Exercise Thallium-201 Myocardial Scintigraphy Research Articles

A case of Werner's syndrome with cardiac syndrome X and heart failure with preserved ejection fraction

We herein report a case of Werner's syndrome (WS) with cardiac syndrome X (CSX) and heart failure with preserved ejection fraction (HFpEF), receiving nicorandil treatment.A 58-year-old woman with chest discomfort on exercise was suspected of having effort-angina pectoris because of broad ST-depression in electrocardiogram of exercise test and reversible defect in the posterior-wall portion of left ventricle in exercise thallium201 myocardial scintigraphy. This patient also exhibited HFpEF, diagnosed by increased ratio of early-transmitral-flow-velocity to tissue-Doppler early-diastolic mitral annular velocity (E/e′) in echocardiography and plasma B-type natriuretic peptide (BNP) levels. However, coronary angiography revealed no organic stenosis in epicardial coronary arteries, and coronary physiological measurements by PressureWire™ (St. Jude Medical, St Paul, MN, USA) demonstrated that coronary flow reserve (CFR) was greatly decreased. Because impaired CFR represents coronary microvascular dysfunction in the absence of obstructive coronary narrowing, we diagnosed CSX, and initiated the administration of nicorandil to improve coronary microcirculation. After three-month-treatment of nicorandil, the patient's symptoms were diminished, and reversible defect in exercise myocardial scintigraphy was improved. Furthermore, both E/e′ and BNP were decreased, indicating the improvement of HFpEF via the restoration of microvascular dysfunction.Thus, nicorandil administration could bring beneficial effects in WS with CSX and HFpEF, accompanied by coronary microcirculation dysfunction.<Learning objective: Contrary to previous case reports regarding Werner's syndrome (WS) with obstructive coronary artery disease (CAD), we herein report a case of WS with cardiac syndrome X (CSX) without obstructive CAD, complicated with heart failure with preserved ejection fraction (HFpEF). Because impaired coronary microcirculation is known to be associated with left ventricular hypertrophy and HFpEF, nicorandil could improve not only CSX but HFpEF via the restoration of coronary microvascular dysfunction.>

Prediction of restenosis after successful percutaneous coronary angioplasty by dobutamine thallium-201 scintigraphy

We evaluated the accuracy of dobutamine thallium-201 myocardial perfusion scintigraphy in predicting restenosis after successful percutaneous coronary angioplasty. Restenosis is one of the most important problems in patients who have undergone percutaneous coronary angioplasty. Exercise thallium-201 myocardial perfusion scintigraphy has been a well accepted non-invasive method to predict the restenosis of the dilated vessel after percutaneous coronary angioplasty, however, the role of thallium-201 myocardial perfusion using dobutamine, as a substitute for exercise in patients unable to exercise, in predicting restenosis is not well known. Therefore, 34 consecutive patients underwent dobutamine tomographic (single photon emission computed tomography) thallium-201 myocardial perfusion scintigraphy following a total of 37 successful angioplasties. No serious side effects during dobutamine infusion occured. The interval between percutaneous coronary angioplasty and scintigraphy ranged between 8 weeks to 2 years. All patients underwent control angiography within one month following myocardial perfusion scintigraphy. Sensitivity, specificity and accuracy of dobutamine myocardial imaging for predicting restenosis were 76%, 79% and 77%, respectively. Sensitivity and specificity related to the vascular territories were: left anterior descending artery 66–69%, left circumflex artery 75–100%, right coronary artery 83–66%, respectively. In conclusion, our findings demonstrating high accuracy of dobutamine myocardial single photon emission tomography for angiographic restenosis suggest its usefulness as a non-invasive tool in the follow-up of percutaneous coronary angioplasty patients.

