Schwartz Score (LQTS)

Developed by Peter Schwartz and colleagues at the University of Pavia, Italy, first published in Circulation in 1985 and updated in 1993. Schwartz had been central to characterising LQTS clinically since the 1970s and created this diagnostic framework before the KCNQ1 and HERG genes were identified (1995/1996). The score was designed as a standardised probability tool for the pre-genetic test era.

Despite the availability of genetic testing, the Schwartz Score remains highly relevant because 20–25% of clinically diagnosed LQTS patients have negative genetic testing (genotype-negative phenotype-positive). The score supports clinical decision-making in these cases and helps direct therapy without relying solely on molecular confirmation. It was updated by Schwartz himself in 2011 to align with modern LQTS genotype-phenotype data.