Asthma knowledge level of child daycare center teachers' in Istanbul, Turkey.

AIM: Teachers are primarily responsible for supervising schoolchildren with asthma during school hours. The purpose of this study was to elucidate the level of knowledge of child daycare center teachers about asthma and factors affecting their knowledge. METHODS: This study was performed on 297 teachers from 20 randomly selected child daycare centers in Istanbul. The teachers' level of knowledge about asthma was assessed by a questionnaire with 32 questions about asthma. The teachers were asked thirteen additional questions about demographic data and other characteristics of the child daycare centers and about themselves. One-way ANOVA and the independent samples t-test were used to determine differences in the level of asthma knowledge. RESULTS: A total of 297 teachers (287 females/10 males) filled in the questionnaire. The mean age of the teachers was 26.4 ± 8.1 years (range, 20-53 year). The teachers' "response score rate for each question" ranged from 38% to 94%. The teachers' "completely true response rate for each question" was lower and ranged from 1.6% to 83.9%. "The mean of asthma knowledge score" for the 32 questions was 113.64 ± 20.26 (71% ± 12.7%) from a maximum of 160 marks. "Asthma knowledge score for all questions" was related to teachers' gender, age, location and property of child daycare center and number of children in child daycare center. CONCLUSION: Although teachers of child daycare centers have some knowledge about asthma, their "completely true response rate for each question" was insufficient. Much more efficient educational programs are needed for these teachers.

Risk factors affecting asthma prevalence in adolescents living in Istanbul, Turkey.

BACKGROUND: Asthma is one of the most important diseases of childhood. The aim of this study was to evaluate the prevalence of asthma symptoms and risk factors affecting asthma. METHODS: In a cross-sectional study design, 9991 children, aged 13-14 years in 61 primary schools in 32 districts of Istanbul were evaluated. Asthma prevalence among the children was assessed using the ISAAC protocol. RESULTS: In our study, a total of 10,894 questionnaires were distributed to 13-14 years old children, and of these 9991 questionnaires were suitable for analysis with an overall response rate of 91.7%. The rates of wheeze ever, wheezing in last 12 months and lifetime doctor diagnosed asthma prevalence were 17.4%, 9.0%, and 11.8%, respectively. There were 4746 boys (47.9%) and 5166 girls (52.1%) with M/F ratio of 0.92. Atopic family history, fewer than three siblings living at home, tonsillectomy or adenoidectomy history, consumption of fermented foods, mixed pickles, margarine and meat were found to be associated with an increased asthma risk. Use of paracetamol in the last 12 months, consumption of fruit and animal fats acted as a protective factor against asthma. The Mediterranean-style diet was not associated with the prevalence of asthma. CONCLUSIONS: Lifetime doctor diagnosed asthma prevalence was found to be 11.8% in 13-14 year olds. History of tonsillectomy and/or adenoidectomy and consumption of fermented foods, mixed pickles, margarine and meat may increase the symptoms of asthma. Usage of paracetamol and consumption of animal fats may be investigated as a protective factor against asthma.

Prevalence of asthma, local risk factors and agreement between written and video questionnaires among Turkish adolescents.

BACKGROUND: There is currently no standard tool for the measurement of asthma in epidemiological studies. The objectives of this study were to determine the prevalence of asthma, to describe the potential local risk factors, and to assess the agreement between written and video questionnaires in 13- to 14-year-old schoolchildren. METHODS: We performed a cross-sectional study involving 5427 adolescents in 26 schools. Prevalence of asthma symptoms were evaluated using the International Study of Asthma and Allergies in Childhood (ISAAC) written and video questionnaire. The adolescents were asked additional questions for risk factors of asthma. RESULTS: The prevalence of lifetime wheeze, wheeze in the last 12 months and doctor-diagnosed asthma with written questionnaire were found as 13.5%, 6.3% and 11.2% respectively. Prevalence of lifetime wheeze, wheeze in the last 12 months, wheeze after exercise in the last 12 months, with video questionnaire were found as 9.6%, 5.5%, 11.9% and 1.9% respectively. The proportion of total agreement between the two questionnaires was high (0.77-0.81) with poor kappa value (0.25-0.50). In multivariate analysis, family history of atopy, stuffed toys and accompaniment of children to their parents after school hours in textile industry were found as risk factors for asthma. In addition kind of bird, such as canary was found as a risk factor. CONCLUSION: Prevalence of asthma is moderate in Turkey. Agreement between the two questionnaires was high. Accompaniment of children to their parents in textile industry is a newly-described risk factor for asthma.

