Rest and redistribution thallium-201 myocardial scintigraphy to predict improvement in left ventricular function after coronary arterial bypass grafting

To examine the value of rest and redistribution thallium-201 imaging in predicting improvement in left ventricular (LV) ejection fraction (EF) after coronary artery bypass grafting (CABG), 26 patients with coronary artery disease (CAD) and abnormal LV function were studied. Nineteen patients had pathologic Q waves preoperatively. Rest and redistribution thallium-201 images and radionuclide ventriculograms were obtained before and after CABG, and the thallium scintigrams were evaluated both quantitatively and qualitatively. The patients were divided according to the preoperative thallium scintigrams into 2 groups: Group I (16 patients) had either normal resting thallium-201 images or reversible resting perfusion defects, and Group II (10 patients) had fixed resting perfusion defects. The resting EF was < 50% preoperatively in all patients. Fourteen patients (54%) showed improvement in EF postoperatively. Three patients (2 in Group I and 1 in Group II) showed new postoperative perfusion defects, and none of the 3 showed improvement in LV function. Of the remaining 14 patients in Group I, 12 (86%) showed improvement in LV function, compared with 2 of 9 patients in Group II (p < 0.01). Improvement in LV function was observed in 8 of the 19 patients (42%) with abnormal Q waves. Nitroglycerin intervention radionuclide ventriculograms were obtained in 20 patients before CABG. Of the 6 patients who showed improvement in LV function with nitroglycerin, 4 also showed improvement postoperatively. Postoperative improvement in LV function was also observed in 6 of the 14 patients who did not improve with nitroglycerin.Thus, rest and redistribution thallium imaging is useful in identifying patients whose LV function will improve after CABG. Normal rest thallium-201 images or reversible resting defects correctly identified 12 of 14 patients (86%) who showed improvement in LV function postoperatively. Nitroglycerin-intervention ventriculography and abnormal Q waves were less useful in this differentiation.     

Value and limitations of exercise radionuclide angiography for detecting myocardial ischemia in healed myocardial infarction

Exercise radionuclide angiography was performed in 65 normal subjects (group I), in 31 patients with exercise-induced transient thallium defects after acute myocardial infarction (AMI) (group II), and in 16 patients without exercise-induced transient thallium defects, angina or electrocardiographic changes after AMI (group III). Absolute left ventricular (LV) volumes were measured using a correction for attenuation in each patient. Similar peak heart rate-blood pressure products were achieved in groups II and III. Although the mean LV ejection fraction (EF) response to exercise in group III (increase of 0.11 +/- 0.10 units) closely resembled that of normal persons (increase of 0.14 +/- 0.09 units) and was significantly different from that of group II (decrease of 0.04 +/- 0.12), there was considerable individual variation. An abnormal EF response to exercise, defined as failure of EF to increase by at least 0.05 units, was found in 6 subjects (9%) in group I, 26 patients (84%) in group II, and 2 patients (13%) in group III. End-systolic volume failed to decrease in 10 subjects (15%) in group I, 25 patients (81%) in group II and 7 patients (44%) in group III. New regional wall motion abnormalities were found in no subject in group I, in 16 patients (52%) in group II and in only 1 patient (6%) in group III. Thus, although group responses of EF or end-systolic volume appeared to correlate with the presence or absence of ischemia, some patients with exercise-induced transient thallium defects after AMI responded normally to exercise radionuclide angiography stress testing and some patients without other evidence of exercise-induced ischemia after AMI responded to exercise radionuclide angiography testing abnormally.(ABSTRACT TRUNCATED AT 250 WORDS)     

