Cardiac Resynchronization Therapy, Dyspnea and Exercise Tolerance in Patients With Congestive Heart Failure (CHF)

Effects of Cardiac Resynchronization Therapy on Dyspnea and Exercise Tolerance in Patients With Congestive Heart Failure

Status

Terminated

Phases

Phase 4

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00700700

Enrollment

Registered

2008-06-19

Start date

2008-10-31

Completion date

2011-06-30

Last updated

2011-07-06

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Congestive Heart Failure

Keywords

Congestive Heart Failure, Cardiac Resynchronization Therapy, Dyspnea, Exercise Tolerance

Brief summary

A new therapy for patients with advanced heart failure (HF) involves the implantation of a specialized pacemaker device (Cardiac Resynchronization Therapy, CRT) that attempts to restore the synchronized contraction of the ventricular chambers of the heart. In some people, CRT improves exertional breathlessness and allows them to exercise for longer periods. However, to date, the mechanisms by which CRT improves symptoms and exercise tolerance is unknown. This study will use in-depth cardiopulmonary exercise testing and pulmonary function testing to explore these mechanisms in greater detail.

Interventions

DEVICEActive Cardiac Resynchronization Therapy (CRT)

Initiation of active biventricular pacing/cardiac resynchronization therapy Devices by Medtronic: 1. Insync Sentry 7298 & 7299 2. Concerto C174 ASK (Most frequently implanted) 3. Insync III 8042 (PM) Devices by Guidant/Boston Scientific: 1. Contak Renewal 4 H190 & H199 2. Contak Renewal 3 H127 Devices by ELA/Sorin: 1\. Ovatio CRT 6750

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Masking

SINGLE (Subject)

Eligibility

Sex/Gender

ALL

Age

18 Years to 90 Years

Healthy volunteers

Inclusion criteria

* clinically stable * being considered for implantation of biventricular pacemaker for CRT * LVEF \<35% * QRS duration \>120 msec * NYHA III-IV functional class * optimized pharmacologic management of CHF * no recent (\<1 month) episodes of decompensated CHF

Exclusion criteria

* inability to perform cycle ergometry or comply with testing * uncontrolled ischemic heart disease * coronary revascularization within 3 months of study entry * concurrent primary lung disease * current use of ambulatory oxygen * rhythm other than sinus * dependency on pacemaker therapy as a consequence of bradyarrhythmias * severe valvulopathy

Design outcomes

Primary

Measure	Time frame
Exercise endurance time	6 weeks

Countries

Canada

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026