Alterations in Left Ventricular Untwisting With Ageing

Abstract

Circulation Journal Official Journal of the Japanese Circulation Society http://www. j-circ.or.jp nderstanding age-associated changes of the cardiovascular system is important because these changes are an important precursor to cardiovascular disease. 1 Marked changes in left ventricular (LV) diastolic function are known to occur in normal, healthy, older people, 2,3 although the processes contributing to these changes are yet to be fully elucidated. The dynamic interaction of subendocardial and subepicardial fibers causes a twisting LV deformation during systole that leads to storage of potential energy. 4,5 Subsequent rapid untwisting during isovolumic relaxation decreases LV pressure, which makes effective sucking of blood into the LV possible once the mitral valve opens. 6 However, conflicting data have been published on the changes in the untwist rate and, in particular, the peak diastolic untwisting velocity with ageing. [7][8][9][10] In order to gain further insight into age-associated changes of LV diastolic function, the purpose of the current study was to investigate alterations in LV untwisting with ageing. Methods Study ParticipantsThe study population consisted of 75 healthy, non-obese (body mass index <27 kg/m 2 ) volunteers without hypertension, diabetes or regular use of medication for cardiovascular disease, with a normal 12-lead ECG, normal left atrial and LV dimensions, and LV ejection fraction by transthoracic echocardiography. None of the patients had complaints that were compatible with cardiac disease. All patients were required to have good echocardiographic image quality that allowed for complete analysis of LV rotation and twist by speckle-tracking echocardiography. Patients were primarily recruited from our department (personnel) or were family members or friends. The subjects were classified into 3 groups: aged 16-35 (Group 1, n=25), 36-55 (Group 2, n=25) and 56-75 (Group 3, n=25) years. Informed consent was given by all patients and the institutional review board approved the study. EchocardiographyTwo-dimensional grayscale harmonic images were obtained in the left lateral decubitus position using a commercially available ultrasound system (iE33, Philips, Best, The Netherlands) equipped with a broadband (1-5 MHz) S5-1 transducer (frequency transmitted 1.7 MHz, received 3.4 MHz). All echocardiographic measurements were averaged from 3 heartbeats. From the M-mode recordings the following data were acquired: left atrial size, LV end-diastolic septal and posterior wall thicknesses, and LV end-diastolic and end-systolic dimensions. The LV ejection fraction was calculated from Background: In order to gain further insight into age-associated changes of left ventricular (LV) diastolic function, the purpose of the current study was to investigate alterations in LV untwisting with ageing.

Revisiting the Anatomy of the Living Heart

“…22 In the field of echocardiography, it is pulsatile rotation along the longitudinal axis of the heart that is currently expressed as torsion, or twisting as opposed to untwisting. 23, 24 It was the report of the working group convened by the European Society of Cardiology and the North American Society of Pacing and Electrophysiology that emphasized the incorrectness of many of the names currently used to describe the cardiac components. 7 Despite the time that has passed since the publication of their report, many of these names still retain their popularity, despite their incorrectness.…”

Myocardial Deformation in Acute Myocarditis With Normal Left Ventricular Wall Motion - A Cardiac Magnetic Resonance and 2-Dimensional Strain Echocardiographic Study -

“…[4][5][6][7][8][9] A transmural heterogeneity of left ventricular (LV) wall deformation has been documented in healthy patients: longitudinal and circumferential strain is higher in subendocardial than subepicardial layers, and a base to apex strain gradient exists, with longitudinal, circumferential and radial strain higher at the apex than at the base. 10, 11 In myocardial infarction, the distribution of strain impairment reveals the extent of necrosis: a transmural infarction is characterized by reduced longitudinal, circumferential and radial strain, while in subendocardial necrosis only the longitudinal and radial strain are reduced, and the circumferential strain is preserved. 8,9, 12 Acute myocarditis is characterized by inflammatory myocardial damage that can result in severe LV dysfunction.…”

Left Ventricular Rotation, Twist and Untwist: Physiological Role and Clinical Relevance

“…Если полости сердца становятся сфе-ричными, например, при сердечной недостаточно-сти, угол становится большим, и миокардиальные во-локна располагаются более перпендикулярно по от-ношению друг к другу. Когда это происходит, вращение и скручивание уменьшаются [20]. Как известно, индекс сферичности определяется как отношение размера продольной оси и размера короткой оси в диастолу.…”

“…Не-смотря на то, что СН обычно рассматривается как ре-зультат систолической дисфункции, рост числа пациентов с диастолической СН позволил предположить, что диастолическая и систолическая дисфункции являют-ся фенотипическими проявлениями одного процесса. Последний развивается постепенно и начинается со сни-жения деформации, изменений ротации, пролонгации скручивания и задержки раскручивания [20,31]. Боль-шинство прогрессивно развивающихся заболеваний миокарда, включая ИБС, вызывают обычно субэндо-кардиальную дисфункцию.…”