Mitral Valve Disease [antikvár]

Foreword Uniqueness is a quality highly to be desired in virtually every publication on whatever subject. While enjoyably engaged in reading through the manuscripts of the several chapters of this remarkably comprehensive monograph on the mitral valve, 1 came to reaUze that there are many unique features that characterize the valve upon which this book focuses, and which likewise typify the book itself The Valve In what ways is the mitral valve special — different from the others.^ In the first place it is the valve called upon to withstand the greatest peak load of pressure. During systole, when the valve is closed, the differential in pressure from its ventricular face to its atrial face equals left ventricular peak systolic pressure minus left atrial pressure. The differential pressure across the aortic valve is somewhat lower, since it does not close until well after left ventricular relaxation has begun. Furthermore, since the area of the mitral orifice is significandy greater than the aortic one, the total force applied against the mitral valve while it is closed is comparatively further magnified. The mitral valve is also unique structurally. It has no significant portion of its anulus attached to the ventricular septum, and no chordal attachments to the septum either. Furthermore, its function is affected by several factors extraneous to its own inherent structure {a quality shared to some extent by the tricuspid valve). This is true since ventricular geometry influences the effecuveness of mitral valvular closure, and ventricular geometry is in turn affected by many common cardiac condidons including ischemic, viral and idiopathic myopathies. Thus, ventricular dilatation of whatever origin, such as in long-standing severe aortic valvular disease, may result in mitral regurgitation despite a structurally normal mitral valve. Even the rather localized and remote presence of septal hypertrophy in hypertrophic cardiomyopathy, through the intermediary influence of the Bernoulli effect, can produce significant mitral regurgitation in the absence of structural abnormality of the valve. The mitral valve is the most often diseased of the four cardiac valves, particularly with its proclivity to rheumatic involvement, and especially if one includes that currendy large group of otherwise apparenUy normal persons in whom the valve prolapses into the left atrium to varying degrees. Clearly, the mitral valve is the one most often treated surgically. A larger armamentarium of techniques is available to the surgeon for acquired disease of the mitral valve than for other cardiac valves, such as commissurotomy, annuloplasty, chordal revision, and plication or resection of redundant leaflet substance - all of these techniques from which to choose in addition to the option of replacing the valve. On the other hand, neither the mitral valve nor the tricuspid valve has been successfully replaced by one designed to simulate the natural corresponding valve. The Book Uniquely comprehensive, these 25 chapters cover the entire range of interests relating to mitral valvular heart disease — far more impressively than the two items would imply which are flagged in the subtide of the book. Every possible perspective is reviewed concerning the effects of disease of the valve on its structure and function, concerning the effects of its disease on the structure and function of related systems and of the patient as a whole and through