Assessment of Left Ventricular Torsion by Echocardiography Study

Assessment of LV Torsion by Tissue Doppler Echocardiography

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.

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.

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