Role Of Myocardial Perfusion Imaging Research Articles

The role of myocardial perfusion imaging in predicting myocardial ischemia in patients diagnosed with long COVID.

Incomplete recovery with long-term complications weeks beyond the acute coronavirus disease 2019 (COVID-19) infection is referred to as long COVID. Among the well-known long-term complications of COVID-19, myocardial damage is a frequently encountered side effect. Yet there is a lack of data for identifying high-risk patients who are more likely to develop long-term cardiovascular complications following COVID-19. Myocardial perfusion imaging (MPI) is the primary functional imaging modality in evaluating myocardial ischemia This study aimed to investigate the role of MPI in predicting myocardial ischemia in patients diagnosed with long COVID. Subjects were selected from eligible long COVID patients and control subjects without a prior history of COVID-19 who were referred to the nuclear medicine department for stress and rest single-photon emission computed tomography (SPECT) MPI. All participants' past medical records and clinical, and demographic characteristics were scanned. In addition, patients undergoing coronary angiography (CAG) following SPECT MPI were documented and patients with critical coronary stenosis were identified. Our results revealed that long COVID patients had higher rates of abnormal summed stress scores compared to the control subjects (p < 0.05). Additionally, serum CRP level, SPECT lung-to-heart ratio (LHR), and the presence of long COVID were independent predictors of ischemia. The presence of long COVID was the best predictor of ischemia among the aforementioned parameters (p < 0.001). Our data indicate that SPECT MPI provides comprehensive information on myocardial perfusion and left ventricular function in long COVID patients.

The Role of Myocardial Perfusion Imaging in the Prediction of Major Adverse Cardiovascular Events at 1 Year Follow-Up: A Single Center's Experience.

Myocardial perfusion imaging via single-photon emission computed tomography (SPECT MPI) is a well-established method of diagnosing coronary artery disease (CAD). The purpose of this study was to assess the role of SPECT MPI in predicting major cardiovascular events. The study population was composed of 614 consecutive patients (mean age: 67 years, 55% male) referred for SPECT MPI due to symptoms of stable CAD. The SPECT MPI was performed using a single-day protocol. We conducted a follow-up on all patients at 12 months via a telephone interview. The majority of our patients (78%) presented findings suggestive of reversible ischemia, fixed defects or both. Extensive perfusion defects were found in 18% of the population, while LV dilation was found in 7%. During the 12-month follow-up, 16 deaths, 8 non-fatal MIs and 20 non-fatal strokes were recorded. There was no significant association of SPECT findings with the combined endpoint of all-cause death, non-fatal MI and non-fatal stroke. The presence of extensive perfusion defects was an independent predictor of mortality at 12 months (HR: 2.90, 95% CI: 1.05, 8.06, p = 0.041). In a high-risk patient population with suspected stable CAD, only large reversible perfusion defects in SPECT MPI were independently associated with mortality at 1 year. Further trials are needed to validate our findings and refine the role of SPECT MPI findings in the diagnosis and prognosis of cardiovascular patients.

Inpatient myocardial perfusion imaging characteristics of patients admitted with suspected type 2 myocardial infarction

Abstract Funding Acknowledgements Type of funding sources: None. Background ESC defines a type 1 myocardial infarction (T1MI) as "MI caused by atherosclerotic coronary artery disease and usually precipitated by atherosclerotic plaque disruption" and type 2 myocardial infarction (T2MI) as "ischaemic myocardial injury in the context of a mismatch between oxygen supply and demand". In practice it can be difficult to differentiate between MI types and the role of myocardial perfusion imaging (MPI) in making this distinction remains unclear. Purpose To establish whether suspected T2MI has different characteristics on MPI compared to suspected T1MI. Methods All inpatient MPI scans at our institution between 01/03/2018 and 28/02/2020 were retrospectively reviewed. Patients were excluded if they had a previous diagnosis of coronary artery disease, an invasive coronary angiogram prior to MPI, or a maximal troponin T &amp;lt; 14ng/l. Diagnoses were categorised based on review of scan request information. Echocardiography images were reviewed if within 30 days of MPI. Results 58 patients were included: 28 with suspected type 2 MI and 30 with suspected type 1 MI (mean age 70 vs. 75). There was no statistically significant difference in maximal troponin T between groups (T2MI 394.0 ng/l, T1MI 415.6 ng/l; p=0.90). 50% T2MI patients and 53% T1MI patients had a territorial defect on MPI (fully reversible defect 25% vs. 17%, partially reversible defect 7% vs. 33%, irreversible defect 14% vs. 3% for T2MI vs T1MI respectively). 25% T2MI patients had an area &amp;gt;10% LV myocardium volume showing reversibility, compared with 33% T1MI (p=0.49). Both groups had similar proportions of left ventricular (LV) impairment (both had 65% of patients with normal LV ejection fraction) and prevalence of regional wall motion abnormalities ((RWMA) 39% for T2MI, 35% for T1MI, p=0.76) on echocardiography. Conclusions A clinically significant proportion of the suspected T2MI group had territorial ischaemia. Additionally, both patient groups demonstrated similar proportion of patients with reversible ischaemia and of LV systolic dysfunction. Therefore differentiation between T2MI and T1MI can be challenging both clinically and with MPI. Prospective studies are required to establish the optimal methods for making the distinction between types of MI.

