Cardiac Rhythm Management | Cardiac Resynchronization Therapy (CRT) Devices | CRT Defibrillator

Unify Assura

Cardiac Resynchronization Therapy Defibrillator (CRT-D)

Product Highlights

  • TailoredTherapy features are designed to customize treatment to each patient's unique needs, including: SecureSense RV lead noise discrimination, ShockGuard® technology, SenseAbility® sensing algorithm and DeFT Response® technology
  • ShockGuard technology with DecisionTx® programming is designed to reduce inappropriate therapy and minimize the need for programming adjustments at implant
  • SecureSense RV lead noise discrimination detects sustained and short bursts of lead noise for the reduction of inappropriate shocks
  • Antitachycardia pacing (ATP) while charging and prior to charging in the VF zone further extends the programming options for terminating tachyarrhythmias without a high-voltage shock
  • The Low Frequency Attenuation filter is designed to enhance sensing performance and may reduce the possibility of oversensing T waves
  • Complete capture confirmation accounts for changing thresholds by automatically monitoring and controlling pacing amplitudes in all chambers of the heart
  • ACap® Confirm assesses capture threshold and adjusts pacing amplitudes in the atrium every eight or 24 hours
  • The SenseAbility sensing algorithm allows flexibility to fine-tune programming around T-wave oversensing without decreasing sensitivity
  • Streamlined DF4 connector simplifies implants and reduces pocket bulk
  • Highest amount of delivered energy (40 J) provides a greater safety margin
  • DeFT Response technology offers the most noninvasive options for managing high defibrillation thresholds (DFTs)
  • QHR®* battery chemistry provides greater capacity for enhanced longevity and improved charge time performance compared to previous SVO batteries
  • Unique vibratory notifier alerts patients to low battery, lead-related complications and more
  • Smallest footprint of any high-voltage device available and narrow shape allow smaller incision and pocket size
  • Triggered pacing with BiVCap® Confirm Trigger Mode helps maintain a high percentage of biventricular (BiV) pacing by triggering pacing in both the left and right ventricles in response to a sensed ventricular event
  • Negative AV hysteresis with search promotes ventricular pacing by automatically reducing the AV delay when intrinsic activity is present, thereby promoting a high degree of ventricular pacing
  • QuickOpt® Timing Cycle Optimization provides quick and effective AV and V-V timing optimization at the push of a button
Unify Assura<sup>™</sup>

Ordering Information

Contents: Cardiac pulse generator

Reorder Number Dimensions (H x W x T, mm) Weight (g) Volume (cc) Connector Defibrillation Connector Sense/Pace
CD3257-40 79 x 40 x 14 78 36 DF1 IS-1
CD3257-40Q 73 x 40 x 14 77 36 DF4 DF4; IS-1

*QHR is a registered trademark of Greatbatch Medical.


Brief Summary: Prior to using these devices, please review the User’s Manual for a complete listing of indications, contraindications, warnings, precautions, potential adverse events and directions for use.

Indications: St. Jude Medical® ICDs and CRT-Ds are intended to provide ventricular antitachycardia pacing and ventricular defibrillation for automated treatment of life-threatening ventricular arrhythmias.

AF Suppressionpacing is indicated for suppression of paroxysmal or persistent atrial fibrillation in patients with the above ICD indication and sinus node dysfunction.

In patients indicated for an ICD, CRT-Ds are also intended:

  • to provide a reduction of the symptoms of moderate to severe heart failure (NYHA Functional Class III or IV) in those patients who remain symptomatic despite stable, optimal medical therapy (as defined in the clinical trials section included in the Merlin® PCS on-screen help) and have a left ventricular ejection fraction less than or equal to 35% and a prolonged QRS duration
  • to maintain synchrony of the left and right ventricles in patients who have undergone an AV nodal ablation for chronic (permanent) atrial fibrillation and have NYHA Class II or III heart failure

Contraindications: Contraindications for use of the pulse generator system include ventricular tachyarrhythmias resulting from transient or correctable factors such as drug toxicity, electrolyte imbalance or acute myocardial infarction.

Adverse Events: Implantation of the pulse generator system, like that of any other device, involves risks, some possibly life-threatening. These include but are not limited to the following: acute hemorrhage/bleeding, air emboli, arrhythmia acceleration, cardiac or venous perforation, cardiogenic shock, cyst formation, erosion, exacerbation of heart failure, extrusion, fibrotic tissue growth, fluid accumulation, hematoma formation, histotoxic reactions, infection, keloid formation, myocardial irritability, nerve damage, pneumothorax, thromboemboli, venous occlusion. Other possible adverse effects include mortality due to: component failure, device-programmer communication failure, lead abrasion, lead dislodgment or poor lead placement, lead fracture, inability to defibrillate, inhibited therapy for a ventricular tachycardia, interruption of function due to electrical or magnetic interference, shunting of energy from defibrillation paddles, system failure due to ionizing radiation. Other possible adverse effects include mortality due to inappropriate delivery of therapy caused by: multiple counting of cardiac events including T waves, P waves or supplemental pacemaker stimuli. Among the psychological effects of device implantation are imagined pulsing, dependency, fear of inappropriate pulsing and fear of losing pulse capability.

Refer to the User’s Manual for detailed indications, contraindications, warnings, precautions and potential adverse events.

Unless otherwise noted, ™ indicates that the name is a trademark of, or licensed to, St. Jude Medical or one of its subsidiaries. ST. JUDE MEDICAL and the nine-squares symbol are trademarks and service marks of St. Jude Medical, Inc. and its related companies.

©2018 St. Jude Medical, Inc. All rights reserved.

Item No. F00126

Customer Support: 855-478-5833

Last Updated: April 19, 2013