Medtronic Cardiac Rhythm Management (CRM) Practice Test

The normal pacing impedances for cardiac devices typically range from 300 to 1500 ohms, making the most appropriate range 300 - 1500 ohms. This range indicates an effective connection between the pacing lead and myocardial tissue, ensuring that electrical impulses can be transmitted properly to stimulate heart contractions.

When pacing impedances fall within this range, it typically signifies good electrode-tissue contact and is generally indicative of a properly functioning pacemaker system. Values that are too low may indicate lead problems such as fracture or insulation failure, while excessively high values could signal lead dislocation or poor contact with the myocardium.

The choice of 200 - 2000 ohms spans a range that exceeds what is considered optimal for normal pacing impedances and may include values indicative of either malfunction or unacceptable conditions. Hence, this choice does not accurately represent the typical operational range for cardiac devices. The values outside the specified range could enhance the risk of ineffective pacing.