Managed Ventricular Pacing (MVP) Feature
The Managed Ventricular Pacing (MVP™) modes promote intrinsic conduction by reducing unnecessary right ventricular pacing. These modes provide atrial-based pacing with ventricular backup. If AV conduction is lost, the device is designed to switch to DDDR or DDD mode. Periodic conduction checks are performed, and if AV conduction resumes, the device switches back to AAIR or AAI mode.
This feature can be found in some Medtronic Pacemaker, ICD, and CRT-D devices. Please go to manuals.medtronic.com or consult with your local Medtronic representative regarding device models available in your geography.
On the mode selection screen, the MVP modes are programmed by selecting AAIR<=>DDDR or AAI<=>DDD.
On the programmer status bar the current operating mode is displayed, as follows:
- In AAIR<=>DDDR mode, either AAIR+ or DDDR is displayed.
- In AAI<=>DDD mode, either AAI+ or DDD is displayed.
In each case, the atrial mode is followed by a “+” symbol to indicate that backup ventricular pacing is available. In the example below, the current operating mode is AAIR+.
- For MVP modes, it is not necessary to program longer PAV and SAV values to promote intrinsic AV conduction. PAV and SAV apply only when loss of AV conduction is detected.
- Upon abrupt loss of AV conduction, prior to switching to DDDR or DDD mode, ventricular pacing support can be as low as one-half the programmed Lower Rate +80 ms for two consecutive intervals. For patients with sinus bradycardia or frequent loss of AV conduction, program the Lower Rate to 60 bpm or higher.
- For patients with complete heart block, the device will drop one beat every 16 hours (AV conduction check). If this is undesirable, permanent DDDR or DDD modes may be more appropriate.
- For patients with long PR intervals, the pacemaker will remain in the AAIR or AAI mode. Permanent DDDR or DDD modes may be more appropriate for patients with symptomatic first-degree AV block.
- Search AV™+ is not pertinent and cannot be enabled if the pacemaker is programmed to an MVP mode.
- The Lower Rate and Sleep Rate parameters must be set to 35 ppm or greater when the pacemaker is programmed to an MVP mode.
- Sinus Preference cannot be enabled if the programmed mode is AAIR<=>DDDR. Sinus Preference is only available if the programmed pacing mode is DDDR.
- Rate Drop Response can be enabled in AAI<=>DDD mode but not in AAIR<=>DDDR mode.
- MVP is available, as a programming option for patients who do not respond to cardiac resynchronization therapy (CRT), starting in Amplia™ and Compia™ devices.
The MVP modes AAIR<=>DDDR and AAI<=>DDD provide AAIR or AAI mode pacing while monitoring AV conduction. For persistent loss of AV conduction, the device switches to DDDR or DDD mode. If AV conduction resumes, the device switches back to AAIR or AAI mode.
For transient loss of AV conduction, the device remains in the AAIR or AAI mode and provides a backup ventricular pace in response to an A-A interval that is missing a ventricular sense. If two of the four most recent nonrefractory A-A intervals are missing a ventricular event, the device identifies a persistent loss of AV conduction and switches to the DDDR or DDD mode.
When MVP is operating in DDDR or DDD mode, all programmable parameters associated with DDDR or DDD mode apply. The device performs periodic one-cycle checks for AV conduction and the opportunity to resume AAIR or AAI therapy. The first check for AV conduction occurs after 1 minute. Subsequent checks occur at progressively longer intervals (2, 4, 8 … min) up to 16 hours and then occur every 16 hours thereafter. Depending on the patient’s intrinsic rhythm and conduction, MVP allows V-V cycle variations and occasional pauses of up to twice the lower rate interval.
When MVP is operating in AAIR or AAI mode, only the programmable parameters associated with AAIR or AAI mode apply. Ventricular backup paces occur following A-A intervals without a valid ventricular sense. The backup paces are timed 80 ms after the A-A escape interval. A ventricular sense that occurs within 80 ms after the A-A interval is considered invalid and does not inhibit the backup pace. Atrial pacing is inhibited and new VA escape intervals are started in response to PVCs and PVC runs after the A-A interval.
- If Mode Switch is enabled, it continues to operate by switching to DDIR during AT/AF episodes.
- While operating in AAIR or AAI mode, the Atrial Refractory Period (ARP) varies as a function of the current heart rate. ARP is 75% of the cardiac cycle length, up to a maximum of 600 ms.
- Several features suspend MVP mode changes and set the pacing mode to DDDR or DDD until their operations are complete:
- Rate Drop Response, while delivering a rate drop intervention therapy
- Lead Monitor, while waiting to gather at least one ventricular lead impedance measurement per day, which requires a ventricular pace
- Atrial Capture Management™ or Ventricular Capture Management, while the pacemaker performs threshold searches
- Magnet mode
- Adapta DR™ pacemakers – While operating in the AAIR or AAI mode, the pacemaker blanking will be 100 ms in the atrial chamber following an atrial pace or sense, 80 ms in the ventricle following an atrial pace, and 100 ms in the ventricle following a ventricular pace or sense. Other blanking periods, such as PVAB are programmable.
