The ventricles are the part of the heart that are responsible for the pumping action to move blood throughout the body. Therefore, the muscles in the ventricles are much larger and thicker to do their job properly. The atrium only has to pump blood through an open valve (the tricuspid valve) into the right ventricle. There is
much less resistance to this flow of blood so much less muscle is needed.
I will answer this assuming that the question is comparing ventricular contractions to atrial contractions.
The upper right part of the heart is where blood comes to the heart to be pumped. Deoxygenated blood enters the right atrium from the vena cava. Oxygenated blood from the lungs enters the left atrium from the pulmonary vein. The blood enters these atria while the atria are relaxed.
A signal from the heart's pacemaker causes the atria to contract pushing blood into the ventricles, the larger more muscular part of the heart. The atria have to push the right volume of blood hard enough to mildly stretch the relaxed ventricular muscle (healthy hearts know how much and how hard - they get lots of practice). By the time the pacemaker's signal reaches the ventricles, the atria have finished pushing.
Now the ventricles contract with a much greater power to make sure that the blood reaches all parts of the body. The right ventricle has a less powerful contraction than the left because it delivers blood only to the lungs. The left ventricle delivers blood everywhere else.
Ventricular contraction is seen as a larger wave on an electrocardiogram (ECG) because the 2 lower chambers of the heart (ventricles) are larger in size than the 2 upper chambers (atria) and therefore, require more electrical energy to make them contract.
Ventricular contractions produce a greater force than atrial contractions, so they are represented by a larger wave pattern on the oscilloscope. The waves are larger because they push blood through the entire body instead of the atrial contractions that only push blood to the heart.
apex
A group of premature ventricular contractions in which the QRS configuration is always the same are referred to as monomorphic premature ventricular contractions.
Premature Ventricular Contractions
Rapid and dangerously uncoordinated ventricular contractions is called ventricular fibrillation, or v-fib. During v-fib, the ventricle is not pumping blood to the body, and thus v-fib is known as a lethal dysrhythmia.
PVC in medical terms is a premature ventricular contraction.Premature Ventricular Contractions. See the related link for more information.Usually PVC stands for Premature Ventricular Contractions. Which basically means the ventricles (lower part of the heart) is contracting too soon.
the ventricular contraction wave is larger
Tachycardia
Ventricular contraction wave is larger
Premature ventricular contractions (PVCs) are extra heartbeats that begin in one of your heart's two lower pumping chambers (ventricles). These extra beats disrupt your regular heart rhythm, sometimes causing you to feel a fluttering or a skipped beat in your chest. Premature ventricular contractions are common — they occur in many people. They're also called: Premature ventricular complexes Ventricular premature beats Ventricular extrasystoles If you have occasional premature ventricular contractions, but you're otherwise healthy, there's probably no reason for concern, and no need for treatment. If you have frequent premature ventricular contractions or underlying heart disease, you might need treatment.
pre ventricular contractions when your ventricles fire before your atrium generally harmless
systolic pressure
When the ventricles begin to quiver and do not employ coordinated contractions, the heart is said to be fibrillating.