Role of Adenosine in Pathogenesis of Syndrome X: Assessment With Coronary Hemodynamic Measurements and Thallium-201 Myocardial Single-Photon Emission Computed Tomography

Objectives. This study was performed 1) to examine the role of adenosine in the pathogenesis of syndrome X in patients with this syndrome and abnormal results on myocardial scintigrams during exercise, and 2) to determine the susceptibility to myocardial ischemia in this subset of patients with syndrome X.Background. A role for adenosine in the pathogenesis of syndrome X has recently been postulated, but there are few clinical data supporting this hypothesis.Methods. Exercise thallium-201 myocardial scintigraphy after intravenous administration of aminophylline, an adenosine receptor blocking agent, or saline solution and adenosine thallium-201 scintigraphy were performed in 26 patients with syndrome X. Hemodynamic variables during exercise and perfusion defect size after aminophylline and saline infusions were compared. At cardiac catheterization, coronary hemodynamic variables during separate infusions of adenosine and dobutamine were also examined and were compared among patients with abnormal or normal scintigrams and 10 control subjects.Results. Perfusion abnormalities on exercise-thallium-201 scintigraphy occurred in 14 of 26 patients with syndrome X. Intravenous infusion of aminophylline suppressed the scintigraphic perfusion defect and prolonged the time to 1-mm ST segment depression in patients with syndrome X with abnormal exercise scintigrams. Intravenous infusion of adenosine induced a perfusion defect in the same myocardial area where the perfusion defect was observed at exercise in 7 of the 14 patients with syndrome X. At cardiac catheterization, patients with syndrome X with abnormal exercise scintigrams had lower coronary flow reserve and a greater frequency of myocardial lactate production and ST segment depression in response to the infusions of adenosine and dobutamine than did the other two groups. During adenosine infusion, great cardiac vein blood flow and oxygen content were significantly increased and myocardial oxygen consumption and lactate extraction were significantly reduced from baseline without a significant increase in rate-pressure product in this subset of patients with syndrome X.Conclusions. Patients with syndrome X with abnormal exercise scintigrams have high susceptibility to myocardial ischemia during exercise or pharmacologic stress tests, probably owing to reduced coronary flow reserve. A heterogeneous response to endogenous adenosine may contribute to scintigraphic perfusion abnormalities and myocardial ischemia during exercise in this subset of patients with syndrome X.

Evaluation of myocardial ischemia and infarction by signal-averaged electrocardiographic late potentials in children with Kawasaki disease

We investigated myocardial ischemia and an old myocardial infarction noninvasively using signal-averaged electrocardiographic late potentials (LPs) in patients with Kawasaki disease. Patients were divided into 4 groups: a noncoronary artery lesion group (n = 136), a coronary artery lesion group (without myocardial ischemia and an old myocardial infarction; n = 33), an ischemia group (n = 16), and an old myocardial infarction group (n = 13). Grouping was based on exercise thallium-201 myocardial scintigraphy, thallium-201 myocardial scintigraphy, exercise electrocardiography, coronary angiography, left ventriculography, and echocardiography. Signal-averaged electrocardiograms were recorded using a high-resolution system. Values of filtered QRS duration (f-QRSd), root-mean-square voltage, and duration of low-amplitude signal were judged using our own body surface area-related criteria (n = 205) to determine positive rates of LPs and sensitivities and specificities to ischemia and infarction. These data were also interpreted using published criteria for adults and compared with those interpreted by our criteria. Positive rates by our criteria were 0% in the noncoronary artery lesion group, 9.1 % in the coronary artery lesion group, 56.3% in the ischemia group, and 69.2% in the old myocardial infarction group. However, using the criteria for adults, these values were 0%, 3.0%, 25%, and 46.2%, respectively. Sensitivities to ischemia and infarction using our criteria were significantly higher (56.3% and 69.2%) than those using the criteria for adults (p < 0.05). Moreover, specificities to ischemia and infarction were very high (93.4% and 93.5%, respectively) using our criteria, and there were no significant differences from specificities using the criteria for adults. Also, we examined the reproducibility of values of LPs and LP parameters. The values of filtered QRS duration showed a high reproducibility in both LP-positive and -negative groups, followed by low-amplitude signal and then root-mean-square voltage. The results of LP presence or absence showed 100% reproducibility for both the LP-positive and -negative groups, supporting the utility of LPs for clinical applications. Thus, LPs provide useful information in a noninvasive manner for clarifying ischemia and infarction in patients with Kawasaki disease.

Relationship between insufficient redistribution in exercise thallium-201 myocardial single-photon emission computed tomography and reverse redistribution at rest.

