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The pumping and left ventricular unloading capabilities of the ventricular synchronous skeletal-muscle ventricle  L.A. Geddes, ME, PhD, FACCa, W. Janas,

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Presentation on theme: "The pumping and left ventricular unloading capabilities of the ventricular synchronous skeletal-muscle ventricle  L.A. Geddes, ME, PhD, FACCa, W. Janas,"— Presentation transcript:

1 The pumping and left ventricular unloading capabilities of the ventricular synchronous skeletal-muscle ventricle  L.A. Geddes, ME, PhD, FACCa, W. Janas, a, M. Hinds, PhDb, J. Cook, BSc  The Journal of Thoracic and Cardiovascular Surgery  Volume 109, Issue 6, Pages (June 1995) DOI: /S (95) Copyright © 1995 Mosby, Inc. Terms and Conditions

2 Fig. 1 VS-SMV consisting of a muscle-wrapped pouch connected to the LV apex (with no valve) and to the aorta via a conduit with a prosthetic heart valve. The Journal of Thoracic and Cardiovascular Surgery  , DOI: ( /S (95) ) Copyright © 1995 Mosby, Inc. Terms and Conditions

3 Fig. 2 A, Timing diagram showing the R wave of the ECG, pressure in the LV, ejection period, stimulus train, and muscle contraction, identifying contraction latency (70 msec) and relaxation latency (100 msec). TD, train duration. B, LV cycle of an animal in which LV ejection starts at B (140 msec from R wave) and ejection period (B-E) is 350 msec. The Journal of Thoracic and Cardiovascular Surgery  , DOI: ( /S (95) ) Copyright © 1995 Mosby, Inc. Terms and Conditions

4 Fig. 2 A, Timing diagram showing the R wave of the ECG, pressure in the LV, ejection period, stimulus train, and muscle contraction, identifying contraction latency (70 msec) and relaxation latency (100 msec). TD, train duration. B, LV cycle of an animal in which LV ejection starts at B (140 msec from R wave) and ejection period (B-E) is 350 msec. The Journal of Thoracic and Cardiovascular Surgery  , DOI: ( /S (95) ) Copyright © 1995 Mosby, Inc. Terms and Conditions

5 Fig. 3 Frank-Starling law of the heart. Inset shows force of each contraction as resting tension is increased continuously. A is operating point and increased loading increases force of contraction; decreased loading decreases force of contraction. The Journal of Thoracic and Cardiovascular Surgery  , DOI: ( /S (95) ) Copyright © 1995 Mosby, Inc. Terms and Conditions

6 Fig. 4 A, VS-SMV pouch with metal-sleeve electrodes. B, Calibration curves for the increase in impedance (Δ Zeta) as blood is withdrawn. The Journal of Thoracic and Cardiovascular Surgery  , DOI: ( /S (95) ) Copyright © 1995 Mosby, Inc. Terms and Conditions

7 Fig. 5 Ventricular electrogram, LV/pouch pressure, pouch impedance, and aortic root flow velocity. On left and right, LV is unassisted. In center, LV is assisted by VS-SMV with pumping ratio of 1:3. To make this record, the outlet (valve) end of VS-SMV was clamped. Note reduction (12 mm Hg) in LV diastolic pressure for the postassisted beats (2). The Journal of Thoracic and Cardiovascular Surgery  , DOI: ( /S (95) ) Copyright © 1995 Mosby, Inc. Terms and Conditions

8 Fig. 6 Augmentation in aortic-root flow velocity (with outlet, valve-end conduit of the VS-SMV clamped) versus train delay (d) for typical dog with stimulus train duration (TD) of 200 msec. The Journal of Thoracic and Cardiovascular Surgery  , DOI: ( /S (95) ) Copyright © 1995 Mosby, Inc. Terms and Conditions

9 Fig. 7 Relationship between VS-SMV stroke volume and train duration (TD), using a delay of 50 msec. The Journal of Thoracic and Cardiovascular Surgery  , DOI: ( /S (95) ) Copyright © 1995 Mosby, Inc. Terms and Conditions

10 Fig. 8 LV pressure during VS-SMV assistance with pumping ratio of 1:5 for stimulus train durations (TD) of 100, 150, 200, and 250 msec with constant delay of 20 msec. Note that as train duration is increased, LV becomes more overemptied, revealed by decrease in diastolic pressures (2, 5, 12, and 16 mm Hg) for the first postassisted beats. The Journal of Thoracic and Cardiovascular Surgery  , DOI: ( /S (95) ) Copyright © 1995 Mosby, Inc. Terms and Conditions


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