Cardiac Resynchronization Therapy Defibrillator

Only the X4 quadripolar CRT-D provides 17 pacing vectors plus industry-leading projected longevity for more streamlined patient care.

Key Resources

Physician Technical Manual


Product Details


Models G172, G173, G175, G177 and G179

  • The X4 CRT-D and ACUITY™ X4 lead portfolio features electrodes on a 3D spiral designed to allow pacing from a basal location without sacrificing fixation or thresholds; 17 pacing vector options to manage around PNS and high thresholds; and multiple lead shapes with a 2.6F (0.86mm) tapered lead tip to improve predictability of accessing target vessels.
  • Projected to last 8+ years under true usage conditions.
  • This small (32.0 cm3) and thin (9.9 mm) high-energy device is designed to enhance patient comfort.
  • RightRate™ features BSC’s MV Sensor—the only sensor clinically proven to restore chronotropic competence.1
  • The PaceSafe™ RV, RA, and LV auto threshold feature is designed to maintain adequate output safety margins.
  • Offers an advanced system solution for patient comorbidities and HF monitoring (AP Scan, HF Perspectiv™ report, LATITUDE™ NXT Remote Patient Management with weight scale and blood pressure sensors, and Respiratory Rate Trend). 
  • Offers AcuShock™ Advanced Technology, multiple programmable options to reduce inappropriate and unnecessary shocks, including a choice of rhythm discriminators, RhythmID™ with RhythmMatch™ (customization of Rhythm ID algorithm), antitachycardia pacing (ATP) therapy in all rates zones, and advanced sensing and filtering.
  • Wireless ECG saves time and simplifies follow-up.
  • EasyView™ header and color coded lead ports designed to make the implant experience more efficient.
  • SafetyCore™ technology is intended to provide lifesaving shock therapy and basic pacing functionality in the event of an unrecoverable fault.

Mechanical Specifications

Model Type Size (cm)
(W x H x D)
Mass (gr) Volume (cm3) Connector Type
G179 X4-CRT-D 5.37 x 8.18 x 0.99 73.8 32.5 RA:IS-1; RV:DF4; LV:IS4
G177 X4-CRT-D
5.37 x 8.08 x 0.99 73.4 32.0 RA:IS-1; RV:IS-1/DF–1; LV:IS4
G172 CRT-D 5.37 x 8.18 x 0.99 73.6 32.5 RA:IS-1; RV:DF4; LV:IS-1
G173 CRT-D 5.37 x 8.08 x 0.99 72.8 32.0 RA:IS-1; RV:IS-1/DF–1; LV:IS-1
G175 CRT-D 5.37 x 8.08 x 0.99 72.9 32.0 RA:IS-1; RV:IS-1/DF–1; LV:LV-1

Pulse Generator Longevity (All Models ᵃ, ᵇ, ᶜ, ᵈ)

Amplitude and Pacing, 
Right Ventricular, Right Atrial, and Left Ventricular Automatic Threshold On
Pacing Amplitude Longevity (years)
at 500Ω and 700Ω Pacing Impedance
(RV and LV) 
PaceSafe On (RA=2.0 V, LV=3.0 V [Assuming an RV threshold of
< 1.0 and an RA threshold of <1.0 and an LV threshold of 2.0])ᵉ
RA/RV LV 500Ω 700Ω
2.0 V/2.0 V 3.0 V 8.4 8.9
2.0 V/2.0 V 3.5 V 8.0 8.5
2.0 V/2.0 V 5.0 V 6.5 7.5

Longevity Information

  • For longevity calculations based on different settings please contact Boston Scientific
    technical services or your local representative.
  • Boston Scientific devices have corporate warranties at 6 years in available geographies.
  • Devices use Li/MnO2  chemistry.
  • The Usable Battery Capacity is 1.9 Amp-hours (typical implant to battery capacity depleted).
  • Shelf life is 2 years (before use by).

Longevity projections as provided in the product labeling.
Specific programmable parameter ranges available in product labeling.
Warranty information