Relation between dorsal and palmar hand skin temperatures during a cold stress test.

Hand skin temperature measurements have previously been performed on either dorsal or palmar sides and it is possible to find arguments for the advantage of both locations. Therefore, the aim of this study was to use dynamic infrared (IR) imaging to examine the relationship between dorsal and palmar hand skin temperature. The palmar and dorsal hand skin temperature before and after a cold stress test was measured with IR thermography in 112 healthy participants. Calculation of surface average temperature was made from nine regions of interest on each hand's dorsal and palmar side. Temperature values were recorded at baseline, directly after immersion of hands in vinyl gloves for one minute in water at 20 ±0.5 °C (gloves removed), and after eight minutes rewarming. Results showed that: a) the skin temperatures on the dorsal and palmar sides of the hand are strongly correlated; b) the correlation is stronger on the fingers than on the carpometacarpal (CMC) area; c) the palmar side of the CMC area is warmer than the dorsal side, but this is reversed in the fingers so that the nail bed is warmer than the finger pad; and d) the temperature difference ∆T between the dorsal and palmar sides of the fingers is independent of the skin temperature, though ∆T on the CMC area of the hand is temperature dependent. Such differences can be important in detailed investigations of thermal phenomena in the hand. In conclusion, results showed a strong correlation between the dorsal and palmar temperatures. If both sides cannot be measured, the purpose of the investigation should determine which side of the hand should be measured.

Comparison of stent free cell area and cerebral lesions after unprotected carotid artery stent placement.

OBJECTIVE: This study evaluates the correlation between closed, semi-closed and open-cell stent design and the association between stent type and clinical outcome as well as magnetic resonance imaging (MRI) findings. DESIGN: A total of 194 patients who underwent unprotected carotid artery stenting (CAS) as well as diffusion-weighted magnetic resonance imaging (DW-MRI) before and after intervention were retrospectively reviewed. MATERIALS AND METHODS: Three stent designs were studied: closed cell, semi-closed cell and open cell. Spearman's Rho test was performed between the stent free cell area and the number and area of ischaemic lesions found after intervention. Adverse events were evaluated. RESULTS: There was no significant difference in clinical outcome between the three stent groups (Zilver, Cook Europe, Denmark; Smart, Codman, MA; and Wallstent, Stryker, MN, USA). A significant correlation was found between the stent free cell area and the number and area of new ischaemic lesions on DW-MRI (P = 0.023). There were significantly fewer new lesions with an open-cell design (Zilver; 12.76 mm(2) free cell area) than with a closed-cell design (Wallstent; 1.08 mm(2) free cell area). CONCLUSIONS: Open-cell stent was related to a lower number and area of silent cerebral ischaemic lesions after unprotected CAS. However, clinical outcome, measured by incidence of adverse events and clinical neurologic assessment, was not significantly different between patients with different stent designs.

Lesion load in unprotected carotid artery stenting.

INTRODUCTION: The purpose of the study was to determine the incidence of new ischemic lesions found on diffusion-weighted MR imaging (DWI) in nonselected patients after unprotected carotid artery stent placement. MATERIALS AND METHODS: We retrospectively reviewed a nonrandomized cohort of 197 patients presenting with carotid occlusive disease who underwent unprotected carotid artery stent placement between 2003 and 2006. Mean degree of stenosis was 86.94% +/- 9.72. In all patients, DWI was obtained before and 24 h after stent placement. New lesions were evaluated according to size and location. RESULTS: In 59 of 197 patients (29.9%), new ischemic lesions were found on DWI in the vessel dependent area. In 23 of 197 patients (11.7%), new ischemic lesions were found in the vessel independent area. Combined stroke/death rate was 3.63%. CONCLUSION: In our series of unprotected carotid angioplasty with stent, we found new DWI lesions in 34% of the patients. Further studies should now show in how far protection devices can reduce these lesions.

Hyperperfusion syndrome after carotid stent angioplasty.