Practical biometric ratios of first-trimester screening.

PURPOSE: The authors aimed to determine some practical contributive biometry ratios of the first trimester screening in order to note more accurate measurements and recognize abnormal/mistaken measurements. MATERIALS AND METHODS: All medical records of singleton pregnancies whose first-trimester screening that was performed between the years of 2004-2010, were evaluated retrospectively. Singleton pregnancies with detected/suspicious anatomical or genetic fetal anomalies, any systemic disease, and familial genetic diseases were excluded. The following ratios were calculated and compared: measurements of biparietal diameter [BPD], head circumference [HC], abdominal circumference [AC], femur length [FL], and crown rump length [CRL] of included fetuses, to each other were calculated. Mean and standard deviations of the ratios were determined for each gestational weeks of 11(0-6), 12(0-6), and 13(0-6). RESULTS: A total of 1,615 singleton pregnancies were included in the data analyses according to exclusion and inclusion criteria. Mean maternal age was 29.5 +/- 4.6 years. Mean gestational age of the fetuses was 12.6 +/- 0.6 weeks. Mean and standard deviation of the ratios were as follows; CRL/BPD: 3.0 +/- 0.2; AC/BPD: 3.0 +/- 0.2; CRL/AC: 1.0 +/- 0.1; CRL/HC: 0.8 +/- 0.1; CRL/FL: 8.8 +/- 1.6; BPD/FL: 2.9 +/- 0.6; AC/FL: 8.9 +/- 1.6; HC/FL: 11.1 +/- 2.2, and HC/AC: 1.3 +/- 0.1. Among these ratios the standard deviation was small in the ratios of CRL/BPD, AC/BPD, CRL/AC, CRL/HC, and HC/AC. The equations of these ratios were derived from linear regression analyses. The AC/BPD, and CRL/AC ratios had lower R2 values than others, indicating a rather constant ratio. CONCLUSIONS: The ratios of CRL/BPD, AC/BPD, and CRL/AC seem more practical to be used in the first-trimester fetal ultrasonography practice.

Assessment of cardiac ultrasonography in predicting outcome in adult cardiac arrest.

OBJECTIVE: A prospective follow-up study to evaluate the ability of cardiac ultrasonography performed by emergency physicians to predict resuscitation outcome in adult cardiac arrest patients. METHODS: Ultrasonographic examination of the subxiphoid cardiac area was made immediately on presentation to the emergency department with pulseless cardiac arrest. Sonographic cardiac activity was defined as any detected motion within the heart including the atria, ventricles or valves. Successful resuscitation was defined as any of: return of spontaneous circulation for ≥ 20 min; return of breathing; palpable pulse; measurable blood pressure. RESULTS: The study enrolled 149 patients over an 18-month period. The presence of sonographic cardiac activity at the beginning of resuscitation was significantly associated with a successful outcome (19/27 [70.4%] versus 55/122 [45.1%] patients without cardiac activity at the beginning of resuscitation). CONCLUSIONS: Ultrasonographic detection of cardiac activity may be useful in determining prognosis during cardiac arrest. Further studies are needed to elucidate the predictive value of ultrasonography in cardiac arrest patients.

Pencil back-projection method for SAR imaging.

We present a high-resolution method for spotlight mode SAR imaging that utilizes parametric modeling of projected target reflectivity density function and tomographic reconstruction. The method requires no polar-to-cartesian interpolation in spectral domain. Utilization of forward-backward total least squares bandpass matrix pencil method allows super resolution to be achieved in range for a single imaging angle. Hence, the quality of the image reconstructed by convolution back-projection is also improved. It is shown that the method is very resistant to noise and can generate images down to very low SNR values. Direct formulation in terms of physical quantities such as electric field and current density is another contribution of this paper.

Identification of the predominant antigenic epitopes in intestinal flora in IBD.

The normal intestinal flora is required for the development of intestinal inflammation in animal models of inflammatory bowel disease (IBD). In humans, several studies indicated a potential association of Escherichia coli (E. coli) with IBD. In addition, we have shown that T-cell clones of IBD patients cross react toward different enteric bacterial species and thus likely respond to conserved bacterial antigens. Therefore, we hypothesized that highly conserved E. coli proteins might be a reasonable candidate to screen for abnormal T-cell responses in IBD. We used high-throughput techniques for cloning, expression, and purification under native conditions of a set of 271 conserved proteins of E. coli, of which 196 were used for whole blood stimulations to assess peripheral T helper (T(H))-cell responses. In addition, because of the association of an adherent-invasive E. coli with Crohn's disease (CD), we included 13 pathogenicity factors of E. coli in the study. We observed that pools of these conserved E. coli proteins less frequently induced interferon-gamma (IFNgamma) production in peripheral T(H) cells in patients with CD and ankylosing spondylitis (AS) compared with healthy controls. In addition, lower percentage of patients with CD and AS responded toward single proteins. The reason for the decreased frequency of an in vitro T(H)-cell IFNgamma response toward E. coli proteins in peripheral blood of CD and AS patients, e.g., increased suppression needs to be clarified.

