The 27-year-old South Africa-born player made his Ireland debut against the Springboks last year. He has won four caps, but missed the whole of last season's RBS 6 Nations Championship because of an ankle ligament injury.
"Following the result of extensive medical tests, it has emerged that Ireland hooker Richardt Strauss has been diagnosed with a heart condition and will be unavailable for selection for the remainder of the season," his provincial team Leinster announced in a statement.
"The management are confident that the 27-year-old, who is set to undergo surgery this week, will make a full recovery."
Strauss joined Leinster in 2009 and he has been an integral part of their squad since then, playing key roles in the 2010 and 2012 Heineken Cup final victories over Northampton and Ulster respectively.
Leinster, meanwhile, rate star centre Brian O'Driscoll as having a 50-50 chance of recovering in time from a calf muscle strain to be fit for next Saturday's Heineken opener against the Ospreys in Swansea.