ABSTRACTS

ANALYSIS OF THE PULMONARY CIRCULATION USING DIGITAL INTRA- VENOUS ANGIOGRAPHY: CORRELATION WITH INDICATOR-DILUTION METHODS Robert Slutsky M.D., Patrick Carey M.D., Valmik Bhargava Ph.D., Charles 6. Higgins M.D., FACC, University of Calif- ornia, San Diego, California Digital techniques allow the videodensitcmetric analysis of chamber to chamber transit time with a high degree of spatial precision. Both the proximal pulmonary artery and left atrium can be identified with ease, and region ass- ignments made simply. Because attenuation and volume are not linearly related, we attempted to correlate the re- lationship between peak-to-peak pulmonary transit times from digital time-attenuation curves (pulmonary arterial peak time from left atria1 peak time) with standard in- dicator-dilution measures. Six anesthetized dogs were instrumented with pulmonary arterial, left atria1 and carotid catheters. Two separate injections were made (one in the LA and one in the PA) and sampled at one site (car- otid artery). Green dye was utilized in all studies. Radio opaque contrast (Renografin 76) was injected with a power injector into the IVC (30 cc/second), the injection cath- eter was located just beneath the diaphragm. This elimin- ated the need to deconvolute the contrast input function curve. Multiple intervention points were produced in each dog, using either isoproterenol (3 dogs) or phenylephrine (3 dogs). Peak-to-peak transit times were calculated at each data point, as was mean transit time from green-dye curves. The curves correlated well (r=.97) in 24 separate data points. From green dye curves, peak-to-peak, median area to median area, and mean to mean transit times were also calculated from the green-dye curves (PA to LA) and all correlated well with each other. We conclude that peak- to-peak transit times may be used as approximates of pulm- onary circulation time when obtained using digital intra- venous angiograms.

COMPARISON OF INTRAVENOUS VERSUS LEFT VENTRICULAR CON- TRAST INJECTION ON LEFT VENTRICULAR FUNCTION. Sharon Norris, M.D., Charles B. Higgins, M.D., FACC, Frank H. Haigler, and Fred G. Werner. University of California San Diego, San Diego, California.

Digitized intravenous (IV) angiography has become a use- ful technique for assessing LV function (LVF); however, quantitation of functional indices must consider the po- tential hemodynamic effects of IV contrast media. Accordingly, the hemodynamic effects of intravenous angiography (IV) on LVF was compared with those of left ventricular injection (LV) in 5 dogs instrumented with pairs of intra-sonocardiometry crystals on the LV endo- cardium (internal LV dimension) and in the myocardial wall (segment length), and LV pressure gauges to obtain LV end diastolic (EDD)and end systolic dimension (ESD), AD, segment length (L) and LV pressure. The mean per- cent change at 10,20, and 30 sets. for LV and IV in- jections were: ESD +27.4, -12.6, -31 and +18.6, +1.4, and -23.6, AD +9.8, +23, +32, and i4.4, +18, +25.6, AL +14.2, +28.2, +29.4 and +6.4, +13 and +24.8; AL/dt +11.8, +32.8, +67, and 0.2; +26.6 and 48.8, respectively.

There was no statistical significant difference between the changes induced by LV or IV injections except for ESD at 20 sets. However, both LV and IV angiography cause profound effects on parameters of global and segmental LV function which must be considered in the quantitation of angiographic studies.

TUESDAY, APRIL 27, 1982 PM CORONARY ARTERY SPASM 4:00-5: 15 SPASM OF A NORMAL CORONARY ARTERY WITH FIXED STENOSES OF THE REMAINING VESSELS Peter Mercurio, MD; Itzhak Kronzon, MD; New York University Medical Center, New York, N.Y.

Five patients (2 males and 3 females) ages 39-68 had recurrent episodes of severe chest pains despite medical therapy. These episodes wet-e often associated with ST segment abnormalities. 1 of 5 patients had recurrent episodes of ventricular tachycardia requiring cardioversion. 3 of 5 patients had prior myocardial infarction. Left ventriculography revealed segmental hypokinesis in two patients and an apical aneurysm in the third. Coronary angiography demonstrated severe fixed lesions in two coronary arteries in 3 patients, and in one vessel in the remaining two.

Intravenous ergonovine maleate induced coronary artery spasm in a normal vessel in each patient and reproduced their typical chest pains and/or arrhythmia. There were no changes in the vessels with fixed lesions. However, in 3 of 5 patients the ergonovine-induced spasm of the normal coronary artery also markedly decreased retrograde filling of a vessel with prior severe, fixed narrowing. Collateral flow from the normal vessel to the vessel with a fixed stenosis decreased markedly with the spasm.

We have observed in patients with recurrent chest pain and fixed coronary artery stenoses that spasm is occurring in a normal vessel. Coronary artery spasm should be carefully looked for in these patients especially if coronary artery bypass surgery is being considered.

CLINICAL OBSERVATIONS ON CORONARY SPASM AND PERCUTANEOUS CORONARY ARTERY ANGIOPLASTY. Jay Hollman, MD; Andreas R. Gruentzig, MD; Maria Schlumpf rA; Spencer B. King III, MD, FACC; John S. Douglas, Jr., MD, FACC, Emory University, Atlanta, Georgia.

In 550 cases with percutaneous transluminal coronary angioplasty (PTCA), coronary spasm (CS) has occurred in four settings. 1) Two patients had hemodynamically in- significant fixed lesions (50% diameter narrowing and debilitating symptoms, documented to be myocardial is- chemia. After PTCA both are free of symptoms and have normal catheterizations 6 months following angioplasty. 2) In two patients CS occurred during the passage of an intracoronary catheter across a fixed coronary stenosis. In both cases this CS was refractory to intracoronary nitroglycerin. The CS resolved only after successful balloon dilatation. 3) Two patients had rest angina 2 weeks and one month following PTCA. Ergonovine pro- vocation demonstrated CS of 90% and 100% obstruction superimposed on trivial ( <20% diameter narrowing) re- sidual stenoses. These patients are asymptomatic on nifedipine and have not undergone repeat PTCA. 4)Four patients have had rest pain with ST segment elevation and severe coronary artery obstruction ( 780% diameter narrowing). All of these patients have had successful dilatation. None have had clinical evidence of CS post PTCA. After 4 years of application of PTCA there is a definite role of this technique in carefully selected patients with CS. It seems to us that it can be used as adjunc- tive treatment in the presence of atherosclerotic lesions and CS but it may also precipitate spasm after otherwise uneventful PTCA.

March 1982 The American Journal of CARDIOLOGY Volume 49 985