Mechanical and Myocardial Factors in Rheumatic Heart Disease with Mitral Stenosis

Abstract

Sixteen patients with rheumatic heart disease and pure mitral stenosis, studied by cardiac catheterization, are presented to illustrate the relative importance of mitral block and myocardial insufficiency in this disease. Analysis of hemodynamic data permitted a separation of those patients with predominantly mechanical mitral block from those in whom myocardial insufficiency appeared to be the predominant lesion. The importance of recognizing the existence of the latter group is emphasized, since commissurotomy will not be of benefit in such cases.C IRCULATORY dysfunction in rheumatic heart disease has long been recognized as springing from at least two main sources, the mechanical difficulties imposed by valvular lesions and the insufficiency of the myocardium itself. This insufficiency may result from longstanding strain inflicted on the cardiac muscle by altered valvular function or, independently of mechanical cause, may occur consequent to intrinsic myocardial damage from the rheumatic process. Our understanding of cardiac function in rheumatic patients would be increased if one could separate the mechanical from the myocardial components in order to investigate further the disability these subjects experience. The surgical approach to rheumatic mitral stenosis, attacking as it does only the mechanical features of valvular lesions, affords an opportunity to study this problem. Furthermore, if it can be shown that myocardial insufficiency exists as a separate dysfunction, it behooves the physician and surgeon to be certain that the prospective candidate foi mitral commissurotomy is suffering from a

Ventilation and haemodynamics in heart disease.

“…Studies in patients with mitral stenosis, before and after valvotomy, confirm that there is a much better correlation between clinical improvement and amelioration of the excessive ventilatory response on the one hand and a fall in pulmonary vascular pressures on the other, than there is with any rise in the cardiac output (Eliasch, 1952;Wade, Bishop, and Donald, 1954;Harvey et al, 1955;Donald et al, 1957). It is noted, however, that Donald and his associates, despite observing a good correlation between resting pulmonary wedge pressure and ventilation, found a very high exercise wedge pressure, sometimes of the order of 50 mm.…”

Pressure-flow studies in man: effect of atrial systole on ventricular function in mitral stenosis

“…One might postulate that poor ventricular compliance is the reason for the lack of dramatic improvement in this patient. This has been suggested by several investigators in the past (15)(16)(17)(18). The most reasonable explanation for the markedly reduced effect of atrial systole in augmenting stroke volume in patients with severe mitral stenosis is the loss of energy secondary to marked turbulence of blood flowing across the deformed mitral valve.…”

Global left ventricular function and regional wall motion in pure mitral stenosis‐Left ventricular function in pure mitral stenosis

“…Many studies have shown that in pure mitral stenosis, the left ventricular function (LVF) impairment is often observed (Bolen et al, 1975;Curry and Elliott, 1972;Ferrer et al, 1952;Flemming and Wood, 1959;Harvey et al, 1955). This LVF impairment can at times be obvious when considering the hemodynamic data at rest (Curry and Elliott, 1972;Herreman et al, 1980;Kennedy et al, 1970), but at other times it becomes evident only when an impairment response of the left ventricle to hemodynamic-induced changes is apparent (Bolen er al., 1975;Linhm, 1972;Ross and Braunwald, 1964).…”

“…This LVF impairment can at times be obvious when considering the hemodynamic data at rest (Curry and Elliott, 1972;Herreman et al, 1980;Kennedy et al, 1970), but at other times it becomes evident only when an impairment response of the left ventricle to hemodynamic-induced changes is apparent (Bolen er al., 1975;Linhm, 1972;Ross and Braunwald, 1964). In some patients the failure of mitral surgery to effect a satisfactory improvement can only be the result of a previous LV deficiency (Ferrer et al, 1952;Flemming and Wood, 1959;Harvey et al, 1955). Many factors may be involved in this ventricular dysfunction, such as a "myocardial factor," subvalvular fibrosis and a rigid "mitral complex," or an important reduction of the LV filling (Ferrer et al, 1952;Flemming and Wood, 1959;Grant, 1953;Harvey et al, 1955).…”

“…In some patients the failure of mitral surgery to effect a satisfactory improvement can only be the result of a previous LV deficiency (Ferrer et al, 1952;Flemming and Wood, 1959;Harvey et al, 1955). Many factors may be involved in this ventricular dysfunction, such as a "myocardial factor," subvalvular fibrosis and a rigid "mitral complex," or an important reduction of the LV filling (Ferrer et al, 1952;Flemming and Wood, 1959;Grant, 1953;Harvey et al, 1955). Some recent publications have pointed out the high incidence of contraction abnormality in pure mitral stenosis, such as posterobasal or anterolateral hypokinesis.…”