INTRODUCTION: This study assesses the incidence and causes of hyperperfusion syndrome occurring after carotid artery stenting (CAS). MATERIALS AND METHODS: We retrospectively reviewed the clinical database of 417 consecutive patients who were treated with CAS in our department to identify patients who developed hyperperfusion syndrome and/or intracranial hemorrhage. Magnetic resonance imaging (MRI) including fluid-attenuated inversion recovery and diffusion-weighted imaging was performed before and after CAS in 269 cases. A Spearman's rho nonparametric correlation was performed to determine whether there was a correlation between the occurrence/development of hyperperfusion syndrome and the patient's age, degree of stenosis on the stented and contralateral side, risk factors such as diabetes, smoking, hypertension, adiposity, gender and fluoroscopy time, and mean area of postprocedural lesions as well as preexisting lesions. Significance was established at p < 0.05. RESULTS: Of the 417 carotid arteries stented and where MRI was also completed, we found hyperperfusion syndrome in 2.4% (ten cases). Patients who had preexisting brain lesions (previous or acute stroke) were at a higher risk of developing hyperperfusion syndrome (p = 0.022; Spearman's rho test). We could not validate any correlation with the other patient characteristics. CONCLUSION: Extensive microvascular disease may be a predictor of hyperperfusion syndrome after carotid stent placement. We believe that further studies are warranted to predict more accurately which patients are at greater risk of developing this often fatal complication.

Reassessment of valve area determinations in mitral stenosis by the pressure half-time method: impact of left ventricular stiffness and peak diastolic pressure difference.

Estimation of the orifice area is of major importance in the timing of valve dilation or surgery in patients with mitral stenosis. Determination of the area has traditionally been accomplished at cardiac catheterization by the Gorlin equation. The valve area can also be estimated noninvasively with Doppler echocardiographic measurements of the pressure half-time, which is inversely proportional to the area. This method has gained widespread acceptance, but its accuracy has recently been questioned and factors other than reduction of orifice area appear to modify the pressure half-time. In the present study, the influence of left ventricular stiffness (defined as diastolic pressure rise per milliliter of mitral flow) and peak atrioventricular pressure difference on the pressure half-time was examined both in a hydraulic model and by review of data from 35 patients with mitral stenosis. Left ventricular stiffness less than 0.13 mm Hg/ml was considered normal. In the model study, the orifice area correlated only moderately with inverted pressure half-time (1/PHT) (r = 0.67). By multiple linear regression, inverted pressure half-time was shown to be dependent on valve area, chamber stiffness and peak pressure difference (R = 0.89), area and stiffness being most important (R = 0.85). In the clinical study, an increased ventricular stiffness was found in 22 of the 35 patients. The pressure half-time method overestimated the Gorlin-derived area by an average of 72% in these patients compared with only 10% in 13 patients with normal stiffness (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Computer-assisted evaluation of dipyridamole thallium-201 SPECT in patients with aortic stenosis.

UNLABELLED: Dipyridamole SPECT detects significant coronary artery disease (CAD) in patients without aortic stenosis. This study was done to establish normal 201Tl distribution limits in patients with aortic stenosis and to apply these normal limits to patients with aortic stenosis and angiographically significant CAD (> or = 75% area reduction). METHODS: Fifty-two patients (mean age 68 yr; mean valve area 0.67 cm2) were examined with 201Tl SPECT after dipyridamole infusion (0.56 mg/kg during 4 min). After tomographic reconstruction, basal, mid-ventricular and apical short-axis slices were selected. The highest activity in each six-degree segment was normalized to the maximal activity of each slice. RESULTS: Significant CAD was found in 24 patients. Five patients without CAD, but with localized hypokinesia or left bundle-branch block, were excluded from the reference group which finally consisted of 16 patients. Sensitivity for CAD was 88% when the lowest relative activity in each segment was used as the lower limit of normal. With -2 s.d. and -2.5 s.d. curves the sensitivity was 83% and 75%, respectively. Gender-specific limits were not used. Nonsignificant CAD was found in seven patients (< 75% stenoses). CONCLUSIONS: This study presents the normal distribution of 201Tl uptake for patients with aortic stenosis, using dipyridamole SPECT. The range method had the highest sensitivity for detection of significant CAD.

Long term follow up of patients with anterior myocardial infarction complicated by left ventricular thrombus in the thrombolytic era.