It is widely accepted that perfusion defects in 3 to 4-h delayed images in exercise thallium-201 (201Tl) myocardial scintigraphy underestimate the viability of myocardium in the infarct region. In the present study, to examine the contribution of the condition of myocardium which demonstrates reverse redistribution in resting scintigraphy to the insufficiency of redistribution in the 4-h delayed image in exercise scintigraphy, we performed exercise and resting 201Tl myocardial single-photon emission computed tomography in 58 patients with acute myocardial infarction and a single diseased coronary artery. Twenty eight patients demonstrated reverse redistribution (group RR) and 28 showed a fixed defect (group FD) in resting scintigraphy. Redistribution in the 4-h delayed image in exercise scintigraphy was significantly more insufficient in group RR than in group FD (p < 0.01), and the degree of the insufficiency of redistribution in exercise scintigraphy closely correlated with the degree of reverse redistribution in resting scintigraphy (r = 0.79, p < 0.001). We conclude that in patients with acute myocardial infarction, the condition of myocardium which demonstrates reverse redistribution in resting myocardial scintigraphy is related to the insufficiency of redistribution in the delayed image in exercise scintigraphy.

Comparison of “Rose questionnaire angina” to exercise thallium scintigraphy: Different findings in males and females

Validation of the London School of Hygiene (Rose) Questionnaire with objective measures of myocardial ischemia is incomplete. Therefore, we compared the Rose Questionnaire with exercise thallium-201 myocardial scintigraphy in 147 male and 97 female patients with chest pain referred for clinical exercise testing. Of those with “Rose Questionnaire angina”, 26% of the females and 73% of the males had positive thallium-201 scans. Negative results on both the Rose Questionnaire and thallium-201 scintigraphy were observed in 71 % of the females and 47% of the males. The sensitivity of the Rose Questionnaire was similar in females (41 %) and males (44%). The specificity was 77% in males, while in females it was significantly lower at 56%. The specificity values reflect the higher ( p < 0.05) prevalence of “false positive” Rose Questionnaire results in females (75%) compared with males (27%). In addition, males had a greater ( p < 0.05) number of “false negative” results (53%) than females (29%). The accuracy of the Rose Questionnaire for myocardial ischemia was 0.19 in females, 0.48 in males, and 0.29 overall when including both males and females. Our results indicate a generally poor relationship between Rose Questionnaire angina and thallium-201 scintigraphy, an objective measure of myocardial ischemia in patients with chest pain referred to clinical exercise testing. Further, there are gender-specific differences in this relationship between the questionnaire and exercise thallium-201 imaging.

Coronary collaterals reduce the duration of exercise-induced ischemia by allowing a faster recovery

The role of collaterals in influencing postischemic recovery after exercise testing has not been investigated previously. We studied 54 patients (mean age 59 ± 6 years) with effort-induced angina and documented coronary disease who underwent exercise testing and thallium-201 myocardial scintigraphy. On angiography, 30 patients (group A) exhibited visible collaterals (grade 2 to 3, Cohen and Rentrop classification) perfusing the ischemic zone, whereas the other 24 (group B) did not. Patients with collaterals had more severe coronary artery disease (Gensini score 46.9 ± 16 vs 28.6 ± 18; p < 0.001) and more severe impairment of coronary flow reserve (time and rate-pressure product to 1 mm ST segment depression 3.5 ± 0.8 vs 4.8 ± 0.6 minutes, p < 0.01; 14189 ± 2451 vs 16081 ± 2215 beats/min × mm Hg, p < 0.04, respectively). However, in these patients the ECG returned to baseline more rapidly after exercise (5.5 ± 1.6 vs 11.7 ± 3.3 minutes; p < 0.001). Therefore, although collaterals do not apparently prevent or delay the development of exercise-induced ischemia, they can limit its duration by allowing a faster recovery.

Assessment of myocardial perfusion with thallium-201 scintigraphy in exercise-induced left bundle branch block: diagnostic value and clinical significance.

