Relation between symptoms and profiles of coronary artery blood flow velocities in patients with aortic valve stenosis: a study using transoesophageal Doppler echocardiography.

Abstract

Objective-To analyse profiles of coronary artery flow velocity at rest in patients with aortic stenosis and to determine whether changes of the coronary artery flow velocities are related to symptoms in patients with aortic stenosis. Design-A prospective study investigating the significance of aortic valve area, pressure gradient across the aortic valve, systolic left ventricular wall stress index, ejection fraction, and left ventricular mass index in the coronary flow velocity profile of aortic stenosis; and comparing flow velocity profiles between symptomatic and asymptomatic patients with aortic stenosis using transoesophageal Doppler echocardiography to obtain coronary artery flow velocities of the left anterior descending coronary artery. Setting-Tertiary referral cardiac centre. Patients-Fifty eight patients with aortic stenosis and 15 controls with normal coronary arteries. Results-Adequate recordings of the profile of coronary artery flow velocities were obtained in 46 patients (79%). Left ventricular wall stress was the only significant haemodynamic variable for determining peak systolic velocity (r = -0-83, F = 88 5, P < 0.001). The pressure gradient across the aortic valve was the only contributor for explaining peak diastolic velocity (r = 0 56, F = 20-9, P < 0.001).Controls and asymptomatic patients with aortic stenosis (n = 12) did not differ for peak systolic velocity [32.8 (SEM 9.7) v 27-0 (8.7) cmls, NS] and peak diastolic velocity [58-3 (18.7) v 61'9 (13.5) cmls, NS]. In contrast, patients with angina (n = 12) or syncope (n = 8) had lower peak systolic velocities and higher peak diastolic velocities than asymptomatic patients (P < 0.01). Peak systolic and diastolic velocities were -7 7 (22 5) cm/s and 81'7 (17.6) cmls for patients with angina, and -19-5 (22.3) cmls and 94*0 (20.9) cmls for patients with syncope.Asymptomatic patients and patients with dyspnoea (n = 14) did not differ. Conclusions-Increased pressure gradient across the aortic valve and enhanced systolic wall stress result in characteristic changes of the profile of coronary flow velocities in patients with aortic stenosis. Decreased or reversed systolic flow velocities are compensated by enhanced diastolic flow velocities, particularly in patients with angina and syncope. This characteristic pattern of the profile of coronary artery flow velocities in patients with angina or syncope may be useful for differentiating those patients from asymptomatic patients.

Mechanisms of Coronary Microcirculatory Dysfunction in Patients With Aortic Stenosis and Angiographically Normal Coronary Arteries

“…4 Hyperemia is hindered by a series of unfavorable hemodynamic changes, including high LV cavity pressure, low coronary perfusion pressure, and increased extravascular compressive forces that lead to an increased minimal coronary resistance. 5 In addition, characteristic pathological changes that contribute to impair microvascular function have been described in the hypertrophied ventricle of patients with AS. These consist of perimyocytic fibrosis 6 and reduction in the number of resistance vessels per unit of weight.…”

Functional Changes in Coronary Microcirculation After Valve Replacement in Patients With Aortic Stenosis

“…3 Perimyocytic fibrosis 4 and reduction in the number of resistance vessels per unit weight 5 may contribute to the reduction in CVR in LVH secondary to hypertension and hypertrophic cardiomyopathy. However, recent work suggests that increased systolic impedance to coronary flow as a result of perivascular compression 6 and, most importantly, a reduction in diastolic perfusion 2 are the primary contributors to impairment of coronary microcirculatory function in AS, predominantly because of curtailment in maximal myocardial blood flow (MBF).…”

Myocardial Infarction in a Patient With Severe Aortic Stenosis and Normal Coronary Arteriograms-Involvement of the Circumferential Subendocardial Wall of the Left Ventricle-

“…It has been demonstrated that reversed systolic flow velocity compensated by enhanced diastolic flow velocity, as seen in this patient (Fig 4), is related to symptoms, such as angina or syncope, caused by the aortic stenosis. 9 The present patient's infarct was very unusual in view of the involvement of the left ventricular circumferential subendocardium. In patients with severe aortic stenosis and normal or nearly normal coronary arteriograms, myocardial infarction can result from factors other than atherosclerosis, such as coronary vasospasm or thromboembolism, including calcium embolization.…”