Joseph K. Perloff

The Mitral Apparatus Functional Anatomy of Mitral Regurgitation

This review deals with the functional anatomy of the six components of the mitral apparatus, namely, the left atrial wall, annulus, leaflets, chordae tendineae, papillary muscles, and left ventricular wall. Each component is considered individually, in the context of the apparatus as a whole, in relation to the mode of closure of the normal mitral valve, and in the light of many acquired and congenital disorders that disturb the harmony of the finely coordinated mitral mechanism and render it incompetent.The left atrium is related to mitral valve competence in terms of contraction and relaxation and in terms of dilatation of its posterior wall. The annulus not only serves as a fulcrum for the leaflets but exhibits sphincteric contraction in systole that decreases the size of the orifice. The two leaflets differ in shape but are nearly identical in area, and together are about two and one half times the area of the orifice that they are required to close. Leaflet abnormalities causing acquired or congenital mitral regurgitation result from deficient leaflet tissue, excessive leaflet tissue, or restricted leaflet mobility. Chordae tendineae are considered according to their leaflet attachments, ventricular attachments, thicknesses, lengths, and arborization patterns. Mitral regurgitation due to chordal abnormalities results from chordae that are abnormally long, abnormally short, ectopically inserted, or ruptured. In this context, systolic clicks and late systolic murmurs are discussed, and severe acute mitral regurgitation is contrasted with severe chronic mitral regurgitation. The papillary muscles and the left ventricular wall represent the two muscular components of the mitral apparatus. An appraisal of papillary muscle dysfunction includes dysfunction with loss in continuity (rupture) and dysfunction without loss in continuity (fibrosis, ischemia, replacement). Finally, the role of altered left ventricular shape is discussed in the context of mitral regurgitation, and the effect of dilatation is ascribed chiefly to alterations in the position of papillary muscles and their directional axes of tension.

The Cardiomyopathy of Progressive Muscular Dystrophy

A prospective study was undertaken in order to examine the histories, physical signs, phonocardiograms, electrocardiograms, vectorcardiograms, X-rays, serum enzymes, pulmonary ventilatory findings, and hemodynamics in a group of 55 patients selected solely on the basis of one of the major types of progressive muscular dystrophy (table 9). The classification included: (1) the classic Duchenne type, (2) the limb girdle type, (3) the facioscapulohumeral type, and (4) a group of patients in whom clinical distinction between benign Duchenne dystrophy and limb girdle dystrophy with pseudohypertrophy could not be made. No patient had recognized heart disease prior to selection. Follow-up periods ranged from a few months to 5 years. The pertinent literature was extensively reviewed.In all groups clinical evidence of heart disease had to be interpreted in the context of the influence of the somatic musculoskeletal defects on “cardiac” symptoms, cardiovascular physical signs, and radiological appearance of the heart. On the other hand, convincing evidence of intrinsic heart disease-subtle to overt-was found in each of the major categories of progressive muscular dystrophy. Detection of cardiomyopathy was simplest and most frequent in the classic Duchenne group because of the highly characteristic features of the scalar electrocardiogram which might direct attention to the systemic myopathy prior to its clinical recognition. However, the presence of heart disease in patients with forms of dystrophy other than the classic Duchenne deserves particular emphasis. Evidence of cardiomyopathy in these latter forms varied from subtle quadruple gallop rhythms in the limb girdle and facioscapulohumeral groups to cardiomyopathic death in the benign Duchenne and limb girdle-pseudohypertrophic group.Currently available information on the heart in muscular dystrophy has as a rule depended upon retrospective studies, upon reviews of published reports of incompletely classified cases, upon discussions of individual cardiovascular features, or upon observations of individual types of dystrophy. The presentprospective study was undertaken to obviate some of these shortcomings. Comprehensive assessment of a large and carefully classified group of dystrophic subjects has provided additional information regarding the clinical spectrum of dystrophic cardiomyopathy.

Severe valvular aortic stenosis in patients over 65 years of age: A clinicopathologic study

Abstract Clinical and anatomic data are presented in 21 autopsy cases of patients over 65 years of age with severe valvular aortic stenosis. Attention is called to the unusual nature of the valvular lesion in the elderly compared to its manifestations in younger adults. The degree of aortic stenosis even in the very elderly may be extreme. The aortic valve in 2 patients was congenitally bicuspid, and in 19, tricuspid. The latter valves usually were characterized by the uniform distribution of nodular calcific deposits on the aortic aspects of the cusps and by the lack or near lack of commissural fusion. Calcification of the mitral annulus occurred in 16 of the 21 patients. Clinically, aortic stenosis in the elderly is characterized by several features that are either absent or more prominent than in younger subjects with this valvular lesion: The systemic arterial pulse pressure may be increased due to systolic hypertension; a harsh right basal systolic murmur may be relatively inconspicuous, whereas a pure musical systolic murmur may be prominent at the apex; a coexisting apical systolic murmur of mitral regurgitation may be related to mitral annular calcification and not to left ventricular failure; and systemic systolic hypertension can result in a comparatively small pressure gradient despite severe left ventricular outflow obstruction.

