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Biomedical subjects

D Katritsis

Publications and source records attributed to D Katritsis.

At least 19 recordsLinked to original sources

"Learning curves" of cardiac surgery in relation to risk stratification and hospital location.

AIM: The purpose of this study was to determine any significant differences in "learning curves" between private and public hospitals when the same senior surgeon was responsible during the initial phases of open-heart surgery programs development, in relation to risk stratification and hospital location. METHODS: A prospective review of 610 patients records was performed at a newly-opened cardiothoracic program in a public University Hospital (PUH) in the periphery of Greece, and a private institution (PI) with an experienced intensive care unit (ICU) in the capital city of Athens. Preoperative risk stratification, mortality and postoperative length of stay (LOS) were analysed between 1999 to 2001. RESULTS: At PUH 298 patients were operated and 312 patients at PI. There were 136 low risk (EuroSCORE 0-2) and 474 medium and high-risk patients (EuroSCORE > or =3). There was no significantly elevated mortality or learning curve in low risk surgery either at PUH (57 patients with 1 death) or PI (79 patients and 1 death). In medium and high-risk surgery at PI there was no mortality in 68 patients operated by the senior surgeon and no learning curve in all 233 such patients. In 240 medium and high-risk patients at PUH there was a learning curve despite the involvement of the same senior surgeon. In 1999 and 2000 the observed mortality (OM) in 150 patients was 15.33%, EuroSCORE 5.98, and in 2001 in 91 patients OM 3.29%, EuroSCORE 5.95 with p=0.00.8 when "experienced" ICU staff was employed. LOS was significantly reduced in 97 patients in 2001 at PUH (8.7 d +/- 2.81 vs 11.07 days +/- 7.9 in 1999 and 2000, p=0.046) confirming the existence of a learning curve at the PUH. No such change was observed at PI (8.2 days vs 7.8, p=0.45). CONCLUSION: No mortality differences or learning curve characteristics were detected for low risk operations either at PUH or PI. For medium and high risk surgery there appears to be a learning curve in PUH but not in PI despite senior surgeon involvement in both. The presence of an experienced ICU appears to play a critical role in the outcome of operations in newly opened cardiothoracic programs.

Analysis of Variance↗

Early mortality and morbidity of bilateral versus single internal thoracic artery revascularization: propensity and risk modeling.

OBJECTIVES: We examined whether bilateral internal thoracic artery (BITA) revascularization is associated with any increased in-hospital mortality and complications compared with single internal thoracic artery (SITA) revascularization. BACKGROUND: Despite proven long-term benefits, BITA revascularization has been slow to be adopted because of fear of increased early morbidity. METHODS: We evaluated 1,697 consecutive patients undergoing BITA (n = 867) or SITA (n = 830) revascularization. We used propensity score analyses and adjusted risk models to address differences between arms. RESULTS: There were 20 (2.3%) deaths in the BITA group versus 26 (3.1%) in the SITA group (odds ratio 0.73, p = 0.30). Propensity analysis identified several parameters that affected the decision to use BITA. Adjusting for propensity score and all potential risk factors, the odds ratio for death with BITA versus SITA was practically 1. Bilateral internal thoracic artery revascularization did not increase the number of in-hospital complications with the possible exception of deep sternal wound infections (11 [1.3%] vs. 3 [0.4%], p = 0.057). In multivariate modeling BITA increased the risk of deep sternal wound infections only in emergent cases and in older patients; the excess risk was negligible among 1,206 patients (71.1% of total) who did not have emergent revascularization and were < or =70 years old (risk difference 0.3%, p = 0.74). There was no difference in length of stay after adjustment for propensity factors (mean 11.3 vs. 11.7 days, p = 0.66). CONCLUSIONS: Bilateral internal thoracic artery revascularization grafting confers no increased risk for early death and does not prolong hospital stay. The small increase in the risk of deep sternal wound infections does not affect the majority of patients.

Aged↗

Identification and catheter ablation of extracardiac and intracardiac components of ligament of Marshall tissue for treatment of paroxysmal atrial fibrillation.

