The effect of confounding data features on a deep learning algorithm to predict complete coronary occlusion in a retrospective observational setting.

Aims: Deep learning (DL) has emerged in recent years as an effective technique in automated ECG analysis. Methods and results: A retrospective, observational study was designed to assess the feasibility of detecting induced coronary artery occlusion in human subjects earlier than experienced cardiologists using a DL algorithm. A deep convolutional neural network was trained using data from the STAFF III database. The task was to classify ECG samples as showing acute coronary artery occlusion, or no occlusion. Occluded samples were recorded after 60 s of balloon occlusion of a single coronary artery. For the first iteration of the experiment, non-occluded samples were taken from ECGs recorded in a restroom prior to entering theatres. For the second iteration of the experiment, non-occluded samples were taken in the theatre prior to balloon inflation. Results were obtained using a cross-validation approach. In the first iteration of the experiment, the DL model achieved an F1 score of 0.814, which was higher than any of three reviewing cardiologists or STEMI criteria. In the second iteration of the experiment, the DL model achieved an F1 score of 0.533, which is akin to the performance of a random chance classifier. Conclusion: The dataset was too small for the second model to achieve meaningful performance, despite the use of transfer learning. However, 'data leakage' during the first iteration of the experiment led to falsely high results. This study highlights the risk of DL models leveraging data leaks to produce spurious results.

Polychlorinated dibenzo(p)dioxin and furan (PCDD/F) congener profiles in cement kiln emissions and impacts.

Cement kilns are known to emit polychlorinated dibenzo(p)dioxins and furans (PCDD/Fs; "dioxins"), but estimates of the amounts and patterns of these emissions vary widely. These variations may stem from a combination of factors, including the design and operating conditions of the kiln, and the fuels and raw materials fed into the kiln. The goal of this study was to examine the patterns of dioxin emissions in a large set of stack-tests at two Portland cement kilns in Portugal that use a variety of fuels. A total of 152 stack-tests provided data on PCDD/F congener concentrations during which the kilns combusted a varied mix of fuels, including petroleum coke, coal, various "special" supplemental fuels, and refinery distillation ends, which are classified as hazardous wastes. The use of coal to fuel the kilns was found to generate significantly different emission-profiles relative to the use of petroleum coke, but the addition of hazardous wastes as a supplemental fuel did not significantly alter profiles. All of the kiln emission profiles were found to differ markedly from profiles in ambient air. However, the small absolute dioxin emission rates from the kilns suggested that kiln impacts would not be detectable via ambient air monitoring, even in rural settings.

The "bladder sign"--an important early marker of retroperitoneal hemorrhage.

Retroperitoneal hemorrhage remains one of the major complications of cardiac and peripheral vascular catheterization. Its high associated morbidity and mortality require vigilance and early intervention. We report six cases of retroperitoneal hemorrhage featuring a "bladder sign." The compression of the bladder described in this series can be visualized on the incidental cystogram that results from contrast given during catheterization. Its significance as a highly specific marker of retroperitoneal hemorrhage should be appreciated.

Emissions of metals and polychlorinated dibenzo(p)dioxins and furans (PCDD/Fs) from Portland cement manufacturing plants: inter-kiln variability and dependence on fuel-types.

Emissions from Portland cement manufacturing facilities may increase health risks in nearby populations and are thus subject to stringent regulations. Direct testing of pollutant concentrations in exhaust gases provides the best basis for assessing the extent of these risks. However, these tests (i) are often conducted under stressed, rather than typical, operating conditions, (ii) may be limited in number and duration, and (iii) may be influenced by specific fuel-types and attributes of individual kilns. We report here on the results of more than 150 emissions-tests conducted of two kilns at a Portland cement manufacturing plant in Portugal. The tests measured various regulated metals and polychlorinated dibenzo(p)dioxins and furans (PCDD/Fs). Stack-gas concentrations of pollutants were found to be highly variable, with standard deviations on the order of mean values. Emission rates of many pollutants were higher when coal was used as the main kiln fuel (instead of petroleum coke). Use of various supplemental fuels, however, had little effect on stack emissions, and few statistically significant differences were observed when hazardous waste was included in the fuel mix. Significant differences in emissions for some pollutants were observed between the two kilns despite their similar designs and uses of similar fuels. All measured values were found to be within applicable regulatory limits.

Clinical characteristics of tako-tsubo cardiomyopathy.

