Electrical Activation Mapping Guided Tailor Made Approach for Cardiac Resynchronization Therapy

Chinese University of Hong Kong93 enrolled

Overview

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, a good response is observed in less than 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 poor response to CRT. Purpose of the clinical investigation The purpose of the Electrical Activation Guided CRT Study is to study the effectiveness of 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 implantation procedure. Conduct of the Investigation This study will include 93 patients with conduction abnormality that known to have a poor response to CRT from Prince of Wales Hospital, Hong Kong.Subjects will be followed up at 3 months and 6 months visit.

The purpose is to prospectively study the feasibility to optimize configuration of CRT delivery for acute correction of electrical dyssynchrony using a noninvasive mapping of global electrical activation. Study Hypothesis: Tailor-made configuration of CRT delivery is feasible and able to improve responder rate compare to single method of CRT delivery in candidates with known poor response to CRT. Primary outcome measure: Responder rate of greater than 10% of LV end systolic volume reduction in patients undergoing tailor-made approach of CRT delivery at 6 months. The responder rate is to compare with pre-defined level of 40% for single method of CRT delivery namely biventricular pacing with LV lead in coronary sinus. Sample Size: The total required sample size is 93 patients with device implanted.

Study Type

INTERVENTIONAL

Allocation

Purpose

TREATMENT

Interventions

Noninvasive electrical dyssynchrony studyPROCEDURE

Ventricular activation maps will be acquired simultaneously with hemodynamic measurements using noninvasive mapping system (ECVUE, Medtronic Inc, USA). A thoracic computed tomographic scan will be acquired with the electrodes attached to the patient. Local ventricular activation times will be defined as the onset of the QRS complex or the pacing spike to the maximal negative slope of each unipolar electrogram. Pacing leads will be placed in high right atrium, His-bundle region, right ventricular apex, high septal RV, coronary sinus posterior/lateral branch, coronary sinus anterior branch, lateral and septal region of endocardial LV in order to deliver CRT in 8 different configurations.

Eligibility

Sex: ALLMin age: 18 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Adult (aged 18 or above) of both sexes * Ischemic or non-ischemic cause of heart failure * QRS duration \> 120 ms, non -LBBB type of conduction disturbance * NYHA class III or above * Sinus rhythm * Informed consent by the patient * Already received stable dose of guideline directed medical therapy for at least 3 months Exclusion Criteria: * LBBB\* patients * Pregnant women * Participation in another study * Patient with contraindication to left ventricle catheterization by a retrograde aortic approach (eg mechanical aortic valve, severe aortic stenosis and aortic dissection) \*The definitions of LBBB (QRS duration ≥130 ms; QS or rS in lead V1; broad R waves in leads I, aVL, V5, or V6; and absent q waves in leads I, V5, and V6).

Outcomes

Primary Outcomes

Responder rate of greater than 10% of LV end systolic volume reduction in patients undergoing tailor-made approach of CRT delivery at 6 months.

Responder rate of greater than 10% of LV end systolic volume reduction measured by echocardiogram comparing baseline and 6 months post implant in patients undergoing tailor-made approach of CRT delivery. Responder rate of greater than 10% of LV end systolic volume reduction measured by echocardiogram comparing baseline and 6 months post implant in patients undergoing tailor-made approach of CRT delivery. The responder rate is to compare with pre-defined level of 40% for single method of CRT delivery namely biventricular pacing with LV lead in coronary sinus.

Time frame: 6 months

Secondary Outcomes

The acute electrical dyssynchrony indices of different methods of CRT delivery.

Time frame: during procedure

The hemodynamic responses of different methods of CRT delivery.

The 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 the optimal CRT delivery method

Procedure duration of the optimal CRT delivery method as determined by the best improvement in electrical dyssynchrony indices.

Time frame: during procedure

Implantation success rate of the optimal CRT delivery method

Implantation success rate of the optimal CRT delivery method as determined by the best improvement in electrical dyssynchrony indices.

Time frame: during procedure

Cine images (PA, LAO 300, RAO 300) and Chest X ray (PA view)

Time frame: during procedure

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: Peri-operative and 6 months

Left ventricular systolic and diastolic volume at baseline and 6 months:

Echocardiogram parameter of left ventricular systolic and diastolic volume at baseline and 6 months.