heart (hart). 1

The organ which propels the blood through the vascular system of all vertebrates and of the higher invertebrates. In its simplest form it consists of a specialized pulsating portion of the vascular system, and in its most complex form of an organ with four distinct chambers, each provided with a set of valves. 2. The central (figuratively, the e ential) part of anything, fatty h. 1. A condition (also called fatty infiltration of the h.) in which the sub pericardial and inter muscular connective ti ue is converted into fat. 2. Fatty degeneration of the muscular ti ue of the h. fetal h. The h. as it exists in the fetus, h. block. The condition in which conduction between auricles and ventricles is interfered with (partial block) or interrupted altogether (complete block), with the result that the normal sequence of auricular and ventricular beat is disturbed. It is usually attributed to an injury to or lesion of the auriculoventricular bundle and supposed to be the condition present in Stokes-Adam's disease, h.- burn. See cardialgia. h.-shaped. See cordate, irritable h. A functional disorder of the h. from muscular exhaustion. It is especially common among soldiers; and with them may be attributed to forced marches, fever, and camp diarrhea, left h. The left cavities of the h. pulmonary h., right h. The right cavities of the h. smoker's h., tobacco h. A condition of the h. characterized by very irritable and forcible action, due to the exce ive use of tobacco. Also seen as result of exce ive use of narcotics and in various neurotic conditions. [Ang.- Sax., heorte.1