One of the many uses of cardiac magnetic resonance (CMR) is the assessment of right ventricular (RV) volumes. There are a number of congenital heart defects and acquired conditions in which management decisions are fundamentally based on ventricular volumes. The "gold standard" for assessment of RV volume is CMR. It has better near-field resolution than echo and excellent contrast between the blood pool and the myocardium. CMR is more suitable to the irregular geometry of the RV. The objectives of this study are (1) to assess ventricular volumes in the fasting state and after oral hydration in order to assess the effect of fluid status on ventricular volumes as measured by CMR; (2) to evaluate the effect of hydration on ventricular volumes compared the effect of with inter-observer and intra-observer variability, and; (3) to evaluate the effects of chamber volume on chamber deformation, including strain and peak strain rate. This study hypothesizes that (1) hydration status has an effect on right and left heart volumes, measured by CMR in healthy volunteers; (2) the effect of volume status will be a more significant contributor to variability in RV volumetry than that of inter-observer variability and intra-observer variability, and; (3) atrial and Ventricular deformation corrected for chamber size or volume is more accurate than when uncorrected for volume.

1. To assess ventricular volumes in the fasting state and after oral hydration in order to assess the effect of fluid status on ventricular volumes as measured by CMR.
2. To evaluate the effect of hydration on ventricular volumes compared the effect of with inter-observer and intra-observer variability.
3. To evaluate the effects of chamber volume on chamber deformation, including strain and peak strain rate.

Inclusion Criteria:

• Participant must be healthy

Exclusion Criteria:

• Individuals who are unable to participate in an overnight fast will be excluded
• Those with known or suspected structural heart disease will be excluded
• A screening form to identify pre-existing cardiac conditions will be completed by the subject prior to participation in this study. If a pre-existing condition cardiac condition is identified, or suspected they will be excluded from the study.
• If any functional abnormality is detected at any stage by echocardiography or by CMR the study will be terminated. Common anatomical variants, which are generally regarded as normal variants (such as a patent foramen ovale, or a persistent left superior vena cava) will not lead to exclusion from the study.

Staff from the Heart Centre at The Hospital for Sick Children will be sent an email notifying them of the study. They will be invited to obtain the particulars of the study by replying to Dr. Daryl Schantz or Dr. Lars Grosse-Wortmann. If they agree to participate Dr. Schantz will obtain written informed consent.