Positive Exercise Test Research Articles

Genomic Reflections of Coronary Artery Disease

Coronary artery disease (CAD) is a multistaged process leading to a wide spectrum of pathoanatomic and clinical presentations.1 Given the diversity of underlying mechanisms, it is reasonable to involve distinct genetic modifiers along the cascade of events. Yet, molecular genetic association studies usually admix patients with stable and acute presentation, stenotic and ectatic forms of CAD, as well as proximal, distal or bifurcational lesions. In this issue of Circulation: Cardiovascular Genetics , Kitsios et al2 address this issue by analyzing the impact of phenotype heterogeneity on the strength of association at previously identified risk loci for CAD. Perhaps surprisingly, the authors found little evidence for a contribution of phenotype definition to between-study heterogeneity of association signals at already known genomic CAD loci. Article see p 58 This meta-analysis clustered 965 individual studies into 3 groups: those involving patients with (1) acute coronary syndromes (ie, myocardial infarction [MI] and unstable angina), (2) angiographically diagnosed CAD, or (3) “broadly defined” CAD.2 The later group included association studies that combined patients with MI, revascularization procedures (angioplasty or bypass surgery), positive exercise test findings, symptomatic angina, history of hospitalization for CAD-related diagnoses, or …

P22 Factors associated with refractoriness to repeat exercise challenge in adults with asthma

IntroductionA proportion of patients with asthma develops a refractory period, during which the bronchoconstrictor response to a second indirect challenge is reduced. A better understanding of factors associated with the...

Cardiac autonomic functions derived from short-term heart rate variability recordings associated with heart rate recovery after treadmill exercise test in young individuals

Analysis of short-term heart rate variability (HRV) may provide useful information about autonomic nervous control of heart rate recovery. We studied 495 individuals (273 men), age range 19-85 years, submitted to treadmill exercise tests and short-term HRV evaluations over time (standard deviation of the normal-to-normal interval [SDNN], the square root of the mean squared differences of successive normal-to-normal intervals [RMSSD], the number of interval differences of successive normal-to-normal intervals greater than 50 ms [NN50 count], the proportion derived by dividing NN50 count by the total number of normal-to-normal intervals [pNN50]) and frequency (low-frequency power [LF], high-frequency power [HF], total power) domains. Among 495 patients, 106 patients (68 men) were elderly (age ≥ 65 years). Male gender and hypertension were significantly higher in elderly patients. The young patients had higher HRR after exercise. HRR at 4 min (54 ± 13 vs 60 ± 12 beats/min; P = 0.003) was the most significant predictor for positive exercise test result. In the young group, both time domain measures (SDNN: correlation coefficient 0.34, P < 0.001; RMSSD: correlation coefficient 0.37, P < 0.001) and frequency domain measures (LF: correlation coefficient 0.21, P < 0.001; HF: correlation coefficient 0.13, P = 0.01; total power: correlation coefficient 0.22, P < 0.001) were significantly associated with HRR at 4 min. HRR at 4 min was significantly associated with short-term HRV of time and frequency domains in young individuals, but not elderly ones, receiving treadmill exercise test.

Early graft patency after off-pump and on-pump coronary bypass surgery: a prospective randomized study

Uncertainty persists regarding the impact of the off-pump technique on coronary bypass graft patency. The primary objective of this study was to assess coronary artery bypass graft patency in patients randomized to off-pump and on-pump multivessel coronary artery bypass grafting (CABG). Secondary objectives were clinical outcomes and neuropsychological functioning. One hundred and fifty patients were randomized to off-pump (n = 75) or on-pump CABG (n = 75). Graft patency was assessed by multidetector computed tomography 5 weeks after surgery. The two groups were similar regarding patients' characteristics and logistic Euroscore (3.6 vs. 3.7%). Mean number of grafts performed was 3.5 ± 0.6 and 3.5 ± 0.6 in off-pump and on-pump, respectively (P = 0.7). Raw graft patency rate was 89.9% in off-pump and 95.0% in on-pump (OR 2.2, 95% CI 1.07-4.44; P = 0.03). Nineteen (27%) off-pump and 9 (13%) on-pump patients had at least one occluded graft (P = 0.04) and the proportion of patent grafts per patient was 0.91 ± 0.2 in off-pump vs. 0.96 ± 0.1 in on-pump (P = 0.06). However, after adjusting by heparin dose, graft patency was not statistically different between groups (OR 0.87, 95% CI 0.25-2.98, P = 0.83). At 30 days, there was no statistically significant difference in major adverse events and neuropsychological functioning between off-pump and on-pump groups. One-year follow-up showed similar functional class and positive treadmill exercise tests. Under the conditions this trial was conducted, CABG performed off-pump had lower overall graft patency rate than on-pump, which was not statistically different after controlling for total heparin dose. Thirty-day complications, neuropsychological functioning, and one-year clinical and functional outcomes were not statistically different between the two techniques.