Randomized comparative study of burr-hole craniostomy versus twist drill craniostomy; surgical management of unilateral hemispheric chronic subdural hematomas.

OBJECTIVE: Although there is a tendency to minimize the surgical procedures for chronic subdural hematomas, there is no agreement on the optimal treatment. In the literature there is only one published result of a randomized study comparing twist drill craniostomy with burr-hole craniostomy. We aimed to compare twist drill craniostomy with burr-hole craniostomy for the treatment of unilateral hemispheric chronic subdural hematomas in adults. MATERIAL AND METHODS: The study was planned as a prospective, randomized, controlled investigation. Between November 2002 and April 2006, 70 patients (54 male and 16 female) with unilateral hemispheric chronic subdural hematomas were operated. 32 patients underwent burr-hole craniostomy and 38 patients were treated by twist drill craniostomy. After discharge, the patients were followed up at 1, 3 and 6 months after operation. Mortality, morbidity, surgical complications requiring reoperation, duration of hospitalization, recurrence, total number of reoperations, and cure rates were compared. RESULTS: Two patients died and one patient developed 6th nerve paresis in the inpatient period. There were three recurrences (two in the burr-hole craniostomy group, one in the twist drill craniostomy group) and in one patient from the burr-hole craniostomy group a chronic subdural hematoma developed on the contralateral side postoperatively. There was no significant difference clinically and radiologically between the two groups at any time period. CONCLUSION: Both surgical methods seem effective for the treatment of unilateral chronic subdural hematomas.

Short-term effect of topical brinzolamide on human central corneal thickness.

PURPOSE: To investigate the effect of short-term brinzolamide application on human central corneal thickness (CCT). METHODS: Seventeen eyes of 16 patients who underwent neodymium:YAG laser posterior capsulotomy were included in the study group. Twenty-two subjects served as controls. Brinzolamide twice daily and fluorometholone four times daily were initiated after the procedure. Corneal thickness was evaluated with an ultrasound pachymetry from the central region. CCT measurements were performed before the procedure, at first day, and at the end of first week. RESULTS: The mean baseline CCT value was 535.1+/-37.8 micronm. In comparison to the control group (546.4+/-22.2 micronm), there was no statistically significant difference (p=0.248). After brinzolamide instillation, the mean CCT values at first day and at first week was measured as 545.1+/-40.1 micronm and 538.8+/-39.4 micronm, respectively. The difference at first day was statistically significant when compared to the baseline values (p=0.00017). When compared to the control group, no statistically significant difference was observed for the mean CCT values of the first day and first week (p=0.906 and p=0.484, respectively). In the fellow eyes, mean CCT values increased following the dorzolamide instillation (529.3+/-42.6 micronm, 534+/-41.7 micronm, and 533+/-41.9 micronm, respectively). No statistically significant difference was observed between the control group and fellow eye group when compared (p=0.162, p=0.247, p=0.270, respectively). CONCLUSIONS: Brinzolamide may cause a short-term increase in the human CCT, particularly on the first day.

Is there a way to avoid surgical complications of twist drill craniostomy for evacuation of a chronic subdural hematoma?

BACKGROUND: Although twist drill craniostomy for evacuation of a chronic subdural hematoma is a rapid and minimally invasive procedure, it carries the risk of complications because it is a 'blind' technique. Our aim was to analyse the complications in a series of patients treated by this technique in order to identify methods of avoidance by modifications in the surgical technique. METHOD: Thirty-nine patients with a chronic subdural hematoma underwent twist drill craniostomy between November 2002 and December 2005 in our clinic. When a surgical complication happened we modified our surgical technique to see if this avoided it in future patients. FINDINGS: Surgical complications happened in 7 patients (17.9%) including inadequate drainage, brain penetration, acute epidural hematoma and catheter folding. After preventive modifications these complications did not recur. CONCLUSIONS: Modifications in the technique of twist drill craniostomy are described in this paper which may minimise the occurrence of surgical complications.

