InterventiOn of Biventricular Pacemaker Function on ventrIcular Function Among Patients With LVAD's

Study Overview
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Brief Summary
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The primary reason the investigators are doing this study are to understand how the right side of the heart functions in heart failure patients with left ventricular assist devices (LVADs, or mechanical hearts). Second, the investigators are interested in understanding how different pacemaker settings influence function of the heart at rest and activity.

Detailed Description
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Healthy individuals, as well as patients with advanced heart failure supported by LVADs, completed invasive hemodynamic analysis at rest and with exercise to characterize right-sided heart function at rest and with exercise during invasive cardiopulmonary exercise testing on upright cycle ergometry.

Official Title
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Randomized interventiOn of Biventricular Pacemaker Function on ventrIcular Function Among Patients With mechaNical Circulatory Support Devices

Conditions
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Heart Diseases, Left Ventricular Dysfunction

Participation Criteria
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Eligibility Criteria
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15 patients with advanced heart failure (HF) who have already undergone implantation of a continuous-flow left ventricular assist device (CF-LVAD) implantation. Inclusion criteria: Have already received CF-LVADs and are clinically stable, Ambulatory outpatients and are fully recovered (at least 3 months) from LVAD implantation; Exclusion criteria: Individuals with clinical right ventricular (RV) failure under resting conditions, defined as moderate-severely reduced RV systolic function on echocardiography, or Clinical evidence of RV failure (elevated jugular venous pressures, 3 or 4+ [significant] peripheral edema); Disorders that adversely influence exercise ability (e.g. arthritis, peripheral vascular disease, pulmonary disease); and 10 healthy individuals will serve as a control group to define normal RV function during exercise. Inclusion criteria: 1) Persons without a past medical history of cardiovascular disease or related disease such as: hypertension, diabetes, peripheral vascular disease, arrhythmias, f. are not taking any cardiac-related medications (e.g. antihypertensive medications). Exclusion criteria: Individuals requiring systemic anticoagulation with vitamin-K antagonists or new/direct oral anticoagulants (NOAC/DOAC); Disorders that adversely influence exercise ability (e.g. arthritis, peripheral vascular disease).

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Healthy Control<br>Individuals free of cardiovascular disease and not on any medications to treat a cardiovascular-related condition | |
| LVAD Group<br>Individuals with history of advanced heart failure who are supported by left ventricular assist devices | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Peak Vo2 | peak Vo2 measured by indirect calorimetry during cardiopulmonary exercise testing | 20 minutes | 
| Cardiac Output | cardiac output measured during invasive cardiopulmonary exercise testing. | 20 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Blood Pressure | mean arterial pressure during exercise | 20 minutes | 
| Respiratory Exchange Ratio | Respiratory exchange ratio derived from indirect calorimetry | 20 minutes | 
| Minute Ventilation | Minute ventilation during cardiopulmonary exercise testing | 20 minutes | 
| Tau | unit of measure of diastolic function during exercise | 20 minutes | 
| Stroke Work | stroke work during exercise | 20 minutes | 
| EES/EA | ventricular arterial coupling during exercise | 20 minutes |