Left ventricular rotation: a neglected aspect of the cardiac cycle.
OBJECTIVE
To describe the mechanics and possible clinical importance of left ventricular (LV) rotation, exemplify techniques to quantify LV rotation and illustrate the temporal relationship of cardiac pressures, electrocardiogram and LV rotation.


METHODS
Review of the literature combined with selected examples of echocardiographic measurements.


RESULTS
Rotation of the left ventricle around its longitudinal axis is an important but thus far neglected aspect of the cardiac cycle. LV rotation during systole maximizes intracavitary pressures, increases stroke volume, and minimizes myocardial oxygen demand. Shearing and restoring forces accumulated during systolic twisting are released during early diastole and result in diastolic LV untwisting or recoil promoting early LV filling. LV twist and untwist are disturbed in a number of cardiac diseases and can be influenced by several therapeutic interventions by altering preload, afterload, contractility, heart rate, and/or sympathetic tone.


CONCLUSIONS
The concept of LV twisting and untwisting closely linking LV systolic and diastolic function may carry potential diagnostic and therapeutic importance for the management of critically ill patients. Future clinical studies need to address the feasibility of assessing LV twist and untwist as well as the relevance of its therapeutic modulation in critically ill patients.
Bloechlinger
Stefan
S
Department of Intensive Care Medicine, University Hospital Bern, Inselspital, Freiburgstrasse, 3010 Bern, Switzerland. stefan.bloechlinger@insel.ch
Grander
Wilhelm
W
Bryner
Juerg
J
Dünser
Martin W
MW
D001696:Biomechanical Phenomena; D006321:Heart / Q000502:physiology*; D006331:Heart Diseases / Q000503:physiopathology; D006801:Humans; D009200:Myocardial Contraction; D012399:Rotation; D016277:Ventricular Function, Left