Accent

ACCENT, accentuation, in clinical medicine is used as a term, mainly in relation to heart tones, particularly to the second tone, whereas the accentuation of the first tone is referred to as 'strengthening.' The accent of the second tone is heard over the aorta, over the pulmonary artery, or over both together. The accent of the second tone over the aorta arises from increased tension of the aortic valves upon closure. It serves as a diagnostic sign of elevated arterial blood pressure in the systemic circulation and hypertrophy of the left ventricle. It is heard in essential hypertension, in hypertensions based on nephritis, shrunken kidneys, in poisoning with sublimate, lead, etc., as well as in temporary increases in pressure, for example, during emotional excitement, physical work, injection of adrenaline. More rarely, the accent of the second tone appears without an increase in pressure, in connection with thickening of the valves themselves or changes in the aortic wall, for example, atherosclerotic. Due to resonance, the second tone may acquire a peculiar metallic timbre, which also occurs in pathological processes in neighboring organs and tissues, tuberculous infiltrates and cavities in the lungs, etc. The accent of the second tone of the pulmonary artery, besides analogous processes in the surrounding area, often forms on the basis of increased blood pressure in the pulmonary circulation with hypertrophy of the right ventricle, for example, in diseases of the mitral valve, emphysema of the lungs with capillary depletion, chronic pneumonia, tuberculosis. In children, the accent of the second tone over the pulmonary artery is usually not given diagnostic significance, since in them the pulmonary artery lies closer to the chest wall and gives a physiological accent. The disappearance of the accent may indicate weakening of the corresponding ventricle and serves as a prognostically bad sign.