The electrical axis of the heart is essentially a vectoral analysis of the direction and magnitude
of a flow of current during various instances, in this case, the QRS Complex.
1. We get a slight Left to Right movement of the predominant electrical activity, because the left
ventricle starts depolarizing slightly a bit before the right one, shown by the small dip in the Q
îXZÀv]o}v]vµ}}o]ÌUÁ[Ptting a primarily downward t towards the
apex t movement of electrical activity, directed almost entirely towards the positive electrode,
and that gives us the big upswing in the R Wave.
ïXZui}]Ç}(ZÀv]o(]v]Z][}o]Ì]}vUZ full depolarization is
represented by the downwards slope at the end of the R Wave and the beginning of the S Wave.
of electrical flow.
4. At the very-very end, the direction of the electrical flow is essentially backwards, towards the
left, leading towards the last bit of the S Wave.
the direction of Lead II.
Any deviation of more than 0 degrees is considered a serious deviation to the left and a
deviation of 120 degrees is considered a serious deviation to the right.
Any deviation is usually accompanied by increase in tissue mass in one of the ventricles t
Obstructive Lung Disease inhibits/hinders expiration.
Pulmonary embolism = a blockage of blood flow in the lungs.
Pulmonary Hypertension = high blood pressure in the pulmonary circuits.
So anything that is obstructing or hindering blood flow through the lungs is going to cause the
right ventricle to enlarge and a swing in the axis to the right, in an attempt to be more forceful
and have stronger contractions, to force blood through this blockage or hindrance to flow. The
swing in the axis is due to more tissue being available for depolarization.
HBP t heart will work harder to pump against that HBP.
blood to move through, so it must pump harder.
The electrical axis is a very useful tool when looking for potential diseases of the heart.