OBJECTIVES: To examine the appearance and resolution of left ventricular thrombi and to study the relation between thrombus and mortality during long term follow up after anterior myocardial infarction. DESIGN: Ninety nine consecutive patients were prospectively studied until the last included patient had been followed for one year. Streptokinase and aspirin were used routinely, anticoagulants only after a decision by the attending physician. Echocardiography was performed within 3 d of admission, before discharge, and after one, three, and 12 months. SETTING: Umeå University Hospital, a teaching hospital in Northern Sweden. MAIN OUTCOME MEASURES: Left ventricular thrombus, segmental myocardial function, and mortality during follow up. RESULTS: Thirty patients (30%) had a thrombus on discharge. One month, three months, and 12 months after hospital discharge, the thrombus had resolved in 81%, 84%, and 90% of the patients, respectively. The proportion of resolved thrombi at one month was high irrespective of whether anticoagulants were given (10/11, 91%) or not (12/16, 75%), P = 0.4. New thrombi appeared in 12 patients after discharge and resolution and reapperance of thrombi continued during the follow up period. Patients who developed a thrombus during the hospital stay (n = 44, 44%) had more extensive myocardial dysfunction on discharge (P < 0.001) and significantly higher mortality during the follow up period than those without a thrombus (23% v 7%, P < 0.01). CONCLUSIONS: With routine thrombolytic and aspirin treatment of anterior myocardial infarction, left ventricular thrombi usually resolve during the first month after hospital discharge. Appearance and resolution of thrombi continue, however, in a significant proportion of the patients during long term follow up. A left ventricular thrombus during the initial hospital stay is associated with high long term mortality.

Photic maculopathy after pterygium excision.

PURPOSE: To report a patient who developed photic maculopathy after pterygium removal. METHODS: A 27-year-old woman underwent pterygium removal with a conjunctival autograft after administration of retrobulbar anesthesia. A coaxial operating microscope was used, with an estimated retinal exposure of approximately 40 minutes. RESULTS: On the first postoperative day, the patient noted a paracentral scotoma. A fluorescein angiogram on the fourth postoperative day documented a phototoxic lesion in the macula. CONCLUSIONS: Phototoxic injury to the macula may occur after pterygium removal. Ophthalmologists should take precautions to minimize prolonged intense coaxial illumination of the retina while performing any ocular microsurgery.

Flow dependence of the aortic valve area in patients with aortic stenosis: assessment by application of the continuity equation.

It has been argued that the aortic valve area (AVA) in patients with aortic stenosis increases with flow. Others, however, have attributed the apparent increase to flow dependence of the empiric constant in the Gorlin formula. We examined the changes in AVA during changes in transvalvular flow induced by dipyridamole infusion in 34 patients with aortic stenosis. Two-dimensional and Doppler echocardiography was used and AVA was calculated according to the continuity equation, which does not include empiric constants. Flow increased in 29, decreased in four, and was unchanged in one patient. There was a linear correlation between percent change in flow and percent change in AVA: delta AVA% = 1.1 + delta flow%. 0.56 (r = 0.72; p < 0.001) In conclusion, AVA was found to be flow dependent. The magnitude of change in AVA observed by noninvasive recordings agrees with previous invasive studies according to the Gorlin formula.

Minoxidil-induced alteration of corneal topography after radial keratotomy.

PURPOSE: To determine the antiproliferative effect of minoxidil on human corneal epithelium (hCE) proliferation in vitro and to assess whether topical minoxidil can significantly alter corneal topography after radial keratotomy (RK) by inhibiting myofibroblast activity in the keratotomy wound. SETTING: Corneal Research Laboratory, University of Chicago, Illinois, USA. METHODS: In the in vitro evaluation, proliferating hCE was exposed to minoxidil (0.1 to 2.0 mM) for 96 hours to determine the minimum inhibitory dose. Human corneal epithelium cell proliferation was assessed by the incorporation of bromodeoxyuridine (BRDU) into DNA. In the in vivo analysis, eight New Zealand albino rabbits had an eight-incision bidirectional RK on one eye and were divided into two groups. The control eyes (n = 3) received tobramycin and dexamethasone (TobraDex), ciprofloxacin hydrochloride (Ciloxan), and balanced salt solution (BSS) drops four times a day for 3 weeks, while the treatment eyes (n = 5) received TobraDex, Ciloxan, and minoxidil 1.0 mM drops four times daily for 3 weeks. The net change in corneal curvature at 3 weeks was analyzed with corneal topography. Myofibroblast activity in the keratotomy wound was assessed using alpha smooth muscle actin staining techniques. RESULTS: At concentrations of 1.0 mM and above, minoxidil caused a statistically significant, dose-dependent reduction in hCE cellular proliferation ranging from 29 to 44% (P < .05). Minoxidil (1.0 mM) caused a statistically significant central corneal flattening effect of 4.66 diopters (D) after RK in the treatment eyes compared with 1.11 D in the control eyes (P = .05). Histologically, minoxidil-treated keratotomy wounds lacked cells with contractile elements consistent with myofibroblast differentiation. Corneal epithelial wound healing was similar in both groups. CONCLUSION: At the appropriate dose, topical minoxidil may be a useful adjunctive treatment that can reduce the number of undercorrections after mini-RK without apparent toxicity to the corneal epithelium.

