Question

We are learning the way in which blood flows through the heart in one of my classes. Could somebody explain the whole process from start to finish for me? And how this correlates to each wave in an ECG? Thank you!

Answer 1

An electric wave generated on the wall of right atrium (SA node) spreads out to the wall of both ventricle and left atrium causes the depolarisation and depolarisation atrium and ventricle results in pumping of blood from the heart .

This electric wave is recorded in electrocardiogram.

By analysing the ECG , it can be identify any problem in the heart.

An electric wave from SA node goes to AV node. At the time atrium starts to depolarise.(P wave ). The wave then goes to bundle of his from there it is divided into left and right bundle branches and Purkinje fibres.the time interval between atrial and ventricular depolarisation is considered as PR interval. When ventricle starts to depolarise ( Q wave) and at extreme contraction( R wave) and at the end of depolarisation S wave. In the whole, QRS complex is ventricular depolarisation ( contraction). Then , ventricle starts to repolarise( T wave) and from the beginning to when it is completely relaxed ,the time taken is considered as ST segment.

blood comes into the atrium ,an impulse from SA node generated. So atrium depolarised(P wave) and pumped blood into the ventricle. Then, atrium repolarised to its initial state ( PR interval).impulse reached both ventricles , and started to depolarise (QRS complex)and pumped blood out from the ventricles. then, ventricle repolarised (T wave). The in between time at the end of depolarisation and complete relaxation of ventricle is ST segment.