3D Real-Time Echocardiography Combined with Mini Pressure Wire Generate Reliable Pressure-Volume Loops in Small Hearts

Figures

• 

  Fig 1. Principle of Pressure-Volume Relations derived from 3D real-time echocardiography and mini pressure wire. Volume-time curves calculated from 3DE-data (a) and pressure-time curves derived from mini-pressure wire (b) are synchronized and used to compute pressure-volume loops (c). Endsystolic elastance (Ees) and indexed enddiastolic volume at an enddiastolic pressure of 10 mmHg (EDV10) were estimated from a single-beat approach [19,20].

• 

  Fig 2. Protocol of the experiment. Solid arrows represent acquisition of PVL3D, Unshaded arrows represent acquisition of PVLCond.

• 

  Fig 3. Bland–Altman plot for multiple observations per individual for parameters obtained from PVL3D and PVLCond. Solid line represents mean bias. Dashed lines represent limits of agreement. Ees, endsystolic elastance; Ea, arterial elastance; Ees/Ea, ventriculoarterial coupling; EDV10, indexed enddiastolic volume at an enddiastolic pressure of 10 mmHg.

• 

  Fig 4. Comparison of PVL3D (gray box) and PVLCond (black box) under various hemodynamic conditions. Significant changes of (a) endsystolic elastance (Ees), (b) arterial elastance (Ea), (c) peak positive rate of pressure over time (dp/dtmax), as well as (d) indexed enddiastolic volume (EDV10) induced by phenylephrine and esmolol were consistently detected by both methods. (n = 17 piglets), paired Student t-tests. * = significant compared to baseline (p<0.05), † = significant compared to phenylephrine (p<0.05), + = mean, box = 25th to 75th percentile, the bar in the box indicates the median, whiskers indicate the range.

• 

  Fig 5. Example of Pressure-Volume Loops derived from 3D real-time echocardiography and mini pressure wire under various hemodynamic conditions. Pressure volume loops at baseline (black line) and phenylephrine (grey line) depicting the decrease of SV and the increase of Ees, Ea, and Pmax during alpha-adrenergic stimulation with phenylephrine. Baseline: Pmax = 100 mmHg; SV = 9.9 ml; Ees = 18.3 mmHg/ml; Ea = 9.8 mmHg/ml; Ees/Ea = 1.87; dp/dtmax = 2293 mmHg/s; dp/dtmin = -2163 mmHg/s; EDV10 = 19.7 ml; Tau = 18 s. Phenylephrine: Pmax = 169 mmHg; SV = 6.0 ml; Ees = 43.2 mmHg/ml; Ea = 28 mmHg/ml; Ees/Ea = 1.54; dp/dtmax = 3641 mmHg/s; dp/dtmin = -2739 mmHg/s; EDV10 = 17.6 ml; Tau = 26.5 s.