Mode switches

Mode switch feature

by golden_snitch - 2015-04-29 03:04:44

There are basically two kinds of mode switches:

The first is a switch when an atrial high rate episode occurs, for instance atrial flutter or atrial fibrillation. If that happens, the pacemaker can switch from a mode where it tracks the atria, and makes the ventricles beat at the same pace, into a mode where it ignores what's happening in the atria, and just paces the ventricles at a steady and appropriate rate. This mode switch is a kind of safety feature to prevent that a fast arrhythmia in the atria causes the ventricles to go into a fast arrhythmia, too. This is type that is usually meant when one talks about mode switches.

But there is another feature that can be called mode switch. Some dual-chamber pacemakers also offer a mode switch feature for intermittent heart block episodes. In this case, the pacemaker is usually working in an AAI(R) mode, so it only senses and paces the atria. Now, when the patient experiences several heart blocks in a certain period of time, the pacemaker switches from AAI(R) to a DDD(R) mode, so that now it paces and senses both, the atria and the ventricles.