Stress myocardial perfusion imaging in patients presenting with syncope: Comparison of PET vs. SPECT

BackgroundThe role of myocardial perfusion imaging (MPI) in patients with suspected coronary artery disease (CAD) presenting with syncope is controversial. We aimed to determine diagnostic yield of MPI for evaluation of syncope in patients without known CAD, as a function of pre-test patient risk and test modality (PET vs SPECT). MethodsBetween 1/2010 and 12/2016, 1324 consecutive patients presenting with syncope without known CAD underwent MPI with PET (n = 640) or SPECT (n = 684). Rates of abnormal MPI (summed difference score (SDS) > 2 or left ventricular ejection fraction (LVEF) reserve ≤ 0 for PET and SDS > 2 or post-stress LVEF ≤ 45% for SPECT) were determined among patients stratified by pre-test risk. In patients who were referred for coronary angiography, diagnostic yield of obstructive CAD was calculated in the overall cohort as well as in a propensity-matched cohort compared to patients without syncope. ResultsAbnormal MPI was noted in 36.5% (201/551) of patients who had PET compared with 13.0% (87/671) who had SPECT (P < 0.001), which is largely related to higher comorbidity burden and greater pre-test CAD risk in the PET population. Among patients who had an abnormal MPI, 8.5% (47/551) with PET and 0.7% (5/671) with SPECT were found to have obstructive CAD if referred for coronary angiography. Patients at intermediate-high pre-test risk had a higher proportion of abnormal MPIs and obstructive CAD as compared to those at low risk in both the PET and SPECT cohorts. The rate of abnormal testing and diagnostic yield of PET MPI was similar and proportionate to pre-test likelihood among matched patients with and without syncope. ConclusionsAmong patients referred for PET MPI with syncope at an intermediate-high pre-test CAD risk, 1 in 3 had an abnormal MPI and 1 in 10 had obstructive CAD. The value of MPI was related to pre-test risk as opposed to the presence of syncope, and MPI testing with PET or SPECT in the low-risk population was low value.

The Role of Myocardial Perfusion Imaging in Patients with Diabetes Mellitus

Abstract Diabetes mellitus is a complex pathology with increasing incidence, associated with an increased risk of coronary heart disease. Myocardial perfusion imaging (MPI) is an important diagnostic tool for the evaluation of coronary artery disease (CAD), with a high prognostic value. Objective. The aim of this study was to evaluate the role of stress-rest MPI in the assessment of patients with DM and suspected or confirmed CAD. Method. We performed a retrospective analysis of 128 patients who underwent stress-rest MPI in our department, all of them with coronary angiography (CA) available. All patients underwent stress rest myocardial perfusion SPECT using a 1-day or 2-day protocol. The radiopharmaceuticals used were 99m-Tc-MIBI or tetrofosmin. The study was performed with a gated protocol SPECT, synchronous with the ECG, using a dual-head gamma camera. Patients were divided in 4 subgroups based on the presence of DM and of significant CA changes. Results. In the group of patients with significant coronary disease on CA and previously diagnosed DM, number of perfusion defects on the stress-rest MPI were higher and also the presence of systolic disfunction and the severity of defects. Our results support the idea that the severity and extent of myocardial perfusion defects are greater in diabetic patients than in non-diabetic patients. Conclusions. We can consider myocardial perfusion SPECT with 99mTc-labeled agents as a feasible method for the diagnosis and evaluation of CAD and for the management of diabetic patients.

