Medical device company nContact, a developer of products to treat arrhythmias or disorders of the heart rate, is halfway through raising a new venture capital financing round of $13 million.

According to an SEC filing made Friday, nContact said it had raised $6.74 million from 10 different investors.

The company wants to raise a total of $13 million.

In January 2012, nContact raised close to half a million dollars in debt financing. 

Over the years, nContact has now raised nearly $50 million in financing, including a 2010 $16 million series D round from venture capital firms Intersouth Partners, Harbert Venture Partners, Finistere Ventures, Massey Burch Capital and ZMV Associates.

Intersouth is based in Durham.

Founded in 2005, nContact focuses on developing catheters and surgical ablation devices for arrhythmia treatment, including atrial fibrillation. The company has developed a way to perform minimally invasive ablation procedures to treat arrhythmias. The devices can work on a beating heart without chest incisions or ports. NContact’s device treats patients with enlarged atria, a group representing the majority of atrial fibrillation patients.