Dr. Howlett is best known for her work on cardiac contraction. She has discovered profound differences in the way male and female heart cells function and how this changes with age. She has pioneered the measurement of frailty with a "frailty index" in aging animals, a major advance that will help translate scientific discoveries in aging research into meaningful clinical interventions.

Feridooni HA, MacDonald JK, Ghimire A, Pyle WG, Howlett SE. Acute exposure to progesterone attenuates cardiac contraction by modifying myofilament calcium sensitivity in the female mouse heart. Am J Physiol, 312:H46-59, 2017. Rockwood K, Blodgett JM, Theou O, Sun MH, Feridooni HA, Mitnitski A, Rose RA, Godin J, Gregson E, Howlett SE. A Frailty Index Based On Deficit Accumulation Quantifies Mortality Risk in Humans and in Mice. Sci Reports, 7:43068, 2017. Jansen HJ, Moghtadaei M, Mackasey M, Rafferty SA, Bogachev O, Sapp JL, Howlett SE, Rose RA. Atrial structure, function and arrhythmogenesis in aged and frail mice. Sci Reports, 7:44336, 2017. Feridooni H, Kane AE, Boroumandi A, Polidovitch N, Rose RA, Tsushima R, Howlett SE. The impact of age and frailty on ventricular structure and function in C57BL/6 mice. J Physiol (Lond), in press, 2017. Whitehead JC, Hildebrand BA, Rockwood MR, Rose RA, Rockwood K, Howlett SE. A clinical frailty index in aging mice: comparisons with frailty index data in humans. J Gerontol A Biol Sci Med Sci, 69:621-32, 2014.