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Peak Aortic Acceleration as a Noninvasive Index of Left Ventricular Contractility
Author(s) -
Reddy Anilkumar,
Heredia Celia Pena,
Coulthard Tonya,
Pham Thuy T,
Taffet George E
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.lb658
Subject(s) - contractility , cardiology , medicine , ventricular pressure , aortic pressure , dobutamine , acceleration , hemodynamics , physics , classical mechanics
Peak left ventricular (LV) pressure derivative (+dP/dtmax) is considered to be the gold standard in the assessment of left ventricular contractility. The measurement of left ventricular pressure with an intravascular pressure catheter is an invasive procedure and is usually done as a terminal procedure in mice and other small animals. In patients mean acceleration derived from aortic outflow velocity which is measured noninvasively by echocardiography was shown to be a good surrogate of left ventricular contractility. In rats peak acceleration of aortic flow whic is measured with invasive extravascular flow probe was shown to be correlated well with dP/dtmax. We believe that echocardiography measurement of aortic outflow in mice may not be sensitive enough (due to angle correction) for serial measurements of left ventricular contractility. We undertook this study to evaluate the utility of peak acceleration of aortic flow velocity measured with a single crystal pulsed Doppler probe (no angle correction needed) as a noninvasive surrogate measurement of left ventricular contractility. In this study we made simultaneous measurements of left ventricular pressure using an invasive pressure catheter and aortic flow velocity using a noninvasive 20 MHz pulsed Doppler probe in normal mice. Measurements were made at baseline and at several time intervals after a single intraperitoneal injection of dobutamine (1μg/g BW). Peak dP/dt and peak aortic acceleration values were calculated at several heart rates (range: 387 to 701 beats/minute) obtained from the 4 wild‐type male mice (5 months old). Linear regression of peak aortic acceleration (y) versus peak dP/dt (x) showed a high correlation between the two measurements (y = 2.8x + 1617; p<0.0001; r 2 = 0.896; n=18 data points). The preliminary findings obtained from this limited study suggest that peak aortic acceleration may be used as a noninvasive index of LV contractility. We expect to further evaluate this relationship between peak aortic acceleration and peak dP/dt under conditions of vasoconstriction and vasodilation along with responses to positive and negative ionotropic agents to validate the potential use of this noninvasive index in mice and other small animals.