It is generally understood that cardiac cells synchronize their beating through electro-chemical signalling. Here we show, theoretically and experimentally, that isolated cardiac cells can communicate with each other through an intervening deformable media. Such communication leads to coupled dynamics and emergence of synchronous beating. The interaction between the cells depends inversely with the elastic modulus of the media, and the distance between them. This finding may explain asynchronous beating of the atrium in patients with atrial fibrillation where the stiffness of the atrial wall becomes significantly harder due to fibrosis .