• rate
  • The contractions of cardiac muscle are stimulated by a special clump of muscle tissue located on the heart (the pacemaker), although the rate of contractions is subject to regulation by the autonomic nervous system. (thefreedictionary.com)
  • Here, we report the identification of a zebrafish mutant, heart and mind , which exhibits multiple cardiac defects, including the primitive heart tube extension abnormality, aberrant cardiomyocyte differentiation, and reduced heart rate and contractility. (biologists.org)