Light : Bright indirect sunlight will keep this lady looking awesome, however she is shade tolerant.
Water: Let the soil dry out between watering and then give her a big drink.
Humidity: She would really like lots of moisture so keep her with other plants and give her a misting.
Temperature: She is not frost tolerant at all and needs to be kept above 16 degrees.
Food: You can feed her once or twice a month in spring and summer. If you see new growth in cooler months then you can feed then too.
Toxicity: Your syngonium red heart is mildly toxic if ingested .