lars per year), but more importantly for the individual patient (67 years of testing time per potential life saved). The authors suggest a pros- pective study of >5,000 patients would be needed to better define the prevalence of blood dyscrasias. This cost analysis strongly suggests such a study needs to be done.

Kenneth M. Kessler, MD

Miami, Florida 13 December 1994

1. Danielly J, DeJong R, R&e-Mitchell LC, Up- richard ACG. Procainamide-associated blood dys- crasias. Am J Cardiol 1994;74:1179-1180.

Characteristics of False-Positive Exercise Treadmill Tests

The report “Diagnostic Signifi- cance of Exercise-Induced ST-Seg- ment Depression in the Inferior Leads in Patients With Suspected Coronary Artery Disease” by Dr. Chikamori and colleagues’ adds to the body of literature describing the low specificity and lack of positive predictive value for significant coro- nary artery disease when exercise-in- duced ST-segment depression is confined to the inferior leads. Prior studies have identified guidelines for recognizing exercise-induced ST- segment depression in the inferior leads alone as a possible cause of a false-positive test. These character- istics include2: 1) pronounced down- sloping of the PR segment at peak exercise; 2) greater augmentation of P-wave amplitude by exercise; 3) ability to complete a significant ex- ercise duration (24 minutes) and to achieve a rapid exercise heart rate (2125 beats/mm); and 4) absence of chest pain. Some of these character- istics are corroborated in Dr. Chika- mori’s observation that patients with inferior ST-segment depression alone “had a longer duration of exercise, a higher peak heart rate, a higher peak blood pressure, a lesser magnitude of maximal ST-segment depression, and a smaller number of leads with ischemic ST-segment depression.” In these patients with a false-positive test, exaggerated atria1 repolarization waves extending into the ST seg- ment are thought to mimick the ST- segment changes observed in myo- cardial ischemia. Therefore, the abil-

ity to complete more exercise and to achieve a higher heart rate and blood pressure are probably simple mark- ers of a generally healthier group of patients. I believe that it is important for physicians to recognize the char- acteristics of false-positive tests so that patient anxiety may be mini- mized and additional invasive test- ing can be avoided. Equally impor- tant is Dr. Chikamori’s observation that, when exercise-induced ST-seg- ment depression is present in the pre- cordial leads in addition to the infe- rior leads, the likelihood of signifi- cant coronary artery disease is high.

Jason Shen, MD

Chapel Hill, North Carolina 29 December 1994

1. Chikamori T, Yamada M, Takata J, Fumno T, Yamasaki F, Yabe T, Doi Y. Diagnostic significance of exercise-induced ST-sezment demession in the inferior leads in patients with suspected coronary artery disease. Am J Cardiol 1994;74:1161-1164 2. Sapin P, Koch G, Blauwet M, McCarthy J, Hinds S, Gettes L. Identification of false positive exercise tests with use of electrocardiographic criteria: a pos- sible role for atria1 repolarization waves. J Am Coil Cardiol 1991;18:127-135.

Announcement of Multicenter Giant-Cell Myocarditis Study

This letter serves as our an- nouncement of the Multicenter Giant- Cell Myocarditis Study. Giant-cell myocarditis is a rare and frequently fatal disorder, which has only been described in case reports and 2 small series.’ The goal of the study is to gather a database of patients with id- iopathic giant-cell myocarditis from American and international cardio- vascular centers. Many questions re- main unresolved regarding the natur- al history and treatment of this rare disease, and can only be answered by assembling multicenter patient data.

The data collection and analysis will be organized at the University of California at San Diego. If you know of any patients with this diag- nosis, we would greatly appreciate your participation. In return for our use of anonymous patient data, you and your medical center will be named in any publications that come from the database (there may be op- portunities for authorship as well).

If you have patients with idio- pathic giant-cell myocarditis, please contact us at the address listed be-

low. We will send a detailed ques- tionnaire and further information. Thank you in advance for any infor- mation you may provide.

Leslie T. Cooper Jr., MD

Ralph Shabetai, MD

USCD Medical Center 200 W. Arbor Drive

San Diego, California 92037-8411 TEL: (619) 552-7504 FAX: (619) 552-7490

17’June 1995

1. Cooper LT, Berry GJ, Rizeq M, Schroeder JS. Giant cell myocarditis. J Heart Lung Transplant 1995;14: 394-401.

Effect of Right Ventricular Infarction/lschemia on Right Precordial T-Wave Polarity in Inferior Wall Acute Myocardial Infarction

In the January 1, 1995 issue of The American Journal of Cardiolo- gy, Wong et al’ reported the effect of concomitant left anterior descending narrowing or posterolateral extent of jeopardized territory on the right pre- cordial T-wave inversion in inferior wall acute myocardial infarction (AMI). The article supplied some in- teresting data and highlighted the fact that relatively little attention has been given to the significance of pre- cordial T-wave polarity in inferior wall AMI. Unless the authors had a chance to read Chest recently, they will not have seen my article2 de- scribing the same phenomenon. The major findings of my study were sim- ilar to theirs, although my analysis was restricted to the right precordial lead Vi; the direction of the ST shift correlated well with T-wave polari- ty, and it appeared that concomitant multivessel disease did not affect T- wave polarity in lead Vi. I also ex- amined the relation of T-wave po- larity in precordial lead V, to right or left circumflex coronary patho- anatomy to test the hypothesis that concomitant right ventricular (RV) involvement may affect the T-wave polarity in the right precordial leads in inferior wall AMI. Given the fre- quent manifestation of an upright T wave in lead V, in patients with proximal right coronary occlusion compared with distal right or left cir- cumflex coronary occlusion, my find- ings suggest that, in inferior wall

640 THE AMERICAN JOURNAL OF CARDIOlOGY@ VOL. 76 SEPTEMBER 15, 1995