Left Ventricular Systolic and Diastolic Function in Healthy Adult Bonnet Macaques (Macaca radiata)

Objectives: Macaques are used in cardiovascular and metabolic research. We determined echocardiographic-derived reference values of left ventricular (LV) systolic and diastolic function in healthy adult bonnet macaques (Macaca radiata). Methods: Transthoracic echocardiography was performed during ketamine sedation in 83 (67% female) healthy monkeys (age 7–26 years). Results: Technically adequate studies were obtained in all subjects and required 10.1 ± 1.3 min of scanning time. Age correlated inversely with the following Doppler indices: E (r = –0.44, p < 0.001), E/A (r = –0.26, p = 0.02), E′ (r = –0.45, p < 0.001, E′/A′ (r = –0.44, p < 0.001), E/E′ (r –0.25, p = 0.03), S′ (r = –0.33, p = 0.003), Vp (r = –0.26, p = 0.049). LV mass was more strongly correlated with crown rump length (r = 0.72, p < 0.001) and body surface area (r = 0.70, p < 0.001) than with body mass index (r = 0.47, p < 0.001) and weight (r = 0.63, p < 0.001). Conclusions: This study demonstrates echocardiography is feasible for characterizing LV function. Age-related changes in Doppler indices in primates are similar to those in humans. LV mass is more closely related to fat-free mass indices. We provide reference values for LV systolic and diastolic function in adult bonnet macaques across the captive life span.