INTRODUCTION: The ligament of Marshall is a left atrial neuromuscular bundle with sympathetic innervation that may be a source of atrial fibrillation (AF)-inducing automatic activity. METHODS AND RESULTS: Twenty-four patients with paroxysmal AF (including 18 with adrenergic AF) and 25 with other arrhythmias underwent catheter mapping. In cases of adrenergic AF, radiofrequency ablation was attempted when Marshall potentials were recorded. Patients were followed for 2 months before and 11.2 +/- 4.2 months after the procedure. Catheterization of the distal superoposterior coronary sinus was feasible in 14 patients with AF (10 with adrenergic AF) and 12 patients without AF. A discrete Marshall potential was recorded in 12 patients with AF versus 3 patients without AF (P = 0.004). In 10 patients with adrenergic AF, this potential followed the atrial electrogram during sinus rhythm by 26 +/- 5 msec on left atrial recordings and 24 +/- 4 msec on coronary sinus recordings, and preceded it during atrial ectopy by 29 +/- 5 msec and 26 +/- 5 msec, respectively. It was abolished by epicardial (n = 1), endocardial (n = 4), or combined epicardial and endocardial ablation (n = 5). Seven patients with ablation showed significant reductions in adrenergic AF, whereas no significant change was seen in 8 adrenergic AF patients not undergoing ablation (P = 0.004). No improvement was seen in 3 of 4 patients with only endocardial ablation, whereas all 6 patients with epicardial ablation improved (P = 0.033). CONCLUSION: Recording of Marshall potential is feasible in patients with paroxysmal AF. Combined epicardial and endocardial catheter ablation of ligament of Marshall tissue may reduce the paroxysms of adrenergic AF.

Adult↗

C-Reactive protein concentrations and angiographic characteristics of coronary lesions.

BACKGROUND: C-Reactive protein (CRP) is a strong predictor of clinical outcome in coronary artery disease (CAD), and inflammation has been implicated in the process. We aimed to evaluate whether CRP concentrations measured with a new, automated particle-enhanced immunoturbidimetric method for high-sensitivity CRP may be related to specific high-risk angiographic features of coronary lesions. METHODS: In a cross-sectional study, we examined 103 consecutive patients undergoing cardiac catheterization for suspected CAD. We assessed the association of preprocedural CRP concentrations with clinical presentation (unstable angina) and angiographic features of coronary lesions. RESULTS: Twenty patients had unstable angina. Independent predictors of unstable angina included increased CRP [odds ratio (OR), 2.93 per 10-fold increase in CRP; 95% confidence interval (CI), 1.28-6.69; P = 0.01] and the presence of macroscopic thrombus (OR, 7.08; 95% CI, 1.33-37.8; P = 0.02). Thirty-two culprit lesions had macroscopic thrombus or eccentric/irregular discrete morphology without total occlusion. Increased CRP was the strongest predictor of such features (OR, 2.04 per 10-fold increase in CRP; 95% CI, 1.03-4.04; P = 0.04), and the effect was independent of the presence of unstable angina. CONCLUSIONS: Among patients with suspected CAD undergoing coronary angiography, increased CRP is strongly associated with unstable angina and with specific high-risk features of the culprit coronary lesions.

Aged↗

Radiation exposure of patients and coronary arteries in the stent era: A prospective study.

Previous studies have investigated the radiation dose to doctors and patients during coronary angiography and angioplasty, but most of them were retrospective, conducted in the prestent era, and results have not been consistent. Effective dose of 57 patients undergoing coronary angiography and/or angioplasty was assessed by using a dose-area product (DAP) to effective dose conversion factor. Radiation exposure risks to patients were then calculated for each procedure. Thermoluminescent dosimeters, mounted on a specially designed catheter that was advanced to the left or right sinus of Valsalva, were used to measure the dose received by the coronary arteries. Mean effective dose received by patients were 5.0 +/- 0.5 mSv for coronary angiography, 6.6 +/- 1.0 mSv for angioplasty, 10.2 +/- 1.5 mSv for angioplasty followed by stent implantation, 13.6 +/- 2.5 mSv for angiography followed by ad hoc angioplasty, and 16.7 +/- 2.8 mSv for angiography followed by ad hoc angioplasty and stent implantation. Patient risk of developing cancer after each procedure was 0.025%, 0.033%, 0.051%, 0.068%, and 0.084%, respectively. Corresponding mean coronary irradiation doses were 24 +/- 2.5, 31.0 +/- 3.6, 43.6 +/- 7.2, 55.0 +/- 7.5, and 64.7 +/- 5.6 mGy, respectively. A linear relationship of the DAP and the dose at the coronary arteries was found: DAP = 1,273 (cm(2)) x coronary dose (mGy). Radiation exposure to coronary arteries and associated risk to patients are relatively low, even following complicated, multivessel angioplasty with stent implantation. Our method can be used for calculation of radiation risk to patients and radiation dose to coronary arteries by using external dosimeters. Cathet. Cardiovasc. Intervent. 51:259-264, 2000.