Disconnect between standardized field‐based testing and mannitol challenge in Scottish elite swimmers

Elite swimmers have high rates of rhinoconjunctivitis and exercise-induced bronchoconstriction. Moreover, exposure to chlorine and chlorine metabolites is known to induce bronchial hyper-reactivity. To assess the early and late effects of chlorine and exercise on the unified airway of elite swimmers, and to compare the response to mannitol and field-based exercise challenge. The Scottish national squad underwent exhaled tidal (FE(NO)) and nasal (N(NO)) nitric oxide measurement, peak nasal inspiratory flow (PNIF), and forced expiratory volume in 1 s before, immediately after, and 4-6 h post-swimming. A sport-specific exercise test was carried out during an intensive lactate set (8 min at >/=80% maximum hear rate). All swimmers underwent mannitol challenge, and completed a health questionnaire. N=61 swimmers were assessed: 8/59 (14%) of swimmers had a positive mannitol challenge. Nine out of 57 (16%) of swimmers had a positive exercise test. Only one swimmer was positive to both. Swimmers with a positive mannitol had a significantly higher baseline FE(NO) (37.3 vs. 18.0 p.p.b., P=0.03) than those with a positive exercise challenge. A significant decrease in FE(NO) was observed pre vs. immediate and delayed post-chlorine exposure: mean (95% CI) 18.7 (15.9-22.0) p.p.b. vs. 15.9 (13.3-19.1) p.p.b. (P<0.01), and 13.9 (11.5-16.7) p.p.b. (P<0.01), respectively. There were no significant differences in N(NO.) Mean PNIF increased from 142.4 L/min (5.8) at baseline to 162.6 L/min (6.3) immediately post-exposure (P<0.01). Delayed post-exposure PNIF was not significantly different from pre-exposure. No association was found between mannitol and standardized field-based testing in elite swimmers. Mannitol was associated with a high baseline FE(NO); however, exercise/chlorine challenge was not. Thus, mannitol may identify swimmers with a 'traditional' inflammatory asthmatic phenotype, while field-based exercise/chlorine challenge may identify a swimmer-specific bronchoconstrictor response. A sustained fall in FE(NO) following chlorine exposure suggests that a non-cellular, perhaps neurogenic, response may be involved in this group of athletes.

SAECG in exercise test for prediction of diabetic coronary artery disease

Abstract Signal averaged electrocardiogram (SAECG) is considered an important noninvasive indicator identifying patients at risk for ventricular arrhythmias. The aim of this study was to improve noninvasive prediction of CAD by integrating SAECG with the result of exercise tests in diabetic patients. Diabetic patients with stable angina pectoris underwent exercise testing and SAECG. Then a diagnostic score was derived that combined results of exercise testing and SAECG. A diagnostic score (0 to 2 points) was calculated by assigning 1 point for a positive exercise test result and 1 point for a positive SAECG. One hundred and seventy patients were included in the study. In patients with a score of 0, the likelihood of CAD is 18% whereas the likelihood of CAD is 95% in patients with a score of 2. Triple vessel CAD is present in 54%, 7% and only 1.5% of patients with score 2, 1 and 0 respectively. Therefore, patients with score 2 have a poor prognosis compared with score 1 or 0. A diagnostic score combining exercise testing and SAECG can distinguish patients with CAD from those without CAD with high accuracy in diabetic patients.