Left ventricular pressure/volume relationship in aortic regurgitation

In this study we examined the left ventricular pressure/volume relationship in 39 patients with moderate or severe aortic regurgitation (AR) and 15 normal subjects. The patients with AR were divided into two groups; patients with normal resting ejection fraction (EF greater than or equal to 50%, group I, n = 21) and patients with abnormal EF (group II, n = 18). The patients in group I were younger (p less than 0.005), exercised to a higher workload, and had better exercise tolerance than patients in group II (p less than 0.01). The patients' exercise heart rate and blood pressure were not significantly different between the two groups. During exercise tests nine patients in group I and seven patients in group II had normal EF response (greater than or equal to 5% increase) (p = NS). The peak systolic blood pressure to end-systolic volume index ratio (SBP/ESVI) was higher in normal subjects than in patients in groups I and II, at rest it was (4.3 +/- 1.0 vs 2.6 +/- 1.2 vs 1.6 +/- 0.8, respectively, p less than 0.0001) and during exercise it was (7.6 +/- 1.8 vs 4.2 +/- 1.4 vs 2.6 +/- 1.3, respectively, p less than 0.0001). The resting SBP/ESVI ratio was below the lower normal limit in 12 patients (57%) in group I and in 16 patients (89%) in group II. Also, the exercise SBP/ESVI ratio was below the lower normal limit in 17 patients (81%) in group I and all of the patients (100%) in group II. Multivariate discriminant analysis identified the change in SBP/ESVI (F = 34.8) and resting end-diastolic volume (F = 6.7) as independent predictors of the EF response to exercise. Thus, most patients with AR, including those with normal resting EF or normal EF response to exercise, have abnormal SBP/ESVI at rest or during exercise.     

Left ventricular response to exercise in aortic stenosis: an exercise echocardiographic study

BACKGROUND: While normal at rest, left ventricular (LV) systolic function may become abnormal during exercise in patients with aortic stenosis. Once contraindicated in patients with aortic stenosis, exercise testing is now recommended in asymptomatic patients with aortic stenosis to elicit symptoms and thereby ascertain the need for aortic valve replacement. However, the clinical significance of an abnormal LV response to exercise in asymptomatic patients with aortic stenosis remains unknown. OBJECTIVE: The aim of this study was to evaluate the clinical implications of an abnormal LV response during exercise in the setting of aortic stenosis. METHODS: We monitored the LV response to exercise by 2D-Doppler echocardiography during a symptom limited semirecumbent bicycle exercise in 50 patients with tight aortic stenosis (aortic valve area < or = 1.0 cm(2)) and a normal LV systolic function (LV ejection fraction, EF > or = 50%) and followed them for an average of 11 months. RESULTS: Twenty patients had an abnormal LV response to exercise with a mean decrease in LV EF from 64 +/- 10 to 53 +/- 12% while 30 patients had a normal LV response to exercise with a mean increase in LV EF from 62 +/- 7 to 70 +/- 8%. Patients with an abnormal LV response during exercise were more likely to develop symptoms during exercise than patients with a normal LV response: 80% versus 27% (P< 0.0001). The survival free of cardiac events was significantly lower in patients with abnormal LV response to exercise than in patients with a normal response (P = 0.03). CONCLUSION: Exercise echocardiography provides objective data that facilitate interpretation of exercise elicited symptoms in asymptomatic patients with severe aortic stenosis. In addition, an abnormal LV response to exercise may predict a poor outcome.     

Myocardial perfusion abnormalities in patients with hypertrophic cardiomyopathy: assessment with thallium-201 emission computed tomography

Myocardial ischemia may play a critical role in the symptomatic presentation and natural history of hypertrophic cardiomyopathy (HCM). To assess the relative prevalence and functional significance of myocardial perfusion abnormalities in patients comprising the broad clinical spectrum of HCM, we studied 72 patients (ages 12 to 69 years, mean 40) using thallium-201 emission computed tomography. Imaging was performed immediately after maximal exercise and again after a 3 hr delay. Regional perfusion defects were identified in 41 of the 72 patients (57%). Fixed or only partially reversible defects were evident in 17 patients, 14 of whom (82%) had left ventricular ejection fractions of less than 50% at rest. Twenty-four patients demonstrated perfusion defects during exercise that completely reversed at rest; all had normal or hyperdynamic left ventricular systolic function (ejection fraction greater than or equal to 50%). Perfusion abnormalities were present in all regions of the left ventricle. However, the fixed defects were observed predominantly in segments of the left ventricular wall that were of normal or only mildly increased (15 to 20 mm) thickness; in contrast, a substantial proportion (41%) of the completely reversible defects occurred in areas of moderate-to-marked wall thickness (greater than or equal to 20 mm, p less than .001). Neither a history of chest pain nor its provocation with treadmill exercise was predictive of an abnormal thallium study, since regional perfusion defects were present in 10 of 18 (56%) completely asymptomatic patients, compared with 31 of 54 (58%) symptomatic patients. These data indicate that myocardial perfusion abnormalities occur commonly among patients with HCM. Fixed or only partially reversible defects suggestive of myocardial scar and/or severe ischemia occur primarily in patients with impaired systolic performance. Completely reversible perfusion abnormalities occur predominantly in patients with normal or supranormal left ventricular systolic function. Such dynamic changes in regional thallium activity may reflect an ischemic process that contributes importantly to the clinical manifestations and natural history of HCM.     