Myocardial perfusion scintigraphy with thallium-201 was performed in 33 subjects (mean age 45 years, range 28-61) with exercise-induced, rate-dependent left bundle branch block (LBBB) in order to assess both the value of Thallium-201 myocardial imaging for the diagnosis of coronary artery disease (CAD) and the pathogenesis (ischaemic or not) of the conduction defect. Of the 33 patients evaluated, 16 had chest pain suggestive of CAD and 17 were asymptomatic. None had a history of prior myocardial infarction or clinical and echocardiographic signs of heart disease. LBBB appeared at a heart rate ranging from 70 to 160 b.min-1. Eighteen patients showed repolarization abnormalities (ST segment depression with deep inverted T waves) compatible with ischaemia, after QRS normalization. Thallium-201 myocardial uptake was normal in 12 subjects; in the remaining 21, reversible Thallium-201 defects were demonstrated in the septum (18 patients), septum and apex (2), and septum and infero-apical wall (1). No patient had irreversible defects and all had normal coronary angiography, with negative ergonovine tests for coronary artery spasm. The patients were followed up for a mean of 43 months (range 16-80). One patient died from sudden death, but no cardiac event occurred in the other patients. In conclusion, exercise Thallium-201 myocardial scintigraphy showed a high prevalence (64%) of reversible perfusion defects in a group of patients with exercise-induced LBBB without any evidence of CAD at angiography or coronary spasm at ergonovine test. Moreover, follow-up showed a relatively low rate of major cardiac events.

Frequency and prognostic significance of silent coronary artery disease in patients with cerebral ischemia undergoing carotid endarterectomy

To evaluate the prevalence and prognostic role of silent coronary artery disease (CAD) in patients with symptomatic high-grade carotid stenosis (70 to 99%) undergoing carotid endarterectomy, and with neither history nor symptoms of CAD, 106 patients (76 men, 30 women, mean age 58.7 years [range 42 to 71]) with recent cerebral ischemia were prospectively studied. Patients were stratified as to the presence (n = 27, 25%) or absence (n = 79, 75%) of silent CAD defined by concordant abnormal exercise electrocardiographic testing and thallium-201 myocardial scintigraphy. The male sex, the severity of the symptomatic carotid lesion (>90%), and the coexistence of contralateral carotid disease identified patients with higher probability of coexisting CAD. The 106 patients underwent 121 operations (bilateral in 15). In the perioperative period, no deaths or cardiac events occurred, 1 patient suffered a recurrent stroke and 3 had a transient ischemic attack. During a mean follow-up period of 5.4 years, 9 patients died (1.7%/year): fatal myocardial infarction occurred in 5 (all in the silent CAD group), cancer in 3 and vertebrobasilar stroke in 1. Nonfatal events occurred in 9 patients: myocardial infarction in 1 (without silent CAD), unstable angina in 3 (with silent CAD), and cerebral ischemic attacks in 5. After 7 years, the Kaplan-Meier estimated survival free from coronary events was 51% in patients with silent CAD, and 98% in patients without CAD (p < 0.01). In conclusion, among patients with symptomatic high-grade carotid stenosis undergoing carotid endarterectomy, even in absence of history or symptoms of CAD, a silent CAD is detectable in one fourth of the patients. Silent CAD did not affect the perioperative outcome, but strongly influenced the long-term prognosis. These results suggest the need for routine screening of silent CAD in patients with severe carotid stenosis to identify those at high long-term risk of cardiac events, for whom a more aggressive management should be warranted.

Collateral circulation as a marker of the presence of viable myocardium in patients with recent myocardial infarction

The relationship between the presence of viable myocardium and the extent of coronary collateral circulation to the infarct area was evaluated in 20 patients with a recent anterior myocardial infarction who had complete obstruction of the left anterior descending coronary artery. The viability of myocardial tissue was assessed by exercise thallium-201 myocardial scintigraphy, and the collateral circulation was angiographically evaluated by means of a collateral index ranging from 0 to 3. Patients were divided into two groups according to the presence (group 1, n = 10) or absence (group 2, n = 10) of viable myocardium in the perfusion territory of the infarct-related artery. The collateral index in group 1 was 2.5 ± 0.5 (SD), which was significantly higher than the 0.7 ± 0.8 in group 2. These findings indicate that the presence of ischemic but viable myocardium is intimately related to the development of collateral circulation in patients with myocardial infarction, and the existence of well-developed collateral channels predicts the presence of viable myocardium in the infarct area.