Tako-tsubo cardiomyopathy (TTC) is increasingly diagnosed in the United States, especially in the Caucasian population. To evaluate the clinical features and outcome of patients with TTC, we evaluated 34 patients (32 women and 2 men) 22 to 88 years of age (mean 66 +/- 14) who fulfilled the following criteria: (1) akinesia or dyskinesia of the apical and/or midventricular segments of the left ventricle with regional wall motion abnormalities that extended beyond the distribution of a single epicardial vessel and (2) absence of obstructive coronary artery disease. Twenty-five patients (74%) presented with chest pain, 20 patients (59%) presented with dyspnea, and 8 patients (24%) presented with cardiogenic shock. Twenty-two patients (65%) had ST-segment elevation and 14 patients (41%) had T-wave inversion on presentation. Twenty-five patients (74%) reported a preceding stressful event. Cardiac biomarkers were often mildly increased, with a mean troponin I (peak) of 13.9 +/- 24. Mean +/- SD left ventricular ejection fractions were 28 +/- 10% at time of presentation and 51 +/- 14 at time of follow-up (p <0.0001). Two patients (6%) died during the hospital stay. Average duration of hospital stay was 6.6 +/- 6.2 days. In conclusion, TTC is common in postmenopausal women with preceding physical or emotional stress. It predominantly involves the apical portion of the left ventricle and patients with this condition have a favorable outcome with appropriate medical management. The precise cause remains unclear.

Hemichannel-mediated inositol 1,4,5-trisphosphate (IP3) release in the cochlea: a novel mechanism of IP3 intercellular signaling.

Inositol 1,4,5-trisphosphate (IP(3)) is an important second messenger that can trigger a Ca(2+) wave prolongated between cells. This intercellular signaling was found defective in some gap junction connexin deafness mutants. In this study, the mechanism underlying IP(3) intercellular signaling in the cochlea was investigated. A gap junction channel is composed of two hemichannels. By using a fluorescence polarization technique to measure IP(3) concentration, the authors found that IP(3) could be released by gap junction hemichannels in the cochlea. The IP(3) release was increased about three- to fivefold by the reduction of extracellular Ca(2+) concentration or by mechanical stress. This incremental release could be blocked by gap junction blockers but not eliminated by a purinergic P2x receptor antagonist and verapamil, which is a selective P-glycoprotein inhibitor inhibiting the ATP-binding cassette transporters. The authors also found that IP(3) receptors were extensively expressed in the cochlear sensory epithelium, including on the cell surface. Extracellular application of IP(3) could trigger cellular Ca(2+) elevation. This Ca(2+) elevation was eliminated by the gap junction hemichannel blocker. These data reveal that IP(3) can pass through hemichannels acting as an extracellular mediator to participate in intercellular signaling. This hemichannel-mediated extracellular pathway may play an important role in long-distance intercellular communication in the cochlea, given that IP(3) only has a short lifetime in the cytoplasm.

Single-center experience with the TandemHeart percutaneous ventricular assist device to support patients undergoing high-risk percutaneous coronary intervention.

UNLABELLED: We describe our experience of patients, from December 2005 through May 2007 who underwent percutaneous coronary intervention (PCI) with severely depressed left ventricle systolic function and complex coronary lesions. The complex coronary lesions included multiple vessel coronary artery disease, left main (LM) coronary artery disease, calcified coronary lesions and bypass graft disease. All patients were clinically assessed to be at too high of a risk for circulatory collapse without maximal hemodynamic support while they underwent high-risk PCI. The TandemHeart percutaneous ventricular assist device (THpVAD) may be able to provide the necessary circulatory support required to enhance procedural success and patient safety during high-risk PCI. METHODS AND RESULTS: We implanted the THpVAD in 6 patients who underwent high-risk PCI. There was unanimity among several physicians in our institution that each patient was an exceptionally high risk for circulatory collapse due to the anticipated procedural complexity. The average ejection fraction was 33% (range 15-65%). Five of the patients were considered to be at an unacceptably high risk for coronary artery bypass surgery. All 6 patients underwent multivessel PCI. Five of the 6 underwent unprotected LM PCI. One patient of the 5 underwent vein-graft PCI as well as a debulking procedure with rotational atherectomy and PCI of the LM. We had a 100% success rate with implantation of the THpVAD. Five of the 6 patients were alive at 30 days post procedure. One patient died 3 days after the procedure due to multiorgan failure. A vascular surgeon performed the removal of the devices with no associated complications. CONCLUSIONS: Our clinical experiences with the TandemHeart pVAD demonstrated that hemodynamic support could be achieved safely, efficiently and effectively by way of a percutaneous route in anticipation of high-risk PCI.

Prevalence of metabolic syndrome in patients < or =45 years of age with acute myocardial infarction having percutaneous coronary intervention.

The prevalence of metabolic syndrome (MS) was determined in patients aged < or =45 years who presented with acute myocardial infarction and underwent primary percutaneous coronary intervention. Two hundred twenty-three consecutive patients aged 18 to 45 years who underwent cardiac catheterization for acute myocardial infarction from June 2001 to December 2004 were reviewed. MS was diagnosed by National Cholesterol Education Program Adult Treatment Panel III guidelines (modified by substituting body mass index > or =28.8 kg/m2 for waist circumference). One hundred sixty-one patients met all 5 criteria for MS available for evaluation. Seventy-six of these patients (47%) met > or =3 of the 5 criteria for MS. Sixteen patients with MS (21%) and 5 patients without MS (6%) had diabetes mellitus. The prevalence of each criterion was significantly higher (p <0.05) in the MS group. Average Framingham risk scores were 7.0 and 4.5 for patients with and without MS, respectively. The prevalence of smoking, male gender, and family history of premature coronary artery disease were the same for the 2 groups. In conclusion, MS was highly prevalent in this population of young patients with acute myocardial infarction.