Adult↗

Release of platelet activation markers during coronary angioplasty.

BACKGROUND: Authors of several studies have reported that activation of platelets occurs during coronary angioplasty, but consistent results have not been obtained. Levels of serotonin in coronary circulation have been found to be elevated during percutaneous transluminal coronary angioplasty but greater than normal concentrations of beta-thromboglobulin and platelet factor 4 have not been detected. OBJECTIVE: To perform a serial analysis of platelet-activation markers with simultaneous measurements of levels of serotonin, beta-thromboglobulin and platelet factor 4 in blood samples from the coronary artery and coronary sinus of patients undergoing coronary angioplasty. METHODS: Twenty patients undergoing elective coronary angioplasty were studied. Measurements of levels of beta-thromboglobulin, platelet factor 4, and serotonin in samples from the ostium of the coronary artery and the coronary sinus were performed immediately before angioplasty and after the first balloon deflation. RESULTS: Concentrations of beta-thromboglobulin and platelet factor 4 in coronary artery and coronary sinus were elevated in all patients before dilatation, whereas concentrations of serotonin were elevated in 85% of the patients. Concentrations of all markers in coronary sinus decreased after the first inflation. The coronary-sinus: coronary-artery concentration ratios before dilatation for beta-thromboglobulin, platelet factor 4, and serotonin were > 1 for the majority of patients, particularly for those with complex culprit lesions, indicating that coronary activation of platelets was occurring. Ratios remained unchanged or decreased after the first inflation, depending on initial values. CONCLUSIONS: Both systemic and coronary activation occur in patients subjected to percutaneous transluminal coronary angioplasty before the onset of intervention. After balloon deflation the greater than normal baseline coronary-sinus:coronary-artery concentration ratios of all markers (beta-thromboglobulin, platelet factor 4 and serotonin) tend to decline or remain unchanged, depending on the level of activation.

Adult↗

Long-term effect of VVI pacing on atrial and ventricular function in patients with sick sinus syndrome.

We conducted a prospective, 6-month echocardiographic study on the effect of VVI pacing on left atrial and ventricular function and dimensions in patients with sick sinus syndrome. Thirty-nine patients (23 women and 16 men, aged 71 +/- 9.2 years; 30 in sinus rhythm and 9 in atrial fibrillation) who had a VVI pacemaker implanted because of sick sinus syndrome were recruited in the study. In 26 patients who presented with and remained in sinus rhythm, paced left ventricular ejection fraction and stroke volume were significantly decreased (71.4% +/- 11.8% to 67.0% +/- 13.6%, and 73.9 +/- 29.0 cm3 to 66.3 +/- 21.1 cm3, respectively, P < 0.001 for both), whereas the paced diastolic dimension of the left atrium was significantly increased (3.2 +/- 0.7 cm to 3.7 +/- 0.9 cm, P < 0.001) at 6 months as compared with preimplantation. In nine patients with atrial fibrillation at implantation paced left ventricular ejection fraction at follow-up was significantly decreased (67.7% +/- 10.1% to 64.2% +/- 10.6%, P =0.003), but paced stroke volume and left atrial diastolic dimension were not significantly changed (75.1 +/- 25.6 cm3 to 79.0 +/- 22.7 cm3, and 4.3 +/- 1.2 cm to 4.6 +/- 1.5 cm, P = NS for both) at follow-up. Cessation of pacing and restoration of sinus rhythm in 21 patients at follow-up did not result in any significant change of ejection fraction (67.5% +/- 10.2% ti 67.6% +/- 9.7%, P = NS) whereas stroke volume was increased (59.1 +/- 19.6 cm3 to 69.1 +/- 22.3 cm3, P < 0.0001) in comparison with paced values. However, compared with preimplantation values, ejection fraction was significantly decreased (70.4% +/- 10.0% to 67.6% +/- 9.7%, P = 0.001), whereas stroke volume was not significantly changed (68.4 +/- 22.3 cm3 to 69.1 +/- 22.3 cm3, P = NS) during sinus rhythm at follow-up. In 14 of those patients, discontinuation of pacing resulted in a significant increase of left atrial fractional shortening (8.1% +/- 1.7% to 20.1% +/- 4.3%, P < 0.001) and significant increase of left atrial diastolic dimension compared with paced and preimplantation levels (3.8 +/- 0.7 cm vs 3.6 +/- 0.7 cm and 3.0 +/- 0.5 cm, respectively, P < 0.001). Long-term VVI pacing in patients with sick sinus syndrome results in increase of the left ventricular end-systolic dimension and permanent reduction of the left ventricular ejection fraction. In the left atrium, VVI pacing causes an immediate reduction of the fractional shortening as well as long-term increase of the diastolic dimension.