Comparison of Usefulness of Exercise Testing Versus Coronary Computed Tomographic Angiography for Evaluation of Patients Suspected of Having Coronary Artery Disease

In patients suspected of having coronary artery disease (CAD), we compared the diagnostic sensitivity and specificity of exercise testing using ST-segment changes alone and ST-segment changes, angina pectoris, and hemodynamic variables compared to coronary computed tomographic angiography (CTA). Quantitative invasive coronary angiography was the reference method (>50% coronary lumen reduction). A positive exercise test was defined as the development of significant ST-segment changes (> or =1 mV measured 80 ms from the J-point), and the occurrence of one or more of the following criteria: ST-segment changes > or =1 mV measured 80 ms from the J-point, angina pectoris, ventricular arrhythmia (the occurrence of > or =3 premature ventricular beats), and > or =20 mm Hg decrease in systolic blood pressure during the test. Positive results on CTA were defined as a coronary lumen reduction of > or =50%. In 100 patients (61 +/- 9 years old, 50% men, and 29% prevalence of significant CAD), the diagnostic sensitivity and specificity of exercise testing using ST-segment changes was 45% (95% confidence interval 53% to 87%) and 63% (95% confidence interval 61% to 84%), respectively. However, the inclusion of all test variables yielded a sensitivity of 72% (95% confidence interval 53% to 87%) and a specificity of 37% (95% confidence interval 26% to 49%). The diagnostic sensitivity of 97% (95% confidence interval 82% to 100%) and specificity of 80% (95% confidence interval 69% to 89%) for CTA, however, were superior to any of the exercise test analysis strategies. In conclusion, in patients suspected of having CAD, the diagnostic sensitivity of exercise testing significantly improves if all test variables are included compared to using ST-segment changes exclusively. Furthermore, the superior diagnostic performance of CTA for the detection and exclusion of significant CAD might favor CTA as the first-line diagnostic test in patients suspected of having CAD.

Rule 3,000 for Screening Vestibular Schwannoma

To the Editor: We are very grateful to the author(s) of this letter for taking the time to read and respond to our recent editorial (1). With all our respect, some of his arguments are good and deserve careful consideration, although we do not find them compelling. In fact, all our patients received both the hearing test (audiometry) and the reference standard test (magnetic resonance imaging [MRI]). There is no different disease, and the sample is the same. Magnetic resonance imaging was done when the hearing test responds to one of the definition of asymmetric sensorineural hearing loss reported in the literature. The 3,000-Hz frequency was not taken into consideration to decide if an MRI is needed. It is true that the performance of a diagnostic test will be distorted if its result influences whether patients undergo confirmation by the reference standard. This situation, sometimes called "verification bias" or "work-up bias" (2), would apply, for example, when patients with suspected coronary artery disease and positive exercise tests were more likely to undergo coronary angiography (the reference standard) than those with negative exercise tests. In fact, when we did the audiogram and we suspected an asymmetric hearing loss independent of the definition, we asked for MRI. Although audiogram is the first line to exceed, we cannot consider the audiogram as the diagnostic test for vestibular schwannoma (VS); therefore, the verification bias was not violated. However, there is no bias, and we do not agree with the author of this letter. The rule 3,000 is valid for our sample and does not represent the population. The limitation of our study, already mentioned in our article, is the limited number of our sample and the important number of VS referred cases. We are processing a study with a larger number of patients from a population who seeks first-line care by the general practitioner instead of referred patients to a specialized care facility in otolaryngology, and results are promising. A comparison of the different existing definition and the rule 3,000 definition was done. Fortunately, the rule 3,000 shows its superiority to the other definition in terms of sensitivity and specificity. Results will be published shortly. In addition, the 3,000-Hz frequency shows its superiority to the other frequencies and to the speech discrimination level. All MRIs were done independently of the 3,000-Hz asymmetry. Retrospectively, during the analysis of our data, we identified that the rule 3,000 alone is simple, practical to use in our daily consultation screening, and a superior criterion to suspect VS, and MRI is therefore needed. Isaam Saliba, M.D. Department of Otorhinolaryngology Head and Neck Surgery Centre Hospitalier de l'Université de Montréal Montreal University Montreal, Quebec, Canada Geneviève Martineau Centre Hospitalier de l'Université de Montréal Montreal University Montreal, Quebec, Canada Miguel Chagnon, M.Sc. Department of Statistics Montreal University Montreal, Quebec, Canada