A study of depression and anxiety among doctors working in emergency units in Denizli, Turkey.

BACKGROUND: Major work has been carried out on the psychological well-being of emergency room doctors in the US, Canada and in other developed countries, but little has been published regarding the same in the countries in economic transition. OBJECTIVE: To determine the level of, and the factors related to, depression and anxiety among doctors working in emergency units in Denizli, Turkey. METHODS: This cross-sectional study was conducted in May 2004, using a sample of 192 doctors employed in emergency units in Pamukkale University Hospital, the City Hospital, the Social Security Hospital, private hospitals, citywide primary healthcare centres and 112 emergency services in Denizli, Turkey. Data were obtained using a self-administered questionnaire, including questions on sociodemographic characteristics and two instruments determining the level of depressive symptoms and anxiety. Logistic regression was the method chosen for multivariate statistical analysis. RESULTS: The mean (standard deviation (SD)) depression score was 10.6 (6.5) and the frequency (%) of depression was 29 (15.1). Not having any hobby and having high anxiety scores were salient factors among doctors experiencing depressive symptomatology in bivariate comparisons. Logistic regression analysis showed that not having any hobby (p = 0.07) and having increased anxiety scores (p<0.001) were positive contributors to depression scores. The mean (SD) anxiety score was 8.7 (8.2) and the frequency (%) of anxiety was 28 (14.6). Being a woman, having a low monthly income and having high depression scores contributed considerably to the anxiety of doctors in bivariate comparisons. Low monthly income (<1000 v 1000-2000 YTL) (p = 0.03), the number of years spent in emergency units (p = 0.03) and having high depression scores (p<0.001) were the factors that contributed significantly to the anxiety of doctors in the multivariate regression analysis. CONCLUSION: The considerable amount of depression and anxiety found among doctors in this study should trigger further work. Studies using more powerful designs would help to illuminate the factors leading to depression and anxiety, which result in attrition among doctors from emergency units.

Occupational working conditions as risk factors for preterm birth in Benin, West Africa.

BACKGROUND: Although many studies from developed countries have established a relationship between various occupational working conditions during pregnancy and preterm birth, there is little data available in developing countries where both maternal physical labor during pregnancy and preterm birth are common. The aim of this study was to examine the association between difficult occupational working conditions of pregnant women and premature births in the Republic of Benin in West Africa. METHOD: The case-control study included 99 women with preterm babies and 104 women with full-term babies. The participants were residents of the Republic of Benin who delivered between May 1, 2000 and April 30, 2002. Preterm delivery was defined as delivery prior to 37 completed weeks of gestation. The study sample was selected randomly from birth records. Data were collected both reviewing birth records and conducting semi-structured personal interviews with mothers. Logistic regression models were adjusted for mother's age, mother's education, health problems during pregnancy, and twin birth. RESULTS: Although working state of mother during pregnancy did not increase the risk for preterm delivery, carrying heavy loads more than 5 days per week was significantly associated with having a preterm baby (adjusted OR: 5.0; 95% CI: 1.38-18.8; P=0.018). Carrying heavy loads and having worked a lot more than 5 days per week was also significantly associated with preterm birth (adjusted OR: 6.88; 95% CI: 1.45-32.2; P=0.015). CONCLUSION: Reducing heavy loads carrying during pregnancy may also prevent preterm delivery in developing countries. Though replication of these data using a prospective design is needed, our results suggest that educating women about the risks associated with heavy labor during pregnancy is indicated.

Patients' awareness of their rights in a developing country.

AIM: To determine the awareness of a regulation on patients' rights passed in 1998 in Turkey. METHODS: All hospitalized patients in the internal medicine and general surgery wards in three large hospitals during the study period were eligible for the study, which was performed in 2001 in the Denizli province, Turkey. The study group consisted of 166 patients. Data were collected during face-to-face interviews using a questionnaire. RESULTS: Only 9% of patients were aware of the regulation about patients' rights. Most patients were given equal access to health care (91%), benefitted from the capabilities of their selected healthcare institutions (86.7%), and their privacy was protected (86.1%). Those patients who stated that they had not received care in accordance with their rights identified the shortcomings as not receiving written (95.2%) or verbal (53%) information from healthcare professionals, and the failure of healthcare personnel to introduce themselves (75.3%). On most occasions, the patients stated that they were not able to request services as stated in the PRR from healthcare professionals. CONCLUSION: Few patients knew about the regulation on patients' rights, indicating a need for extensive education of patients and healthcare professionals.

