Measurements of cardiac efficiency and internal work of the left ventricle via reconstructed impedance cardiography

Abstract

Objective. The aim of this study was to investigate methods for measuring the cardiac efficiency (CE) and internal work (IW) of the left ventricle via reconstructed impedance cardiography (RICG). Approach. On the basis of the physiological context and Bernoulli’s equation in physics, methods of measuring the CE and IW were proposed. The CE, IW, internal work index (IWI), and other data from 180 healthy adults and 144 patients with cardiovascular disease were measured. Main results. The CE of 180 healthy adults was 22.5 ± 2.2%, and the IWI was 22.3 ± 5.2 J l−1 m−2. CE decreased with age, and the CE of the younger group (23.5 ± 1.9%) was larger than that of the older group (21.5 ± 1.9%), P < 0.01. The IWI increased with age, and the IWI of the younger group (19.0 ± 3.8 J l−1 m−2) was smaller than that of the older group (24.8 ± 4.3 J l−1 m−2), P < 0.01. There were no significant difference in CE (22.4 ± 2.2% and 22.6 ± 2.2%) or in the IWI (21.9 ± 5.1 J l−1 m−2 and 22.6 ± 5.2 J l−1 m−2) between the male and female groups. The CEs and IWIs of patients with hypertension, coronary heart disease, and heart failure were 17.4 ± 2.4% and 41.8 ± 15.6 J l−1 m−2, 17.6 ± 3.0% and 35.1 ± 10.4 J l−1 m−2, and 15.8 ± 3.5% and 42.1 ± 15.6 J l−1 m−2, respectively. These CEs were all smaller than that (21.6 ± 2.0%) of the healthy contrast group P < 0.01, while the IWIs were all larger than that (24.6 ± 4.8 J l−1 m−2) of the healthy contrast group, P < 0.01. Significance. The CEs and IWIs measured in this study may reflect physiological changes in healthy humans and pathogenic conditions in patients with cardiovascular disease.

Features of Reactive Changes in Circulatory System Parameters Under the Influence of Cyber Sports

“…Most cells in the human body lose the possibility of direct contact with the outside world and are located in the liquid environment surrounding the cells. It is from the tissue or intercellular fluid that they receive the substances they need and excrete metabolic products [17,18]. The composition of these liquid media is constantly updated, including due to their close contact with blood, which is constantly moving.…”

“…Більшість клітин людського організму втрачають можливість прямого контакту із зовнішнім світом і знаходяться в рідкому середовищі, що оточує клітини. Саме з тканинної або міжклітинної рідини вони отримують необхідні їм речовини і виводять продукти метаболізму [17,18]. Склад означених рідких середовищ постійно оновлюється, в тому числізавдяки їхньому тісному контакту з кров'ю, яка постійно рухається.…”

Non-invasive pulse arrival time is associated with cardiac index in pediatric heart transplant patients with normal ejection fraction

“…Impedance cardiography has gained attraction as a non-invasive modality to measure CI; however, this methodology requires additional electrodes, and the measured signals can be disrupted by respirations and patient movement (Nederend et al 2017 ). Novel applications of impedance cardiography and carotid waveform analytics have been associated with cardiac efficiency and left ventricular function, though largely in adult models (Cooper et al 2021 , Kuang et al 2021 , Cheng et al 2023 , Suriani et al 2023 ).…”