Cardiac involvement in polymyositis: Role of myocardial perfusion imaging

Cardiac involvement in polymyositis: Role of myocardial perfusion imaging

The prognostic value of myocardial perfusion imaging in patients with type 2 myocardial infarction

ObjectivesThe aim of this retrospective study is to evaluate the prognostic role of myocardial perfusion imaging (MPI) in patients with type 2 myocardial infarction (T2MI). BackgroundT2MI is an increasingly common diagnosis in clinical practice. The management of this condition is controversial and the prognostic value of MPI has not been established in this setting. MethodsWe retrospectively studied T2MI patients who underwent vasodilator gated MPI within 90 days of T2MI at a single tertiary care institution in 2013. Abnormal myocardial perfusion was defined as the perfusion defect involving ≥ 5% of left ventricular (LV) myocardium. Abnormal LV ejection fraction (EF) was defined as < 50% by gated images. The primary outcome was a composite of death, myocardial infarction (other than index event) or coronary revascularization (CR). ResultsThere were 234 patients (62 ± 14 years, 57% men) with T2MI (peak troponin 0.2 ng/ml, interquartile 0.1-1.4), of whom 136 (58%) had an abnormal MPI. During a median follow-up of 20 months, 155 patients (66%) had the primary outcome (39% death, 42% MI, 5% CR). An abnormal MPI was associated with an increased risk of the primary outcome with a hazard ratio of 1.56, 95%CI (1.12-2.18, P = .008) that remained statistically significant after multivariate adjustment (1.45, 95%CI (1.02-2.06, P = .04))). ConclusionsPatients with T2MI are at high risk for death or cardiac events in the intermediate term. More than one-half of patients with T2MI have an abnormal MPI and this is associated with the increased risk of cardiac events during follow-up. Risk stratification with MPI after T2MI may identify patients who would benefit from aggressive risk reduction.

The role of myocardial perfusion imaging in the identification of the obstructive coronary artery lesions: a tertiary cardiology center experience

Objectives: Because of the moderate accuracy of treadmill electrocardiogram and fear of a claim if a diagnosis is missed, cardiologists usually order Myocardial Perfusion Imaging (MPI) as a first-step test in most of patients with chest pain admitted to cardiology department. The performance of the MPI in diagnosing obstructive CAD depends on the population studied. Thus we aimed to assess the agreement between MPI and coronary angiography in the identification of the obstructive coronary lesion. Methods: A total of 231 patients who underwent MPI due to suspicion of coronary ischemia and had a coronary angiogram within the last three months were included in this retrospective study. MPI and coronary angiography findings were analyzed to weigh the performance of MPI in determining obstructive coronary lesion. Results: The mean age was 63.9 ± 8.9 years, 54.5% being males. MPI showed a sensitivity of 0.86 in determining patients who had a significant (&amp;gt; 70%) coronary lesion. While evaluating the ability of MPI to detect ischemia in the left ventricle region which is supplied by the lesioned vessel, the sensitivity was found to be; 60% in determining anterior ischemia associated with significant LAD lesion, 77.4% in determining inferior ischemia associated with significant RCA lesion, and 44.4% in determining lateral ischemia associated with significant CX lesion. Conclusions: Our findings have shown that MPI with visual assessment has 86% sensitivity for detecting significant coronary artery stenosis. However, the sensitivity of MPI in determining ischemia in the left ventricle region which is supplied by the lesioned coronary artery was found to be 44.4 to 77.4%.

P4701The elusive role of myocardial perfusion imaging for the patients with insufficient fractional flow reserve after drug eluting stent implantation

P4701The elusive role of myocardial perfusion imaging for the patients with insufficient fractional flow reserve after drug eluting stent implantation

TCT-311 The comparison of myocardial perfusion imaging with fractional flow reserve to detect ischemic territory for patients with multi-vessel disease

The role of myocardial perfusion imaging (MPI) in patients with multi-vessel disease is uncertain because the accuracy of MPI to identify myocardial ischemia is limited in the multi-vessel settings. The aim of this study was to assess the ability of stress MPI to detect myocardial ischemia in

Newer Applications of Nuclear Cardiology in Systolic Heart Failure: Detecting Coronary Artery Disease and Guiding Device Therapy

Radionuclide-based imaging techniques can be applied to the heart failure population to derive clinically useful information. This review discusses the specific role of myocardial perfusion imaging for determining heart failure etiology, and the potential application of radionuclide-based imaging techniques for the optimal selection of patients with heart failure for device therapy.

