Transit Visa Required?

[immihelp]

I will be flying on virgin Atlantic from new Delhi to JFK- new york with a 2 hour stop over at London Heathrow airport. I hold an Indian passport but have a 10 year multiple entry visitor visa for the US. I will be staying for 2 months and returning to Delhi again with a stopover of 2 hours at LHR.
Do I need to get any transit visa for the UK in this case

I would appreciate a response

[immihelp]

Not rqeuired.