Effect of trimetazidine on myocardial ischemia in patients with stable angina pectoris

Objective To evaluate the efficacy of trimetazidine on myocardial ischemia in patients withstable angina pectors. Methods 40 stable exertional angina patients with two positive exercise tests within oneweek and the difference of duration of exercise between two tests ≤ 10％ were included, with routine treatmentwere given trimetazidine 20 mg, tid for 12 weeks. Treadmill exercise testing was adopted and the following indexes were invesgated before and after therapy: ①times of angina petoris attack every week; ② consumption of nitroglycerin every week;③heart rate systolic pressure and their product;④time for inducing angina pectoris byexercise; ⑤time for inducing 1 mm ST segment depression by exercise; ⑥the total exercise time; ⑦total workload. Results After 12 weeks therapy of trimetazidine angina petoris attack and consumption of nitroglycerinevery week were decreased obviously(P ＜ 0.05 ), howerer heart rate systolic pressure and their product did notchange significantly(P ＞ 0.05). The results showed that trimetazidine significantly increased exercise durationtotal work load time to onset of angina and time to 1 mm ST segment depression( P ＜ 0.01 ). There were very fewadverse drug effects reported. Conclusion For patients with stable exertional angina, trimetazidine can increasethe exercise capacity, improve myocardial ischemia induced by exercise. The drug is safe and effective and well tolerated by patients. Key words: Angina pectotis; Trimetazidine; Myocardial ischemia; Exercise test

ST-Segment Depression in Hyperventilation Indicates a False Positive Exercise Test in Patients with Mitral Valve Prolapse

Objectives. Mitral valve prolapse (MVP) is a known cause for false positive exercise test (ET). The purpose of this study was to establish additional electrocardiographic criteria to distinguish the false positive exercise results in patients with MVP. Methods. We studied 218 consecutive patients (53 ± 6 years, 103 males) with MVP (according to echocardiographic study), and positive treadmill ET was performed due to multiple cardiovascular risk factors or angina-like symptoms. A coronary angiography was performed to detect coronary artery disease (CAD). Results. From 218 patients, 90 (group A) presented with normal coronary arteries according to the angiography (false positive ET) while the rest 128 (group B) presented with CAD. ST-segment depression in hyperventilation phase was present in 54 patients of group A (60%) while only in 14 patients of group B (11%), P < .05. Conclusions. Presence of ST-segment depression in hyperventilation phase favors a false positive ET in patients with MVP.

166 A risk score for predicting outcome in asymptomatic aortic stenosis

The management of patients with asymptomatic severe aortic stenosis remains controversial. We sought to develop a continuous risk score for predicting the mid-term development of symptoms or adverse events in this setting. We prospectively followed 107 patients with asymptomatic aortic stenosis (aged 72 years [63-77]; 35 women; aortic-jet velocity, 4.1 m/s [3.5-4.4]) at a single center in France. Predefined endpoints for assessing outcome were the occurrence within 24 months of death or aortic valve replacement necessitated by symptoms or by a positive exercise test. Variables independently associated with outcome were used to build a score that was validated in an independent cohort of 107 patients from Belgium. Independent predictors of outcome were female gender, peak aortic jet velocity and B-Type Natriuretic Peptide (BNP) at baseline. Accordingly, the score could be calculated as: Score = [Peak velocity (m/s) x 2] + [natural logarithm of BNP x 1.5] + 1.5 (if female gender). Event-free survival after 20 months was 80% for patients within the first Score quartile, as compared to only 7% for the fourth quartile (Figure). Areas under the ROC curve for the score were 0.90 and 0.89 in the development and validation cohorts respectively. If further validation is achieved, this score may be useful to predict outcome in individual patients with asymptomatic aortic stenosis in order to select those who might benefit from early surgery.

