The Telectronics 1250 Meta MV DDDR pacemaker caused undesirable mode switching in 7 of 8 evaluated patients (87.5%) during low levels of exercise.
Observational (n=8)
No
Does the Telectronics 1250 Meta MV DDDR pacemaker cause undesirable mode switching in patients with AV conduction disorders?
Patients with intact sinus node function and AV conduction disorders are at risk of undesirable mode switching with the Telectronics 1250 Meta MV DDDR pacemaker and should be programmed to DDD mode unless specifically indicated.
The Telectronics 1250 Meta MV DDDR pacemaker is a new device featuring automatic mode switching from DDDR to VVIR pacing in the event of an atrial arrhythmia. Although mode switching is a valuable feature, sinus tachycardia can cause an undesirable mode switch to occur. Of 24 implants at this institution, 11 have been for an AV conduction disorder. Eight of these 11 patients were specifically evaluated for undesirable mode switching. During exercise testing and/or Holter monitoring, mode switching was repeatedly seen in seven of the eight at low levels of exercise. Factors precipitating mode switching were a low rate response factor, low upper rate setting, long base postventricular atrial refractory period (PVARP) and a long AV delay. During Holter monitoring, patients spent up to 50% of the time in VVIR pacing as opposed to DDDR pacing. It is concluded that patients with intact sinus node function are at risk of undesirable mode switching and should probably be programmed to the DDD mode unless there is a specific indication for DDDR pacing. If the DDDR mode is chosen, careful selection of the aforementioned pacing parameters is required.
Pitney et al. (1993) conducted an observational in AV conduction disorder (n=8). Telectronics 1250 Meta MV DDDR pacemaker was evaluated on Undesirable mode switching during exercise testing and/or Holter monitoring. The Telectronics 1250 Meta MV DDDR pacemaker caused undesirable mode switching in 7 of 8 evaluated patients (87.5%) during low levels of exercise.