Aged↗

Patient radiation doses during cardiac catheterization procedures.

The objective of the present project was the determination of the dose received by patients during cardiac procedures, such as coronary angiography, percutaneous transluminal coronary angioplasty (PTCA) and stent implantation. Thermoluminescent dosemeters (TLDs), suitably calibrated, were used for the measurement of the dose received at four anatomical locations on the patient's skin. A dose-area product (DAP) meter was also used. The contribution of cinefluorography to the total DAP was higher than that of fluoroscopy. A DAP to effective dose conversion factor equal to 0.183 mSv Gy-1 cm-2 was estimated with the help of a Rando phantom. Thus, the effective dose received by the patients could be assessed. Mean values of effective dose equal to 5.6 mSv, 6.9 mSv, 9.3 mSv, 9.0 mSv and 13.0 mSv were estimated for coronary angiography, PTCA, coronary angiography and ad hoc PTCA, PTCA followed by stent implantation and coronary angiography and ad hoc PTCA followed by stent implantation, respectively.

Angioplasty, Balloon, Coronary↗

Cannulation of the coronary sinus via the femoral vein--a new technique.

BACKGROUND: Cannulation of the coronary sinus usually has been accomplished by advancing a catheter through the sub-clavian or internal jugular veins. HYPOTHESIS: We have developed a new technique for cannulation of the coronary sinus with a modified 6F Judkins L5 coronary catheter positioned through the femoral vein. RESULTS: The technique was tried successfully in 20 consecutive patients by the same operator and the average fluoroscopy time for coronary sinus cannulation was 1.6 +/- 1.0 min. CONCLUSION: Analysis of the results showed evidence of a learning curve with improvement of time with an increasing number of patients. The method provides a safe and inexpensive solution for catheterization of the coronary sinus, easily accessible to every catheter laboratory.

Catheterization, Peripheral↗

Use of troponin-T concentration and kinase isoforms for quantitation of myocardial injury induced by radiofrequency catheter ablation.

BACKGROUND: Although there remains particular concern about late malignant ventricular arrhythmias arising from myocardial damage induced by catheter ablation, the extent of myocardial injury resulting from clinical ablation procedures has not been fully studied. We conducted a prospective, controlled study to investigate the use of two newer markers of myocardial integrity, troponin-T concentration and creatine kinase isoforms, and a traditional marker, creatine kinase-MB concentration, in the assessment of myocardial injury following radiofrequency catheter ablation. METHODS AND RESULTS: The study population consisted of 28 consecutive patients subjected to radiofrequency catheter ablation, and the control group comprised eight subjects undergoing diagnostic electrophysiology study. Prior to ablation and at 30 min, 1, 2, 6, and 12 h following the procedure, blood samples were taken to measure troponin-T and creatine kinase-MB concentrations, and the separation of creatine kinase isoforms (MM3/MM1 and MB2/MB1 ratios). The troponin-T concentration was above normal in all but two patients following radiofrequency ablation, and the MB2/MB1 ratio was raised in all but one patient following ablation, but was also abnormal in the pre-ablation samples in seven patients. The MM3/MM1 ratio failed to detect myocardial injury in 75% of patients. Of patients subjected to ablation, in only 36% was the creatine kinase-MB concentration raised at least once post-ablation. Thirty minutes post-ablation, there was a statistically significant difference between the control and patient groups only as regards troponin-T concentration. There was a significant association between troponin-T concentration immediately post-procedure, the number of discharges delivered (r = 0.52, P = 0.006) and maximum power used (r = 0.48, P = 0.009). CONCLUSION: Our results indicate that catheter ablation inflicts a cumulative, detectable injury upon the myocardium. This injury can be quantitated by using newer analytical techniques, such as serial, post-ablation measurements of troponin-T concentration.

