#heart

• Acardiac — Lacking a heart, or possessing a rudimentary, completely non-functional heart. In neonatology and fetal medicine, the term describes an 'acardiac fetus' (or acardiac twin), an extremely rare congenital anomaly occurring exclusively in monochorionic twin pregnancies due to Twin Reversed Arterial Perfusion (TRAP sequence). In this condition, the malformed fetus survives in utero only because it receives blood pumped by the heart of its healthy co-twin (the pump twin).
• Acardia — A congenital absence of the heart or a complete cessation in the ontogenetic development of the cardiac structure in a fetus. This severe structural anomaly is incompatible with independent extrauterine life and is documented almost exclusively within monochorionic multiple pregnancies with asymmetric development (TRAP sequence), where the affected fetus's blood circulation is maintained solely by its twin's heart through placental vascular anastomoses.
• Acardiotrophy — Atrophy of the cardiac muscle or a lack of nutritional and structural development of the myocardium, caused by severe vascularization disorders (chronic ischemia), local metabolic deficiencies, or a lack of nervous and endocrine trophic stimulation. This phenomenon leads to the thinning of the heart walls, decrease in cardiac muscle mass, and a drastic reduction in the blood-pumping capacity of the body.
• Actinocardiography — A rare technical or historical medical term defining a graphical method of recording or visualizing the activity and movements of the heart using radiation (X-rays or radioactive tracers). This early structural technique, a precursor to modern angiocardiography and advanced nuclear medicine methods, allowed physicians in the last century to obtain crude visual data regarding the outline and dynamics of cardiac chambers during the systolo-diastolic cycle.
• Actinocardiogram — An archaic graphic recording or image obtained through the technique of actinocardiography, reflecting the dynamics, movements, and volume variations of the heart under the action of or with the help of radiation (X-rays). This vintage medical document structurally served as a diagnostic tool in the first half of the last century, providing a crude representation of myocardial pulsations printed directly onto photosensitive film or paper.
• Adromischus trigynus — A dwarf, compactly branched perennial succulent plant species in the Crassulaceae family, native to a wide range in South Africa (from the Great Karoo and Northern Cape to the Free State) and Namibia. It features a tuberous, much-branched base bearing dense, elliptic to orbicular leaves with distinctive acute, horny margins wrapping their upper sections. The grayish-green foliage is heavily mottled with chocolate-brown or purplish-maroon spots, earning it the common name 'Calico Hearts'. In late spring, it produces long inflorescences up to 35 cm tall with pale yellowish-green tubular flowers tinged with white or pink.
• Archaic chimney form — A rare or archaic term of oriental (Ottoman) origin used in the past in commercial charters or regional dialects to designate a type of stove, fireplace, hearth, or smoke exhaust chimney (bugeag/ogiac); by extension, it can indicate a simple shelter, a hut, or a rudimentary house with an open hearth.
• Sapwood — The outer, younger, and less dense zone of the woody cylinder in tree stems and roots, located immediately beneath the bark (cambium). Sapwood consists of living cells with an active physiological role, responsible for conducting raw sap from the roots to the leaves and storing reserve substances, gradually converting into heartwood as the tree ages.
• Anacrotism — A structural pathological anomaly of the arterial pulse, visible on a sphygmogram as a notch or a secondary wave on the ascending limb of the graphic curve. This clinical phenomenon is characteristic of tight aortic stenosis, indicating a slowing of blood ejection from the left ventricle due to the narrowing of the valvular orifice, which alters the normal dynamics of the arterial shock wave.
• Angiocardiogram — A graphical representation, radiological image, or digital recording of the heart cavities and great blood vessels, obtained following an angiocardiography with a contrast medium. This clinical diagnostic structural element allows specialist physicians to analyze with three-dimensional precision the vascular lumen diameter, bloodstream dynamics, and potential structural defects or congenital cardiac malformations.
• Angiocardiopathy — A generic term used clinically to denote any disease or pathology that simultaneously affects the heart and its associated vascular system. This structural concept encompasses a wide range of complex cardiovascular diseases, such as ischemic heart disease, hypertensive disease with systemic involvements, or complex congenital malformations, which alter the correct functioning of the organism's hemodynamics.
• Angiocarditis — An acute or chronic inflammatory disease that simultaneously affects the internal structures of the heart (endocardium, myocardium, or pericardium) and the walls of the associated great blood vessels. This structural pathological process, often infectious, immunological, or toxic in nature, alters normal hemodynamics and requires early diagnosis to prevent severe valvular or vascular complications.
• Forehearth — A reception basin or external refractory compartment situated in front of the taphole of a cupola or blast furnace, serving for the temporary collection, homogenization, and temperature maintenance of molten iron or liquid metal before casting. This structural element optimizes the metal smelting process by allowing lighter residual slag to separate at the surface.
• Antacid — A chemical substance or medication with basic or alkaline properties, used to neutralize excess gastric acid and relieve symptoms of heartburn or gastroesophageal reflux. In chemistry, it describes compounds capable of counteracting acids.
• Antinoacid — A chemical substance, pharmaceutical preparation, or biological compound capable of reducing, neutralizing, or inhibiting the excessive secretion of hydrochloric acid in gastric juice; a therapeutic agent used to alleviate symptoms of hyperacidity, heartburn, and esophageal discomfort associated with gastritis or gastroesophageal reflux disease.
• Anubis — A major deity in the ancient Egyptian pantheon, guide of souls in the afterlife (psychopomp), protector of graves, and patron of embalming; iconographically represented as a man with the head of a black jackal or as a full jackal, he held the crucial role of weighing the hearts of the dead during the judgment of Osiris.
• Aorta — The largest artery of the human and mammalian body, originating from the left ventricle of the heart and distributing oxygenated blood throughout the organism via its branches. Its resilient, elastic paired structure allows it to withstand high cardiac ejection pressures, making it essential for maintaining systemic blood flow.
• Apexocardiogram — A graphic tracing recorded with a special apparatus (apexocardiograph) that registers low-frequency vibrations and mechanical displacements of the chest wall caused by the movements of the cardiac apex (heart tip) during the cardiac cycle. It is a historical non-invasive method for evaluating left ventricular function.
• Scorched earth — A regional or archaic form derived from the root of the verb 'a arde' (to burn), used in certain rural dialects to denote a barren place, a patch of land scorched by the sun, a burned stubble field, or the ash and debris remaining in the hearth of an industrial or pottery kiln. In a structural-ethnographic sense, ardiștea describes the residual space or thermal imprint left on the soil following agricultural clearing fires.
• Arrhythmia — A disruption of the normal heart rhythm, characterized by an alteration in the frequency, regularity, or sequence of cardiac contractions. This structural and electrophysiological anomaly occurs when the electrical impulses that coordinate heartbeats do not function properly, causing the heart to beat too fast (tachycardia), too slow (bradycardia), or completely irregularly (such as atrial fibrillation).