Impact of Aortic Valve Disease and Thoracic Aortic Aneurysm on Kinocardiographic Signals

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.