Search results
Results from the WOW.Com Content Network
In a healthy heart all activities and rests during each individual cardiac cycle, or heartbeat, are initiated and orchestrated by signals of the heart's electrical conduction system, which is the "wiring" of the heart that carries electrical impulses throughout the body of cardiomyocytes, the specialized muscle cells of the heart.
A Wiggers diagram modified from [1]. A Wiggers diagram, named after its developer, Carl Wiggers, is a unique diagram that has been used in teaching cardiac physiology for more than a century.
This process is of vital importance as it allows for the heart to beat in a controlled manner, without the need for conscious input. EC coupling results in the sequential contraction of the heart muscles that allows blood to be pumped, first to the lungs ( pulmonary circulation ) and then around the rest of the body ( systemic circulation ) at ...
In a normal heart, the heart rate is the rate at which the sinoatrial node depolarizes since it is the source of depolarization of the heart. Heart rate, like other vital signs such as blood pressure and respiratory rate, change with age. In adults, a normal heart rate is between 60 and 100 bpm (normocardic), whereas it is higher in children. [57]
Diagram showing how the polarity of the QRS complex in leads I, II, and III can be used to estimate the heart's electrical axis in the frontal plane. The QRS complex is the combination of three of the graphical deflections seen on a typical electrocardiogram (ECG or EKG). It is usually the central and most visually obvious part of the tracing.
Normal heart rate (classically 60 to 100 beats per minute for an adult). Regular rhythm, with less than 0.16-second variation in the shortest and longest durations between successive P waves; The sinus node should pace the heart – therefore, P waves must be round, all the same shape, and present before every QRS complex in a ratio of 1:1.
Normally the heartbeat is initiated in the SA node of the atrium but initiation can also occur in the Purkinje fibres of the ventricles, giving rise to premature ventricular contractions, also called ventricular extra beats. When these beats become grouped the condition is known as ventricular tachycardia. [citation needed]
In medicine, the pulse is the rhythmic throbbing of each artery in response to the cardiac cycle (heartbeat). [1] The pulse may be palpated in any place that allows an artery to be compressed near the surface of the body, such as at the neck (carotid artery), wrist (radial artery or ulnar artery), at the groin (femoral artery), behind the knee (popliteal artery), near the ankle joint ...