Prognostic implications of left ventricular function during exercise in asymptomatic patients with aortic regurgitation

Few data are available that address the prognostic implications of the response of the left ventricle (LV) to exercise in asymptomatic patients with aortic regurgitation (AR) who have normal resting LV function. Thirty-one such patients were contacted two to seven years after rest and exercise radionuclide ventriculography. Eleven had had significant cardiovascular events. Event-free survival at forty-eight months was 64%. Ten of eleven events occurred in 21 patients with decline in ejection fraction (EF), but the magnitude of decline did not further separate the group with regard to prognosis. Eight events (73% of total events) occurred in the 11 patients (35% of total patients) with an EF during exercise of 0.55 or less. The short and intermediate outlook for asymptomatic patients with AR and normal resting LV function is good regardless of the response of the EF to exercise, but an exercise EF less than or equal to 0.55 does identify a relatively high-risk subset for deterioration beyond twenty-four months.     

Age-related changes in left ventricular diastolic performance

Previous studies show that the radionuclide-derived indices of left ventricular (LV) diastolic performance are abnormal at rest in many patients with coronary artery disease (CAD), even in those with normal resting ejection fraction (EF) and no prior myocardial infarction. This study examined the age-related changes in LV peak filling rate and time to peak filling rate in 65 subjects between the ages of 20 and 75 years with a low likelihood of CAD. All subjects had normal resting EF (greater than or equal to 50%), and none had prior infarction. There was a significant age-related decline in resting peak filling rate (r = -0.47, p less than 0.001) and exercise peak filling rate (r = -0.52, p less than 0.001), but no age-related effect in the time to peak filling rate. Of the 29 subjects less than 50 years of age, 26 (90%) had resting peak filling rate greater than or equal to 2.5 EDV/sec (3.1 +/- 0.6, mean +/- SD) compared to 17 of 36 subjects (47%) greater than or equal to 50 years of age (2.6 +/- 0.6) (p = 0.002). In a subgroup of 28 subjects with a history of hypertension, the age-related effect was more marked than in the remaining 37 subjects without such a history (r = -0.66 vs -0.33). Thus, the peak filling rate at rest and during exercise decreases with advancing age; the high frequency of observed abnormality in the peak filling rate at rest in patients with CAD may conceivably be related in part to age differences between patients with CAD and the control group.     

Association of heart rate response with scan and left ventricular function on adenosine myocardial perfusion imaging.

To evaluate the association of heart rate (HR) response with abnormal scan and/or left ventricular (LV) function in patients undergoing adenosine myocardial perfusion imaging, we retrospectively studied 188 consecutive patients who underwent a standard adenosine stress test (without exercise) and myocardial perfusion imaging (MPI) using technetium-99m sestamibi radioisotope. Change in HR was calculated by subtracting HR at rest from peak HR. The percentage change in HR was calculated. All patients underwent stress and resting single-photon emission computed tomography (SPECT) imaging. LV ejection fraction (EF) was calculated using gated SPECT. Mean age was 60 +/- 12 years and 135 of the patients (72%) were women. We divided the patients into 2 groups: group 1 (142 patients, 75%) had normal scans and group 2 (46 patients, 25%) had abnormal scans; abnormal scans were defined as presence of either fixed defects, reversible defects, or both. Average HR increased by 29 beats/min in the normal scan group compared with 19 beats/min in the abnormal scan group (p = 0.0004). Forty-seven patients (25%) had reduced EF (<45%). This group had an average HR and percentage HR increase of 20 beats/min (29%) compared with an increase of 29 beats/min (44%) in patients with normal EF (p = 0.002 and p = 0.002, respectively). Thus, a diminished HR response had a significant association with both an abnormal scan and reduced EF on adenosine MPI.     

