1. Left Ventricular Architecture and
Mechanics: An Historical Perspective
Michael Geoffrey Katz
Senior Assistant Resident
Duke University, Internal Medicine
November 11, 2009
46. āBeing now amazed at the novelty of the thing, I
search it again and again, and having diligently
enough enquired into all, it was evident, that that old
and vast ulcer (for want of the help of a skilfull
physician) was miraculously healed, and skinned over
with a membrane on the inside, and guarded with
flesh all about the brimmes or margent of it. By its
pulse, and the difference or rhythm thereof, or the
time which it kept, (and laying one hand upon his
wrest, and the other upon his heart) and also by
comparing and considering his respirations,
concluded it to be no part of the lungs, but the
cone or substance of the heart.ā
52. Essentially correct, but not an improvement on
Harvey's observation that there is constriction
and dilatation.
53.
54. The complexity of ventricular form and of the
changes in configuration during systole
preclude assigning quantitative values for
volume from measurements of any single
dimension. With these reservations, pressure-
circumference loops have been employed to
indicate changes in the stroke work performed by
those myocardial fibers lying directly beneath
the circumference gauges and contributing to the
change in circumference.ā
-Rushmer 1954
55. Ventricular Muscle is
Not Homogeneous
Does not account for
multiple fiber directions
Does not account for
ventricular twisting
Three Main Short Coming of early 20th Century Model of
Cardiac Function
77. Thank You!
My parents
My fellow Internal Medicine Residents
ā¢And especially the hard working interns.
Chief Residents
ā¢Present
ā¢Rob Harrison, M.D.
ā¢Erin Hommel, M.D.
ā¢Jamie Todd, M.D.
ā¢Past
ā¢Al Sun
ā¢Christina Barkauskas
Program Leadership and Key Faculty
ā¢Diana McNeill, M.D.
ā¢Harvey Jay Cohen, M.D.
ā¢Andrew Muir, M.D.
ā¢Thomas Bashore, M.D.
ā¢Joseph Greenfield, M.D. ā āThe quail population of Florida is dangerously high and Iāve been called in
to reduce it.ā
78.
79. Selected References
Ballester-RodeĀ“s M et al. European Journal of Cardio-thoracic Surgery. 2006; 29S:S139
Bertini M et al. JACC. 2009;54:1317
Bowman IA. Texas Heart Institute Journal. 1987;14:5
Buckberg G et al. Circulation. 2008;118:2571
Buckberg GD et al. European Journal of Cardio-thoracic Surgery. 2006; 29S: S165
Buckberg GD. European Journal of Cardio-thoracic Surgery. 2006; 29S:S286
Carreras F et al. European Journal of Cardio-thoracic Surgery. 2006; 29S:S50
Corno AF et al. European Journal of Cardio-thoracic Surgery. 2006; 29S:S61
Fukuda N et al. Journal of Muscle Research and Cell Motility. 2005;26:319
Garber A et al. UWOMJ. 2008;77:22
Isomura T et al. European Journal of Cardio-thoracic Surgery. 2006; 29S:S245
Katz A. Dialogues Cardiovasc Med. 2004;9:45
Key JD et al. The American Journal of Cardiology. 1979;43:1026
MacCallum JB. Johns Hopkins Hosp. Rep. 1900;9:307
McKechnie MDJ et al. Resuscitation. 2002;55:133
Maclver DH et al. Heart. 2008;94:446
Manner J. European Journal of Cardio-thoracic Surgery. 2006; 29S:S69
Rushmer RF. Physiol. Rev. 1956; 36: 400
Streeter DD et al. Circ. Res. 1973;33:656
Torrent-Guasp F et al. European Journal of Cardio-thoracic Surgery. 2005;27:191
Tubbs RS et al. International Journal of Cardiology. 2008;128:17
Wang J et al. JACC. 2009;54:1326
Editor's Notes
Leonardo da Vinci (1452-1519): Leonardo is said to have dissected 30 cadavers and to have made nearly 800 anatomic drawings. He and a friend intended to publish a treatise on anatomy, but this was never accomplished. Most of his drawings were not published until early in the 20th century.
He thought of the heart, as a pump and believed that the heartbeat and the pulse were synchronous. The drawings were superb, but their influence was late and restricted. Note, image on the right demonstrates Galenās holes.
Before proceeding, itās worth taking a moment to reflect on what was going on in the world of pop-culture and science during the 17th century.
In 1957, Torrent-Gausp discovered the helical heart by simple hand dissection.
The hearts were prepared by simple boiling in water (without any additive), in order to loosen the connective tissue. The period of boiling was judged empirically, on the appearance of fibres and depended on the size of the specimen - about 10 minutes or less for a hen heart and up to 2 hours for an adult bovine heart.
After boiling, the atria, aorta and pulmonary artery were removed from the heart. The fat from the atrio-ventricular sulci was removed and all visible, superficial coronary vessels excised.
Dissection of the myocardial mass was undertaken with non-toothed forceps, scalpel and scissors. Blunt dissection by fingers was generally the most satisfactory way of identifying the direction of the linear (fibre) and laminar layer) pathways.
Refolding the heart into its natural biological configuration allows definition of 2 loops, termed the transverse basal and oblique apical loops.
The basal loop is circumferential and wraps around both the LV and right ventricle but does not involve the septum, a finding supported by recent diffusion tensor MRI analysis.
The apical loop is composed of a descending and ascending segment that conforms to the right- and left-handed helical arrangement described by anatomists over many years.
