Structure/function interface with sequential shortening of basal and apical components of the myocardial band

European Journal of Cardio-thoracic Surgery 29S (2006)
S75-S97
Buckberg GD, Castellá M, Gharib M, Saleh S.

Objective

To study the sequential shortening of Torrent-Guasp’s ‘rope-heart model’ of the muscular band, and analyse the structure—function relationship of basal loop wrapping the outer right and left ventricles, around the inner helical apical loop containing reciprocal descending and ascending spiral segments.

Methods

In 24 pigs (27—82 kg), temporal shortening by sonomicrometer crystals was recorded. The ECG evaluated rhythm, and Millar pressure transducers measured intraventricular pressure and dP/dt.

Results

The predominant shortening sequence proceeded from right to left in basal loop, then down the descending and up the ascending apical loop segments. In muscle surrounded by the basal loop, epicardial muscle predominantly shortened before endocardial muscle. Crystal location defined underlying contractile trajectory; transverse in basal versus oblique in apical loop, subendocardial in descending and subepicardial in ascending segments. Mean shortening fraction average 18 ± 3%, with endocardial exceeding epicardial shortening by 5 ± 1%. Ascending segment crystal displacement followed descending shortening by 82 ± 23ms, and finished 92 ± 33 ms after descending shortening stops, causing active systolic shortening to suction venous return; isovolumetric relaxation was absent.

Conclusion

Shortening sequence followed the rope-like myocardial band model to contradict traditional thinking. Epicardial muscle shortened before endocardial papillary muscle despite early endocardial activation, and suction filling follows active systolic unopposed ascending segment shortening during the ‘isovolumetric relaxation’ phase.

Structure/function interface with sequential shortening of basal and apical components of the myocardial band

European Journal of Cardio-thoracic Surgery 29S (2006) S75-S97
Buckberg GD, Castellá M, Gharib M, Saleh S.

Objective

To study the sequential shortening of Torrent-Guasp’s ‘rope-heart model’ of the muscular band, and analyse the structure—function relationship of basal loop wrapping the outer right and left ventricles, around the inner helical apical loop containing reciprocal descending and ascending spiral segments.

(more…)

Non spiral and spiral (helical) flow patterns in stenoses. In vitro observations using spin and gradient echo magnetic resonance imaging (MRI) and computational fluid dynamic modelling

Int Angiol. 2004 Sep;23(3):276-83.
Stonebridge PA, Buckley C, Thompson A, Dick J, Hunter G, Chudek JA, Houston JG, Belch JJ.
Vascular Diseases Research Unit, Department of Surgery, The Institute of Cardiovascular Research, Ninewells Hospital and Medical School, Dundee, Scotland, UK. p.a.stonebridge@dundee.ac.uk

Aim

Physiological blood flow patterns are themselves poorly understood despite their impact on arterial disease. Stable spiral (helical) laminar flow has been observed in normal subjects. (more…)

The characteristic flow pattern of a “thrill” in Autologous AV Fistulae above the swing segment is spiral flow rather than turbulence

Presented at the Vascular Access for Haemodialysis XIII Symposium, May 9-11, 2012, Orlando, Florida, USA
Nick G. Inston, MD, Yazin Marie, Stephen J. Mallor, Hari Krishnan and Robert Jones

Objectives

In healthy individuals arterial blood flow has been characterized as having a spiral laminar pattern (Stonebridge P et al 1991). A loss of this pattern of flow is associated with pathology (Houston G et al 2004). (more…)

The Presence of Spiral Laminar Flow in Autologous Arterio-venous Fistulae

Poster at the Vascular Access Society of Britain and Ireland Symposium, September 2011, Brighton, UK
Guthrie, Suttie, Ross, Levison & Stonebridge

Purpose

In non-atherosclerotic vessels, flow is predominantly ‘spiral laminar’ rather than laminar. Spiral Laminar Flow (SLF) stabilises flow patterns at regions of arterial branching. (more…)

Spiral laminar flow in the abdominal aorta: a predictor of renal impairment deterioration in patients with renal artery stenosis?

Nephrol Dial Transplant. 2004 Jul;19(7):1786-91. Epub 2004 May 25
Houston JG, Gandy SJ, Milne W, Dick JB, Belch JJ, Stonebridge PA.
Tayside University Hospitals, Clinical Radiology, Dundee, UK. graeme.houston@tuht.scot.nhs.uk

Background

Spiral or helical arterial blood flow patterns have been widely observed in both animals and humans. The absence of spiral flow has been associated with carotid arterial disease. (more…)

Two-dimensional flow quantitative MRI of aortic arch blood flow patterns: Effect of age, sex, and presence of carotid atheromatous disease on prevalence of spiral blood flow

J Magn Reson Imaging. 2003 Aug;18(2):169-74.
Houston JG, Gandy SJ, Sheppard DG, Dick JB, Belch JJ, Stonebridge PA.
Department of Clinical Radiology, Ninewells Hospital and Medical School, Tayside University Hospitals NHS Trust, Dundee, Scotland, UK. graemeh@tuht.scot.nhs.uk

Purpose

To determine the effect of age, sex, and presence of carotid atheromatous disease on the presence of aortic spiral blood flow pattern using two-dimensional flow quantitative magnetic resonance imaging (MRI).

(more…)