Accurate Detection of Dobutamine-induced Haemodynamic Changes by Kino-Cardiography: A Randomised Double-Blind Placebo-Controlled Validation Study

Abstract

Non-invasive remote detection of cardiac and blood displacements is an important topic in cardiac telemedicine. Here we propose kino-cardiography (KCG), a non-invasive technique based on measurement of body vibrations produced by myocardial contraction and blood flow through the cardiac chambers and major vessels. KCG is based on ballistocardiography and measures 12 degrees-of-freedom (DOF) of body motion. We tested the hypothesis that KCG reliably assesses dobutamine-induced haemodynamic changes in healthy subjects. Using a randomized double-blinded placebo-controlled crossover study design, dobutamine and placebo were infused to 34 volunteers (25 ± 2 years, BMI 22 ± 2 kg/m², 18 females). Baseline recordings were followed by 3 sessions of increasing doses of dobutamine (5, 10, 20 μg/kg.min) or saline solution. During each session, stroke volume (SV) and cardiac output (CO) were determined by echocardiography and followed by a 90 s KCG recording. Measured linear accelerations and angular velocities were used to compute total Kinetic energy (iK) and power (Pmax). KCG sorted dobutamine infusion vs. placebo with 96.9% accuracy. Increases in SV and CO were correlated to iK (r = +0.71 and r = +0.8, respectively, p < 0.0001). Kino-cardiography, with 12-DOF, allows detecting dobutamine-induced haemodynamic changes with a high accuracy and present a major improvement over single axis ballistocardiography or seismocardiography.

Modification of the mechanical cardiac performance during end-expiratory voluntary apnea recorded with ballistocardiography and seismocardiography

“…Data were exported and processed offline using a specific toolbox written in Matlab version 9.5 R2018b (Mathworks ® ). Further details regarding this methodology have been published previously (Prisk et al 2001, Migeotte et al 2012, Migeotte et al 2016, Hossein et al 2019. P, Q, R, S, and T waves on the ECG were automatically identified and used as reference points for the identification of each cardiac cycle.…”

“…A hybrid model which records BCG and SCG signals at the same time as a one-lead ECG, was developed in 2015 (Migeotte et al 2016). This hybrid technique, called kinocardiography (KCG), provides quantitative information on the contractility status of the heart (Hossein et al 2019). It allows the simultaneous observation of ballistic and seismic events, including the force of cardiac contraction, the velocity and acceleration of blood mass, and the displacement of the heart axis, and results in corresponding surface waveforms.…”

“…We have recently demonstrated that the iK TOT recorded with both SCG and BCG accurately estimates dobutamine-induced changes in stroke volume (SV) and cardiac output (CO) in healthy subjects, with a high sensitivity and specificity when compared to echocardiography (Hossein et al 2019).…”

“…Figure 1shows the EA of K LIN and K ROT derived from a SCG signal over a set of contractile cycle. More details regarding the computation of the above values can be found in(Migeotte et al 2016, Hossein et al 2019.…”

Detection and Analysis of Heartbeats in Seismocardiogram Signals

“…First of all, the signals were downsampled from the original 5 kHz sampling rate down to 500 Hz. In fact, it is known that most of the SCG information is just contained within 1 Hz and 20 Hz [34], and that 50 Hz are adequate to capture the signal's kinetic energy [35]. At the same time, a similar bandwidth is adequate to capture QRS peaks in the ECG signal, later used for performance assessment purposes.…”