Can the Dipyridamole-Doppler Stress Test Detect Myecardial Ischemia? Agati et al’ report that Doppler interrogation of aortic flow during dipyridamole stress is highly sensitive in the detection of myocardial ischemia. Numerous exerciseDoppler studies have emphasized the limitations of this approach in detecting coronary artery disease (CAD).* We would like to make the following points. First, the aim of the study was to establish whether the dipyridamole-Doppler test could detect myocardial ischemia and yet this question remains unanswered. Experimental and clinical attempts to use Doppler indexes to do this have failed, except in special situations such as during percutaneous transluminal coronary angioplasty or during coronary ligation studies in animals.3 To answer the question, CAD patients who developed ischemia during the test need to be compared with well-matched CAD patients who did not, whereas Agati et al compared their CAD group (some of whom did not develop ischemia) with a control group. Second, 3 group II patients showed an increase in Doppler parameters despite the occurrence of new wall motion abnormalities, which the authors speculate could have been due to the development of compensatory hyperkinesia in normal myocardial segments. Was this seen in these patients or in any of the others with wall motion abnormalities? Third, although no CAD patient had a pretest wall motion abnormality, the baseline ejection fraction is not given; because 22 of 29 CAD patients had multivessel CAD, this is likely to have been abnormal in a proportion. Impaired pretest left ventricular systolic and diastolic function could account for the increase in left ventricular end-diastolic pressure, decrease in stroke volume and minimal change in peak positive left ventricular dP/dt induced bv dinvridamole in the CAD group. These changes could therefore represent the interaction of a hemodynamic change with an abnormal ventricle rather than be a manifestation of myocardial ischemia. Similarly, patients with a higher coronary angiographic jeopardy score may have had poorer left ventricular function, which would account for the apparently higher sensitivity of Doppler variables in this subgroup. Last. baseline (temnoral) variabilitv is generally greater-than intraobserver and interobserver variability (because it incorporates intraobserver, physiologic and technical variation) and is much more relevant to serial measures, but is not quoted. We studied 40 natients during dinvridamole stress and compared CAD patients who developed ischemia with those who did not using 2-dimensional echocardiographic and electrocardiographic criteria.4 Groups were well-matched for baseline left ventricular systolic and diastolic function. Doppler indexes of aortic flow

were insensitive in detecting ischemia; similar negative conclusions have been reached by others.5 We observed a highly variable response to dipyridamole between patients, resulting in considerable overlap in the changes in Doppler indexes between groups. We also found that Doppler parameters of global left ventricular systolic function are generally preserved in the setting of localized ischkmia unless ischemia is profound or associated with left ventricular dilatation. The effect of the marked drop in systemic vascular resistance induced by dipyridamole on aortic flow probably overrides the effect of localized transient left ventricular dysfunction, which is, in any case, compensated for by hyperkinesia of nonischemit myocardium, a common observation in our patients.

vival of only 10 to 20%.3 In addition, 1

Peter Mazeika, MRCP Nikoyannopeulor, MD Celia M. Oakley, MD London, United Kingdom

J.J. Dunning, mcs P.A. Mullins, MRCP J.P. Scott, FRICP E. %liS, MD P.M. Schofield, MD S.R. Large, mcs J.W. Wallwork, mcs

patient underwent

peutic agents and radiotherapy

18 June 1990

Cardiac Transplantation Cancer

and

selection,

overall

survival

at 1

year was 57%, which compares poorly with the overall survival figures of 85% at 1 year quoted by the International Society for Heart Transnlantation.* The tvne and extent of malignant disease must bk evaluated with care. It appears inappropriate to transplant a patient with a Duke’s stage C2 adenocarcinoma of the colon when this stage of disease has a known 5-year sur-

THE AMERICAN

without

Cambridge, United Kingdom 24 May 1990 1. Edwards BS, Hunt SA, Fowle MB, Valantine HA. Stinson EB. Schroeder JS. Cardiac transplantation in patients with preexisting neoplastic disease. Am J Cardiol 1990; 65:501-504. 2. Heck CF. Shumway SJ, Kaye MP. The Registry of the International Society for Heart Transplantation: sixth official report-1989. J Heart Transplant 1989 July-August 8(4):27 l276. 3. Clark ML, Price AB, Williams CB. In: Oxford Textbook of Medicine (second edition) Volume I. Oxford University Press, 1987;12: 157.

4. Baumgartner WA. In: Heart and HeartLung Transplantation. W.B. Saunders, 1990: 279-283.

Atrial Septal Aneurysm as a “Newly Discovered” Cause of Stroke in Patients with Mitral Valve Prolapse The recent report of an increased prevalence of atria1 septal aneurysm (ASA) in mitral valve prolapse (MVP)’ has impor-

In their recent article, Edwards et al’ concluded that a history of neoplastic disease need not serve as a contraindication to cardiac transplantation. However, we feel that their results do not support this conclusion. It must be noted that the total number of patients is small (n = 7) and the selection criteria are not clear. Despite “careful”

after

considering other systemic side effects, including pulmonary disease. Treatmentrelated respiratory failure was the cause of death in 1 patient and suggests inadequate preoperative assessment. We agree that transplantation is feasible in carefully selected patients who are “cured” after treatment of malignant disease, but is it a prudent use of scarce donor resources? It is not our practice to transplant patients who are known to have malignancy.

Petros

1. Agati L, Arata L, Neja CP, Manzara C, Lacoboni C, Vizza CD, Pence M, Fedele F, Dagianti A. Usefulness of the dipyridamoleDoppler test for diagnosis of coronary artery disease. Am J Cardiol 1990;65:829-834. 2. Harrison MR, Smith MD, Friedman BJ, Demaria AN. Uses and limitations of exercise Doppler echocardiography in the diagnosis of ischaemic heart disease. J Am Coil Cardiol 1987;10:809-817. 3. Pandian NG, Wang SS, Thanikachalam S. Role of Doppler echocardiography in ischaemic heart disease. In: Kerber RE, ed. Echocardiography in Coronary Artery Disease. New York: Futura Publishing, 1988;262-265. 4. Mazeika P, Nihoyannopoulos P, Joshi J, Oakley CM. Failure of dipyridamole-Doppler echocardiography to detect myocardial ischaemia and coronary artery disease (abstr). C[in Sci 1990;79(suppl 23). 5. Grayburn PA, Popma JJ, Pryor SL, Walker BS, Simon TR, Smitherman TC. Comparison of dipyridamole-Doppler echocardiography to thallium-201 imaging and quantitative coronary arteriography in the assessment of coronary artery disease. Am J Cardiol 1989;63: 1315-1320.

retransplantation

recurrent rejection episodes. The results for early retransplantation are poor4 and in our view it is difficult to justify this management. It is not sufficient to assess only cardiotoxic effects of chemothera-

JOURNAL

tant clinical

implications

besides estab-

lishing a definitive association. The latter was first brought to our attention in 1984.2,3 ASA is often associated with interatrial shunting,4s5 which can, in turn, lead to paradoxical embolism.6 Systemic embolism, especially into the cerebral circulation, is one of the serious complications of MVP, which is otherwise a benign and common condition.’ The most likel; cause of cerebral ischemic attacks and strokes in natients with MVP is embolism of a nonInfective contact thrombus, originating either from the atria1 surface of the prolapsing mitral leaflet or in the angle formed by the junction of the left atria1 endocardium and the atria1 surface of the prolapsing

OF CARDIOLOGY

FEBRUARY

1, 1991 327