Journal of the ?uncrican Society o f Echocardiography 398 Abstracts May-June 1996

6 0 1 N DOES ATROPINE INJECTION PRIOR TO EXERCISE ECHOCARDIOGRAPHY INCREASE THE HEART RATE DURING IMAGE ACQUISITION? A RANDOMIZED TRIAL Christine H. Attenhofer, M.D.; Mary Ann Capps; Veronique L. Roger, M.D.; Robert B. McCully, M.D.; Jae K. Oh, M.D.; Anne M. Hepner, M.D.; Patricia A. Pellikka, M.D. Mayo Clinic, Rochester, MN

The rapid decline of heart rate (HR) that occurs after exercise is a potential limitation of treadmill stress echocardiography (TM-SE). We assessed the impact of intravenous administration of 0.5 mg atropine (ATR) prior to exercise in a prospective, prospective double-blind placebo-controlled study in 43 consecutive patients (pts) referred for TM-SE for evaluation of known or suspected coronary artery disease. Pts received either saline (22 pts) or 0.5 mg ATR (2i pts) I0 minutes (min) prior to symptom-limited treadmill exercise. The HR was measured at 1 minute intervals after ATR or saline injection, during exercise, and for 10 minutes into recovery. There were 28 men and 15 women, mean age 63 ± 8 years. There was no significant difference in work load, age, gender, cardiac medication, and body weight between the two groups (p=NS). Prior to the injection, the HR was 67 _+ 11 bpm in the ATR and 69 ± 9 bpm in the saline group (p=NS). As shown in the table, the increase in HR from the HR at rest (in bpm) was significantly higher after ATR injection than after saline throughout recovery; at peak exercise, there was no significant difference.

Peak 1 min 2 rain 3 rain 10 rain Saline 79_+19 50_+18 35+17 27_+19 20±8 Atropine 85-+20 62+21 45+15 37_+13 27±14 p value 0.27 0.048 0.048 0.009 0.05 The HR during the image acquisition tended to be higher after ATR (124 ± 26 bpm) than after saline injection (114 ± 20 bpm; p=0.19). Asymptomatic self-limiting supraventricular premature atrial contractions and short runs of supraventricular tachycardias were more common in the ATR pts (33% vs 9%, p=0.046), but none required treatment. A dry mouth was more common in ATR pts (33% vs 0%, p=0.0I). No other side effect was noted. Conclusion: The injection of 0.5 mg of atropine prior to TM-SE is safe and increases the heart rate during the critical period of image acquisition in TM-SE.

6 0 1 P CAN DOBUTAMINE STRESS ECltOCARDIOGRAPHY BE A QUANTiTATiVE METHOD TO EVALUATE MYOCARDIAL ISCHEMIA ? Satoshi Yamada MD, Taisei Mikami MD, Hiroya Takatsuji MD, Naotaka Saito MD, Hisao Onozuka MD, Jun-ichi Teranishi MD, Mitsunori Ohtsubo MD, Koh-ichi Okita MD, Kazuya Yonezawa MD, Kazushi Urasawa MD, Akira Kitabatake MD, Hokkaido University School of Medicine, Sapporo, Japan

We inves t iga ted the provoca t ion threshold of myocard ia l ischemia in dobutamine and exercise stress tests and compared the parameters of cardiac work and contractility at the threshold between these two methods. Dobutamine stress echocardiography (DSE; 5-401ug/kg/mio) and upr ight b icyc le exercise echocardiography (BEE) were perlbrmed in 20 patients (Pts) with angiographically proven coronary artery disease (CAD; >-75% di- ameter stenosis) but without myocardial infarction. Both tests were positive in 10 Pts. At the points just before wall motion ab- normality was provoked in the area perfused by the culprit artery, rate-pressure product (RPP) and mean velocity of circumferential tiber shortening (mVcf) were measured and compared between DSE and BEE. Results:Mean Vcf in DSE was significantly higher than that in BEE and RPP in DSE was lower than that in BEE. Close correla- tion were observed between DSE and BEE both in mVcf and in RPP.

f/1 mm y=0.79x+0.54 1=0.96

F/ .7 100 0 " ' 100 150 200 250 0 1 2 3

RPP in BEE txl02 mmHg/min) mVcfin BEE (circ/sec) Conclusion: Since the threshold mVcf and RPP for myocardial ischemia induced by dobutamine stress correlated well with that by exercise stress, we would infer that DSE can be a quantitative method to evaluate myocardial ischemia.

