Quality-of-life in DDDR pacing: Atrioventricular synchrony or rate adaptation?

Although differences in exercise performance have been observed between different rate adaptive modes, the relative impact of atrioventricular (AV) synchrony and rate adaptation on quality of life (QOL) have not been determined. Thirty-three patients with either sinoatrial disease (18) or complete atrioventricular (AV) block (15) received DDDR pacemakers (16 minute ventilation sensing, 17 activity sensing). There were 11 males and 22 females, with a mean age of 66 ± 1 (range 39-78) years. The study was a double-blind, triple cross-over study comparing DDDR, DDD, and VVIR modes. At the end of each 8-week study period in each mode. QOL was assessed by a questionnaire evaluating patients functional class (Classes I-IV), physical malaise inventory (41 items), illness perception (43 items), and overall QOL rating based on a 48 items measure covering different aspects of the patients daily life adjustment. Two patients required early crossover from VVIR mode during the study. Patients experienced significantly fewer physical malaise such as temperature intolerance, dyspnea, and palpitations in the DDDR mode, compared with either DDD or VVIR pacing, DDDR pacing reduced the perception of illness in 5 of 43 items compared to VVIR pacing, and improved stamina and appetite compared to DDD pacing. The overall QOL score was 102 ± 2, 105 ± 2, 113 ± 2 in the DDDR, DDD, and VVIR modes, respectively, with a higher score indicating a poorer QOL (DDDR/DDD vs VVIR, P < 0.02). There was no change in functional classes between the three pacing modes. In conclusion, VVIR pacing has a lower QOL compared with DDD pacing, which can be further enhanced with rate augmentation.link_to_subscribed_fulltex

The 'automatic mode switch' function in successive generations of minute ventilation sensing dual chamber rate responsive pacemakers

Automatic mode switch (AMS) from DDDR to VVIR pacing is a new algorithm, in response to paroxysmal atrial tachyarrhythmias, With the 5603 Programmer, the AMS in the Meta DDDR 1250 and 1250H (Telectronics Facings Systems, Inc.) operates when VA is shorter than the adaptable PVARP. With the 9600 Programmer, an atrial protection interval can be defined after the PVARP. The latest generation, Meta DDDR 1254, initiates AMS when 5 or 11 heart cycles are > 150, 175, or 200 beats/min. From 1990 to 1993, 61 patients, mean age 61 years, received a Meta DDDR: in 24 a 1250, in 12 a 1250H and in the remaining 25 a 1254 model. Indication for pacing was heart block in 39, sick sinus syndrome in 15, the combination in 6, and hypertrophic obstructive cardiomyopathy in 1. Paroxysmal atrial tachyarrhythmias were present in 43. All patients had routine pacemaker surveillance, including 52 Holter recordings. In 32 patients, periods of atrial tachyarrhythmias were observed, with proper AMS to VVIR, except during short periods of 2:1 block for atrial flutter in 4. In two others, undersensing of the atrial arrhythmia disturbed correct AMS. With the 1250 and 1250H model, AMS was observed on several occasions during sinus rate accelerations in ten patients. This was never seen with the 1254 devices. Final programmation was VVIR in 2 (chronic atrial fibrillation), AAI in 2 (fracture of the ventricular lead), VDDR in 1 (atrial pacing during atrial fibrillation), DDD in 5, and DDDR in 53, 48 of whom had AMS programmed on. The AMS detection algorithm in the successive models of the Meter DDDR appears to have become more specfic