Electrocardiogram (QRS amplitude, duration & axis)

Twenty-five consented healthy volunteers were studied. Each participant was given 250 ml of cold water, room temperature water, and warm water to drink with a ten minute interval between each drink. An electrocardiographic experiments were conducted on the participants following each drink to record their frontal plane electrocardiogram in a digital form. The frontal plane 12-lead electrocardiogram was acquired, by first recording the lead I and lead II of the bipolar leads. This was then used to calculate the four other limb leads using Einthoven laws. Each chest lead was recorded together with the six limb leads to obtain the full twelve leads of the electrocardiogram. The QRS amplitudes and duration of the four conditions were acquired using the integrated software of the recording system while the QRS axis was calculated manually using the bipolar method on a Vectorgram. These measurements were analyzed using one-way repeated measures analysis of variance, and the analysis of the coefficient of variations.