Delayed keratitis after laser in situ keratomileusis.

We report 2 cases of delayed keratitis that occurred after uneventful laser in situ keratomileusis (LASIK). The first patient presented with a peripheral corneal infiltrate 3 months after a LASIK enhancement procedure. The infiltrate progressed despite treatment with topical combination tobramycin-dexamethasone. The flap was then lifted and the interface was irrigated with fortified antibiotics. The keratitis promptly resolved, and the patient recovered a best corrected visual acuity (BCVA) of 20/20. The second patient presented with decreased vision, inflammation, and a sublamellar infiltrate 1 month after primary LASIK. The flap was promptly lifted and irrigated with antibiotics. Cultures were positive for Staphylococcus epidermidis. One week later, the infiltrate had resolved and BCVA had returned to 20/20. Delayed bacterial keratitis has been described as a rare occurrence after incisional refractive surgery. To the best of our knowledge, it has not yet been reported after LASIK. It is important to consider infectious keratitis in the differential diagnosis of a patient who presents with corneal inflammation, even months after having LASIK.

Surfactant protein-A in bronchoalveolar lavage fluid from neonates with RDS on conventional and high-frequency oscillatory ventilation.

Surfactant protein-A (SP-A) was measured in bronchoalveolar lavage (BAL) samples from ventilated neonates in order to study the concentration of SP-A with regard to: 1) high-frequency oscillatory ventilation (HFOV) vs. conventional mechanical ventilation (CMV); 2) the postnatal course and ontogeny of SP-A; and 3) the correlation with measurements of pulmonary function. Patients on HFOV had markedly lower BAL SP-A concentrations on days 1 and 2 compared to those on CMV, which may indicate influence of mode of ventilation on surfactant metabolism. The SP-A concentrations increased postnatally concurrent with resolution of acute respiratory distress syndrome. Finally, there were only weak correlations between BAL SP-A concentration and dynamic lung compliance and oxygen requirement.

Dynamics of left ventricular thrombi in patients with acute anterior myocardial infarction treated with thrombolytics.

BACKGROUND: Limited data exist concerning left ventricular thrombi during and after hospitalization in patients treated according to modern principles. The purpose of the present study was to examine the formation and resolution of left ventricular thrombi during the first month in patients with acute anterior myocardial infarction treated with streptokinase and aspirin. METHODS: Seventy-seven consecutive patients were studied prospectively during the hospital stay and 1-month follow-up study. Aspirin was used routinely, whereas anticoagulants were only used after a decision by the attending physician. Echocardiography was performed within 3 days of admission, before hospital discharge and after 1 month of follow-up. RESULTS: At the first examination, 17 of 77 patients (22%) had a thrombus. At discharge, 73 patients remained in the study. In five (31%) of the 16 patients with early thrombus, the thrombus persisted; in 18 (32%) of the 57 patients without early thrombus, a new thrombus was diagnosed. One month later, 65 patients remained eligible for follow-up study. In three of 20 patients (15%) the thrombus from the second examination persisted and in four of 45 patients (9%) a new thrombus was diagnosed. The disappearance rate between the second and third examination was high irrespective of whether patients were treated with anticoagulants (eight of nine, 89%) or not (nine of 11, 82%). Extensive left ventricular segmental dysfunction and signs of congestive heart failure were associated with the appearance of a left ventricular thrombus. No embolic events were recorded. CONCLUSION: In patients with anterior myocardial infarction treated with streptokinase and aspirin the development and disappearance of left ventricular thrombi is a highly dynamic process. A large proportion of thrombi resolve without additional anticoagulant therapy.

Technetium-99m pyrophosphate single-photon emission computed tomography of the heart in familial amyloid polyneuropathy.

