Background Electroanatomic mapping systems track the position of electrodes in the heart. We assessed the feasibility of characterizing left ventricular (LV) performance during cardiac resynchronization therapy (CRT) implant utilizing an electroanatomic mapping system to track the motion of CRT lead electrodes, thus deriving ventricular contractility surrogates. Methods During CRT implant, atrial, right ventricular (RV), and LV leads were connected to the EnSite NavX™ mapping system (St. Jude Medical Inc., St. Paul, MN, USA). The relative displacement of electrodes was averaged over 10 cardiac cycles during RV, LV, and biventricular (BiV) pacing in DOO mode. Three contractility surrogates indicative of ventricular performance were extracted from the RV‐LV distance waveform: systolic slope (SS), time to peak systolic contraction (TPSC), and fractional shortening (FS). Results In the 20 patients included, there were detectable differences in each of the three contractility surrogates responding to the different pacing configurations. Median SS varied 42%, median TPSC varied 35%, and median FS varied 19% across RV, LV, and BiV pacing interventions. The RV‐LV distance waveform showed subtle sensitivity to varying pacing timing cycles when measured in a subset of patients. For all pacing configurations, RV‐LV distance waveforms were stable during 2‐minute recordings. Conclusions Tracking the motion of CRT pacing electrodes with a mapping system to derive contractility surrogates during implant is feasible.

Interventricular mechanical dyssynchrony (VVMD) is a strong predictor of cardiac resynchronization therapy (CRT) response. However, no simple and reliable clinical method of measuring VVMD during CRT implant is currently available. We tested the hypothesis that the EnSite™ NavX™ system (St. Jude Medical, St. Paul, MN, USA) can be used intraoperatively to determine VVMD, thereby facilitating CRT optimization.

Hemodynamic assessment plays a role in CRT optimization. However, there is no simple and reliable method to assess hemodynamics. We tested the hypothesis that a non-invasive PPG sensor could be used to measure surrogates of standard hemodynamics, thereby facilitating fast and easy CRT device interval optimization.

eIRA codes are iteratively decodable low-density parity-check (LDPC) codes. They not only offer superior performance to alternative approaches, but they allow linear-time encoding. Well-designed eIRA codes also achieve extremely low error-rate floors. In this letter, we successfully implement a common FPGA platform for eIRA codes. As a demonstration, we took an example parity-check matrix from Example 4 in . For a maximum of seven iterations and 7 bits precision, the error-rate degradation is less than two tenths of a decibel compared to the double precision floating point result. It is important to note that there is no error rate floor close to BER of 10 -12 . Such a performance is often requested in practical applications, but has never been achieved by graphic codes in the literature so far as we know.