Location of myocardial necrosis as an independent determinant of left ventricular performance: Analysis of 96 patients

This study determines whether the location of myocardial scarring has an effect independent of its size on left ventricular (LV) ejection fraction (EF) in patients with coronary artery disease. Two groups of patients were studied: Group I (n = 44) had resting thallium-201 perfusion defects involving the anterior wall or septum or both, and Group II (n = 52) had perfusion defects involving the inferior wall or posterior wall or both. The thallium images were divided into 5 segments in each of 3 projections, and the thallium score was determined from the number of abnormal segments and the degree of reduction of thallium uptake; the higher the score, the more severe the perfusion deficit.If the thallium score was <- 10, EF was 45 ± 14% (mean ± standard deviation) in Group I and 47 ±11% in Group II (p = not significant [NS]). If the thallium score was > 10, EF was 30 ± 12% in Group I and 32 ± 11% in Group II (NS). Similarly, EF was not significantly different between the 2 groups when the perfusion defects were assessed by the number of abnormal segments. In each group EF was significantly lower as the number of abnormal segments increased or as the thallium score was higher (p < 0.01). The results were unchanged when patients with resting ischemic defects or women were excluded.Thus, the location of myocardial scar itself is not important in determining LV function. However, the size of the scar is important in determining LVEF. Therefore, the fact that LVEF is lower in patients with anterior infarction than in those with inferior infarction must be related to the extent of muscle necrosis rather than to an anatomic factor.     

Role of resting thallium201 perfusion in predicting coronary anatomy, left ventricular wall motion, and hospital outcome in unstable angina pectoris

We performed quantitative thallium scintigraphy in 66 unstable angina patients, 5.6 +/- 5.1 hours after rest pain, to predict coronary anatomy, left ventricular wall motion, and hospital outcome. Thallium defects and/or washout abnormalities were present in 5 of 10 (50%) patients with coronary stenoses less than 50%, 27 of 33 (82%) patients with coronary stenosis greater than or equal to 50% and no history of previous myocardial infarction, and in 23 of 23 patients (100%) with histories of previous infarction. Defects were uncommon in the territory of vessels with less than 50% (13 of 61, 21%), but significantly more common in the territory of vessels with greater than or equal to 50% stenosis (57 of 137, 42%), p less than 0.005. With the addition of washout abnormalities to defect analysis, sensitivity for detection of coronary stenoses improved to 67% (92 of 137), p less than or equal to 0.005, but specificity fell to 59% (36 of 61), p less than 0.01. Segmental wall motion abnormalities were less common in segments with normal perfusion (21%) or in those with washout abnormalities alone (19%), than in segments with thallium defects (45%, p less than 0.005). Defects in patients with previous infarction were common in both segments, with normal (26 of 66, 40%) or abnormal (24 of 45, 53%) wall motion. Eleven of 18 patients with in-hospital cardiac events, but no history of myocardial infarction, had resting thallium defects, whereas only 8 of 25 patients without cardiac event had thallium defect (p = 0.056).(ABSTRACT TRUNCATED AT 250 WORDS)     

Evaluation of exercise electrocardiography and thallium tomographic imaging in detecting asymptomatic coronary artery disease in diabetic patients