A patient with familial amyloid polyneuropathy and congestive heart failure underwent myocardial imaging using technetium-99m pyrophosphate. Planar scintigraphy showed an intense, diffuse biventricular uptake of the radiotracer. Single-photon emission computed tomography demonstrated an unevenly distributed uptake of the isotope. The greatest activity corresponded to regions with marked echocardiographic changes. Emission tomography may aid in assessing the degree and distribution of the infiltrative lesions in cardiac amyloidosis.

Noninvasive determination of the valvar area in aortic valve disease by Doppler echocardiography and radionuclide angiography.

To assess the severity of outlfow obstruction in patients with aortic valve disease, the aortic valvar area was noninvasively determined in 22 patients with isolated aortic stenosis or combined stenosis and regurgitation. The ejection time (ET), maximal velocity (Vmax), and systolic velocity integral (SVI) of the aortic flow was obtained by continuous wave Doppler ultrasound. Left ventricular stroke volume (SV) was determined by radionuclide angiography, using a counts-based nongeometric technique with individual attenuation correction. Aortic valve area (AVA) was calculated using a modified Gorlin formula; AVA = SV/(71.2 X ET X Vmax), and also by dividing the stroke volume by the systolic velocity integral; AVA = SV/SVI. The two noninvasive determinations correlated closely with the valve areas obtained by invasive measurements; r = 0.95, SEE = +/- 0.13 cm2 by the modified Gorlin formula, and r = 0.94, SEE = +/- 0.14 cm2 by the integration method. The two noninvasive calculations showed almost uniform results; r = 0.98, SEE = +/- 0.09 cm2. In conclusion, aortic valve area can be determined with reasonable accuracy by combining Doppler echocardiography and radionuclide angiography. This noninvasive approach may reduce the need for invasive measurements in patients with suspected aortic valve disease. In addition, radionuclide angiography provides important information about left ventricular function.

Invasive evaluation of mitral regurgitation: the importance of hemodynamic measurements during exercise.

BACKGROUND AND AIMS OF THE STUDY: In patients with mitral regurgitation, left ventricular angiography is usually performed to grade the regurgitation. This is a semi-quantitative method which gives some information related to the regurgitant volume at a certain time. The aim of our study was to evaluate the benefits of invasive hemodynamic examinations during stress. Patients with mitral regurgitation according to Doppler color flow mapping, and regurgitation of no more than grade 2+ according to left ventricular angiography, were of special interest. METHODS: One hundred and four consecutive patients were examined with transesophageal echocardiography (TEE), left ventricular angiography and cardiac catheterization during rest and during hemodynamic stress. RESULTS: All patients had mitral regurgitation according to Doppler color flow mapping. Thirty eight patients had a mitral regurgitation of grade 0, 1+ or 2+ according to left ventricular angiography. Of these, seven had a resting v-wave < or = 25 mmHg, and a v wave > or = 50 mmHg during stress. When these seven patients were compared with those with severe grade 3+ and 4+ regurgitation, there was a significant difference between the v-wave at rest (p = 0.02) but no significant difference during stress (p = 0.42). CONCLUSIONS: Mitral regurgitation is a dynamic lesion, the complete assessment of which cannot be obtained from a single measure during one hemodynamic situation. Additional information from v-wave recordings during hemodynamic stress identified a subgroup of patients who had near-normal pressures at rest, but whose v-wave measurements during stress did not differ significantly from those of patients with severe angiographically assessed regurgitation (grades 3+ and 4+). In patients with only minor mitral regurgitation which is suspected to contribute to their clinical symptoms, the monitoring of invasive hemodynamic parameters during stress is important.

Hemodynamic changes during dipyridamole stress in patients with aortic stenosis.

Dipyridamole is a potent vasodilator used in pharmacologic stress testing. Patients with severe aortic stenosis are not suitable for exercise, and are usually not subjected to testing with vasodilator substances. The aim of the present study was to investigate hemodynamic changes during dipyridamole stress test in patients with aortic stenosis and to see if these changes where reversible by theophylline, an aminophylline derivative. Ten patients with aortic stenosis underwent right and left heart catheterization. Simultaneous recordings of cardiac output, left ventricular and aortic pressures were performed at baseline, after intravenous dipyridamole infusion (0.56 mg/kg dissolved in 250 ml of saline given over four minutes), and after intravenous theophylline injection (115 mg). There was an increase in heart rate, stroke volume and flow, and a decrease in systolic and diastolic blood pressure and in systemic vascular resistance after dipyridamole infusion. Left ventricular stroke work index and pressure time per minute increased after dipyridamole infusion suggesting an increase in myocardial oxygen demand, but there was no significant change compared to baseline after theophylline administration. Less than one third of left ventricular work was due to the resistance of the aortic valve. The aortic valve area changed with changes in flow. It is concluded that cardiac output, left ventricular work and myocardial oxygen demand after dipyridamole infusion increased in patients with aortic stenosis. The systemic vascular resistance seems to be more important determinant of cardiac output than the aortic valve obstruction. The calculated valve area appears to be flow-dependent.(ABSTRACT TRUNCATED AT 250 WORDS)

