sec ensures that the intervals between heartbeats and the morphology of the cardiac waves can be accurately assessed, which is crucial for diagnosing various cardiac conditions. When practitioners analyze the data, having a consistent paper speed helps in comparing ECGs over time or across different patients, making the interpretation more reliable.

Other speeds, while they may be utilized in specific situations (such as 10 mm/sec for slower heart rates or different diagnostic needs), are not the standard practice in most clinical settings. Thus, 25 mm/sec is the recognized and most commonly employed speed for routine ECG recordings.