Cardiac Strains for Optimization of CRT in Non-Responders

Use of Cardiac Strains for Optimization of Cardiac Resynchronization Therapy in Non-Responders

The aim of this study is to investigate the possibility of optimizing the performance of CRT-D in non-responding patients through utilization of cardiac strain speckle tracking

In approximately 30% of patients, cardiac resynchronization therapy (CRT) fails to lead to any improvement of the patients' status.

In this study, an investigation of a possible method of optimization through speckle tracking of cardiac strains is attempted.

Patients not responding to Cardiac Resynchronization Therapy-Defibrillators (CRT-D) after 3 months are randomly divided into control and intervention groups. Atrioventricular interval is adjusted so that E and A waves do not overlap and the interventricular interval subsequently optimized to yield maximum improvement of the sum of longitudinal+radial+circumferential strains. The left ventricular ejection fraction (LVEF) and NYHA (New York Heart Association Classification improvement 3 months after optimization are evaluated and use of other strain combinations assessed.

Inclusion Criteria:

• patients with symptomatic heart failure with NYHA III/IV, pharmacological treatment options exhausted, LVEF below 30%, and QRS duration over 130ms who did not respond to the implantation of CRT-D

Exclusion Criteria:

• Age below 18
• response to the original CRT implantation