elektrokardiogrammilla

Elektrokardiogrammilla refers to the recording and analysis of the heart’s electrical activity using a surface electrocardiograph. The procedure captures voltages generated by cardiac depolarization and repolarization, producing tracings that reflect the timing and sequence of heartbeats. The modern electrocardiogram originated in the early 20th century with Willem Einthoven, who developed the string galvanometer and standard limb leads; his work laid the foundation for routine clinical use and earned him the Nobel Prize in 1924.

A standard recording, typically called a 12-lead ECG, uses ten electrodes placed on the limbs and chest to provide multiple viewpoints of the heart’s activity. Recordings are usually brief (about 10 seconds) but can be extended with ambulatory monitors (Holter) or event recorders for longer surveillance. Proper skin preparation and correct lead placement help minimize artifacts from motion or poor contact.

Interpretation focuses on rhythm and rate, conduction intervals, and the morphology of the waves. The P wave reflects atrial activation, the QRS complex ventricular depolarization, and the T wave ventricular repolarization. Key measurements include the PR interval, QRS duration, and QT interval, as well as rhythm regularity and electrical axis. Common findings include sinus rhythm, atrial fibrillation, ventricular or AV conduction blocks, and ST-segment or T-wave changes suggestive of ischemia, injury, or electrolyte disturbances.

Electrocardiography is widely used for initial evaluation of chest pain, arrhythmias, syncope, preoperative screening, and monitoring in various therapies. Limitations include variability in interpretation, artifacts, and occasional normal results despite disease; confirmatory tests may be required for definitive diagnosis.