AV Synchrony Restored

1. RYTHMIQ™ Operation RYTHMIQoperates in AAI(R) pacing mode with VVI backup during times of normal conduction, switching to DDD(R) mode when a conduction block is detected Loss of AV Synchrony AV Synchrony Restored

2. RYTHMIQ™ Operation During normal conduction, RYTHMIQ operates like two pacemakers running concurrently – one in AAI(R) mode and one in VVI mode. • The device provides AAI(R) at the LRL and/or sensor indicated rate with backup VVI pacing at a rate of 15 bpm slower than the LRL • When there is good conduction, ventricular pacing does not occur as the VVI backup mode runs in the background Normal Conduction

3. RYTHMIQ™ Operation • The device monitors for loss of AV synchrony to determine when to switch to DDD(R) mode • If 3 slow ventricular beats are detected in a window of 11 beats, then the device automatically switches to DDD(R) mode. • A slow beat for RYTHMIQ is defined as a ventricular pace or ventricular sensed event that is at least 150 ms slower than the AAI(R) pacing rate. Loss of AV Synchrony Loss of AV Synchrony

4. RYTHMIQ™ Operation INGENIO™ records a RYTHMIQ Episode along with 20 seconds of electrogram data when RYTHMIQ detects loss of AV synchrony. This can help the clinician to diagnose patient rhythm conduction disorders and determine appropriate algorithms and pacemaker settings #1 #2 #3

5. RYTHMIQ™ Operation • The device uses AV Search+ to periodically check for a return of intrinsic conduction and determine when to mode switch back to AAI(R) with VVI backup. If AV Search+ remains in AV hysteresis for at least 25 cardiac cycles, and less than 2 of the last 10 cycles are ventricular paced, then the device automatically switches the pacing mode back to AAI (R) with VVI backup. AV Synchrony Restored Normal Conduction Restored

6. RYTHMIQ™ Operation RYTHMIQis designed to adapt to a patient’s conduction disorder, by mode switching when AV synchrony is lost or restored, without clinically significant pauses AV Synchrony Restored Loss of AV Synchrony

7. RYTHMIQ™ Exception During ATR Mode Switch If RYTHMIQwent directly from AAI(R) into ATR Mode Switch, when the mode switch ends, it goes directly back into AAI(R) mode

8. RYTHMIQ™ Operation • RYTHMIQ is designed to minimize unnecessary pacing without clinically significant pauses • RYTHMIQ operates like two pacemakers running concurrently—one in AAI(R) and one in VVI • RYTHMIQ does not require dropped ventricular beats to switch to DDD(R) pacing Reference Guide, INGENIO Pacemaker, Page 2-53, 358577-001EN US 11/10

9. RYTHMIQ™ Managing RV Pacing – Two Algorithms Patients may require different algorithms at various stages of their conduction disease. RYTHMIQ adds another RV pacing algorithm to Boston Scientific devices, because no one algorithm is appropriate for every patient. BSC also offers AV Search+ • AV Search+ is designed to reduce unnecessary RV pacing by providing backup ventricular pacing for every beat while searching for intrinsic activity

10. RYTHMIQ™ Managing RV Pacing – Two Algorithms INGENIO™ pacemakers have two algorithms to help minimize unnecessary RV pacing With both RYTHMIQ™ & AV Search+, clinicians now have options to appropriately manage RV pacing in patients with varying degrees of conduction block • Therapy recommendations made by Indications-Based Programming • 2) Source: Medtronic Adapta/Versa/Sensia Pacemaker Programming Guide (M929948A001C 2008-01-18) • 3) Source: St. Jude Medical Unity Platform Reference Guide (60020476A, 07/09) • Boston Scientific Indications-Based Programming would recommend paced/sensed AV delays. While not an algorithm, an equivalent setting would be available in competitor devices