CardioMEMS landed Arcapita Ventures of Atlanta as lead investor in the round, along with other new investors Deerfield Capital Management of Boston, Vision Capital Advisors of Burlingame, Calif., Aperture Venture Partners LLC of New York and Rockport Venture Securities of Boston.

Returning to invest were Boston Millennia Partners of Boston, Medtronic Inc. of Minneapolis, Easton Capital Partners LP of New York, Foundation Medical Partners of Rowayton, Conn., and Arboretum Ventures of Ann Arbor, Mich.

The deal brings total investment in the Atlanta-based company to more than $85 million, and is expected to take CardioMEMS to an initial public offering in its next round.

CardioMEMS founder and CEO Jay Yadav said the company specifically sought new crossover investors that were likely to help the company in preparing for the public markets, and that would potentially hold stock through a public offering. The company worked with Rockport Venture Securities in identifying new investors, and while Yadav would not disclose a valuation for the round, he said it came at a significant increase to the company's previous funding.

CardioMEMS won approval from the U.S. Food and Drug Administration in 2006 for a wireless implant to monitor pressure in patients with aneurysms. Yadav said the company is enrolling patients in a six-month trial to implant the device inside the heart to measure pressure and output.

"This product gives doctors warning by monitoring things that there is no other way to measure without using a catheter," Yadav said. "The heart failure product uses the same materials manufacturing methods and operational concepts as the approved product, so it will follow a similar regulatory path."

CardioMEMS' product uses wireless technology approved by the Federal Communications Commission that eliminates the need for a battery and leads by transmitting power to the device through radio waves. Yadav said the absence of leads and batteries provides a substantial safety advantage.

CardioMEMS' miniature wireless sensors are implanted using minimally invasive techniques and transmit data to a device outside the body. Without the need to replace a battery, Yadav said the product theoretically could last forever, allowing patients to continuously monitor performance of the heart to regulate treatment, eliminating the need for hospitalization.

John Huntz, executive director at Arcapita, said CardioMEMS has made rapid progress in all aspects of its business and that the firm was attracted to the investment based on a combination of managerial talent, innovative technology, intellectual property and operational effectiveness.

Dan Bauer, who joined the company as chief financial officer in November, said the company worked with Frank Rahmani of Cooley Godward Kronish LLP in Palo Alto, Calif., in closing the transaction, and that King & Spalding LLP in Atlanta re-presented investors.