TABLE 1.

Cardiac response to dobutamine assessed by echocardiography 10 weeks after induction of KO by tamoxifen.

Data are presented as mean ± SEM (n = 11 C and 7 KO) and analyzed by 2-way Repeated Measure ANOVA followed by Holm–Sidak test for pairwise comparisons. Following pairwise comparisons are shown: basal vs. dobutamine within C and KO; and KO vs. C within basal and dobutamine groups. A value of P or p < 0.05 (for interaction P < 0.1) was considered statistically significant (in bold). Highlighted in gray: results with significant interaction (see Materials and Methods).

The detailed description of abbreviations, measurements, and calculations:

HR, heart rate, ECG.

PSLA M-Mode

IVS;d, Inter-ventricular septum (diastole), M-Mode.

IVS;s, Inter-ventricular septum (systole), M-Mode.

LVID;d, Left ventricular internal diameter (diastole), M-Mode.

LVID;s, Left ventricular internal diameter (systole), M-Mode.

LVPW;d, Left ventricular posterior wall (diastole), M-Mode.

LVPW;s, Left ventricular posterior wall (systole), M-Mode.

Calculation

EF, LV ejection fraction, 100 × ((LV Vol;d-LV Vol;s)/LV Vol;d).

FS, LV fractional shortening, 100 × ((LVID;d-LVID;s)/LVID;d).

LV Vol;d, Left Ventricle volume diastole, (7.0/(2.4 + LVID;d)) × LVID;d³.

LV Vol;s, Left Ventricle volume systole, (7.0/(2.4 + LVID;s)) × LVID;s³.

SV, Stroke volume, LV Vol;d – LV Vol;s.

CO, Cardiac output, (SV × HR)/1000.