Myocardial imaging with 99mTc macroaggregates. Clinical, hemodynamic, ECG, surgical and autopsy...
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ABSTRACTS EXERCISE INDUCED DECREASES IN PLATELET AGGREGATION: COMPARISON OF NORMALS AND CORONARY PATIENTS SHOWING SIMILAR PHYSICAL ACTIVITY RELATED EFFECTS James Joye, MD; Anthony N. DeMaria, MD, FACC; John Giddens; Roy Kaku, MD; Ezra A. Amsterdam, MD, FACC; Dean T. Mason, MD, FACC; Garrett Lee, MD, University of California, Davis, California Although exercise alters blood coagulation, no data are available regarding exercise effects on platelet aggrega- tion (PA). Thus PA studies were performed on eight coronary patients (CAD) and 12 normal subjects. All underwent multistage treadmill exercise (MTE) and PA was measured at 3 minute (min) intervals, at termination, and 10 min after MTE using 4x10-5 adenosine disphosphate stimulation after normalization of platelet count. Nine- teen individualscoxpleted 3 r,inMTE and manifested reduc- tion in PA from 56.2 to 48.0%, pq.001. Sixteen exercised 6 min and PA decreased 54.9 to 46.4%, pc.01. Nine completed 9 min MIE and PA decreased 52.2 to 43.6%, pc.01. Ten min post-KTE PA remained reduced 57.2 to 49.8, pc.05. Decreased PA was observed in both CAD and normal sub.jects, and reduction of PA was identical at exercise levels of equivalent maximal percentage. These data indicate exer- cise produces decrease in PA related to level of exertion. No rebound of PA was observed immediate post-KTE. These observations demonstrate that exercise-induced reduction in platelet aggregation is similar in normals and coronary patients. IN VIVO DEMONSTRATION OF THE FRANK-STARLING MECHANISM IN THE HUMAN DENERVATED HEART Stephen E. Pope, MD; Beil B. Ingels Jr., PhD; George T. Daughters II, PhD: John S. Schroeder, MD, FACC. Cardiology Division, Stanford Medical Center and Palo Alto Medical Research Foundation, Palo Alto, California The denervated human heart provides a” ideal clinical model for the in viva description of the Frank-Starling mechanism, unmodified by autonomic influences. Six long- term cardiac transplant recipients uRre studied by com- puter-assisted fluoroscopic analysis of radiopaque tanta- lum markers located in the left ventricular (LV) mid-wall. This permitted sequential quantitation of routine hemo- dynamic recordings and LV volumes as a direct measure of mid-wall fiber length changes, Acute volume loading was achieved by sudden leg elevation from the supine position. k3 Control Elwat ion %A P Value HB(beats/min) 100+4 101+4 1x NS LVEDV(ml) 91?6 10126 +12x c.01 SVW) 42?2 50?2 +20x c.001 CO(L/mi”) 4.2+.3 5.12.4 +19x c.01 VCF(circ/sec) .70’.04 .84?.06 +20x; < .os LVEDV= left ventricular end-diastolic volume; SV = stroke volume; CO 0 cardiac output; VCF - velocity of circumferential fiber shortening. We conclude that acute volume loading of the denervated heart (with 12% increase in EDV) results in a substantial (20%) rise in CO and VCF, reflecting auipnented contrac- tility and LV wrk, independent of neurally-mediated changes in HR or LV contractility. COMPARATIVE BENEFITS OF EXERCISE TRAINING IN GRAFTED AND UNGRAFTED CORONARY PATIENTS Andrew C. Drakonakis, MD, FACC; Allan H. Ross, MD, FACC, VA Hospital, West Haven, and Yale Univ., New Haven, Ct. Nineteen vein bypass operated (OP) and 30 unoperated cor- onary disease (CD) patients (pts) had 35-40 thrice weekly heart rate (HR) monitored sessions of exercise training (TR), 30 min. each, at &I-R5% of max HR determined by 2 pre TR tests. Treadmill retesting was done at 6 and 12 wks of TR. HR. systolic pressure (SP) and their product (HRSP) were analyzed at rest, at two levels corresponding to l/2 and 2/3 of initial work capacity (WC) in mats, and at max effort. In both groups the WC increased siqifi- cantly (*=p<O5 paired t vs initial value, table & text) after TR; in OP by 23%" at 6 and by 30%+ at 12 wks; in CD by 212” and 24%“. HR, SP and HRSP (see table) did not change at est or max effort but decreased significantly at submaximal levels. Thus the ratios of HR, SP and HRSP over WC decreased at all levels of exercise. HRSPx10-3 SP (mm Hg) HEART RATE INITIAL1 12 WEEK INITIAL 12 WEEK INITIAL 12 WEEK OP CD IOP CD OP CD OP CD OP CD OP CD Pest /ID 9 1 9 9 124 127 124 120 79 73 75 71 1/2max 16 14 13" 12* 146 139 l30* 127" 108 101 i 99* 94* Y3max 20 17 17" IS:+ 159 150 146* 137" 126 114'113* 106a Max 24 21 25 21 166 159 171 154 141 128 145 132 Of 18 CD pts with angina limited stress testing, 3 became angina