CardioFocus landed a $21 million debt investment from GPB Capital and plans to use the proceeds to back the commercial launch of its HeartLight catheter for treating atrial fibrillation.

The funding consists of a $21 million senior secured convertible note due to mature in April 2021. CardioFocus, which won FDA approval for its HeartLight Excalibur balloon last month, reeled in the first $13 million from the round in April. The remaining $8 million, pegged to revenue milestones, is slated to be released during or before the first quarter of 2019.

“The HeartLight endoscopic balloon’s new launch reflects our ongoing dedication to bringing new levels of precision and control to the treatment of atrial fibrillation,” chairman Paul LaViolette said in prepared remarks. “The investment from GPB Capital will help us make this groundbreaking cardiac ablation system available as an advanced tool that physicians can use to improve heart health in their communities.”

“We are pleased to partner with CardioFocus to roll out its next innovation, which has the potential to revolutionize the treatment of atrial fibrillation,” added GPB Capital managing partner Evan Myrianthopoulos. “By offering the support CardioFocus needs to successfully bring the HeartLight Endoscopic Balloon system to market, we seek to achieve both a return on investment and a global impact – one that could improve the quality of life for atrial fibrillation patients on multiple continents.”