BIOTRONIK CRM Reocor D Manuel Technique page 80

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81
Pacing Modes and Parameters
Pacing the heart with rates higher than 180 ppm over
a long time period can cause severe hemodynamic
complications. Pacing at high rates should only be
performed when continuous monitoring is ensured.
The mode for high-frequency pacing is used to termi-
nate certain supraventricular tachycardias (SVT) and
should only be considered for atrial applications. The
application of asynchronous high-frequency stimuli
can interrupt an SVT by depolarizing portions of a
reentry path. When an ectopic atrial focus is respon-
sible for an SVT, the application of high-frequency
stimuli in the atrium can also lead to increased
suppression of the ectopic center.
Various risks have to be considered in association 
with high-frequency atrial pacing. The risks include
possible ventricular pacing and ventricular tachy-
cardia or fibrillation. This can be caused by poor
placement of the leads or the presence of anomalous
stimulus conduction paths that circumvent the nor-
mal atrioventricular stimulus conduction (e.g. Wolff-
Parkinson-White Syndrome). Patient discomfort and
asystole after high-frequency pacing are other
possible problems.