CRT Optimization

Overview:

Electrical Cardiometry monitors have been proven to aid in the optimization of cardiac resynchronization therapy (CRT).

CRT aims to resynchronize the contractions of the heart in order to improve contractility, blood flow, and eventually improve the quality of life in patients with advanced heart failure. CRT is achieved with the use of a three chamber pacemaker (right atrium, right ventricle, left ventricle), and subsequent modification of the contractions in order to synchronize the RV and LV contractions.

The optimization of CRT allows pacing to meet the needs of each individual patient by determining the optimal timing setting between the atrium and right ventricle (AV-delay), as well as between the right and left ventricles (VV-delay). Determining ideal timing for each patient allows them to receive more, and even the full benefit from their CRT device by achieving optimal hemodynamics.

With both the ICON and AESCULON, the CRT device can be cycled through a number of different combinations of AV-delay and VV-delay timings, to determine at which setting would give the patient the optimal hemodynamic response, and thus the optimal output.

In addition, the AESCULON’s Pacemaker Clinic™ feature provides a systematical and organized approach to CRT Optimization by formulating an easy to read table with clearly indicated results. With each timing combination, the Pacemaker Clinic automatically records the cardiac output/hemodynamic measurement for easy comparison to other timing combinations. At the end of the optimization procedure, Pacemaker Clinic will determine the “optimal” timing based on preset hemodynamic variables such as CO or SV. Data can also be exported to a PC in Excel format.

Studies have been conducted comparing and validating CRT optimization with EC monitors to that of echocardiography, showing that:

  1. CRT optimization with EC monitors is identical, and for some patients superior than optimization through echocardiography.
  2. EC monitors provide a user-independent form of optimization that is fast and easy to perform, and more cost and time efficient than echocardiography.

Optimized temporary biventricular pacing:

In addition to the benefits of CRT optimization for patients with heart failure and implanted pacemakers, there is recent evidence showing advantages for the optimization of biventricular pacing post cardiac surgery. Low left ventricular ejection fraction and cardiac output are risk factors for poor outcomes after cardiac surgery.

The interface of the Aesculon and the PACE 300 temporary 3-chamber pacemaker create the ideal combination to achieve rapid optimization through temporarily paced patients. Once the user chooses the upper and lower limits and step widths for both the AVD and VVD, the Pacemaker Clinic will automatically run through all possible timing combinations and record hemodynamics, without any user input.

Smart Scan:

The smart scan optimization setting can reduce the duration of an optimization procedure in half. Smart scan follows the commonly accepted optimization protocol of determining the optimal AVD, then cycling through different VVD timings with the already accepted AVD.

Graphs & Posters:

Figure 1. Ismer et al, AV Delay optimization using electrical velocimetry, Cardiostim 2006 - See Full Poster

Figure 2. Schaumann et al, Optimization of AV and BV in biventrical pacing in HF patients, ESC 2008 - See Full Poster