ARSTRACTS

CLINICAL UTILITY OF COLD PRESSOR RADIONUCLIDE VENTRICULO- GRAPHY IN CORONARY ARTERY DISEASE. Joshua Wynne, MD, FACC; B. Leonard Holman, MD, FACC; Gilbert H. Hudge, MD; Kenneth M. Borow, MD, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA.

To evaluate the utility of cold pressor radionuclide ven- triculography (RVG) in coronary artery disease (CAD), 20 patients (I5 with and 5 without CAD) underwent RVG before and during cutaneous exposure to iced water for an average of 4.8kl.l minutes. Heart rate (64.%10.3 to 67.7210.6, p<O.Ol) and systolic blood pressure (11~18 to 143k30 mmHg, p<O.OOOS) rose, while left ventricular ejection fraction (LV EF) fell (55.1+16.4 to 52.1216.5, p<D.O025). To establish the expected response of LV EF in normals to a pressor challenge alone, systolic blood pressure in 14 volunteers was raised with methoxamine to a level similar to that obtained during the cold pressor RVG (IO&29 to 14125 mmHg), and LV EF determined echocardiographically. LV EF declined 4ir2.9%, thus establishing that LV EF might be expected to decline during the cold pressor RVG up to 10% (mean + 2 SD) merely on the basis of increased after- load, and independent of any possible effect of cold on coronary blood flow. Using the criterion of >lO% decline in LV EF as the definition of an abnormal response, the cold pressor RVG had a sensitivity of only 33% (S/15) and a specificity of 80% (4/S) for the diagnosis of CAD. We conclude that while the cold pressor RVG may be of occa- sional value in patients unable to perform adequate levels of exercise, its low sensitivity suggests that it is in- ferior to exercise RVG or even exercise electrocardiogra- phy in the diagnosis of CAD.

COLD PRESSOR THALLIUM 201 MYOCAPDIAL SCINTIGRAPHY IN DETECTION OF CORONARY ARTERY DISEASE: AN ALTERNATIVE TO

EXERCISE SCINTIGRAPHY Masood Ahmad,MD,FACC; Jersy P. Dubiel,MD,FACC; Helmut Haibach,MD; Scott H. Goldberg: John F. Sanfelinw.MD: _. __ Richard H. Martin,MD,FACC, VA and University Hospitals, Columbia, MO. Thirty patients (pts) (age range 37-69 yrs) with chest

pain syndromes underwent myocardial scintigraphy follow- ing injection of Thallium 201 during the standard cold pressor test (CPT). Twenty-three of 25 pts with cine- angiographically confirmed coronary artery disease (CAD) developed transient perfusion deficits which normalized 4 hours later. All 5 pts without CAD (confirmed by coronary cineangiography) had normal scintigrams. In 22 pts who had previously performed a symptom-limited maximum exer- cise stress test, the sensitivity of exercise ECG in detecting ischemia was 88% and specificity 75% in compar- ison to a sensitivity of 89% and a specificity of 100% by CPT-Thallium 201 scintigraphy. Exercise Thallium 201 scintigraphy was performed in 14 pts. Eleven of 12 pts with CAD developed transient perfusion deficits following exercise and the 2 pts without CAD had normal scintigrams. Identical results were obtained by CPT-Thallium 201 scintigraphy in these 14 pts. Systolic pressure x heart rate was 103.0+17.0 at 2 minutes of CPT compared to 210.0+18.0 at peak exercise (p<O.O05). Coronary cine- angiograms obtained during CPT in 6 pts with positive exercise and CPT-Thallium 201 scintigrsms did not demonstrate coronary spasm.

In conclusion, our data suggest that CPT-Thallium 201 scintigraphy is highly sensitive in detecting coronary artery disease and may be helpful in evaluating patients who are unable to perform exercise. The cause of abnormal scintigrams in patients with coronary artery disease following cold pressor test is unclear.

THE REGIONAL EJECTION FRACTION IMAGE (REFI) - AN ACCURATE METHOD FOR THE DETECTION OF CORONARY HEART DISEASE Hvlton I. Miller, MB; Jack Baron, BSc; Shimon Braun, MD; Shlomo Laniado, MD, FACC ; Tel Aviv Medical Center, Israel

Computer generated colcur coded REFI’s derived from ECG synchronised radionuclide cardiac blood pool imaging, using an Anger camera and a simple data processing system, were ob- tained in 101 patienta undergoing coronary angiography, at rest and during handgrip exercise (HG). Angiographic diameter narrowing of&50% of 1 or more major coronary branches was considered diagnostic of CHD. A regional reduction of the colour coded REFIAl2% during HG and regional ventricular border motion abnormalities (BMA) induced by HG was consider -ed positive for significant CHD. 34/101 patients had normal coronary arteries (NCA), 32/67 (46%) of CHD patients had Q waves on ECG. Results No. Positive HG REFI Positive HG BMA NCA 34 2/34 (6%) CHD 67 66/67 is&,

2/34 (6%) 52;67 i&)

For detection of CHD using REFI sensitivity was 99% spscifi- city 94% aa compared to sensitivity of 76% and specificity of 94% for HG BMA. Changes in ejection fraction with HG did not allow differentiation of patients wlth CHD. HG with REFI was a sufficient stress for detection of CHD. It is more sensitive than conventional assessment of BMA and may prove useful aa a screening test.

ACCURACY OF RADIONUCLIDE ANGIOCARDIOGRAPHY IN THE DIAG- NOSIS OF CORONARY ARTERY DISEASE - A PROSPECTIVE STUDY Erle H. Austin, M.D.; Frederick R. Cobb, M.D.; R. Edward Coleman, M.D.; Robert H. Jones, M.D., FACC, Duke Univer- sity Medical Center, Durham, NC

The purpose of this investigation was to assess prospect- ively the accuracy of rest and exercise (R/E) radionuclide angiocardiography (RNA) in detecting coronary artery di- sease (CAD). By retrospective analysis of 496 patients we determined optimal RNA criteria for the presence or ab- sence of CAD. Multivariate analysis of catheterization proven normals provided a formula to predict normal exer- cise ejection fraction (EF) in a given patient. The pre- sence of CAD was indicated by one or more of the following RNA measurements: 1) rest EF c.50. 2) exercise EF .06 or more <predicted, 3) exercise increase in end-systolic volume>20 ml, 4) exercise-induced wall motion abnormal- ity. The absence of CAD was indicated by the absence of all four criteria. These criteria were used to define a positive or negative RNA, and the diagnostic accuracy was assessed in 125 consecutive patients by comparison with coronary arteriograms. Significant CAD (,75X stenosis) was present in 70 of 86 men and in 15 of 39 women. Sen- sitivity (SFNS), specificity (SPEC) and efficiency (EFFIC) for RNA were:

SENS SPEC EFFIC

86 Men .87 .69 .a4 39 Women .80 .50 .61 125 Patients .86 .56 .76

We conclude that R/E RNA is sensitive and specific in men. However, poor specificity limits its value as a diagnostic tool in women.

444 February 1981 The American Journal of CARDIOLOGY Volume 47