Assessment of Right Ventricular Volume using the VentriPoint Medical system in patients with Tetralogy of Fallot following repair; a comparison study to cMRI.

The objective of this study is: To evaluate the accuracy of the VentriPoint Medical System to calculate right ventricular volumes in patients with Tetralogy of Fallot following surgical repair.

Secondary objectives are: To validate Inter and Intra observer variability at 3 clinical sites.

The analyses will be the same for EDV and ESV. For either right ventricular volume, the primary effectiveness measure is the % difference between VMS and cMRI results, i.e. (VMS-cMRI)*100%/average of VMS and cMRI results. There will be two null hypotheses for the primary analysis:

H0+: true mean % difference > 10% and H0-: true mean % difference < -10%

The observed mean % difference will be presented with 95% confidence intervals. The VMS right ventricular volume estimates will be regarded as equivalent to cMRI estimates if both H0+ and H0- are rejected at a 1-sided 0.025 level by a paired t test for both EDV and ESV. Since H0+ and H0- cannot both be true, the total type I error rate for each measure is 0.025 and the overall type I error rate for both EDV and ESV is 0.05.

Inclusion Criteria:

• Patients with Tetralogy of Fallot following surgical repair
• Patients who can be expected to lie motionless during imaging

Exclusion Criteria:

• Lack of informed consent
• Surgical repair for Tetralogy of Fallot with RV-PA conduit
• Known arrhythmia that interferes with image acquisition.
• Implanted cardiac defibrillator, pacemaker, or other devices containing ferromagnetic materials
• Pregnant woman
• Contraindications for MRI

Primary Care Clinic Cardiac Clinic