Is excessive soda drinking risky?

The European Heart Rhythm Association presented a study in Greece this of excessive soda drinkers having heart conditions.  They showed six different reports of soda drinkers having heart-related health problems.

One woman in France was taken to the hospital after collapsing.  She admitted to her doctors that the only liquid she had drunk in the last 16 years was cola.  She never consumed water during that time.  Her level of consumption was high, about two quarts or 64 ounces a day.