Adult↗

Electrophysiological effects of E 4031, a drug with selective class III properties, in man.

We studied the electrophysiological effects of E 4031, given in a dose ascending manner (1.5, 3.0, and 6.0 micrograms/kg over 5 min followed by 0.1, 0.2, and 0.4 microgram/kg per min for 60 min, respectively) to 19 volunteers. There were significant, dose related linear increase in QT and QTc intervals, in atrial functional and effective refractory periods (ERPs) at a paced cycle length of 400 ms, and in ventricular functional and ERPs at a paced cycle length of 600 ms. There was no significant change in the AH and HV intervals or QRS duration. No significant proarrhythmic or other side effects were encountered during the administration of the drug. E 4031 prolongs atrial and ventricular refractoriness without significantly affecting AV or intraventricular conduction, consistent with selective Class III properties. At the doses used in the present study, intravenous infusion of E 4031 appears to be safe and well tolerated.

Adolescent↗

Ablation therapy of type I atrial flutter may eradicate paroxysmal atrial fibrillation.

In patients with paroxysms of atrial fibrillation preceded by episodes of atrial flutter on Holter monitoring, eradication of the flutter circuit may also abolish the episodes of atrial fibrillation. At electrophysiology study, these patients are identified by documentation of simultaneous flutter of the right atrium and fibrillation of the left atrium.

Adult↗

Restrictive and hypertrophic cardiomyopathies in Noonan syndrome: the overlap syndromes.

A woman with Noonan syndrome had clinical and haemodynamic features of restrictive cardiomyopathy. There was no ventricular hypertrophy on echocardiography but myocardial biopsies showed myocyte hypertrophy without pathological disarray. This case illustrates the overlap of the cardiac phenotypes of Noonan syndrome, restrictive cardiomyopathy, and hypertrophic cardiomyopathy.

Adolescent↗

Catheter ablation for successful management of left posterior fascicular tachycardia: an approach guided by recording of fascicular potentials.

OBJECTIVE: To assess whether catheter ablation of fascicular tachycardia can be facilitated by the recording of sharp deflections arising from the mid-septum---inferior apical septum of the left ventricle. PATIENTS AND METHODS: Seven consecutive patients (mean age 29 (range 16-43) years) with ventricular tachycardia originating from the left posterior fascicle underwent electrophysiology study and detailed mapping of endocardial activation. Selection of ablation sites in the last five patients was based on the recording, during left posterior fascicular tachycardia and sinus rhythm, of a discrete potential preceding the earliest ventricular electrogram, which was thought to represent conduction through the posterior fascicle. RESULTS: Patients were treated with low energy direct current or radiofrequency current ablation. The median fluoroscopy and procedure times were 23 (range 6-42) min and 110 (range 50-176) min, respectively. In a follow up period of 4 to 16 months, six patients were asymptomatic and one had minor symptoms. No patient had any change in intraventricular conduction. Similar potentials were also recorded from the left posterobasal septum in three of eight patients who underwent catheter ablation of left free wall accessory pathways. CONCLUSION: Fascicular potentials can be reproducibly recorded in left posterior fascicular tachycardia and may serve as a reliable marker for successful ablation procedures. The relation of these potentials with the substrate of the tachycardia, however, remains obscure.

Adult↗

Rapid angiographic progression of coronary artery disease in patients with angina pectoris. The role of complex stenosis morphology.

BACKGROUND: Rapid disease progression commonly underlies acute coronary events, and "complex" stenosis morphology may play a role in this phenomenon. METHODS AND RESULTS: We studied the role of complex stenosis morphology in rapid disease progression in 94 consecutive patients awaiting routine coronary angioplasty. Coronary arteriography was repeated at 8 +/- 3 months' follow-up, immediately preceding angioplasty (68 patients) or after an acute coronary event (26 patients). Disease progression of 217 stenoses, of which 79 (36%) were "complex" and 138 (64%) were "smooth," was assessed by computerized angiography. At presentation, 63 patients had stable angina pectoris and 31 had unstable angina that settled rapidly with medical therapy. At follow-up, 23 patients (24%) had progression of preexisting stenoses and 71 (76%) had no progression. Patients with progression were younger (55 +/- 12 years) than those without (58 +/- 9 years) but did not differ with regard to risk factors, previous myocardial infarction, or severity and extent of coronary disease. Twenty-three lesions (11%) progressed, 15 to total occlusion (11 complex and 4 smooth; 65%). Progression occurred in 17 of the 79 complex stenoses (22%) and in 6 of the 138 smooth lesions (4%) (P = .002). Mean stenosis diameter reduction was also significantly greater in complex than in smooth lesions (11.6% versus 3.9% change; P < .001). Acute coronary events occurred in 57% of patients with progression compared with 18% of those without progression (P < .001) and were more frequent in patients who presented with unstable angina (P = .002). CONCLUSIONS: Rapid stenosis progression is not uncommon, and complex stenoses are at risk more than smooth lesions.

