Cardiac Thrombosis.

Definition.—Cardiac Thrombosis is the formation of blood-clots in the cavities of the heart.

Etiology.—Though alteration in the integrity of the blood may have some influence in bringing about cardiac thrombi, the chief causes undoubtedly lie in a diseased endocardium, and may occur in acute or chronic disease of this membrane. It may be due to the obstruction of a free circulation by roughened valves or mural coat, thus furnishing a resting-place for fibrous deposits. The acute diseases, most liable to prove the exciting cause are, rheumatism, pneumonia, diphtheria, pyemia, and puerperal wrongs.

Pathology.—The blood-clots are found most frequently in the right side of the heart, in the auricular appendix more often than in the right ventricle. They vary in size, color, and consistency, and may be found from the size of a pinhead to that of a hen's-egg. If recent, they will be of a bright-red or reddish-brown color, and become gray or colorless as they age.

They are usually quite firmly attached to the endocardium by a sessile or pedunculated base, though the spherical or ball thrombi are free of attachments. They are firm in consistency in the earlier stages; but when degeneration takes place, softening follows, and sometimes particles become dislodged and float off to set up thrombi in other viscera. Calcareous degenerations have been noted.

They may occur singly or in groups. Thrombi have been known to project from one cavity into another, as from the left ventricle into the aorta.

Symptoms.—The symptoms are not very characteristic, and depend upon the size and rapidity of formation of the clot. The symptoms are those of obstructed circulation, the pulse being rapid and irregular, the apex-beat weak, and dyspnea more or less pronounced. Dizziness, vertigo, and attacks of syncope are common, and, later, cyanosis may appear.

In the advanced stage a clot may undergo necrosis, and blood-poisoning from absorption takes place. If a clot form suddenly and obstruct an orifice or coronary artery, sudden death results.

If the thrombi be in the right heart, and particles become dislodged, pulmonary embolism follows, with great dyspnea, pain, and cough, with bloody expectoration. Should the emboli be in the left ventricle, and a portion become detached, it would be swept into the general circulation, giving rise to cerebral, renal, or splenic embolism.

The physical signs are not very pronounced. The pulse is irregular and the apex-beat faint. The heart sounds are usually very feeble. Percussion gives negative results.

Diagnosis.—A positive diagnosis can only be made postmortem.

Prognosis.—The prognosis is always unfavorable, and sudden death may be anticipated.

Treatment.—The treatment will be altogether symptomatic.

The Eclectic Practice of Medicine, 1907, was written by Rolla L. Thomas, M. S., M. D.