Bolus response to DN and OM measured by LV strain mechanics. Analysis of LV radial strain and SR mechanics 1 min after infusion of either vehicle control (DMSO), DN at 3 mg/kg (DN Low), DN at 6 mg/kg (DN High), OM at 0.75 mg/kg (OM Low), or OM at 1.5 mg/kg (OM High). (A and B) Group average ± 95% confidence interval radial strain and (B) SR waveform at baseline (Pre) and after (Post) drug infusion. Panels are annotated with where Pk. SRS, T2P SRS, Pk. SRSR, and T2P SRSR are measured from. (C–F) Absolute change (∆) in (C) Pk. SRS, (D) T2P SRS, (E) Pk. DRSR, and (F) T2P DRSR. †P < 0.05 compared with the DMSO control group, *P < 0.05, **P <0.01, ***P < 0.001, ****P < 0.0001, ns P > 0.05 as determined by ANOVA and Tukey’s HSD. Exact P values are as follows: (C) DN Low–DN High, P = 0.0043; OM Low–OM High, P = 0.023; DN Low–OM Low, P = 0.057; DN High–OM High, P = 0.16; DMSO–DN Low, P = 9e-6; DMSO–DN High, P < 1e-7; DMSO–OM Low, P = 0.00062; DMSO–OM High, P < 1e-7. (D) DN Low–DN High, P = 0.0052; OM Low–OM High, P < 1e-7; DN Low–OM Low, P = 1.0; DN High–OM High, P = 0.024; DMSO–DN Low, P = 1.0; DMSO–DN High, P = 0.002; DMSO–OM Low, P = 1.0; DMSO–OM High, P < 1e-7. (E) DN Low–DN High, P = 0.043; OM Low–OM High, P = 0.00029; DN Low–OM Low, P = 0.52; DN High–OM High, P = 1.0; DMSO–DN Low, P = 0.13; DMSO–DN High, P < 1e-7; DMSO–OM Low, P = 0.88; DMSO–OM High, P = 2e-5. (F) DN Low–DN High, P = 0.00063; OM Low–OM High, P < 1e-7; DN Low–OM Low, P = 0.61; DN High–OM High, P = 0.024; DMSO–DN Low, P = 0.086; DMSO–DN High, P = 2e-7; DMSO–OM Low, P = 0.78; DMSO–OM High, P < 1e-7. Group sizes are as follows: (C) DMSO, N = 9; DN Low, N = 8; DN High, N = 8; OM Low, N = 9, OM High, N = 9. (D) DMSO, N = 10; DN Low, N = 9; DN High, N = 9; OM Low, N = 9, OM High, N = 9. (E) DMSO, N = 9; DN Low, N = 8; DN High, N = 9; OM Low, N = 10, OM High, N = 10. (F) DMSO, N = 9; DN Low, N = 10; DN High, N = 10; OM Low, N = 9, OM High, N = 10. Pk. SRSR, peak systolic radial strain rate; SR, strain rate; T2P SRS, time-to-peak radial systolic strain; T2P SRSR, time-to-peak diastolic radial strain rate.