free. The remainder irrproved their WC by 22%". For 9 DP angina pts, WC increased by 33%“. CONCLUSIONS: There Is no difference in response to TR between operated and non-operated pts. For both groups nax HRSP was un- changed after TR whereas max WC Increased, and the ratios of HR, SP and HRSP over submax and max work loads de- creased slmllarly. THURSDAY, MARCH 0, 1978 AM HYPERlROPHtC CARlWMYO?AlHY AND THE MITRAL PROLAPSE SYNDROME &SO to 12:oo OBJECTIVE ANG.IOGPAF'HIC CRITERIA FOR THE DIAGNOSIS OF MIT- RAL VALVE PROLAPSE. Eldon R. Smith, MD; David 8. Fraser, MD; Amar S. Kapoor, MD; Henry Gewirtz, MD; and Bosalind MacDonald. Dal:?ousieUniversity, Halifax, N.S. Canada. Although angiography (angio) generally has been accep- ted as the diagnostic standard for mitral valve prolapse (MVB), recent reports question the specificity of angio criteria. Thus in a recent study from our laboratory, 43% of unselected patients (ptsl undergoing angio had end- systolic bulging of the posterior mitral leaflet. Since most of the apparent "false-positives" resulted from bul- ging of the postero-medial scallop (PMS), we have attemp- ted to quantitate the angio assessment of this scallop. Using end-systolic outlines of the 30 degree right anter- ior oblique angio, the best criterion identified was the perpendicular distance which the PMS extends from a line connecting the posterior aortic root - left ventricular (LV) junction to the fornix of the mitral valve - LV in- ferior wall, normalized for LV minor axis. Of 17 pts with the click-murmur syndrome and typical echocardiographic (echo) features of MVP, all had a PMS length index (PMSLI) ~0.27 (range 0.27 to 0.68; mean 0.39). This index has been assessed in a prospectively studied series of 104 pts with clinical, phono, echo and angio data in all. By subjective assessment of angio, 44 (39.69) had MVP involving the PMS, a finding in close agreement with the previous study. Of 94 pts in whom the PNSLI could be measured, only 17 (18%) had values ~0.27 and 8 of these had phone and/or echo features of MVP. One pt, with a mid-systolic click but normal echo, had a PMSLI of 0.26. We conclude that the specificity of angio diagnosis of MVP (involving the PMS) can be considerably improved by objective measure, with a PMSLI ~0.27 probably reflecting normal variation in the LV end-systolic configuration. 432 Fobrumy 1978 lho Amrlcn Jmmal of CARDiOLOQY Volume 41
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Transcript of Myocardial imaging with 99mTc macroaggregates. Clinical, hemodynamic, ECG, surgical and autopsy...
ABSTRACTS
LEFT VENTRICULAR FUNCTION IN PATIENTS WITH
NONTRANSMURAL MYOCARDIAL INFARCTION
Pierre Rigo, M.D., H. William Strauss, M.D., Dean R. Taylor, M.D.,
David T. Kelly, M.D., Myron L. Weisfeldt, M.D., Bertram Pitt, M.D.
Johns Hopkins University and Hospital, Baltimore, Md. 21205
Patients with nontransmural myocardiol infarction (NTMI) as diog-
nosed by ST-T wave changes on the electrocardiogram and elevation
of serum enzymes are thought to have less left ventriculardysfunction
and a better prognosis than those with transmurol myocardial inforc-
tion (TMI) with Q waves. Myocordial performance wos assessed in
11 patients with NTMI, 7 of whom were uncomplicated (Class I) and
4 of whom had evidence of mild to moderate congestive heart failure.
(Class II); and in 25 with TMI, 14 in Class I, and 13 in Class II.
The left ventricular filling pressure (LVFP) and cordioc index (Cl)
were measured with a Swon-Gonz thermodilution catheter. Left ven-
tricular ejection fraction (LVEF), end diastolic volume (EDV), and
percent of left ventricular wall akinesis were measured by gated car
disc blood pool scanning (GBPS) with I.V. technetium99n albumin.
NTMI TMI
LVEF % 39+8 37+6
EDV ml 116T28 127738
% Akinesis 24+13 30Tll
LVFP mm Hg 1475 16?8
Cl liters/min/M2 2.871 2.7T.6
There were no significant diRerences between thevalues in those
with NTMI and TMI. LVEFand EDV in both groups were significant-
ly different (P<O.Ol) from that obtained in 10 normol patients using
GBPS 56+3% and 81+4 ml respectively. In conclusion this study
suggests patients with NTMI hove the same degree of myocordial
dysfunction as TMI and does not support functional seporotion of
potients on these electrocardiographic criteria.
MYOCARDIAL IMAGING WITH 99mTc MACROAGGREGATES. CLINICAL, HRMODYNAMIC, ECG, SURGICAL AND AUTOPSY CORRELATIONS James Ritchie, MD, Glen Hamilton, MD, John Murray, MD, Eugene Lapin, MD, VA Hospital, Seattle, Washington.
