Ray Dalio pushes gold as shield as US markets risk ‘heart attack'

1. Ray Dalio warns of a financial 'heart attack' in American markets. 2. He advises 10-15% of portfolio in gold as crisis insurance. 3. Gold is nearing record highs, up nearly 40% year-to-date. 4. Central banks are diversifying reserves, increasing gold holdings. 5. Wall Street indexes rise despite concerns about US debt sustainability.