Asymptomatic myocardial infarction in Kawasaki disease: Long-term prognosis

Eight patients with Kawasaki disease who had sustained asymptomatic myocardial infarction 8-15 years ago (mean, 13.1 years) were reexamined by various noninvasive cardiac function tests to assess long-term prognosis. At present, electrocardiograms (ECGs) are normal in six patients. However, all eight patients had a prolonged preejection period (PEP) to left ventricular ejection time (LVET) ratio 30 s after amylnitrate (AN) inhalation. Six patients had perfusion defects by exercise thallium-201 myocardial scintigraphy, and two patients developed ST segment depression in treadmill exercise testing. These patients are symptom-free even though their physical activity has not been restricted. Yet they proved to have serious abnormalities suggesting sequelae of myocardial infarction or existing myocardial ischemia. Judging from the results of noninvasive cardiac function tests and recently performed coronary angiography, five of the eight patients require coronary bypass surgery.

Exercise Thallium-201 Scintigraphy in the Diagnosis and Prognosis of Coronary Artery Disease

To determine the discriminant accuracy of exercise thallium-201 myocardial perfusion scintigraphy for the diagnosis and prognosis of patients with known or suspected coronary artery disease. A survey of the National Library of Medicine MEDLINE database. The key medical subject headings used were coronary disease, myocardial infarction, radionuclide imaging, and thallium. A total of 122 retrieved studies were considered relevant and were reviewed in depth. Only studies reporting both the sensitivity and specificity of thallium scintigraphy were analyzed. Discriminant accuracy for diagnosis and prognosis was summarized in terms of pooled sensitivity and specificity. Exercise thallium scintigraphy is useful in the noninvasive diagnosis of coronary artery disease, especially in patients with abnormal resting electrocardiograms, restricted exercise tolerance, and intermediate probability of having disease at the time of testing as well as of defining the prognosis of patients with known or suspected coronary artery disease, especially in those with previous myocardial infarction. Because of various shortcomings in the published record, however, the marginal discriminant accuracy and cost effectiveness of thallium scintigraphy compared with conventional clinical assessment and exercise electrocardiography remain controversial.

Sequential thallium-201 myocardial perfusion studies after successful percutaneous transluminal coronary artery angioplasty: delayed resolution of exercise-induced scintigraphic abnormalities.

To characterize the sequential changes of myocardial perfusion scintigraphy in patients with coronary artery disease (CAD) after complete revascularization, 43 patients underwent exercise thallium-201 (201Tl) myocardial perfusion scintigraphy before and at 9 +/- 5 days, 3.3 +/- 0.6, and 6.8 +/- 1.2 months after percutaneous transluminal coronary angioplasty (PTCA). Only patients with single-vessel CAD, without previous myocardial infarction, and without evidence of restenosis at 6 to 9 months after PTCA were included. Perfusion scans were analyzed blindly with the use of a new quantitative method to define regional myocardial perfusion in the topographic distribution of each coronary artery, which was shown to be reproducible (r = .94 or higher and SEE of 7% or less, between repeated measures by one and two operators). At 4 to 18 days after PTCA, the mean treadmill walking time increased by 123 +/- 42 sec, mean exercise-induced ST segment depression decreased by 0.6 +/- 0.3 mm, group maximal heart rate increased by 20 +/- 9 beats/min, and group systolic blood pressure at peak exercise increased by 24 +/- 10 mm Hg, compared with pre-PTCA values (p less than .001). However, no group differences were noted in these variables between the three post-PTCA stages. Myocardial perfusion in the distribution of the affected (dilated) coronary artery, on the other hand, improved progressively. In the 45 degree left anterior oblique view for instance, myocardial perfusion increased at 9 days after PTCA (from 68 +/- 24% before PTCA to 91 +/- 9%, p less than .001) and at 3.3 months after PTCA (101 +/- 8%, p less than .05 vs 9 days after PTCA), but no further significant changes were seen at 6.8 months after PTCA (102 +/- 8%). Similar changes were noted in the other two views. No relationship between minor complications during PTCA and delayed improvement on the 201Tl was observed. Myocardial ischemia was diagnosed in 12 of the 43 scans recorded a few days after PTCA, but in none recorded at later stages. We conclude that 201Tl scans after PTCA often show delayed improvement and therefore, an abnormal myocardial perfusion scan soon after PTCA does not necessarily reflect residual coronary stenosis or recurrence.

