Following Siemens Healthineers AG’s announcement that it was picking up Varian Medical Systems Inc. for $16.4 billion, another multibillion-dollar deal has emerged. This time, Teladoc Health Inc. and Livongo Health Inc. have inked a definitive merger agreement with a value of $18.5 billion. The transaction is expected to close by the end of the fourth quarter, subject to shareholder approvals and other customary closing conditions.