Assessment of Left Ventricular Torsion by Echocardiography Study

Study Overview
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Brief Summary
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The purpose of this study is to learn about the twisting or wringing motion of the heartbeat called Left Ventricular Torsion (LV Torsion) which can be seen on ultrasound.

Detailed Description
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This study is designed to characterize the myocardial torsional behavior in patients with a variety of cardiac pathologies. Simple and inexpensive methods for measurement of LV torsion could facilitate more widespread investigation of LV torsion, which might reveal significant relationships between torsional alterations and clinical outcomes and eventually lead to routine clinical application. Recently, Doppler tissue imaging (DTI) has been shown to accurately reflect myocardial velocity24,25 with better temporal resolution than MRI.26 Investigators hypothesize therefore that DTI might be used for quantification of LV rotation and torsion of the human heart. The purpose of the present study was to examine the accuracy of a novel method with DTI for quantifying the LV torsion in humans and tagged MRI as the reference standard.

Official Title
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Assessment of LV Torsion by Tissue Doppler Echocardiography

Conditions
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Hypertrophic Cardiomyopathy

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male and female patients age 18 to 70 years Patients with hypertrophic cardiomyopathy Patients with the ability to exercise using a supine bicycle Ability to provide informed consent Exclusion Criteria: Aortic valve stenosis classified as moderate to severe Severe left ventricular obstruction at rest (high gradients > 4m/second) Uncontrolled arrhythmias including atrial fibrillation, atrial flutter, frequent premature ventricular ectopic beats History of sustained ventricular tachyarrhythmia at any time

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 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 |
| --- | --- |
| Cardiac Pathologies<br>Patients with cardiomyopathy, ischemic heart disease, will have tissue Doppler echocardiograms performed | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Accuracy of Doppler Tissue Imaging | The purpose of the present study was to examine the accuracy of a novel method with DTI for quantifying the LV torsion in humans and tagged MRI as the reference standard. LV torsion reflects the torsion (twisting deformation) occurring across the length of the ventricle (from the base to the apex) during the time interval defined by the beginning and end of contraction (or in physiologic terms, from end -diastole to end systole). In this study, end diastole was defined by the R wave of the ECG, while end systole is defined by minimum end-systolic volume or maximum of twisting deformation. The deformation is measured in degrees. Once the measurements are performed by experimental method (i.e. TDI imaging) and reference method (i.e. MRI imaging) these two methods are then compared using Bland Altman analysis. In a current study, mean difference between methods of torsion quantification was 0.57 degrees, while the standard deviation (SD) was 1.98 degrees. | 1 1/2 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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HCM, HOCM, hypertrophic cardiomyopathy, tissue doppler echocardiography, myocardial torsion