The Novo, St. Jude and Kaiser Permanente-backed cardiac diagnostics technology developer floated above its range and closed its first day of trading 53% up on its IPO price.

US-based cardiac arrhythmia diagnostics technology developer iRhythm Technologies went public yesterday in an upsized initial public offering that valued the company at $107m and gave pharmaceutical firm Novo an exit.

The company priced 6.3 million shares at $17 each, above the $13 to $15 range it set earlier this month, when it planned to offer 5.35 million shares. It opened at $26.75 on its first day of trading on Nasdaq yesterday and closed at $26.05.

Founded in 2006…