The role of myocardial perfusion imaging in evaluating patients with myocardial bridging

BackgroundMyocardial bridging (MB) is a common, congenital coronary-abnormality that is found on average in one out of every three adults at autopsy (Moehlenkamp et al in Circulation, 106:2616-2622, 2002; Erbel et al in Circulation, 120:357-359, 2009). However, its clinical significance and impact on myocardial ischemia remains controversial and unclear. Myocardial perfusion imaging (MPI) is widely used to assess myocardial ischemia in patients with known or suspected coronary artery disease, and is frequently performed to evaluate the hemodynamic significance of MB. This study was undertaken to determine the use of MPI in evaluating MB and to identify the characteristics of MB associated with perfusion defects using MPI. Methods and ResultsThirty-nine patients with MB of the left anterior descending (LAD) artery as documented by coronary angiography (CA) were enrolled for this study. None of the patients exhibited other forms of heart disease as determined by both CA and stress-rest MPI, no later than 1 month prior to the study. Using MPI, eight patients (20.5%) were found to have perfusion defects in the corresponding myocardial areas. This frequency was significantly higher when compared with results obtained by stress electrocardiogram. The difference in the mean systolic narrowing of bridging segments was statistically significant between patients with and without ischemia. The positive rate of reversible defects in patients with severe systolic narrowing was significantly higher than in patients with mild-to-moderate systolic narrowing. However, there was no significant difference either between the mean length of the tunneled artery in patients with and without abnormal MPI or the positive rate of abnormal MPI in patients with different locations of the tunneled artery. ConclusionsMPI is an effective, noninvasive technique for the evaluation of patients with MB. The myocardial ischemia that resulted from bridging is associated more closely with the degree of systolic narrowing than with the length of tunneled artery or the location of MB.

Achieving an Exercise Workload of ≥10 Metabolic Equivalents Predicts a Very Low Risk of Inducible Ischemia: Does Myocardial Perfusion Imaging Have a Role?

We sought to identify prospectively the prevalence of significant ischemia (> or =10% of the left ventricle [LV]) on exercise single-photon emission computed tomography (SPECT) imaging relative to workload achieved in consecutive patients referred for myocardial perfusion imaging (MPI).High exercise capacity is a strong predictor of a good prognosis, and the role of MPI in patients achieving high workloads is questionable.Prospective analysis was performed on 1,056 consecutive patients who underwent quantitative exercise gated (99m)Tc-SPECT MPI, of whom 974 attained > or =85% of their maximum age-predicted heart rate. These patients were further divided on the basis of attained exercise workload (<7, 7 to 9, or > or =10 metabolic equivalents [METs]) and were compared for exercise test and imaging outcomes, particularly the prevalence of > or =10% LV ischemia. Individuals reaching > or =10 METs but <85% maximum age-predicted heart rate were also assessed.Of these 974 subjects, 473 (48.6%) achieved > or =10 METs. This subgroup had a very low prevalence of significant ischemia (2 of 473, 0.4%). Those attaining <7 METs had an 18-fold higher prevalence (7.1%, p < 0.001). Of the 430 patients reaching > or =10 METs without exercise ST-segment depression, none had > or =10% LV ischemia. In contrast, the prevalence of > or =10% LV ischemia was highest in the patients achieving <10 METs with ST-segment depression (14 of 70, 19.4%).In this referral cohort of patients with an intermediate-to-high clinical risk of coronary artery disease, achieving > or =10 METs with no ischemic ST-segment depression was associated with a 0% prevalence of significant ischemia. Elimination of MPI in such patients, who represented 31% (430 of 1,396) of all patients undergoing exercise SPECT in this laboratory, could provide substantial cost-savings.

Cardiovascular events in Japanese asymptomatic patients with type 2 diabetes: a 1-year interim report of a J-ACCESS 2 investigation using myocardial perfusion imaging

