The document discusses three common tests used to detect heart conditions: Doppler ultrasound, Holter monitor, and electrocardiography (ECG). Doppler ultrasound uses sound waves to estimate blood flow and only takes a few moments. The Holter monitor measures and records heart activity over 24-48 hours using small, portable, and painless electrodes and equipment. ECG uses electrodes placed on the arms, legs, and chest to measure the heart's electrical activity and collects important data over a short period.