Outcomes of temporal clear cornea versus superior scleral tunnel phacoemulsification incisions in a university training program.

BACKGROUND AND OBJECTIVES: To evaluate the complication and visual outcomes of residents performing temporal clear cornea (TCC) compared to superior scleral tunnel (SST) phacoemulsification. PATIENTS AND METHODS: We conducted a retrospective analysis of complications and visual outcomes for 534 phacoemulsification procedures done by third-year residents over a five-year period (June 1992-July 1997) at the department of ophthalmology, University of Chicago. All cases were completed using a TCC or SST incision. RESULTS: There was vitreous loss in 6.0% of 348 eyes with TCC incisions and in 11.8% of 186 eyes with SST incisions (P < 0.02). Posterior capsule breaks occurred in 1 1.5% of the TCC group versus 17.7% in the SST group (P < 0.0453). Best corrected visual acuity of 20/40 or better was achieved in 82.5% of all eyes with TCC incisions and in 75.3% of all eyes with SST incisions (P < 0.05). When 151 patients with previous ophthalmic conditions were excluded, the difference in BCVA between the two groups was not statistically significant. CONCLUSIONS: Most institutions train residents with the SST technique prior to advancing to TCC. This study demonstrates that with proper teaching, residents can achieve excellent outcomes using TCC incisions, and can therefore be trained in this technique concurrently with SST incisions.

Anesthetic recovery after ambulatory laparoscopy: a comparison of isoflurane and alfentanil infusion.

Women undergoing ambulatory laparoscopy are known to experience a variety of minor postoperative morbidity which prolongs recovery time and delays discharge. The purpose of this study was to investigate general anesthetic recovery of ambulatory laparoscopy patients receiving two rapid-acting, but disparate, anesthetic techniques. Thirty-one ASA I and II patients between 19 and 44 years of age were randomly divided into two groups. Group I received an isoflurane-based anesthetic, and Group II received an alfentanil continuous infusion. Through analysis of covariance (ANCOVA), Group II recovery scores were found to be significantly higher at T0 (p less than .0001), (p less than .0001), T15 (p less than .001), T30 (p less than .01) and T45 (p less than .02). There was no difference between groups at T60, at which time all patients received the maximum score of 10. No other factor besides anesthetic technique significantly affected recovery scores. Group II patients spent an average of 166 minutes (+/- 59 standard deviation) in the recovery room in comparison with 192 minutes (+/- 32 standard deviation) for Group I patients. Despite this finding, an ANCOVA determined that only presence of postoperative vomiting significantly affected recovery room time (p less than .03). Further research is indicated in the endeavor to reduce postoperative morbidity of this patient population.

The utilization of automated ST segment analysis in the determination of myocardial ischemia.

Perioperative cardiac morbidity is a recognized complication of anesthesia and surgery. Morbidity includes myocardial infarction, new onset of unstable angina, congestive heart failure, and arrhythmias. Almost one third of all patients undergoing noncardiac surgery may be at increased risk of cardiac complications by virtue of age, coronary artery disease (CAD), or presence of two or more risk factors for CAD. Although postoperative ischemia has been identified as a significant risk factor for morbidity, automated ST segment analysis systems available with the new generation bedside monitors have not been used to identify ischemic episodes in patients recovering from anesthesia. Twenty-eight patients, age 41 to 80 years, were monitored in the postanesthesia care unit for ST segment changes (mean monitoring period, 97 minutes). Four patients had ischemic episodes from 7 to 44 minutes, and two of these patients had subsequent postoperative morbidity. All episodes were clinically silent. Automated ST segment analysis is an easily used technology that shows promise as a means of early detection of clinically silent perioperative myocardial ischemia.