Diabetic patients have a high risk for cardiovascular events. The role of myocardial perfusion imaging was investigated in asymptomatic diabetic patients to evaluate short-term prognosis in a Japanese population. A total of 506 asymptomatic patients ≥ 50 years of age who had carotid artery maximum intima-media thickness ≥ 1.1 mm, urinary albumin excretion of ≥ 30 mg/g creatinine, with additional criteria of abdominal obesity, low HDL cholesterol, high triglyceride level, and hypertension were enrolled and followed up over a 3-year period. Gated SPECT with stress-rest protocol was performed and analyzed by summed defect scores and QGS software. One-year cardiovascular events were analyzed. Myocardial ischemia was observed in 17% of patients, and abnormal perfusion findings of ischemia and/or scar were observed in 32% of patients. By the end of the 1-year follow-up, 33 (6.5%) cardiovascular events occurred including 6 all-cause deaths. Patients with summed stress score (SSS) >8 had a higher incidence of either death or cardiovascular events. Event-free survival rates for SSS 0-3, 4-8, 9-13, and ≥ 14 were 0.96, 0.95, 0.82, and 0.76, respectively. Multivariate Cox regression analysis showed that significant variables were SSS, history of cerebrovascular accident, and electrocardiographic abnormality at rest. The 1-year interim summary showed that cardiovascular events were significantly higher in patients with SPECT abnormality, although hard cardiac event rate was relatively low. Targeted treatment strategy is required for asymptomatic but potentially high-risk diabetic patients.

Role of Myocardial Perfusion Imaging in Patients With End-Stage Renal Disease Undergoing Coronary Angiography

Patients with end-stage renal disease (ESRD) are at high risk of cardiovascular events. This study examined the prognostic power of stress myocardial perfusion imaging (MPI) in 150 patients with ESRD (mean age 53 +/- 9 years; 30% women; 66% with diabetes mellitus) being evaluated for renal transplantation with known coronary anatomy using angiography. Baseline data in addition to perfusion and angiographic parameters were compared between survivors and nonsurvivors. All-cause mortality was defined as the outcome measure. An abnormal MPI result was present in 85% of patients, 30% had left ventricular (LV) ejection fraction (EF) < or =40%, and 40% had multivessel coronary artery disease using angiography. At a mean follow-up of 3.4 +/- 1.5 years, 53 patients died (35%). LVEF < or =40%, LV dilatation (LV end-diastolic volume >90 ml), and diabetes mellitus were associated with higher mortality (all p <0.05). Both total perfusion defect size and mean number of narrowed coronary arteries using angiography were significantly higher in those who died (p <0.05). In a multivariate model, abnormal MPI results (low LVEF or abnormal perfusion) and diabetes alone were independent predictors of death, whereas number of narrowed arteries using coronary angiography was not. Thus, MPI was a strong predictor of all-cause mortality in patients with ESRD. In conclusion, abnormal MPI results independently predicted worse survival and provided more powerful prognostic data than coronary angiography.

Is this heart broken?