Usefulness of thallium-201 scintigraphy during right ventricular pacing for detecting myocardial ischemia with angiographically normal coronary arteries

Exercise thallium-201 (Tl-201) myocardial scintigraphy has been widely accepted as the procedure for detecting limited coronary perfusion reserve. 1 However, in some patients incapable of exercise, pacing stress is often substituted to increase myocardial oxygen demands. Tl-201 scintigraphy during atrial pacing has been shown to be comparable to exercise imaging for detecting coronary artery disease. 2 In patients with impaired atrioventricular conduction, right ventricular (RV) pacing is introduced to augment myocardial metabolic activity. The disturbance in conduction sequence that causes any change in the distribution of myocardial perfusion in subjects with no evidence of coronary artery narrowing has not been clearly defined.

Role of exercise thallium-201 myocardial perfusion scintigraphy in predicting prognosis in suspected coronary artery disease

While exercise thallium imaging has improved sensitivity and specificity for detection of coronary artery disease (CAD), Its predictive value for morbid cardiac events is unclear. Of 532 consecutive patients who underwent exercise thallium Imaging, follow-up was complete in 515 (97%) after an average of 36 months (range 31 to 48). Two hundred six patients had an abnormal exercise thallium response and 309 had a normal response. Twenty morbid cardiac events occurred (13 deaths and 7 acute myocardial Infarctions [AMI]). Of the 13 patients who died, 12 had abnormal thallium results. Overall, 5.8% of the patients with abnormal thallium results died, in contrast to 0.3% of patients with normal results. Of the 7 patients who had a nonfatal AMI, 3 had abnormal exercise thallium results. Moreover, similar proportions of patients (1.4% and 1.3%) with normal and abnormal exercise thallium results had nonfatal AMI. Presence or absence of pathologic Q waves and inclusion of exercise electrocardiographic results did not significantly after the results. Thus, although a normal exercise thallium response significantly reduces the likelihood of cardiovascular death, its predictive value for nonfatal AMI is limited. Moreover, the relatively low event rate for patients with a positive exercise thallium response further limits Its prognostic value.

Cerebral ischemia and asymptomatic coronary artery disease: a prospective study of 83 patients.

A prospective cardiologic evaluation was performed in 83 consecutive patients with transient cerebral ischemia or mild stroke and without symptoms or electrocardiographic signs of ischemic heart disease. Patients were studied with an electrocardiographic exercise test; a positive test was followed by exercise Thallium-201 myocardial scintigraphy. Results were compared to those obtained in a group of 83 age and sex-matched healthy subjects submitted to the same study protocol. Asymptomatic coronary artery disease was detected in 28% of cerebrovascular patients with adequate electrocardiographic exercise test. A scintigraphic perfusion defect of variable extension was found in 19 of them. In the control group the electrocardiographic exercise test was positive in only 6% (p less than 0.01). Our results support the concept that: asymptomatic ischemic heart disease is often associated with cerebrovascular disease; therefore cerebral ischemic attacks may be a marker of coronary artery disease, an active investigation of the heart should be considered in cerebrovascular patients in order to plan optimal, comprehensive management.

Alterations in myocardial perfusion during exercise after isosorbide dinitrate infusion in patients with coronary disease: Assessment by thallium-201 scintigraphy

We studied the effect of intravenous isosorbide dinitrate (ISDN) on myocardial perfusion of patients with coronary artery disease, by using exercise thallium-201 (TI-201) myocardial scintigraphy. A control study was conducted initially to assess regional myocardial perfusion rate. Left ventricular myocardium was divided into six parts: anterior, lateral, apical, inferior, posterior, and septal segments. The segmental myocardial perfusion was characterized according to TI-201 initial uptake index (IUI) of relative distribution and redistribution index (RDI) of TI-201 washout. The normal limit of IUI and RDI was established from the data of 17 persons with normal coronary arteries, and then the IUI ≤ 84% and the RDI ≥ 1.12 was defined as abnormal. Based on IUI and RDI, each segment was characterized into three types: A type = IUI ≦ 84%, RDI ≧ 1.12; B type = IUI ≦ 84%, RDI < 1.12; and C type = IUI > 84%, RDI < 1.12. ISDN was given as a dose of 0.1 mg/kg/hr, and then treadmill testing was repeated for the same duration of exercise time using the same protocol as in the control period. The segments of A type showed a significant improvement in IUI and RDI after receiving ISDN infusion, while the B and C type segments showed no change. It was also shown that the improvement of IUI and RDI of the A type segments was not as marked in multivessel disease as in cases of single-vessel disease. The results of our study suggest that ISDN particularly improves myocardial perfusion in ischemic myocardium, and the degree of improvement is influenced by myocardial viability and the severity of coronary artery disease.