Inordinately Sluggish Coronary Artery Flow in an Angiographically Normal Coronary Artery

A 53-year-old male smoker, without any significant medical history was admitted via the emergency room to the cardiac care unit due to a single episode of unstable angina lasting for approximately 10 minutes. Over the last one year he admits to symptoms indicative of effort angina of class II according to the Canadian Cardiovascular Society (CCS) classification. He had been submitted to an exercise stress test a year earlier which was characterized as positive based on clinical criteria only. On admission no ischemic ECG changes were noted; chest pain had subsided upon arrival to the emergency room, thus an ECG recording during the episode of chest pain was lacking. Cardiac enzymes were normal. However, due to the typical clinical presentation, prior history of effort angina and report of a positive exercise test in the past, a decision was made to proceed with cardiac catheterization, which was performed the following day. Coronary angiography revealed no significant atherosclerotic lesions, however an impressively sluggish flow was observed in the left anterior descending (LAD) coronary artery (Figure 1). During injection of contrast material into the left coronary artery, the left circumflex (LCx) coronary artery (panel A, left side) fills up quickly, while there is an inordinate delay of flow in the LAD which has only filled half-way (panel A, right side). Only several frames later when the circumflex has started to empty (panel B, left side), has the LAD filled up with the contrast material (panel B, right Images In medIcIne

The relationship between Myocardial SPECT and Fractional Flow Reserve: Is it drifting apart?

In the paper, Tc-99 m sestamibi single photon emission computed tomography for guiding percutaneous coronary intervention in patients with multivessel disease: a comparison with quantitative coronary angiography and fractional flow reserve by Forster et.al. the authors correctly point out that FFR (Fractional Flow Reserve) was initially validated against non-invasive studies which included Thallium SPECT, Stress Echocardiography and standard exercise testing. In the paper by Pijls et.al.in 1995 which was one of the first validation studies of FFR [1] there were a significant number of negative SPECT and stress echo results at FFR values significantly lower than .75 although in all patients myocardial ischaemia was demonstrated on one of the three tests used. In the same study two patients had positive exercise tests and one patient a positive Thallium SPECT scan with FFR values significantly above .75. Later studies have confirmed that a FFR results can have a prognostic significance which can be better than SPECT in a selected group of patients with untreated intermediate lesions after PCI of a severe lesion [2]. In contrast SPECT itself has a significant prognostic value in patients with low or intermediate risk of coronary disease and has been recommended as a first line diagnostic method in coronary disease by the UK National Institute of Clinical Excellence (http:// www.nice.org.uk/nicemedia/pdf/TA073guidance.pdf). A normal Myocardial SPECT scan has been shown in large studies to have a very good prognostic value with adverse event rates of 0.6%/year quoted in one study of 7,376 consecutive patients [3]. The prognostic value of SPECT scanning may be improved by using cardiac gating [4] and when ejection fraction and end-systolic volumes are also considered as additional data the overall prognostic value of SPECT scanning improves further [5]. The patient conditions under which FFR is measured also have to be taken into account. In this study the patients had multivessel disease. Although a single stenosis in each vessel would not modify the result multiple stenoses in a vessel require a modified approach to FFR measurement [6] and patients with a prior myocardial infarction resulting in microvascular dysfunction [7] may also have a falsely elevated FFR but usually by 5% however in chronic myocardial infarction FFR may still be accurate [8]. So can the relative merits of these two tests be put into perspective? How also should we view the role of QCA (quantitative coronary angiography) in this context? This study concludes that SPECT gives a Editorial comment on the article of Forster et al. (doi:10.1007/s10554-009-9510-x).

Clinical diagnosis of acute coronary syndrome in patients with chest pain and a normal or non-diagnostic electrocardiogram

Background: Clinical features may be used to determine which patients with suspected acute coronary syndrome (ACS), but a normal or non-diagnostic ECG, should be selected for further investigation or inpatient...

Effects of chlorine and exercise on the unified airway in adolescent elite Scottish swimmers