Scintillation camera‘myocardial perfusion images were performed in 51 patients (pts) with proven or suspected ischemic disease. 1.5 mCi 99mTc macroaggregated albumin was injected directly into one or both coronary arteries.
Myocardial images were classified as normal (26) or abnormal (25) and the location of abnormality noted. 25 pts with abnormal images had myocardial infarction based on history (16/25), Q wave (19/25), or local contractile abnormality (22/25) singly or in combination. No pt with a normal image had a Q wave and only one of 25 had a local contractile abnormality. There was no correlation between an image defect and the presence of exercise in- duced ST depression. Ejection fraction was reduced (p c.001) in pts with abnormal images (43+14% vs. 61+11%). Pts with image defects (11) had trans&ral scar (TO) or inferior hypokinesis (1) observed at surgery or autopsy; pts with normal images all had normal ventricles at sur- gery (414). A single pt with preinfarction angina with- out evidence of infarction had an image defect. Pts with less than 50% stenosis all had normal myocardial images (19 of 19). Pts with complete occlusions had correspond- ing image defects. Two pts with complete occlusions without infarctions had normal images. Six patients with stenoses of 75-99X had image defects; 5 had normal images
We conclude that this technique identifies myocardial scarring secondary to infarction rather than areas of is- chemia. Its sensitivity in the diagnosis of myocardial scar was better than the ECG or clinical history and com- parable to the presence or absence of local contractile abnormalities on ventriculography. It appears useful in identifying scar and as a baseline for stress studies which may induce ischemia.
INCREASED CARDIAC OUTPUT DURING INDUCED IRRlIGULARRHYTHMS
Keith Ritchie, MD; Robert Lux; G. Michael Vincent, MD; Ray Millar, MD, University of Utah, Salt Lake City, Utah.
Irregular rhythm (IR) can increase cardiac output (CO), probably by potentiating contractility. Additional evi- dence for increased inotropic state during IR was obtain- ed in 10 dogs. Aortic flow and left ventricular pressure were measured during regular rhythm (RR) and IR induced by simultaneous atria1 and ventricular pacing from com- puter generated stimuli. IR patterns included 1) random sequences of cycle lengths with a flat distribution (RF), 2) ordered sequences alternating short and long cycles from the same flat distribution (ASL), and 3) sequences alternating maximum and minimum cycle lengths present in those patterns (AWM). Stimulus patterns had the same mean cycle length and the RF and ASL patterns contained equal numbers of any given cycle length. CO was higher with IR than with RR in all experiments. Compared to RR, increases in CO were 5% during RF rhythm, 15% during ASL rhythm and 25% during AMM. Since the cycle lengths in RF and ASL rhythms were identical, it is likely that differ- ences in CO were due to differences in inotropic state. However, the Frank-Starling mechanism could not be total- ly excluded. Evidence that differences were due to vary- ing inotropic state was obtained in 3 experiments in which pressures were recorded in a balloon in an isovol- umic left ventricle preparation. Average peak pressures, maximum dP/dt and dP/dt at selected pressures were higher with IR than with RR and in most observations higher with ASL than with RF. Findings confirm that IB results in changed inotropic state, and show the maximizing of this effect by optimal sequencing of cycle lengths. A new method for study of rhythm effects on the cardiac state by controlling the sequence of a set of identical cycle lengths is reported.
LONG TERM SURVIVAL FOLLOWING AORTIC VALVE REPLACEMENT Douglas L. Roberts, MD; James A. DeWeese, ND; Earl B. Ma- honey, MD; Paul N. Yu, MD, FACC, University of Rochester, Rochester, New York.
Study is made of 77 long term survivors of aortic valve replacement. During follow up (24-98 mos, avg 50.2) an- gina was the leading cause of morbidity (21%) followed by symptoms of congestive heart failure (CHF) (19%). Compli- cations consisted of peripheral emboli (8 pts), hepatitis (5 pts.), and endocarditis (3 pts.). Over one quarter of the patients had a persistent diastolic aortic murmur and 16% clinical evidence of hemolysis. Of the 7 deaths oc- curring in these patients over the follow up period, post mortem information was available in 6. These long term survivors (77) were compared to the group dying within 1 month of valve replacement (24) and those short term sur- vivors (18) living less than 2 years. CHF was the most frequent preoperative disability and occurred with equal incidence in all 3 groups. Angina and syncope, however, were found with a statistically higher incidence in the short term survivors and hospital mortality groups, re- spectively. No statistical difference was found among the 3 groups in respect to patient age, functional class, hemodynamic lesion, duration of preoperative symptoms, left ventricular end diastolic pressure (LVEDP) or right ventricular systolic pressure (RVSP). There was, how- ever, a significantly lower cardiac index (c.i.) of the hospital mortality group as compared with the 2 surviving groups. No significant correlation was noted between the duration of survival and the c.i., LVEDP, or RVSP. 59% of the patients were alive at the end of the follow up. Life table analysis showed marked drops at the end of 12 and 36 mos. It would appear that cardiac index is the best predictor of hospital mortality and that once a pa- tient has survived 3 years, his chances for long term survival are excellent.
January 1974 The American Journal of CARDIOLOGY Volume 33 165