Angina Pectoris↗

Effect of flecainide on atrial and ventricular refractoriness and conduction in patients with normal left ventricle. Implications for possible antiarrhythmic and proarrhythmic mechanisms.

We studied the effects of intravenous flecainide (2 mg.kg-1) on atrial and ventricular refractoriness and conduction during sinus rhythm, induced atrial fibrillation and atrial pacing at rates of 100, 120 and 150 ppm, in 14 patients with normal left ventricle. Flecainide caused a significant increase in QRS duration during sinus rhythm (mean +/- SD: 87.2 +/- 8.4 ms vs 102.8 +/- 9.1 ms, P < 0.001), atrial fibrillation (87.8 +/- 10.0 ms vs 108.8 +/- 13.7 ms, P < 0.001) and at all paced rates. The duration of the atrial electrogram was significantly increased during sinus rhythm (54.9 +/- 13.2 ms vs 64.8 +/- 16.6 ms, P = 0.003) and at all pacing rates. The PA interval was also significantly prolonged, as was the pacing stimulus-to-atrial-electrogram interval at all pacing rates. There was increased QRS duration and atrial electrogram prolongation at higher pacing rates. Atrial refractoriness was prolonged during sinus rhythm (216.4 +/- 28.2 vs 228.6 +/- 36.1, P = 0.02), but not during atrial pacing at any rate. The QT interval, but not the JT interval or ventricular refractoriness, was significantly prolonged during sinus rhythm and at all pacing rates. Flecainide slows atrial conduction in a use dependent manner and increases atrial refractoriness during sinus rhythm but not during faster atrial pacing, thus not displaying a use-dependent effect. QRS duration is prolonged in a use-dependent manner without a commensurate increase in ventricular refractoriness. In the presence of rapidly conducted atrial fibrillation, which was not found to be slowed by flecainide, this effect may constitute a proarrhythmic mechanism even in patients with no apparent myocardial abnormality.

Adult↗

Localization of accessory pathways from the 12-lead electrocardiogram using a new algorithm.

A new algorithm (St. George's algorithm), based on the polarity and morphology of QRS complexes rather than delta waves, was developed for localizing accessory pathways to 1 of 9 sites on the atrioventricular annuli. This was compared with algorithms previously proposed by Skeberis et al (localizing to 1 of 7 sites) and Milstein et al (localizing to 1 of 4 sites). The preexcited 12-lead electrocardiograms recorded during sinus rhythm in 106 consecutive patients (including 60 retrospectively analyzed patients and 46 prospectively analyzed patients) who underwent successful radiofrequency catheter ablation of a single accessory pathway were analyzed by 3 blinded observers using all 3 algorithms. The results were compared with the actual localization of accessory pathways as derived from endocardial mapping during catheter ablation. In all 106 patients, the accuracy of the 3 algorithms for 4 sites on the atrioventricular annuli (as considered by Milstein's method) was 72%, 79%, and 92% for Milstein's, Skeberis', and St. George's algorithms, respectively. For 7 sites (as considered by Skeberis' method), the accuracy was 65% (Skeberis' algorithm) and 88% (St. George's algorithm), and for 9 sites (as considered by our method) the accuracy was 86% (St. George's algorithm). In 46 prospectively analyzed patients, the accuracy of the 3 algorithms for 4 sites was 70% (Milstein's), 67% (Skeberis'), and 87% (St. George's); for 7 sites the accuracy was 61% (Skeberis') and 85% (St. George's), and for 9 sites the accuracy was 85% (St. George's). The reproducibility of St. George's and Skeberis' methods was better than that of Milstein's method.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