Skip to main content
. Author manuscript; available in PMC: 2022 Jun 1.
Published in final edited form as: Clin Endocrinol (Oxf). 2021 Feb 22;94(6):1043–1053. doi: 10.1111/cen.14426

FIGURE 2.

FIGURE 2

Functional syncytia of mature human induced pluripotent stem cell-derived cardiomyocytes from a patient carrying a variant (LMNA R349W) causative of familial partial lipodystrophy (FPLD) were submitted to optical mapping for assessment of membrane voltage changes. (A) LMNA mutant cardiomyocytes had a higher frequency of spontaneous depolarization in relation to control cell line (MCH) (P < .001). (B) APD80% of repolarization was shorter in cells carrying the LMNA variant. (C) Duration of spontaneous action potential duration at 80% of repolarization was adjusted to the frequency of spontaneous depolarization with Fridericia correction and showed that LMNA mutant cardiomyocytes presented shorter corrected APD80% compared to control cardiomyocytes (P < .001). (D) Additionally, LMNA mutant cardiomyocytes presented several rhythm alterations (red arrows) such as early afterdepolarizations, spontaneous quiescence and spontaneous tachyarrhythmia; none of those were observed in the control cell lines. (E) Finally, both control and LMNA mutant cardiomyocytes showed a positive chronotropic response to isoproterenol. Nevertheless, isoproterenol recovery rate was significantly lower in the LMNA mutant cardiomyocytes