Background Cardiac Resynchronization Therapy (CRT) is proven to improve survival and heart function of patient with certain electrical conduction abnormality and heart failure. However, in patient with certain electrical conduction abnormality, being nonresponder is observed in up to 40% in patient receiving CRT. Conventionally the surgical approach of CRT is to implant one pacing lead in the right heart and one in the left heart to resynchronize the contraction and the pacing lead in the left heart is usually placed in the posterior or lateral portion of the left heart. However, this single approach may not be optimal, especially for those patients with conduction abnormality known to have no response to CRT. Purpose of the clinical investigation. The purpose of the Electrical Activation Guided CRT for Nonresponders Study is to study the effectiveness of an addition of Hisbundle pacing approach to CRT nonresponder by direct His-bundle pacing to improve the responder rate of nonresponder of conventional CRT and a tailored made approach to CRT procedure by using a noninvasive globally mapping system studying the electrical conduction under different approaches to delivery CRT. The pacing approach that optimally corrects conduction abnormality will be determined before the actual addition of new lead procedure. Conduct of the Investigation This study will include 18 patients already implanted with device delivering conventional CRT that known to have no response to the conventional CRT after 6 months of the CRT therapy from Prince of Wales Hospital, Hong Kong. You will be followed in the device clinic as per usual care after your participation in the study is completed.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
18
To study the feasibility to optimize configuration of CRT delivery for acute correction of electrical dyssynchrony using a noninvasive mapping of global electrical activation
The Chinese University of Hong Kong
Shatin, Hong Kong
RECRUITINGLeft Ventricle end systolic volume reduction
The responder rate of greater than 10% of LV end systolic volume reduction measured by echocardiogram.
Time frame: 6 months
Electrical desynchrony index
The acute electrical desynchrony indices (the standard deviation of activation times throughout the epicardium) of different methods of CRT delivery. Lower indicate larger improvement.
Time frame: During procedure
Hemodynamic response monitoring
Monitor the difference in hemodynamic responses of different methods of CRT delivery. The hemodynamic response will be maximal dp/dt as measured by pressure wire introduced into the left ventricle during the procedure.
Time frame: During procedure
Procedure duration of different methods of CRT delivery
Procedure duration of the optimal CRT delivery method as determined by the best improvement in electrical desynchrony indices.
Time frame: During procedure
Implantation success rate of different methods of CRT delivery
Implantation success rate of the optimal CRT delivery method as determined by the best improvement in electrical desynchrony indices.
Time frame: During procedure
Cine images and chest X ray
Cine images (PA, LAO 300, RAO 300) and Chest X ray (PA view) of patients will be obtained for evaluation of changes in disease
Time frame: 6 months
Echocardiogram parameters: left ventricular systolic and diastolic volume
Echocardiogram parameters: left ventricular systolic and diastolic volume at baseline, 3 months and 6 months.
Time frame: 6 months
Echocardiogram parameters: left ventricular ejection fraction
Echocardiogram parameters: left ventricular ejection fraction at baseline, 3 months and 6 months
Time frame: 6 months
Echocardiogram parameters: degree of mitral regurgitation
Echocardiogram parameter: degree of mitral regurgitation at baseline, 3 months and 6 months.
Time frame: 6 months
Echocardiogram parameters: strain imaging
Echocardiogram parameters: strain imaging at baseline, 3 months and 6 months
Time frame: 6 months
Change in New York Heart Association (NYHA) class
Overall changes in QoL measured by change in NYHA class at baseline, 3 months and 6 months.
Time frame: 6 months
Device set-up parameter: defibrillation threshold
Device parameters including defibrillation threshold at implant and 6 months follow-up.
Time frame: 6 months
Post-operation Complication rate
Peri-operative and 6 months follow-up complications rate: 1. Thromboembolic event 2. Dislodgement and migration of pacing leads 3. Phrenic nerve stimulation 4. Others
Time frame: 6 months
Change in 6 minute hall walk test
Compare result of 6 minute hall walk test at baseline, 3 months and 6 months.
Time frame: 6 months
Change in HF Patient Global Assessment Questionnaire
Compare result of HF Patient Global Assessment Questionnaire at baseline, 3 months and 6 months.
Time frame: 6 months
Change in quality of life
Change in quality of life assessed by Minnesota's living with heart failure (MLWHF) questionnaire at baseline, 3 months and 6 months.
Time frame: 6 months
Device set-up parameter: defibrillation sensitivity
Device parameters including defibrillation sensitivity at implant and 6 months follow-up.
Time frame: 6 months
Device set-up parameter: lead impedance
Device parameters including lead impedance of pacing leads at implant and 6 months follow-up.
Time frame: 6 months
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