Bundle Branch Blocks
When a bundle branch or fascicle becomes injured (due to underlying heart disease, myocardial infarction, or cardiac surgery), it may cease to conduct electrical impulses appropriately. This results in altered pathways for ventricular depolarization. Since the electrical impulse can no longer use the preferred pathway across the bundle branch, it may move instead through muscle fibers in a way that both slows the electrical movement and changes the directional propagation of the impulses. As a result, there is a loss of ventricular synchrony, ventricular depolarization is prolonged, and there may be a corresponding drop in cardiac output. When heart failure is present, a specialized pacemaker may be used to resynchronize the ventricles. In theory a pacemaker like this will shorten the QRS interval, thus bringing the timing of contraction of the left and right ventricles closer together and perhaps tweaking up the Ejection Fraction.
Read more about this topic: Bundle Branch Block
Famous quotes containing the words bundle, branch and/or blocks:
“We styled ourselves the Knights of the Umbrella and the Bundle; for, wherever we went ... the umbrella and the bundle went with us; for we wished to be ready to digress at any moment. We made it our home nowhere in particular, but everywhere where our umbrella and bundle were.”
—Henry David Thoreau (1817–1862)
“What can the dove of Jesus give
You now but wisdom, exile? Stand and live,
The dove has brought an olive branch to eat.”
—Robert Lowell (1917–1977)
“Good blocks of oak it was I split,
As large around as the chopping block;
And every piece I squarely hit
Fell splinterless as a cloven rock.”
—Robert Frost (1874–1963)