Thallium tomographic imaging and exercise electrocardiography were performed on 136 diabetic patients without symptoms of heart disease. Thirty three patients had post-exercise thallium defects and 19 had ST 1 mm greater than or equal to segment depression during exercise electrocardiography. Both tests were positive in 13 patients. Coronary angiography was subsequently performed on 33 patients with either scintigraphic and/or electrocardiographic evidence of myocardial ischaemia. Angiographically significant coronary artery disease (greater than or equal to 50% narrowing of the coronary artery lumen) was detected in 13 patients. Six patients had minimal coronary artery stenosis (less than 50%), and 14 had normal coronary arteries. Six patients refused cardiac catheterisation. In 14 out of 27 patients with post-exercise thallium defects coronary angiography did not show any coronary artery stenoses (positive predictive accuracy 48%). Exercise electrocardiography showed only one false positive result (positive predictive accuracy 94%) but failed to detect coronary artery disease in three patients with a positive scintigraphic result. The accuracy of a positive exercise electrocardiographic test seems to be better than that of a positive thallium tomographic scan for detecting asymptomatic coronary artery disease in diabetic patients. The high number of false positive thallium defects may be the result of technical features inherent in thallium tomography and/or the possible disease of the small intramyocardial arteries in diabetic patients.     

Atrial pacing and thallium 201 scintigraphy: combined use for diagnosis of coronary artery disease

To evaluate the presence of coronary artery disease (CAD), atrial pacing and thallium 201 scintigraphy were performed in 36 patients with stable angina pectoris who were unable to perform an adequate exercise stress test. All patients underwent cardiac catheterization. Nine patients had previously undergone coronary artery bypass surgery. Significant CAD (one or more lesions greater than or equal to 50%) was present in 33 patients. Atrial pacing produced ischemic ST segment depression (greater than or equal to 1 mm) in 18 (55%) patients with CAD, and angina in 20 patients (61%). As the number of vessels with CAD increased, there was no significant change in the sensitivities of pacing-induced angina or ST segment depression for detecting CAD. In the 3 patients without CAD, ST segment depression occurred in 1 patient and angina in none. Thallium 201 scintigraphy demonstrated perfusion defects in 27 (82%) patients with CAD, with fixed defects seen in 13 studies (39%) and reversible defects in 15 (45%). In the 3 patients without CAD, no perfusion defects were seen. The thallium 201 scan successfully predicted the presence of CAD in patients with single-vessel disease but usually underestimated the number of vessels involved in patients with multivessel disease. Combined sensitivity of pacing-induced ST segment depression and an abnormal thallium 201 scan finding for detecting CAD was 91%. The authors conclude that combined atrial pacing and thallium 201 scintigraphy is a useful test for detecting CAD in patients unable to perform an adequate exercise stress test.     

Evaluation of exercise electrocardiography and thallium tomographic imaging in detecting asymptomatic coronary artery disease in diabetic patients.

Thallium tomographic imaging and exercise electrocardiography were performed on 136 diabetic patients without symptoms of heart disease. Thirty three patients had post-exercise thallium defects and 19 had ST 1 mm greater than or equal to segment depression during exercise electrocardiography. Both tests were positive in 13 patients. Coronary angiography was subsequently performed on 33 patients with either scintigraphic and/or electrocardiographic evidence of myocardial ischaemia. Angiographically significant coronary artery disease (greater than or equal to 50% narrowing of the coronary artery lumen) was detected in 13 patients. Six patients had minimal coronary artery stenosis (less than 50%), and 14 had normal coronary arteries. Six patients refused cardiac catheterisation. In 14 out of 27 patients with post-exercise thallium defects coronary angiography did not show any coronary artery stenoses (positive predictive accuracy 48%). Exercise electrocardiography showed only one false positive result (positive predictive accuracy 94%) but failed to detect coronary artery disease in three patients with a positive scintigraphic result. The accuracy of a positive exercise electrocardiographic test seems to be better than that of a positive thallium tomographic scan for detecting asymptomatic coronary artery disease in diabetic patients. The high number of false positive thallium defects may be the result of technical features inherent in thallium tomography and/or the possible disease of the small intramyocardial arteries in diabetic patients.     