We present the case of a woman presenting with chest pain that illustrates the importance of recognizing an atypical presentation of coronary artery disease in women, as well as the role of myocardial perfusion imaging in the differential diagnosis. Case presentation. A 54-year-old black woman presented to the emergency department with atypical chest pain and left shoulder and arm pain of 8 hours’ duration. She was known to have fibromyalgia and an anxiety disorder, with a recent exacerbation related to domestic unrest. Her risk factors for coronary artery disease consisted of hypertension, hyperlipidemia, tobacco use, and a family history of myocardial infarction. The 12-lead electrocardiogram at presentation showed sinus bradycardia and T-wave inversion in the inferior and lateral leads. The cardiac troponin I level was elevated, at 0.5 g/L. Aspirin, -blocker, heparin, and intravenous nitrate therapy was initiated. Several hours later, the patient had worsening chest discomfort associated with diaphoresis, bradycardia, and nonsustained ventricular tachycardia. An electrocardiogram showed more pronounced and extensive T-wave inversion (Figure 1), and the second troponin I level was 9.8 g/L. Emergent cardiac catheterization was performed and revealed a left anterior descending coronary artery that tapered distally, with luminal irregularity ( 50% diameter stenosis) in its midportion. The left circumflex and right coronary arteries were normal (Figure 2). Contrast left ventriculography was remarkable for severe regional dysfunction localized to the left ventricular (LV) apex and the adjacent anterior and inferior walls, with hypercontractility of the basal portions of the ventricle (Figure 3). A clinical diagnosis of takotsubo cardiomyopathy, also referred to as transient LV apical ballooning or “broken heart” syndrome, was entertained. The cardiac troponin I level peaked at 32 g/L on serial testing. A resting technetium 99m sestamibi myocardial single photon emission computed tomography (SPECT) scan was performed the next day. It revealed a severe perfusion abnormality involving the apex and the adjacent anterior and inferior walls, with a complete absence of Tc-99m sestamibi uptake (Figure 4). A rest thallium 201/exercise Tc-99m sestamibi myocardial gated SPECT study was performed 2 months later and showed a large fixed defect associated with regional dysfunction, essentially unchanged from the initial scan (Figure 5). An echocardiogram obtained shortly thereafter showed persistent LV apical dyskinesis (Figure 6). Discussion. Several features of this patient’s initial presentation were typical of takotsubo cardiomyopathy. These include her gender, age, recent emotional distress, and severe regional LV dysfunction in the absence of epicardial coronary obstruction. Takotsubo cardiomyopathy, originally described in Japanese patients, is being increasingly recognized in the Western world, including the United States, and is characterized by acute, reversible LV apical dysfunction in the absence of obstructive epicardial coronary disease. The prevalence of this syndrome is reported to be 1% to 2% in patients presenting with clinical features suggestive of an acute coronary syndrome. The majority of patients are postmenopausal women, with the following features common to most accounts: (1) chest symptoms, electrocardiographic changes, and mild elevation in cardiac biomarkers consistent with acute myocardial ischemia; (2) a temporal relationship to a recent stressful event, giving this condition its alternate name of “broken heart” syndrome (some form of either emotional or physical stress preceded onset in about 65% of cases); (3) regional dysfunction localized to the LV apex, associated with hyperkinesis of the basal portions of the left ventricle with normal epicardial coronary arteries (Takotsubo is Japanese for octopus trap or pot and refers to the characteristic shape of the dysmorphic left ventricle seen on the ventriculogram of patients with this syndrome); and (4) complete resolution of the regional dysfunction in days to weeks after the acute event. The pathogenesis of myocardial perfusion and functional abnormalities in takotsubo cardiomyopathy remains speculative. Proposed mechanisms include (1) coronary spasm, (2) LV dysfunction induced by From the Department of Internal Medicine and Division of Cardiology, University of Pittsburgh Medical Center, Pittsburgh, Pa. Reprint requests: Prem Soman, MD, PhD, MRCP(UK), Division of Cardiology, University of Pittsburgh Medical Center, Room A 429, Scaife Hall, 200 Lothrop St, Pittsburgh, PA 15213; somanp@ upmc.edu. J Nucl Cardiol 2008;15:142-5. 1071-3581/$34.00 Copyright © 2008 by the American Society of Nuclear Cardiology. doi:10.1016/j.nuclcard.2007.11.011

The Role of Myocardial Perfusion Imaging in the Clinical Evaluation of Coronary Artery Disease in Women

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The Role of Myocardial Perfusion Imaging in the Clinical Evaluation of Coronary Artery Disease in Women

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Frequency and severity of myocardial perfusion abnormalities using Tc-99m MIBI SPECT in cardiac syndrome X

BackgroundCardiac syndrome X is defined by a typical angina pectoris with normal or near normal (stenosis <40%) coronary angiogram with or without electrocardiogram (ECG) change or atypical angina pectoris with normal or near normal coronary angiogram plus a positive none-invasive test (exercise tolerance test or myocardial perfusion scan) with or without ECG change. Studies with myocardial perfusion imaging on this syndrome have indicated some abnormal perfusion scan. We evaluated the role of myocardial perfusion imaging (MPI) and also the severity and extent of perfusion abnormality using Tc-99m MIBI Single Photon Emission Computed Tomography (SPECT) in these patients.MethodsThe study group consisted of 36 patients with cardiac syndrome X. The semiquantitative perfusion analysis was performed using exercise Tc-99m MIBI SPECT. The MPI results were analyzed by the number, location and severity of perfusion defects.ResultsAbnormal perfusion defects were detected in 13 (36.10%) cases, while the remaining 23 (63.90%) had normal cardiac imaging. Five of 13 (38.4%) abnormal studies showed multiple perfusion defects. The defects were localized in the apex in 3, apical segments in 4, midventricular segments in 12 and basal segments in 6 cases. Fourteen (56%) of all abnormal segments revealed mild, 7(28%) moderate and 4 (16%) severe reduction of tracer uptake. No fixed defects were identified. The vessel territories were approximately the same in all subjects. The Exercise treadmill test (ETT) was positive in 25(69%) and negative in 11(30%) patients. There was no consistent pattern as related to the extent of MPI defects or exercise test results.ConclusionOur study suggests that multiple perfusion abnormalities with different levels of severity are common in cardiac syndrome X, with more than 30 % of these patients having at least one abnormal perfusion segment. Our findings suggest that in these patients microvascular angina is probably more common than is generally believed.