Background In heart failure patients requiring cardiac resynchronization therapy (CRT), there is no reliable method to determine the optimal site to place the coronary sinus (CS) lead. The equilibrium radionuclide angiogram (ERNA) provides an assessment of left ventricular function and the location of dyssynchrony. We compared using the findings from ERNA to guide CS lead placement with the traditional method of placing the CS lead in a lateral CS branch to determine whether ERNA-guided placement improved response to CRT.
Methods We obtained ERNA studies on 14 patients with NYHA Class III and IV heart failure referred for CRT device implantation or upgrade from a right-ventricular device. Each pixel of an ERNA is defined by its phase (ø) and amplitude (Amp), which together define its vector; the Amp gives the vector's length. The vector sum of all Amps, based on the angular distribution of ø, divided by the scalar sum of the length of all the vectors defines a new parameter, synchrony (S). With complete synchrony, S = 1, and with complete dyssynchrony, S = 0. Using ERNA studies obtained before and after CRT, we evaluated S, ejection fraction (EF), and NYHA Class at both times.
Results 3 out of 6 patients who underwent traditional CS lead placement did not show any improvement in NYHA class (50%). 7 of the 8 patients who had ERNA-guided CS lead placement had an improvement in NYHA class (88%). More patients in the ERNA-guided group had clinical improvement as compared to the traditional group (p = .02 by chi-square analysis). One patient in the ERNA-guided group did not benefit since the location where the CS lead had been placed showed nonviable tissue by a subsequent PET scan. The degree of change in S also significantly predicted the clinical response to CRT.
Conclusions In heart failure patients requiring CRT, ERNA is a novel method that can be used to assess dyssynchrony and guide CS lead placement. The use of this method resulted in significant improvements in NYHA class and S but not in EF. Given these findings, this is a novel technique that warrants further study.
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.