ECG

The heart's primary function is to pump blood throughout the body to deliver oxygen and nutrients to tissues, remove carbon dioxide, and transport waste products.

The systemic circuit carries oxygenated blood from the heart to the body's tissues and returns deoxygenated blood to the heart.

The pulmonary circuit carries deoxygenated blood from the heart to the lungs for oxygenation and returns oxygenated blood to the heart.

Rhythmic contractions of the heart are responsible for pumping blood.

Valves in the heart and blood vessels ensure one-way blood flow, preventing backflow.

The sinoatrial (SA) node is the natural pacemaker of the heart, generating electrical signals that initiate heart contractions.

The sympathetic nervous system increases heart rate and contractility, while the parasympathetic nervous system slows it down.

Respiratory sinus arrhythmia (RSA) is the variation in heart rate during breathing, driven by the parasympathetic nervous system.

The contraction phase of the heart where blood is ejected into the aorta.

The relaxation phase of the heart where the chambers fill with blood.

The amount of blood ejected from the heart with each beat.

A technique that measures changes in blood volume by detecting variations in light reflected from blood vessels.

The electrical activity of the heart, measurable through electrodes placed on the skin.

The placement of electrodes to measure ECG, with the positive electrode on the left ankle, the negative electrode on the right wrist, and the ground electrode on the right ankle.

The ability to continuously monitor heart rate during daily activities, exercise, and sleep using smart devices.

A method of pulse plethysmography using light transmitted through the tissue, typically the earlobe or fingertip.

The delay between the electrical signal that triggers ventricular contraction and the actual ejection of blood from the heart.

The sympathetic nervous system's influence on the heart cannot be measured solely from an ECG.

Measures the variability in heart rate over time.

HRV can provide insights into states of stress, mental effort, and attention.

The ability to accurately perceive one's own heartbeat.

Heart rate increases during physical exertion, even exceeding 200 beats per minute in young individuals.

After exercise, heart rate gradually decreases to resting levels.

A method of placing ECG electrodes that reduces movement-related noise and provides a clear signal for identifying key electrical events of the heart.

The first positive deflection in the ECG waveform representing atrial depolarization.

The complex of deflections in the ECG representing ventricular depolarization and contraction.

The final positive deflection in the ECG waveform representing ventricular repolarization and relaxation.

The time difference between the electrical event in the heart (R-peak) and the peak of the blood pressure wave.

The number of heartbeats per minute, a measure of heart activity.

The time interval between two consecutive heartbeats, measured in milliseconds.