What represents one cardiac cycle on an ECG?
A typical ECG tracing of the cardiac cycle (heartbeat) consists of a P wave (atrial depolarization ), a QRS complex (ventricular depolarization), and a T wave (ventricular repolarization). An additional wave, the U wave ( Purkinje repolarization), is often visible, but not always.
What happens during a single cardiac cycle?
The cardiac cycle is the performance of the human heart from the beginning of one heartbeat to the beginning of the next. It consists of two periods: one during which the heart muscle relaxes and refills with blood, called diastole, following a period of robust contraction and pumping of blood, called systole.
What are the events of the cardiac cycle?
Cardiac cycle events can be divided into diastole and systole. Diastole represents ventricular filling, and systole represents ventricular contraction/ejection. Systole and diastole occur in both the right and left heart, though with very different pressures (see hemodynamics below).
What are the main events recorded by an ECG?
12 Cards in this Set
| The sinoatrial node has a common name. What is it? | Pacemaker |
|---|---|
| What are the main events recorded by an ECG? | depolarizations and repolarizations occurring in heart muscles |
| What electrical event in the heart does the QRS complex represent? | depolarization of ventricles |
What is cardiac cycle explain with diagram?
The cardiac cycle is the performance of the human heart, beginning from one heartbeat to the beginning of the next. It consists of two phases:- 1) Diastolic phase, 2) Systolic phase. In the diastolic phase, the heart ventricles are relaxed and the heart fills with blood.
What is the cardiac cycle and what events occur in one cardiac cycle?
The cardiac cycle is defined as a sequence of alternating contraction and relaxation of the atria and ventricles in order to pump blood throughout the body. It starts at the beginning of one heartbeat and ends at the beginning of another.
What happens during each part of ECG?
Components of ECG The P wave represents the normal atrium (upper heart chambers) depolarization; the QRS complex (one single heart beat) corresponds to the depolarization of the right and left ventricles (lower heart chambers); the T wave represents the re-polarization (or recovery) of the ventricles.
What are the 3 stages of the cardiac cycle and what happens during them?
The cardiac cycle has 3 stages: Atrial and Ventricular diastole (chambers are relaxed and filling with blood) Atrial systole (atria contract and remaining blood is pushed into ventricles) Ventricular systole (ventricles contract and push blood out through aorta and pulmonary artery)
What does the T wave represent?
The T wave on the ECG (T-ECG) represents repolarization of the ventricular myocardium. Its morphology and duration are commonly used to diagnose pathology and assess risk of life-threatening ventricular arrhythmias.
How do you read an ECG graph?
Standard ECG paper allows an approximate estimation of the heart rate (HR) from an ECG recording. Each second of time is represented by 250 mm (5 large squares) along the horizontal axis. So if the number of large squares between each QRS complex is: 5 – the HR is 60 beats per minute.
What do the R and S waves show on the ECG?
The convention is that the Q wave is always negative and that the R wave is the first positive wave of the complex. If the QRS complex only includes an upward (positive) deflection, then it is an R wave. The S wave is the first negative deflection after an R wave.