6 0 1 0 A NEW DOBUTAMINE-ATROPINE STRESS ECHOCARDIOGRAHY PROTOCOL: FEASIBILITY, ACCURACY, AND SAFETY K. Schr6der, MD, B, K0rsten, MD, R, Dissmann, MD, and H-P. Schultheiss, MD. Kiinikum Benjamin Franklin, Oepl. of Cardiology, Free University Berlin, Berlin, Germany.

In a retrospective analysis of 100 pts undergoing routine dobutamine-atropine stress echocardiography (DASE), we could demonstrate that only pts with a heartrate (HR)<100 bpm at 20pg/kg dobutamine (DOB) infusion (6 th minute of the test) will need atropine (AT) application to reach their age predicted target heartrate (THR).

The aim of this study was to test a new protocol, which intended to eliminate the problems inherent in the regular DASE (1. relative long examination time, and 2. overshooting of the HR leading to unpleasant palpitations and tachycardias) by addition of AT early in the course of the test as compared to standard procedure of AT application following the max DOB dose.

Methods: 50 consecutive pts (mean age 58.3 yrs) scheduled for a routine DASE were entered into the study. Pts with a HR<100 bpm at 20 pg/kg of DOB and were randomized to either AT addition after 20 IJg/kg (group A) or 40 pg/kg of DOB (group B). The remaining pts (i.e. HR>100 bpm) continued the test in the standard way and received AT only if necessary after the max DOB dose of 40 IJg/kg.

Results: 31 (62%) pts had a HR>100, all reached the THR without AT. Of the remaining 19 pts 8 were randomized to group A and 11 to group B. The baseline characteristics of the groups were not different. All 19 pts reached the THR, 4 however without AT. The total duration of the test and the time to max HR were significantly shorter (p< 0.001) in A as compared to B (22.9:~2..5 vs. 27.8_+2.7 rain; 9.4_+0.7 vs. 13.9.+..2,2 min resp.). A showed slightly (p=ns) more over- shooting HR than B (difference to THR 5.7+4.4 vs. 2.0+4.1 bpm). The diagnostic accuracy and the adverse effects were not different in both groups and comparable to the non-randomized group.

Conclusion: The new DASE protocol lead to a significant decrease in examination time without altering the safety or diagnostic accuracy of the test, It however failed in reducing the sometimes unpleasan! overshooting HR response to DASE. Further studies wRh a larger population are necessary to prove the definite merits of the new test.

6 0 1 Q QUANTIFYING THE MYOCARDIAL RESPONSE TO DOBUTAMINE: NEW INSIGHTS INTO THE DYNAMICS OF REGIONAL FUNCTION Danita M. Yoerger MD, Geoffrey A. Rose MD, Nell J. Weissman MD, John B. NeweU, and Michael H. Picard MD Massachusetts General Hospital, Boston, MA

While dobutamine (DOB) influences both the degree and rate of myocardial thickening, the precise manner and time course over which these changes develop in response to graded doses of DOB has not been established. Greater understanding of the expected evolution of DOB-induced changes in regional function could enhance sensitivity of DOB stress echocardiography (DSE). We therefore examined parasternal M-mode echoes in 12 patients without evidence of inducible isehemia on DSE. The myocardial response to DOB was quantified at each dose by measuring the following indices: [1] slope of posterior wall thickening (mTh, mm/sec); [2] time to peak thickening (TPT, msec); [3J cycle length (CL, msec); and [4]absolute change in wall thickness (ATh, ram). Indices were normalized to cycle length. Differences from baseline were detected by multivariate ANOVA (*p<O.05):

Dobutamine Dose (~e/k~/min) _ _ 0 5 10 20 30 40

ruTh 45+5 45+_3 54+_6 57k5" 62±8* 77±9* TPT 361±20 349±19 336±15 326 ±19 291+23" 244+~20" CL 868+63 876_+62 828±38 795 +43 677 ±47* 548_+35* ATh 13.6±,9 13.9±1 15.6±1.4 15.4+1.2 14.9+-1.2 16.2±1.5"

Conclusions: In patients without inducible ischemia, DOB first increases the rate of thickening prior to affecting a change in absolute wail thickness or heart rate. Measuring the rate of myocardial thickening allows earlier recognition of changes in regional function, and may therefore improve the sensitivity of DOB stress echo in assessing both myocardial ischemla and viability.