Plot these voltages on a polar coordinate graph. Draw lines perpendicular to the axes at each of these voltages. Connect point of intersection of these perpendiculars to axis origin with a vector. The line formed by this vector represents the axis of depolarization. 2 o Heart Block - Some pulses from SA node traverse the AV node while others do not.
Reentry can occur when two conditions exist.
Bifurcating path for activation, paths A and B, that converge on the same tissue. An impulse arrives at the bifurcation of paths A and B and is conducted down each. A. c. Impulse reaches point of convergence and enters path B in retrograde direction. Impulse conducts successfully back to bifurcation of paths A and B, reentering previously excited tissue. Reentrant impulse conducts antegrade down path A, retrograde up path B and cycles repetitively, with each cycle the entire heart contracts.