Exercise testing and Thallium-201 myocardial perfusion scintigraphy in the clinical evaluation of patients with Wolff Parkinson White syndrome

In 58 patients with Wolff Parkinson White syndrome (WPW), we performed exercise stress testing in order to investigate the incidence of normalization of the auriculo-ventricular conduction and the ST-segment changes. For a more accurate evaluation of the latter, exercise and redistribution radionuclide images with Thallium-201 were obtained in 18 cases. Forty-nine had type A and nine had type B of WPW. Forty-eight had permanent, four had alternant and six had no pre-excitation (PE) when they started the test. Mean maximal functional capacity, mean maximal heart rate and mean maximal double product were not different when compared to an age-matched control group. Of the 48 patients who began the test with PE, in 23 (48%) it disappeared while PE persisted in 25 (52%). In 16 cases the disappearance of the PE was sudden and in seven it was progressive. Pre-excitation persisted in 39.5% of patients with type A and in 88.8% with type B (p less than 0.01). ST-segment depression was observed in 76.6% of patients with PE and in 28.6% of cases without PE (p less than 0.01). ST-segment depression occurred in 44.8% of patients with type A and in 100% of cases with type B (p less than 0.05). Transient abnormal Thallium-201 scans were observed in 62.5% of patients without PE and in 20% with PE. No patients showed exertional arrhythmias. This study suggests the possibility of measuring the duration of the refractory period of the accessory pathway in those patients in which the PE disappears suddenly, at a given heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Noninvasive diagnostic test choices for the evaluation of coronary artery disease in women: A multivariate comparison of cardiac fluoroscopy, exercise electrocardiography and exercise thallium myocardial perfusion scintigraphy

Several diagnostic noninvasive tests to detect coronary and multivessel coronary disease are available for women. However, all are imperfect and it is not yet clear whether one particular test provides substantially more information than others. The aim of this study was to evaluate clinical findings, exercise electrocardiography, exercise thallium myocardial scintigraphy and cardiac fluoroscopy in 92 symptomatic women without previous infarction and determine which tests were most useful in determining the presence of coronary disease and its severity. Univariate analysis revealed two clinical, eight exercise electrocardiographic, seven myocardial scintigraphic and seven fluoroscopic variables predictive of coronary or multivessel disease with 70% or greater stenosis. The multivariate discriminant function analysis selected a reversible thallium defect, coronary calcification and character of chest pain syndrome (p less than 0.05) as the variables most predictive of presence or absence of coronary disease. The ranked order of variables most predictive of multivessel disease were cardiac fluoroscopy score, thallium score and extent of ST segment depression in 14 electrocardiographic leads. Each provided statistically significant information to the model. The estimate of predictive accuracy was 89% for coronary disease and 97% for multivessel coronary disease. The results suggest that cardiac fluoroscopy or thallium scintigraphy provide significantly more diagnostic information than exercise electrocardiography in women over a wide range of clinical patient subsets.

Assessment of the myocardial perfusion pattern in patients with multivessel coronary artery disease

We studied 42 symptomatic patients with coronary artery disease involving two or three vessels using exercise thallium-201 myocardial scintigraphy. Qualitative analysis of the images predicted multivessel disease in 75% of the patients with two-vessel disease and in 82% of the patients with three-vessel disease. Quantitative analysis of the size of the perfusion defect indicated that approximately 40% of the left ventricular perimeter showed abnormal perfusion pattern during stress in these patients, and there was no significant difference in the size of the defect in patients with two-vessel disease or three-vessel disease (41 ± 17% vs 42 ± 14%, respectively, mean ± SD). The exercise heart rate, exercise ECG response, and severity of narrowing did not correlate with the size of the perfusion defect. Patients with anterior infarction had larger defects in the distribution of the left anterior descending artery than those without infarction. Collaterals offered partial protection during exercise only when they were not jeopardized. This study confirms the value of qualitative analysis of exercise thallium-201 imaging in predicting multivessel disease, and describes a simple method of assessing the extent of perfusion abnormalities during stress in patients with multivessel disease. The results may be important in patient management and prognosis.