FUNCTIONAL DISORDERS OF THE HEART Definition-Etiology-Pathogenesis-Section I. Cardiac Pain; Local and Referred-Section II. Palpitation; Definition; Causation; Features of Paroxysm-Section III. Cardiac Asthenia-Section IV. Alterations in the Rhythm of the Heart's Action; Arrhythmia; Intermittence and Ir- regularity-Section V. Alterations in the rate of the Heart's Action- Section VI. Tachycardia — Section VII. Decrease in the rate of the Heart's Action-Section VIII. Diagnosis; Prognosis; Treatment LIST OF ILLUSTRATIONS FIG. 1. Section through the base of the heart, showing the relations of the cardiac orifices and valves 2. Relation of the heart and aorta to the ribs and sternum 3. The position of the valvular orifices, and their relation to the cardiac dulness 4. Diagrammatic representation of the cardiac cycle 5. Normal Cardiogram (Sansom after Galabin) 6. Diagrammatic representation of the cardiac sounds with reference to the cardiac cycle 7. Diagrammatic representation of the diagnosis 8. The areas in which the sounds produced at the various cardiac orifices are most distinctly heard 9. Diagrammatic representation of a systolic murmur 10. Diagrammatic representation of an entire diastolic murmur 15. Mahomed's scheme of the tidal wave 16. High-tension pulse tracing 17. Low-tension pulse tracing 18. Dicrotic pulse tracing PAGE 3 5 7 12 19. Virtual-tension pulse tracing 20. Pulse tracing from a case of dilatation of the heart showing respiratory curves 21. Pulse tracing from a case of aortic regurgitation 22. Pulse tracing from a case of aortic stenosis 23. Anacrotic pulse tracing 24. Pulsus Bisferiens 25. Pulse tracing from a case of mitral regurgitation 26. Pulse tracing from a case of mitral stenosis 27. Pulse tracing taken from the left radial artery in a case of aneurism FIG. 28. Pulse tracing taken from the right radial artery in the same case (Fig.27) 29. Normal cardiogram (Sansom after Galabin) 30. Cardiogram from a case of mitral stenosis (Sansom) PAGE 93 94 96 31. Cardiogram from a case of mitral stenosis (Sansom) 32. Cardiogram from a case of mitral stenosis (Sansom after Galabin) 33. Cardiogram from a case of mitral regurgitation (Sansom) 34. Cardiogram from a case of aortic obstruction (Sansom after Galabin) 35. Cardiogram and sphygmogram from a case of aortic regurgitation 36. The aortic arches, showing mode of transformation into permanent arterial trunks (after MacAlister, modified) 37. Diagrammatic outline of the organs of circulation in the foetus of six 38. Diagrammatic representation of an entire diastolic murmur 98 ΙΟΙ 103 189 189 189 189 332 332 DISEASES OF THE HEART CHAPTER I ANATOMY Position and shape of Heart and Pericardium-Size and weight of the HeartDimensions of the Auricles and Ventricles-Relative position of the Cardiac Orifices and Valves-Relative size of the Orifices of the Heart-Relation of the Heart and its Orifices to the Sternum and Ribs THE heart is situated in that portion of the cavity of the chest which is known as the middle mediastinum. The Pericardium: its shape and connections.-The pericardium, wherein the heart is contained, is a cone-shaped membranous sac, which is attached by its base to the middle leaflet of the tendon of the diaphragm, and by its apex is continuous with the fibrous sheaths of the great vessels, and through them with the cervical fascia. This, the outer or fibrous layer of the pericardium, is lined by a serous coat, which is reflected along the great vessels on to the surface of the heart, and completely envelops the whole viscus. The space between the two layers of the serous covering is known as the cavity of the pericardium. Under normal conditions this space is potential rather than real, since the two layers of the sac are in close apposition. The general shape of the heart is that of a blunt, flattened cone, the anterior convex surface of which faces upwards and forwards, while the more flattened posterior looks downwards and backwards. The shape and position of the heart.-The base of the organ is directed upwards, backwards, and to the right, extending from the level of the sixth to the eighth dorsal vertebra, and the apex points downwards, forwards, and to the left. During life the apex beat is palpable in the space between the cartilages of the fifth B and sixth ribs, about 31⁄2 inches, or 9 cm., from the mid-sternal line. In the child the apex beat is situated in the fourth interspace. Of the two borders of the heart, which are formed by the junction of the anterior and posterior surfaces, the one (margo acutus), longer and thinner, looks forwards and downwards, while the other (margo obtusus), shorter and more rounded, is directed backwards and to the left. The axis of the heart is inclined to the horizon at an angle of 40°, and the greater portion of the organ is situated to the left of the median line. The position of the heart is affected to some extent by posture, and by the degree of distension of the lungs. Except at its base, where it is attached to the great vascular trunks, the heart lies entirely free within the pericardial sac. It will be observed that although the pericardium and heart are both conical in shape, the bases of the two cones do not coincide. Thus in the case of the pericardium the base of the cone looks downwards, while in that of the heart it is directed upwards, backwards, and to the right. The relations of the heart.-The anterior surface of the heart is completely overlapped by the pleuræ and lungs, except over its lower part, where a roughly triangular area, to the left of the median line, remains uncovered. This uncovered portion of the wall of the heart, which corresponds with the area of superficial cardiac dulness, will be more accurately defined in a subsequent paragraph. The size and weight of the organ.—The size and weight of the heart are liable to considerable variation, in accordance with the age, sex, stature, and muscular development of the subject, as well as with the method of removal that is adopted. The following figures, therefore, must be looked upon as representing average measurements only. The weight of the adult male heart averages 11 ounces, or about 310 grammes; the weight of the adult female heart 9 ounces, or about 255 grammes. As a general rule, the adult has about 5 grammes of heart weight for each kilo of body weight; or, stated more exactly, the proportion of heart weight to body weight in the male is as 1 to 178, and in the female as 1 to 169 (Macalister). External markings. The external surface of the heart is divided into auricular and ventricular portions by a deep transverse groove —the auriculo-ventricular furrow. The division between the ventricles is shown by two shallow interventricular grooves, which, running from and at right angles to the auriculo-ventricular furrow, become continuous with one another a little to the right of the apex. It will thus be seen that the apex of the heart is formed entirely by the left ventricle. Moreover, owing to the position of the organ, |