Chlorine metabolites and high training load may produce exercise-induced bronchospasm (EIB) in elite swimmers. The aim of this study was to assess the combined effects of chlorine and exercise on the unified airway of adolescent elite swimmers. The Scottish Midlands District squad were assessed during an indoor pool session at the National Swimming Academy. Athletes trained at least 8 h per week. Subjects underwent tidal (T(NO)) and nasal (N(NO)) exhaled NO and peak nasal inspiratory flow (PNIF) pre and post a 2 h session. A physiological exercise challenge assessed EIB in n = 36 swimmers (>10% fall in forced expiratory volume in 1 s (FEV(1))). Combined and free chlorine levels (mg/l) were 1.66 and 0.3 respectively. n = 36 swimmers (mean age 13.3 years) were assessed: n = 8 (22%) had known asthma; n = 13 (36%) had a positive physiological challenge; 18 (50%) complained of symptoms suggestive of EIB. n = 10/28 (36%) who did not have asthma were found to have a positive exercise challenge. There was no significant association between reported exercise symptoms and positive exercise test. There was no significant change in T(NO) or N(NO) for pre vs postexposure, irrespective of asthma diagnosis or AHR. n = 15 (42%) swimmers complained of worsening nasal symptoms postexposure, but only n = 7 (14%) had a demonstrable fall in PNIF (mean 33 l/min). No significant association was found between PNIF and symptoms. Combined exposure to chlorine and exercise did not affect surrogate markers of inflammation in the unified airway. There was a high prevalence of undiagnosed EIB.

Additional prognostic value of physical examination, exercise testing, and arterial ultrasonography for coronary risk assessment in primary prevention

The choice of noninvasive tests used in primary prevention of cardiovascular diseases must be based on medical evidence. The aim of this study was to assess the additional prognostic value, over conventional risk factors, of physical examination, exercise testing, and arterial ultrasonography, in predicting a first coronary event. A prospective cohort study was conducted between 1996 and 2004 (n = 2,709), with follow-up in 2006 (response rate 96.6%). Participants had no history or symptoms of cardiovascular disease and had a standardized physical examination, a cardiac exercise testing, and carotid and femoral ultrasonography at baseline. Incident cases of definite coronary events were recorded during follow-up. Over the Framingham risk score, femoral bruit, positive exercise test, intima-media thickness >0.63 mm, and a femoral plaque provided significant additional information to the prediction model. The addition of the exercise test to the traditional risk factors, then the intima-media thickness and lastly the presence of femoral plaques, produces incremental increases in the area under the receiver operating characteristic curve (0.73-0.78, P = .02) and about a 50% increase in the positive predictive value (15.8%-31.4%), with no effect on the negative predictive value (96.4%-96.9%). Physical examination, exercise testing, and arterial ultrasonography provide incremental information on the risk of coronary event in asymptomatic adults. Exercise testing and femoral ultrasonography also improve the accuracy of the risk stratification.

Risk Score for Predicting Outcome in Patients With Asymptomatic Aortic Stenosis

The management of patients with asymptomatic severe aortic stenosis remains controversial. We sought to develop a continuous risk score for predicting the midterm development of symptoms or adverse events in this setting. We prospectively followed 107 patients with asymptomatic aortic stenosis (aged 72 years [63 to 77]; 35 women; aortic-jet velocity, 4.1 m/s [3.5 to 4.4]) at a single center in France. Predefined end points for assessing outcome were the occurrence within 24 months of death or aortic valve replacement necessitated by symptoms or by a positive exercise test. Variables independently associated with outcome were used to build a score that was validated in an independent cohort of 107 patients from Belgium. Independent predictors of outcome were female sex, peak aortic-jet velocity, and B-type natriuretic peptide at baseline. Accordingly, the score could be calculated as follows: Score=[peak velocity (m/s) x 2]+(natural logarithm of B-type natriuretic peptide x 1.5)+1.5 (if female sex). Event-free survival after 20 months was 80% for patients within the first score quartile compared with only 7% for the fourth quartile. Areas under the receiver operating characteristic curve for the score were 0.90 and 0.89 in the development and validation cohorts, respectively. If further validation is achieved, this score may be useful to predict outcome in individual patients with asymptomatic aortic stenosis to select those who might benefit from early surgery.