Cost of Alzheimer's disease in a developing country setting.

PURPOSE: To evaluate the economic impact of AD in Denizli, Turkey. DESIGN AND METHODS: This observational study was conducted with 42 AD patients and their primary caregivers. During the initial interview, demographic data and medical histories were collected with questionnaires. For an observational period of 15 days, data on time spent for patient care were collected using standard forms. Calculations on direct cost (e.g. per day medication, outpatient physician visits during the last 3 months), indirect cost (e.g. time spent for care by caregiver for daily living (ADL) and instrumental activity of daily living (IADL)) were made by summing up and taking averages of the appropriate items. ANOVA, and linear regressions were the methods for comparisons. RESULTS: The primary caregivers of the patients mainly were their children and/or spouses. The maximum mean time spent (h/week) was 21.0 (17.5) for severely damaged cognition. The average annual cost per case was between $1,766 [95% Confidence Intervals (CI); 1.300-2.231] and $4,930 (95% CI; 3.3714-6.147). The amount of caregiver cost was the most significant item in the overall cost and it showed an increase with the declining cognitive function of patients. Daily medication cost reflected the same pattern. In contrast, cost of outpatient physician was the lowest among the patients with the worst cognition. CONCLUSIONS: These results suggest that recently AD has become a significant cost for developing countries. This pilot study gives an idea of the cost of AD in developing countries where determining the actual cost can be difficult.

The effects of cyclopentolate on intraocular pressure and retrobulbar hemodynamics in patients with pseudoexfoliation syndrome and pseudoexfoliation glaucoma.

PURPOSE: To evaluate the changes of intraocular pressure (IOP) and retrobulbar hemodynamics after cyclopentolate administration in patients with pseudoexfoliation syndrome and pseudoexfoliation glaucoma. METHODS: Eighteen patients with pseudoexfoliation syndrome and 18 patients with pseudoexfoliation glaucoma were enrolled in the study. After baseline measurements of IOP, the peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistivity index (RI) of the ophthalmic, central retinal, and posterior ciliary arteries were investigated by color Doppler imaging. Then, 1% cyclopentolate was instilled in one eye of each subject. After 45 minutes of instillation of the cyclopentolate, the measurements of IOP and retrobulbar blood flow velocities were repeated. The results were compared with those of 20 age-matched normal subjects. RESULTS: Neither IOP nor retrobulbar blood flow velocities changed significantly in control subjects after cyclopentolate administration. IOP increased significantly after cyclopentolate instillation in pseudoexfoliation syndrome (p = 0.004). Retrobulbar blood velocities did not change significantly after the cyclopentolate in this group. In pseudoexfoliation glaucoma group, it was observed that basal mean IOP showed a statistically significant increase after cyclopentolate drop (p = 0.002). Although blood flow velocities of ophthalmic artery did not change significantly, PSV and EDV of the central retinal and posterior ciliary arteries decreased significantly (p < 0.05) and RI of the posterior ciliary artery increased significantly (p = 0.01) after cyclopentolate instillation. CONCLUSIONS: On the basis of our findings, pseudoexfoliation appears to be a predictive factor for an IOP rise after cyclopentolate. In pseudoexfoliation glaucoma patients, an increase of IOP after cyclopentolate could lead to a decreased retrobulbar blood flow. IOP must be rechecked after cyclopentolate administration in these patients to avoid further damage to the ganglion cells.

Non tuberculous mycobacteria (NTM) in patients with underlying diseases: results obtained by using polymerase chain reaction-restriction enzyme analysis between 1997-2002.

In this study, we aimed to evaluate the frequency of non-tuberculous mycobacteria (NTM) isolated from clinical specimens using Polymerase Chain Reaction-Restriction Enzyme Analysis (PCR-REA) and to investigate the patients who had clinically significant NTM infections in our hospital through the five year period from May 1997 to June 2002. A total of 364 mycobacterial strains isolated from clinical specimens which gave positive growth index in the BACTEC 460 radiometric system in Hacettepe University Hospital Clinical Microbiology Laboratory were evaluated by PCR-REA and clinical data were obtained from the patient records. Three hundred and one of the strains (82.7%) were identified as Mycobacterium tuberculosis and 63 (17.3%) were identified as nontuberculous mycobacteria. Seven (11.1%) of 63 NTM patients were regarded as having clinical mycobacteriosis. Chronic obstructive pulmonary disease and other pre-existing lung diseases were seen in 39 (61.9%) of the patients, 11 (17.5%) of'the patients had chronic renal failure. Four (6.3%) and 9 (14.3%) of them had AIDS and carcinomas, respectively. PCR-REA was found to be a reliable method for typing of our mycobacterial isolates to the species level. These data may shed light on the epidemiology of the mycobacterial species and help to select a proper treatment regimen.

