Evaluation of aortic valve replacement in patients with valvular aortic stenosis.

Abstract

Echocardiographic and hemodynamic studies were obtained in 42 consecutive patients undergoing aortic valve replacement for isolated aortic stenosis. Concentric left ventricular (LV) wall thickening, the most common preoperative abnormality, occurred in 95% of patients. LV dilation with reduced fractional shortening was noted in approximately 25% of patients but was severe in only one patient. Six months after operation, LV wall thickness had decreased on average but had not returned to normal and fractional shortening was unchanged. Repeat measurements in 13 patients an average of 37 months after operation were unchanged compared with measurements made 6 months after operation. When patients were subdivided into those with LV dilatation and those without, we found that patients with dilated ventricles preoperatively had a greater decrease in LV internal dimension and mass than those without preoperative dilatation. The patient data also were examined for possible association with mortality. One operative (2%) and five late cardiac (13%) deaths occurred. No preoperative or 6-month postoperative echocardiographic or hemodynamic measurement was strongly associated with these deaths, nor were any late deaths due to congestive heart failure. Compared with preoperative measurements in symptomatic patients who were operated for isolated aortic regurgitation, patients with aortic stenosis had smaller left ventricles with less depression of systolic function, as well as less aortic root and left atrial dilatation. Our data do not support the concept that the aortic valve should be replaced before the onset of symptoms to prevent irreversible LV damage in patients with isolated aortic stenosis.

Complete reversibility of cat right ventricular chronic progressive pressure overload.

“…Recent clinical observations of hypertrophy induced by volume (Clark et al, 1980) (Henry et al, 1980) overloads show that only a partial rather than full anatomical regression of ventricular enlargement follows replacement of an abnormal cardiac valve. The functional abnormalities associated with each hemodynamic overload also show only a partial reversal (Kennedy et al, 1977;Pantely et al, 1978).…”

Fluid dynamics of aortic stenosis: subvalvular gradients without subvalvular obstruction.

“…'I--3 Aortic valvular stenosis can coexist with various types of subvalvular obstruction.2-14A9 These associated lesions cannot always be demonstrated angiographically, even by left ventriculography in several views. In such cases, obstructive lesions are best diagnosed from pressure gradients detected by catheter pullback from the ventricle to the proximal aorta.2 3, 10, 12, 19 Persistence or recurrence of intraventricular gradients shown by repeated or serial postoperative catheterization signals inadequate resection or regrowth of subvalvular obstructive lesions and possibly the need for further surgical resection.6 [20][21][22][23][24][25] Clinical investigation of normal ejection dynamics has shown that dynamic factors associated with flow contribute to physiologic transvalvular pressure gradients.26 Studies of flow dynamics in hypertrophic cardiomyopathy have cast strong doubt on the premise that large intraventricular pressure gradients are always a consequence of an anatomic obstruction of the outflow tract region.27 Improved instrumentation for measuring pressure28 33 has led to the frequent observation of subvalvular gradients in patients with valvular aortic stenosis without subvalvular pathology in our *The term gradients in this paper is used in the conventional hemodynamic sense, but in fluid dynamic terms represents a driving pressure difference evaluated across a finite distance in the direction of flow. …”

Assessment of Ventricular Function by Radionuclide Angiography: Applications and Results

“…Moreover, when valve replacement is per formed because symptoms have developed, long-term postoperative survival is excellent: in our prospective natural history/prognosis series, survival during an average 4.4 years after operation was 83%. Late postoperative mortality, which was largely related to pros thesis-mediated complications or to coexist ing coronary artery disease, was not predicted by any objective functional characteristic [87]. Therefore, it would appear that symp tom status generally is an excellent indicator as to the appropriate timing of valve replace ment in the patient with aortic stenosis: when valve replacement is undertaken at the time of symptom onset, symptoms almost always are relieved, irreversible left ventricular dys function generally does not occur, and post operative prognosis is excellent.…”