Rest and exercise electrocardiograms and radionuclides in patients presenting for cardiac rehabilitation

The rest and exercise ECG, ²⁰¹thallium myocardial scintigram (²⁰¹T1), and radionuclide ventriculography are noninvasive procedures which can be used to evaluate myocardial damage and ischemia. To compare these procedures and to obtain baseline information, 85 male patients with coronary heart disease were evaluated prior to beginning an exercise program. Findings at rest included Q waves or bundle branch block in 54%; 47% had ²⁰¹T1 redistribution defects and 33% an abnormal ejection fraction (EF). Of the 39 patients with normal ECGs, 31 had no ²⁰¹T1 defects and only 1 of these 31 (3%) had an abnormal EF. Abnormal EF or ²⁰¹T1 redistribution defects did not occur in patients without a history of myocardial infarction. Abnormal resting EF occurred in 63% of patients with abnormal versus 7% of those with normal ²⁰¹T1 redistribution scans. Exercise test results included an abnormal ST-segment response in 80%, an abnormal EF response in 65%, and a ²⁰¹T1 ischemic defect in 37%. Twenty patients had exercise-induced ST elevation, and this phenomenon was more related to ventricular aneurysms than to ischemia. ²⁰¹Thallium imaging, radionuclide ventriculography, and the ECG provide results regarding myocardial damage that agree by more than chance, while the exercise-induced ST-segment changes did not agree with the radionuclide indications of exercise-induced ischemia.     

Left ventricular performance during exercise in patients with left bundle branch block: evaluation by gated radionuclide ventriculography

To investigate changes in left ventricular (LV) function during exercise in patients with left bundle branch block (LBBB), 22 patients without a history or physical findings of previous myocardial infarction or LV dysfunction were studied by gated radionuclide ventriculography (GRNV) at rest and during bicycle exercise. Coronary arteriography demonstrated greater than 75% diameter narrowing of at least one coronary artery in nine patients. Of the remaining 13 patients, GRNV demonstrated wall motion abnormalities in seven patients either at rest or with exercise. During exercise, mean ejection fraction (EF) did not increase in patients without coronary artery disease (CAD). Patients with CAD had a 12-point fall in mean EF with exercise. We conclude that LV reserve, as demonstrated by ability to increase EF with exercise, is impaired in patients with LBBB even in the absence of CAD or other underlying cardiac disease and that standard GRNV criteria to exclude the presence of CAD (a greater than five-point increase in EF with exercise and normal wall motion) are not strictly applicable in screening patients with LBBB.     

Relationship of thallium-201 myocardial perfusion pattern to regional and global left ventricular function with exercise

Thallium-201 redistribution pattern after exercise was related to rest and exercise left ventricular regional and global function, measured by radionuclide ventriculography, in 61 patients, 50 with coronary artery disease (CAD). Sixteen patients had exclusively transient thallium defects, suggesting ischemia: in this group, mean left ventricular ejection fraction (LVEF) was 65% at rest, falling to 58% during exercise (p < 0.01). Eight patients had exclusively persistent thallium defects, suggesting scar: LVEF was unchanged during exercise, 58% to 59%. LVEF increased during exercise in the 17 patients without exercise thallium defects, seven with CAD: 66% to 73% (p < 0.05). Individual LV wall segments which exhibited translent or persistent thallium defects contracted abnormally both at rest and during exercise as compared to LV segments without exercise thallium defects. We conclude that: (1) only transient thallium defects rellably predict worsening left ventricular global function during exercise; (2) both transient and persistent thallium defects can be associlated with resting dyssynergy; and (3) in some CAD patients, apparent hypoperfusion does not necessarlly predict left ventricular dysfunction during exercise.     

