A bubble chart displays the relationship between maximum heart rate and resting blood pressure, with bubble size encoding age and color indicating the slope of the ST segment. The visualization uses D3 v7 with SVG rendering, employing `d3.scaleLinear` for position and radius, `d3.scaleOrdinal` with `schemeSet1` for colors, and `d3.axisBottom` and `d3.axisLeft` for axes. Data is loaded from a CSV file using `d3.csv`.