Repeatability And Validity Of IUATLD Respiratory Questionnaire Responses As A Measure Of Asthma In An Ethiopian Population

To assess the repeatability and validity of the IUATLD respiratory symptoms questionnaire in relation to exercise-induced bronchoconstriction or bronchodilator responses in a community in southern Ethiopia. A case-control study. Rural and small town setting in southern Ethiopia, April to May 2006. Two hundred and forty seven adults and children who previously reported wheeze in the past year, and 174 who did not. Administered IUATLD bronchial symptoms questionnaire; standardised free-running exercise test or (for those with airflow obstruction) assessment of bronchodilator response to inhaled salbutamol. Kappa values for four-week repeatability for the wheeze and asthma questions were 0.61 (95% CI 0.52 to 0.70) and 0.75 (0.63 to 0.87), respectively. Of the 58 people who reported wheeze in 2003 and in April 2006, only five had a positive exercise test or bronchodilator challenge (Positive Predictive Value (PPV) 0.09, 95% CI 0.01 to 0.22). Of the 12 who reported asthma in 2003 and April 2006, three had a positive result to either to exercise test or bronchodilator challenge test (PPV 0.25, 95% CI 0.05 to 0.50). Our findings suggest that self-reported wheeze and asthma have good short-term repeatability, but do not closely reflect exercise-induced bronchospasm or bronchodilator responsiveness. The validity of questionnaire methods of studying asthma epidemiology in developing countries needs further investigation.

Head-to-head comparison between bicycle exercise testing and coronary calcium score and coronary stenoses on multislice computed tomography

To perform a head-to-head comparison between signs of ischemia during bicycle exercise testing and coronary atherosclerosis on multislice computed tomography (MSCT) in patients with suspected coronary artery disease (CAD). Two hundred and one patients underwent exercise testing, followed by 64-slice MSCT. A subgroup of 63 (31%) patients also underwent conventional coronary angiography. The exercise test was positive or negative based on electrocardiographic signs of ischemia. On MSCT, total calcium score was obtained. Based on MSCT angiography, the patients were classified as having normal MSCT or coronary atherosclerosis [with nonobstructive and obstructive CAD (>/=50% luminal narrowing) present]. In 178 patients with interpretable examinations, the exercise test was positive in 36 (20%) and negative in 142 (80%) patients. Calcium score was identical in patients with a positive [median (interquartile range) 11 (0-343)] and a negative exercise test [18 (0-335), P=NS]. The prevalence of nonobstructive CAD was the same in two patients groups [13 (36%) patients with a positive vs. 54 (38%) patients with a negative exercise test, P=NS]. Although obstructive CAD was observed in 15 (42%) patients having a positive exercise test, obstructive lesions were also present in 38 (27%) patients without ischemia on exercise testing. The findings were confirmed by conventional coronary angiography. No correlation was observed between ischemia on exercise testing and both calcium scoring and nonobstructive CAD on MSCT. A large proportion of obstructive lesions on MSCT were not observed on exercise testing. Potentially, MSCT may provide additional information on CAD.

Utilization Of Exercise Sestamibi In The Evaluation Of Cardiac Ischemia In Pediatric Patients

PURPOSE: We evaluated the utility of exercise sestamibi (SM) in the diagnosis of exercise cardiac ischemia in pediatric patients with heart disease or referred for evaluation of chest pain or syncope. METHODS: We evaluated 40 pediatric patients (19 female, mean age 13.6 years) presenting with possible exercise induced cardiac ischemia with a standard cycle ergometer (31 patients) or treadmill protocol (9 patients). The group consisted of: 13 Kawasaki, 5 TGV, 3 HLHS, 3 CM, 2 Heart Transplant, 3 Coronary Artery Abnormality, 2 PS, 9 with cardiac symptoms. SM was injected 1 minute before termination of the exercise test with a follow-up perfusion scan post exercise. The exercise test and the nuclear medicine report were interpreted by separate physicians blinded to the results of the coexisting test. A positive exercise test was based on ST depression in any lead greater than or equal to 1.5mm. RESULTS: All exercise tests were maximal with a mean respiratory quotient of 1.14 and a maximal heart rate of 187 BPM. There were 10 positive exercise tests for ischemia with 2 showing normal SM perfusion. Both patients had abnormal apical myocardial thinning delineated by the perfusion report. There were 11 positive SM tests for perfusion defects, 3 of these showed normal exercise tests (no ST segment depression). In patients with a cardiac diagnosis, 9 of 31 showed perfusion defects. In patients referred for symptoms, 2 of 9 showed perfusion defects.TABLECONCLUSION: These results demonstrate good agreement between a positive exercise test and the presence of SM perfusion defects. However, there was not a 100% agreement between the 2 methods. This could be a lack of sensitivity of one or both methods or as a need to utilize both methods in the evaluation of cardiac ischemia.