During the cardiac cycle the heart’s four valves ( Fig. 2-1 ) channel blood flow in a single direction: from the atria to the ventricles and from the ventricles to the aorta and pulmonary artery. The numerous diseases that can alter the structure and function of these valves should be identified by a process of “valve analysis” involving cardiologists and surgeons. The challenge is to establish a precise diagnosis to recommend the most appropriate therapeutic option: continued medical therapy, percutaneous valve procedure, valve replacement, or valve reconstruction. This crucial choice implies that both surgeons and cardiologists use the same terminology and share the same understanding of valvular pathology, which has not been the case for decades.
FROM THE “BABEL SYNDROME” TO THE “PATHOPHYSIOLOGICAL TRIAD”
In Genesis, the Bible tells us that when the people building the Tower of Babel ceased to speak the same language, they could not work together anymore. Yet the “ Babel syndrome ” *
* See Glossary .
often prevails in medicine when different terms are introduced by different specialists to define similar findings. A sterling example of this is found in the multiple terminologies used to describe mitral valve pathology. Terms such as prolapse, flail, partial flail, redundant, overshooting, stretching, elongation, floppy, billowing, ballooning, Barlow, dysplasia, myxoid, and myxomatous, for example, have different meanings for different specialists. The confusion comes first from the fact that several of these terms are synonyms. For example, flail leaflet, overshooting leaflet, and leaflet prolapse are synonyms. Other synonyms are Barlow, billowing, ballooning, myxomatous valve, and mitral valve prolapse. Another source of confusion comes from the fact that for some specialists a given term such as “prolapse” means a dysfunction (leaflet prolapse) while for others it refers to a disease (mitral valve prolapse). The same chaotic situation applies to the term “floppy valve,” which is used to define either a valve morphology, or a dysfunction, or a disease. Similar confusion exists in tricuspid and aortic valve diseases, in which many of the previously listed terms are used without clear distinction. If surgeons and cardiologists do not speak the same language, how can they work together, proceed to a comprehensive valve analysis, and present valuable clinical data? These difficulties emphasize a pressing need to define precisely terminology in valve pathology.A clarification can be obtained by using a pathophysiological triad with a sound distinction between the terms describing valve etiology (i.e., the cause of the disease), valve lesions resulting from the disease, and valve dysfunction resulting from the lesions ( Table 2-1 ).
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Classifying terms into these three groups permits selection of one single term among several synonyms. Taking as an example the case of degenerative mitral valve diseases, Table 2-2 outlines our selection based on historical, scientific, and semantic considerations.
| Etiology | Barlow’s disease instead of myxoid, myxomatous, billowing, floppy valves and mitral valve prolapse |
| Fibroelastic deficiency should be recognized as a cause of degenerative valve disease (see Ch. 26 ) | |
| Lesions | Leaflet billowing instead of stretching, distension, ballooning and overshooting leaflet |
| Chordae elongation instead of chordae stretching or distension | |
| Dysfunctions | Leaflet prolapse instead of flail, partial flail, overshooting leaflet, floppy valve, mitral valve prolapse etc. |
A comprehensive understanding of valvular pathology implies clear distinction between etiology, lesions, and dysfunctions. This triad can be applied to all cardiac valves.
The pathophysiological triad facilitates communication between cardiologists, echocardiographers, and surgeons and greatly clarifies clinical investigations. In addition, it has significant clinical relevance for the individual patient because “long-term prognosis depends upon etiology, repair strategy depends upon dysfunction, and surgical techniques depend upon lesions.”
ETIOLOGY
Cardiac valves can be affected by numerous diseases ( Table 2-3 ). Primary valve diseases involve the valvular tissue. Secondary valve diseases affect the supporting structures of the valves—that is, the ventricles for the mitral and tricuspid valves and the aorta and pulmonary artery for the aortic and pulmonary valves, respectively. The determination of the etiology of valvular disease is important because it helps to establish the medical treatment, which should precede or follow valve reconstruction. In addition, it is the single most important predictor of long-term prognosis.
Primary Valve Diseases
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Secondary Valve Diseases
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* Includes three types of degenerative valvular diseases—Barlow’s disease, Marfan disease, and fibroelastic deficiency—described in Chapter 26 .
LESIONS
Any of the previously listed diseases can cause lesions affecting one or several components of the heart valves: the annulus, the leaflets, and the supporting structures ( Table 2-4 ). These lesions may be complex, multiple, and associated, making a comprehensive description by echocardiography difficult. This difficulty is overcome by a “functional approach,” which focuses attention on the dysfunctions resulting from lesions rather than on the lesions themselves .