The Recognition of Strictly Posterior Myocardial Infarction by Conventional Scalar Electrocardiography

This study was undertaken in order to determine whether the standard scalar electrocardiogram contains sufficient information to permit the recognition of strictly posterior myocardial infarction. Sixteen patients were selected on the basis of vectorcardiographic evidence and four on the basis of autopsy evidence. One hundred normal adult electrocardiograms served as controls. The data indicate that strictly posterior infarction causes (1) R waves of 0.04 second in V1 and in contiguous right anterior chest leads with upright T waves and, in the acute phase, ST-segment depressions, (2) Q waves of 0.04 second in an area posteriorly between the spine and the left scapula, (3) R/S ratios equal to or greater than one in V1 and V2, (4) slurring of the descending limb of the R wave in lead V1 due to abrupt change in QRS direction, and (5) no pathologic Q waves in the standard 12 leads unless diaphragmatic or lateral infarction coexists. Extra chest leads derived from the right anterior and left posterior thorax serve principally to corroborate the diagnoses. R waves of 0.04 second or R/S ratios equal to or greater than one in lead V1 were also found in the normal child, complete right bundle-branch block, the Wolff-Parkinson-White syndrome with an anteriorly directed delta wave, right ventricular hypertrophy, and an occasional normal adult especially with vertical frontal plane electrical axis. Attention to these differential diagnoses and to the foregoing manifestations of strictly posterior infarction facilitate its recognition by conventional scalar electrocardiography.

Congenital Aortic Stenosis Resulting From a Unicommissural Valve: Clinical and Anatomic Features in Twenty-one Adult Patients

Clinical, electrocardiographic, phonocardiographic, radiographic, hemodynamic, and anatomic findings are presented in 21 adult patients with stenotic unicommissural aortic valves. Distinction between congenitally unicuspid and bicuspid aortic valves before operation or autopsy was not possible. Although the basic structure of the valve may render it inherently stenotic, the age at which a murmur was first noted (average, 19 years), the duration of a known murmur (average, 25 years), and the age of onset of first symptoms of left ventricular outflow obstruction (average, 41 years) strongly suggest that stenosis at least in part is acquired. The relationship of the true and false commissures to the coronary arterial ostia could be determined with certainty in 12 patients. The basic division of the aortic valve into left, right, and noncoronary cusps is maintained, but the raphes do not extend to the valve orifice. Because the aortic valve is attached to the ascending aorta at only one point (the true commissure), which is at the level of the orifice, valvotomy is hazardous, and valve replacement appears indicated when operative treatment becomes necessary in the adult patient with a stenotic unicommissural aortic valve.

Systolic clicks and the late systolic murmur: Intracardiac phonocardiographic evidence of their mitral valve origin☆

Abstract The use of intracardiac phonocardiography has been employed as a method of documenting the origin of systolic clicks associated with an isolated late systolic murmur in a patient with hemodynamic evidence of mitral incompetence. Registration of both of these acoustical events within the left atrial chamber has not been hitherto described. Response of the clicks and murmur to the infusion of pressor amine and to the inhalation of amyl nitrite adds further weight to the concept of their origin at the mitral orifice. These observations confirm and extend previous information relating the late systolic murmur to organic mitral incompetence even if the murmur is accompanied by systolic clicks.

Auscultatory and phonocardiographic manifestations of pure mitral regurgitation

Summary Auscultatory and phonocardiographic studies are reported in 33 patients in whom pure, organic mitral regurgitation was believed to be the sole hemodynamic fault. Comments were made regarding the nature of the systolic murmur, second heart sound, third heart sound, middiastolic murmur, and opening snap. The study included a discussion of the effects of pressor amine infusion and amyl nitrite inhalation. Comment was made on the additional acoustic events that might occur when mitral incompetence is associated with pulmonary hypertension.

Clinical Recognition of Tricuspid Stenosis

Clinical criteria for the recognition of tricuspid stenosis were studied in 13 cases, all personally observed by the authors. The results suggest that application of these criteria not only allows a confident diagnosis of tricuspid stenosis in a substantial majority of cases, but also allows the lesion to be recognized relatively early in its natural history.

THE STRAIGHT BACK SYNDROME: CLINICAL CARDIOVASCULAR MANIFESTATIONS.

Analysis of the cardiovascular manifestations caused by loss of thoracic kyphosis has been incomplete. Accordingly, this study was designed to investigate the physical signs and the electrocardiographic, radiologic, hemodynamic, and pulmonary ventilatory features of this skeletal defect. Twenty-three patients with straight thoracic spines in lateral chest x-rays were selected. Ratios of anteroposterior to transthoracic dimensions were uniformly below a mean derived from 100 normal subjects. Cardiac features included pulmonic ejection murmurs, palpable left parasternal systolic impulses, loud delayed sounds of tricuspid valve closure, exaggerated respiratory splitting of the second heart sound, vertical electrical axes, rSr′ patterns in leads V1 or aVR, radiologic prominence of the pulmonary arteries, levodisplacement of the heart, a “pancake” cardiac configuration simulating cardiomegaly, occasional alterations in height or contour of the right ventricular diastolic pressure pulse, and an occasional mild pulmonary ventilatory restrictive defect. Differential diagnoses principally included atrial septal defect, mild pulmonic stenosis, and idiopathic dilatation of the pulmonary artery.

The isolated systolic click with bacterial endocarditis

Abstract The mitral valve and its supporting structures have been convincingly implicated as a source of late systolic murmurs as well as mid to late systolic (nonejection) clicks. Although attention has been called to theoretical susceptibility to endocarditis in subjects with these auscultatory signs, the patient whose case is described here represents the first example of the occurrence of endocarditis in this context. The endocarditis had its inception when only an isolated systolic click was heard. A late systolic murmur appeared for the first time during the course of treatment. In view of the difficulty in distinguishing intracardiac from extracardiac systolic clicks, consideration must be given to prophylaxis for endocarditis even when these mid to late systolic clicking sounds occur without an accompanying late systolic murmur.