Aerosmith have canceled their show this evening (Wednesday, Aug. 13) in Concord, Calif. as drummer Joey Kramer is reportedly dealing with heart issues.

According to TMZ, a source close to the band stated that Kramer has had heart issues in the past. It was also stated by the source, but not confirmed by TMZ, that the 64-year-old drummer is planning to undergo heart surgery.

The band regrets not being able to perform for their fans," states a message at Aerosmith's Facebook page. The posting also directs those who were planning to attend the 'Let Rock Rule' tour show to receive their refunds at the point of purchase.

TMZ is also reporting that the band's Saturday show in George, Washington will be canceled as well. Aerosmith are currently touring with Slash with dates scheduled into September.

We send our best to Aerosmith's Joey Kramer.