Dobutamine effects on systolic and diastolic left ventricular long-axis excursion and timing – significance for the interpretation of s′ and e′

Abstract

Background

Dobutamine effects on the relationships of the peak velocity of left ventricular (LV) long-axis systolic motion (s′) with systolic excursion (SExc), systolic duration (SDur) and heart rate, of LV long-axis early diastolic excursion (EDExc) with SExc, and of the peak velocity of LV long-axis early diastolic motion (e′) with EDExc, early diastolic duration (EDDur) and isovolumic relaxation time (IVRT') are unknown.

Methods

Two groups of adult subjects, one young and healthy (n = 10), and one with impaired LV long-axis function (n = 10), were studied, with the aim of identifying consistent findings for the two groups and for the septal and lateral walls. Dobutamine was infused at doses of 5 and 10 µg/kg/min. The relationships between tissue Doppler imaging (TDI) variables acquired before and during dobutamine infusion were analysed using mixed effect multivariate regression modelling.

Results

In both groups, heart rate increased and SDur decreased during dobutamine infusion, and there were independent inverse correlations of SDur with heart rate and dobutamine dose. In contrast, there was no change in EDDur during dobutamine infusion, and no consistent changes in IVRT' independent of heart rate. s′ was positively correlated with SExc and inversely correlated with SDur, and there were positive correlations between EDExc and SExc and between e′ and EDExc.

Conclusion

Dobutamine increases s′ due to effects on both systolic excursion and duration and it increases e′ due to the associated increases in systolic and early diastolic excursion. A lack of effect on diastolic times does not support the presence of a lusitropic effect of dobutamine.

Keywords:

• Inotropic
• lusitropic
• diastolic function
• systolic function
• dobutamine

Authors contributions

Conceptualization: JC, OM, RP; Data curation: OM, RP; Formal analysis: RP; Writing of the original draft: RP; Validation: RP, OM, JC.

Ethical approval

The study design was approved by the Monash Health Human Research and Ethics committee and all clinical investigation was conducted according to the principles expressed in the Declaration of Helsinki.

Patient consent

Written informed consent was obtained prospectively from all subjects.

Consent for publication

Not applicable

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

There was no external funding for this study.