1. Date of download: 9/18/2016 From: Multiple-Sensor Systems for Physiologic Cardiac Pacing Ann Intern Med. 1994;121(12):960-968. doi:10.7326/0003-4819-121-12-199412150-00010 Changes in pacing mode use in North America in the past decade (see[3]).Table 1The ordinate indicates the percentage of pacemakers of a given pacing mode (see for definitions) that were implanted during the year indicated on the abscissa. There has been a trend toward more frequent use of dual-chamber pacing (DDD and DDDR modes) and a greater reliance on devices with rate-adaptive capability (DDD, DDDR, and VVIR modes). Single-chamber atrial pacing (AAI and AAIR modes) is used infrequently (fewer than 1% implants annually) and therefore is not plotted on this graphic. Figure Legend: Copyright © American College of Physicians. All rights reserved.American College of Physicians

2. Date of download: 9/18/2016 From: Multiple-Sensor Systems for Physiologic Cardiac Pacing Ann Intern Med. 1994;121(12):960-968. doi:10.7326/0003-4819-121-12-199412150-00010 Oxygen kinetics analysis during abrupt-onset, fixed-workload (subanaerobic) exercise may be useful to distinguish subtle differences in sensor-system operation or programming.O2O2This type of exercise protocol mimics the transient activities of daily living and therefore may be useful to assess the clinical utility of new pacing systems and their programming. Ultimate peak oxygen consumption levels (V, mL/min, abscissa) are identical in the two panels. However, the times taken to achieve these responses differ. In panel A, V equilibrium is delayed because of a relatively slow chronotropic response. Panel B depicts a more physiologically desirable outcome, with a smaller oxygen deficit and a shorter mean response time (MRT). The region of oxygen deficit at onset of exercise is noted by the shaded area in each panel. Figure Legend: Copyright © American College of Physicians. All rights reserved.American College of Physicians

3. Date of download: 9/18/2016 From: Multiple-Sensor Systems for Physiologic Cardiac Pacing Ann Intern Med. 1994;121(12):960-968. doi:10.7326/0003-4819-121-12-199412150-00010 Two sensors, one relatively fast responder and one slower but more workload proportional, can work together to elicit a more physiologic heart rate response than either would if used alone.The ordinate indicates pacing rate. The abscissa shows the duration of exercise. The individual sensor responses and the combined response are shown. Figure Legend: Copyright © American College of Physicians. All rights reserved.American College of Physicians