Dysfunctional sarcomeric relaxation in the heart.

Since cardiac relaxation is commonly impaired in heart failure caused by many different etiologies, identifying druggable targets is a common goal. While many factors contribute to cardiac relaxation, this review focuses on sarcomeric relaxation and dysfunction. Any alteration in how sarcomeric proteins interact can lead to significant shifts in sarcomeric relaxation that may contribute to diastolic dysfunction. Considering examples of sarcomeric dysfunction that have been reported in 3 different pathologies, hypertrophic cardiomyopathy, restrictive cardiomyopathy, and heart failure with preserved ejection fraction, will provide insights into the role sarcomeric dysfunction plays in impaired cardiac relaxation. This will ultimately improve our understanding of sarcomeric physiology and uncover new therapeutic targets.