Investigation of Dysynchrony in Patients With Pulmonary Hypertension

Study Overview
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Brief Summary
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The purpose of the study is to determine whether patients with pulmonary hypertension (PH) have dysynchrony, and if so whether it is electrical or mechanical. Once this has been determined, during a catheterization the investigators will test if pacing the heart improves blood circulation.

Detailed Description
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This is a two part study of ventricular dysynchrony in patients with pulmonary hypertension. The first part is an observational study, reviewing routinely obtained clinical information (such as echocardiograms) to assess whether patients with pulmonary hypertension have electrical or mechanical dysynchrony. If so, we will proceed to the second part of the study which will assess whether temporarily pacing the right ventricle, during a clinically indicated catheterization can acutely improve hemodynamics. We will also gather control data for phase 1 from clinically indicated echos and ECG's in patients with ASD's (RV volume load) and in patients who are evaluated for an innocent murmur ( Nl heart). We hope to learn whether patients with pulmonary hypertension, and compromised right ventricles have electrical and mechanical dysnchrony. If this is true, it is theoretically possible that resynchronization (pacing) of the right ventricle could improve hemodynamics, symptoms and long term outcomes.

Official Title
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Investigation of Dysynchrony in Patients With Pulmonary Hypertension

Conditions
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Pulmonary Hypertension

Intervention / Treatment
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* Procedure: Catheterization Pacing


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Pulmonary artery mean pressure at rest of 25 mm Hg Controls (for phase 2) Patients undergoing transcatheter closure of secundum ASD Patients undergoing echocardiogram and ECG as part of work-up for functional murmur who have normal intracardiac anatomy Exclusion Criteria: Reversible cause of pulmonary hypertension Age < 5 yrs (for phase 2)

Ages Eligible for Study
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Minimum Age: 5 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Study<br>Patients with pulmonary hypertension. | Procedure: Catheterization Pacing<br>* The second part of the study will include patients with pulmonary hypertension >5 who are scheduled for a cardiac catheterization for clinical reasons. We will at the conclusion of the routine catheterization, place two pacing catheters within the right atrium and right ventricle and pace the heart at a rate approximately 10% higher than sinus rhythm for 5 minutes. We will then measure dP/dT max in the ventricles, blood pressure and cardiac output using a Fick equation to assess hemodynamics. We will repeat this 3 times using different sites in the right ventricle while simultaneously obtaining echoes to assess mechanical synchrony.<br>|
| Control<br>ASD patients or patients with normal hearts | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Electrical or Mechanical Dysynchrony |  | Open | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Mechanical Dysynchrony, Electrical Dysynchrony