Aortic valve disease (AVD) is a common but under-diagnosed disease which can cause
various cardiovascular complications. AVD, including aortic stenosis and aortic
regurgitation, can be associated with dilatation of the ascending thoracic aorta as a
result of hemodynamic mechanisms and genetic predisposition. In the assessment of an AVD,
it is important to consider if it is associated with a thoracic aortic aneurysm (TAA),
and vice versa.
The prevalence of TAA in the general population is difficult to assess because most
patients are asymptomatic, and their lethal complications (rupture and dissections) are
often misdiagnosed as myocardial infarctions. The insidious evolution of aortic pathology
motivates physicians to make the diagnosis as early as possible before the appearance of
irreversible lesions causing significant morbidity and mortality. Traditional semiology
can be useful for AVD screening (auscultation of a murmur, or observation of some visible
semiological signs). However, it relies on the proficiency of care providers and may not
allow a timely diagnosis of less severe forms of the disease. Moreover, imaging
techniques used in current clinical practice are not appropriate for the organization of
large-scale screening in asymptomatic patients. In addition, none of these techniques are
accessible for the people living far away from a healthcare institution.
Kinocardiography (KCG) is a portable measurement technique developed to estimate cardiac
mechanical performance by studying the vibrations produced by myocardial contraction
during each heartbeat and transmitted to the body surface. Signals are recorded thanks to
a sensor placed on the sternum, another sensor placed on the lower back and
electrocardiogram electrodes.
Smartphones are equipped with accelerometers and gyroscope, and may allow anyone to
measure their own cardiac mechanical function similarly to KCG.
Phonocardiography (PCG) enables the detailed recording and analysis of heart sounds
produced by the blood flow during the opening and closing of heart valves thanks to a
microphone. It allows the extraction of heart sound information that reveals valvular
diseases, such as the timing of heart valve closure, the frequency content of heart
sounds, and the presence of diastolic or systolic murmurs.
Video image processing by Remote photoplethysmography (RPPG) or by Eulerian video
magnification (EVM) allow the analysis of color changes and movements, invisible to the
naked eye.
The primary objective of this prospective observational study is to better understand and
assess KCG signals modifications due to aortic valve disease (AVD) and/or thoracic aortic
aneurysm (TAA). It will be possible thanks to imaging techniques such as 4D flow MRI, and
thanks to a comparison with PCG. The secondary objective of our study is to evaluate if a
smartphone can be used for the diagnostic and characterization of AVD, using KCG, PCG or
video image processing.
The possible participants will be identified, according to inclusion/exclusion criteria.
Informed consent will be given to the patients. Immediately after the echocardiography
and/or the cardiac MRI, the investigators will record KCG and PCG data, and then perform
similar measurements using a smartphone placed on the torso. These measurements are
followed by two short video recordings of 30 seconds, simultaneously to a KCG recording.
For patients undergoing aortic valve replacement or thoracic aortic aneurysm surgery, the
investigators will also perform the KCG measurements post-operatively, immediately after
de post-operative cardiac MRI and/or echocardiography.