What type of signals does an electrocardiograph specifically record?

An electrocardiograph (ECG or EKG) specifically records electrical impulses generated by the heart. These electrical impulses coordinate the contraction of heart muscles, leading to the heartbeat. By placing electrodes on the skin, the ECG detects these electrical signals and translates them into a visual representation on graph paper or a digital screen, which can be analyzed for various cardiac conditions.

Understanding that electrocardiographs focus on electrical activity is crucial for interpreting ECG readings. This distinction sets it apart from measuring other physiological parameters such as muscle contractions, blood flow, or oxygen saturation, which are assessed by different types of diagnostic tools. For example, muscle contractions might be monitored using electromyography, while blood flow can be evaluated through ultrasound or Doppler studies, and oxygen saturation is typically measured with pulse oximetry. Thus, recognizing that the primary function of an electrocardiograph is to capture and record the electrical impulses of the heart is essential for anyone in the field of clinical patient care.