sa node वाक्य

The SA node receives several different inputs and the instantaneous heart rate or RR interval and its variation are the results of these inputs.
Sometimes an ectopic pacemaker sets the pace, if the SA node is damaged or if the electrical conduction system of the heart has problems.
The escape arrhythmia is a compensatory mechanism that indicates a serious underlying problem with the SA node or conduction system ( commonly due to syncope.
Tbx18 gene therapy has been successful in rodent hearts, converting atrial muscle cells into SA node cells by expression of the Tbx18 transcription factor.
When atrial fibrillation occurs, several areas of the heart other than the SA node send signals to the atria in a rapid and chaotic manner.

These cells are found in the conduction system of the heart and include the SA node, AV node, Bundle of His and Purkinje fibers.
The AV node's normal intrinsic firing rate without stimulation ( such as that from the SA node ) is 40-60 times / minute.
Ordinarily, the SA node, or natural pacemaker of the heart, sends an electrical signal that causes contraction of the atria, or upper heart chambers.
Stimulation sympathetic fibers of the spinal nerves causes an " increase " in the SA node rate, increasing the heart rate and force of contraction.
Since this accessory pacemaker also activates independently of the impulse generated at the SA node, two independent rhythms can be noted on the electrocardiogram ( ECG ).