- ICDs and Advisa MRI DR™/EnRhythm™/Revo MRI™ pacemakers – PVAB cannot be programmed to Absolute when the device is programmed to an MVP mode.
- PVCs and ventricular tachyarrhythmias (for ICDs) – When MVP is operating in AAIR or AAI mode, the device inhibits atrial pacing in response to PVCs, PVC runs, and ventricular tachyarrhythmia episodes. This behavior is intended to prevent unnecessary atrial pacing when the ventricular rate is faster than the pacing rate. It also allows tachyarrhythmia detection features to operate without disruption from blanking periods caused by atrial pacing.
- After cardioversion or defibrillation therapy – After either of these therapies, the device operates in the DDDR or DDD mode for 1 min. If an AV conduction check was scheduled to occur during this time, the check is postponed until after 1 min has passed.
- Amplia™/Compia™ CRT-D devices – When MVP pacing mode (AAIR<=> DDDR or AAI <=> DDD) is programmed On, CRT pacing is disabled and V Pacing configuration is programmed to RV only.
- Ventricular pacing > 40% of the time in DDDR mode was associated with a 2.6-fold increased risk of heart failure hospitalization as compared with < 40% V-pacing.1
- The risk of AF increased linearly with increasing cumulative percent V-pacing from 0% pacing up to 80-85% pacing in both DDDR and VVIR pacing modes.1
- Long-term DDDR pacing induces LA dilation, and a high proportion of RV pacing decreases LV function.2
- In addition, it has been documented that many pacemaker patients have natural PR conduction intervals that extend into the 300-350 ms range.3,4
|Danish II Trial2
AAI(R) vs. DDD(R) w/Short AV
vs. DDD(R) w/Long AV
DDD(R) or AAI(R)
DDD(R) vs. AAI(R)
DDD(R) vs. VVIR
|HF Hospitalization||Not specifically measured; study indicates that high proportion of RV pacing reduces LV function||Not measured||1 yr event-free rate of composite endpoint (death or HFH) was worse in DDDR group when %V-pacing > 40%||2.6-fold increased risk when %V-pacing > 40% (for DDDR group)|
|Hemodynamic Performance||Long-term DDDR pacing induces LA dilation, and a high proportion of RV pacing decreases LV function||Patients with preserved LV function, no history of MI or CAD, derived most benefit from physiologic pacing||Not measured||Supports conclusion that ventricular dyssynchrony imposed by RV-pacing may be most dramatic in patients with failing left ventricles|
|Incidence of AF||Freedom from AF during follow-up is significantly better with AAIR pacing (p=0.03); 17% RV-pacing in DDDR-long AV group||Physiologic pacing reduces annual rate of development of chronic AF||Not measured||Risk increased linearly by 1% for each 1% increase in V-pacing (up to ~ 85%)|
- Sweeney MO, Hellkamp AS, Ellenbogen KA, et al, for the Mode Selection Trial (MOST) Investigators. Adverse effect of ventricular pacing on heart failure and atrial fibrillation among patients with normal baseline QRS in a clinical trial of pacemaker therapy for sinus node dysfunction. Circulation. 2003; 23: 2932–2937.
- Nielsen JC, Kristensen L, Andersen HR, et al. A randomized comparison of atrial and dual-chamber pacing in 177 consecutive patients with sick sinus syndrome: echocardiographic and clinical outcome. JACC 2003;42(4);614 – 623.
- Linde C, Nordlander R, Rosenqvist M. Atrial rate adaptive pacing: what happens to AV conduction? PACE. 1994;17(10):1581-1589.
- Copeman C. EnRhythm Clinical Study Overview. January 2005. Medtronic, Inc. Data on file.
- Connolly SJ, Kerr CR, Gent M et al. Effects of physiologic pacing versus ventricular pacing on the risk of stroke and death due to cardiovascular causes. Canadian Trial of Physiologic Pacing Investigators. N Engl J Med. 2002; 342: 1385-91.
- Wilkoff BL, Cook JR, Epstein AE, et al; Dual Chamber and VVI Implantable Defibrillator Trial Investigators. Dual-chamber pacing or ventricular backup pacing in patients with an implantable defibrillator: the Dual Chamber and VVI Implantable Defibrillator (DAVID) Trial. JAMA. 2002;288:3115-3123.
Sources: Medtronic Adapta™/Versa™/Sensia™ Reference Guide; Medtronic Consulta™ CRT-P Clinician Manual; Medtronic Protecta™ XT DR Clinician Manual; Medtronic Protecta™ XT CRT-D Clinician Manual, Amplia MRI™/Amplia MRI™Quad, Compia MRI™/Compia MRI™Quad CRT-D Reference Manual.