The effects of cyclopentolate on intraocular pressure and retrobulbar hemodynamics in patients with pseudoexfoliation syndrome and pseudoexfoliation glaucoma.

PURPOSE: To evaluate the changes of intraocular pressure (IOP) and retrobulbar hemodynamics after cyclopentolate administration in patients with pseudoexfoliation syndrome and pseudoexfoliation glaucoma. METHOD: Eighteen patients with pseudoexfoliation syndrome and 18 patients with pseudoexfoliation glaucoma were enrolled in the study. After baseline measurements of IOP, the peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistivity index (RI) of the ophthalmic, central retinal, and posterior ciliary arteries were investigated by color Doppler imaging. Then, 1% cyclopentolate was instilled in one eye of each subject. After 45 minutes of instillation of the cyclopentolate, the measurements of IOP and retrobulbar blood flow velocities were repeated. The results were compared with those of 20 age-matched normal subjects. RESULTS: Neither IOP nor retrobulbar blood flow velocities changed significantly in control subjects after cyclopentolate administration. IOP increased significantly after cyclopentolate instillation in pseudoexfoliation syndrome (p=0.004). Retrobulbar blood velocities did not change significantly after the cyclopentolate in this group. In pseudoexfoliation glaucoma group, it was observed that basal mean IOP showed a statistically significant increase after cyclopentolate drop (p=0.002). Although blood flow velocities of ophthalmic artery did not change significantly, PSV and EDV of the central retinal and posterior ciliary arteries decreased significantly (p<0.05) and RI of the posterior ciliary artery increased significantly (p=0.01) after cyclopentolate instillation. CONCLUSIONS: On the basis of our findings, pseudoexfoliation appears to be a predictive factor for an IOP rise after cyclopentolate. In pseudoexfoliation glaucoma patients, an increase of IOP after cyclopentolate could lead to a decreased retrobulbar blood flow. IOP must be rechecked after cyclopentolate administration in these patients to avoid further damage to the ganglion cells. (Eur J Ophthalmol 2004; 14: #-400).

Technetium-99m-tetrofosmin imaging with incremental nitroglycerin infusion to detect severely ischaemic but viable myocardium: a comparative study with thallium-201.

The aim of this study was to assess the influence of incremental nitroglycerin infusion (NTG+Inf) on the myocardial uptake of 99mTc-tetrofosmin (TF) in order to determine whether nitrates enhance the detection of viable myocardium with TF in patients with coronary artery disease (CAD) and left ventricular dysfunction. Fifty patients (39 males, 11 females; 54 +/- 11 years) with previous myocardial infarction and left ventricular dysfunction, who had been referred for coronary revascularization procedures, were studied. Myocardial single-photon emission tomography (SPET) images were obtained 1 h after injection of 750 MBq TF at baseline and after NTG+Inf, using a 2 day protocol. NTG+Inf was performed starting at 0.4 microg x kg(-1) x min(-1), with equal increments every 5 min up to 2 microg x kg(-1) x min(-1). Within 1 week of the TF study, rest-redistribution (R-RD) 201Tl SPET was performed after the injection of 111 MBq 201Tl. For each study, quantitative analysis was performed in 17 segments. Viability was defined as the presence of tracer uptake of > 50% of the peak activity on baseline studies or reversibility. There was significant correlation between quantitative regional RD 201Tl activity and TF activity after NTG+Inf (r = 0.90, P < 0.001). Of the 131 segments with severely reduced tracer uptake on resting TF images, 34 (26%) were reversible, showing increased tracer uptake after NTG+Inf (from 41%+/-7% to 57%+/-12% of peak activity; P < 0.001). All reversible segments after NTG+Inf had viability criteria on 201Tl studies. There was 95% concordance between TF with NTG+Inf and RD 201Tl imaging with regard to the presence of myocardial viability. We conclude that TF imaging with incremental NTG+Inf improves the detection of ischaemic but viable myocardium, correlating with the viability criteria observed on 201Tl studies. When the advantages of TF imaging are considered, rest TF imaging with NTG+Inf may be a practical diagnostic protocol in patients with CAD and left ventricular dysfunction who are being considered for revascularization.