Assessment of mitral flow velocity with exercise by an index of stress-induced left ventricular ischemia in coronary artery disease

Exercise-induced myocardial ischemia results in both diastolic and systolic left ventricular (LV) dysfunction. To investigate the utility of Doppler assessment of LV diastolic function with exercise, 28 consecutive patients underwent digital stress echocardiography, including measurement of mitral flow velocity by pulsed-wave Doppler and simultaneous stress thallium imaging. The mean mitral flow velocity was measured as the integrated area under the LV diastolic inflow Doppler spectral display. The change in mean mitral flow velocity from baseline to immediate postexercise was compared among 3 patient groups: (1) patients with thallium redistribution or exercise-induced wall-motion abnormalities, or both, consistent with exercise-induced ischemia (n = 18), (2) patients with no evidence of stress-induced ischemia, with or without resting wall-motion abnormalities (n = 10), and (3) 10 control subjects of similar age with normal resting 12-lead electrocardiograms, normal resting and postexercise 2-dimensional echocardiograms and normal electrocardiographic treadmill stress testing. The percent increase in mean mitral flow velocity was 101% (+/- 59) for controls and 86% (+/- 53) for patients without stress-induced ischemia versus 33% (+/- 24) in patients with stress-induced ischemia (p less than 0.005). An increase in mean mitral flow velocity with exercise of greater than 50% correctly identified 9 of 10 nonischemic control patients. An increase in mean velocity of less than 50% predicted ischemia in 15 of 18 patients with evidence of stress-induced ischemia (p less than 0.005) Thus, Doppler assessment of LV diastolic function with exercise expressed as a change in the mean velocity of mitral flow is a useful indicator of stress-induced ischemia.     

Exercise two-dimensional echocardiography for diagnosis of coronary artery disease

To improve ultrasound images during exercise 2-dimensional echocardiography (2-D echo), a device was developed to hold the transducer and maintain its orientation relative to the heart. The value of this technique in detecting wall motion abnormalities and changes in ejection fraction was evaluated in 54 men undergoing stress test for angina. Thallium-201 scanning, electrocardiography and exercise 2-D echo were recorded concurrently. Technically satisfactory echo studies were obtained in 47 patients (87%). The sensitivity and specificity of exercise echo in the detection of myocardial ischemia as judged by wall motion abnormalities were 100% and 93%, respectively. Sixteen patients with normal thallium scans increased their ejection fraction (EF) estimated by echo (from 52 +/- 1% at rest to 67 +/- 1% at maximal exercise, p less than 0.001); all showed an increase of 5% or more. In contrast, 11 patients who had reversible thallium scan defects showed a consistent decrease in EF (from 53 +/- 2% at rest to 43 +/- 2% during exercise, p less than 0.001); 20 patients with irreversible thallium scan defects showed no specific trend in the EF (48 +/- 2% at rest and 50 +/- 2% during exercise, difference not significant). Changes in heart rate and blood pressure did not distinguish the 3 groups of patients. Our technique of exercise 2-D echo may be useful for detecting wall motion abnormalities and EF changes during exercise and possibly enhance the sensitivity of thallium scanning in the noninvasive diagnosis of coronary artery disease.     

Relation between site of origin of ventricular tachycardia and relative left ventricular myocardial perfusion and wall motion

To assess the relation between the site of origin of ventricular tachycardia (VT) and relative myocardial perfusion and wall motion, 18 patients with a history of recurrent sustained VT underwent cardiac catheterization, invasive electrophysiologic study with endocardial mapping, and resting radionuclide ventriculography. In addition, 6 patients had exercise and redistribution thallium-201 scintigraphy, whereas the remaining 12 patients had resting thallium scans. The site of origin of VT (determined by catheter and intraoperative endocardial mapping) was correlated with relative myocardial perfusion (thallium) and left ventricular (LV) wall motion. All patients had significant (>50% narrowing) coronary artery disease and 16 had LV aneurysms.Twenty sites of origin of VT (28 morphologies) were identified in these 18 patients. Of the 9 patients with multiple VT morphologies, the VT originated at disparate sites in 2 patients. All 18 patients had thallium defects at rest and 3 patients had additional reversible (ischemic) defects on exercise. Of the 20 sites of origin of VT, 16 were at the periphery of the thallium defect, 1 was adjacent to it, and 3 were in the center of it. In the 16 patients with LV aneurysm, there were 18 sites of origin: 15 at the border of the aneurysm, 1 adjacent to it, and 2 within it.The data suggest that in patients with VT and coronary artery disease the site of origin is usually the periphery of a resting thallium defect, and in patients with LV aneurysm the site is the border of the aneurysm.