Stroke complicating percutaneous coronary intervention in patients with acute myocardial infarction.

BACKGROUND: Stroke associated with percutaneous coronary intervention (PCI) is a tragic complication. Despite advances in the practice of PCI, the incidence of stroke complicating PCI has not changed over the decades. The objective of the present study was to evaluate incidence and correlates of stroke occurring in patients with myocardial infarction (MI) undergoing PCI. METHODS AND RESULTS: Stroke was defined as the presence of any new focal neurological deficit lasting > or =24 h that occurred anytime during or after PCI until discharge. In 2,281 consecutive patients with PCIs for non-ST-elevation MI, or ST-elevation MI (STEMI), 20 strokes were identified (0.88%). Strokes were ischemic in 95%. On multivariate analyses, ejection fraction < or =30% (odds ratio =4.3, p=0.003) was the only independent predictor for stroke. In patients who developed stroke within 24 h of PCI, PCI of vein grafts was more frequent, and use of glycoprotein IIb/IIIa inhibitor was less frequent. Those patients tended to present late in the course of MI. Stroke found more than 24 h after PCI was related to diabetes, higher serum creatinine, lower ejection fraction, anterior wall STEMI and emergency use of intra-aortic balloon pumps. CONCLUSIONS: Low ejection fraction was the only independent predictor for stroke, but risk factors for periprocedural stroke are different from those of stroke occurring more than 24 h after PCI. Upstream use of glycoprotein IIb/IIIa inhibitor might decrease the risk of periprocedural stroke.

Management of frontal sinus fractures: a review of 96 cases.

OBJECTIVES: The optimal treatment algorithm for frontal sinus fracture management remains ill-defined. The purpose of the study was to classify fracture types, review management methods, document associated injuries, and identify complications associated with various treatment options. STUDY DESIGN: The authors conducted a retrospective chart review evaluating a 13-year experience with frontal sinus fracture management. METHODS: Complete medical records of 96 frontal sinus fracture patients treated by the University of Kentucky Otolaryngology Service from 1990 to 2003 were reviewed. RESULTS: The average patient age was 39 years. Fifty percent of the fractures involved the anterior table of the frontal sinus alone, and 50% involved both anterior and posterior tables. Forty-seven percent of the injuries were managed with observation, whereas 50% of patients underwent surgical repair. In the surgical group, 60% underwent open reduction and internal fixation (ORIF), 23% had a cranialization procedure, and 17% underwent sinus obliteration. The average length of follow up was 9 months. Complications occurred in 17% of the patients (5% in the nonsurgical group and 12% in the surgical group). CONCLUSION: Our results support conservative management of nondisplaced or minimally displaced fractures based on the low complication rate seen in this series. Significant bone displacement can frequently be managed with simple ORIF. Complex fractures affecting the orbit or intracranial contents require cranialization or possibly obliteration. A subset of patients with suspected frontal sinus outflow obstruction can be considered for observation or simple ORIF with close follow up and endoscopic repair if outflow complications manifest.

Retroperitoneal hemorrhage from inferior epigastric artery: value of femoral angiography for detection and management.

Laceration of the inferior epigastric artery during cardiac catheterization is under-reported in the literature, but it is a serious complication leading to retroperitoneal hemorrhage and even death. We report on two cases of retroperitoneal bleeding from unintentional puncture of the inferior epigastric artery during cardiac catheterization. Femoral angiography is a valuable tool to promptly recognize this complication.

Myocardial infarction as a presentation of clinical in-stent restenosis.

BACKGROUND: In-stent restenosis is considered to be a gradual and progressive condition and there is scant data on myocardial infarction (MI) as a clinical presentation. METHODS AND RESULTS: Of 2,462 consecutive patients who underwent percutaneous coronary intervention between June 2001 and December 2002, clinical in-stent restenosis occurred in 212 (8.6%), who were classified into 3 groups: ST elevation MI (STEMI), non-ST elevation MI (NSTEMI) and non-MI. Of the 212 patients presenting with clinical in-stent restenosis, 22 (10.4%) had MI (creatine kinase (CK)>or=2xbaseline with elevated CKMB). The remaining 190 (89.6%) patients had stable angina or evidence of ischemia by stress test without elevation of cardiac enzymes. Median interval between previous intervention and presentation for clinical in-stent restenosis was shorter for patients with MI than for non-MI patients (STEMI, 90 days; NSTEMI, 79 days; non-MI, 125 days; p=0.07). Diffuse in-stent restenosis was more frequent in MI patients than in non-MI patients (72.7% vs 56.3%; p<0.005). Renal failure was more prevalent in patients with MI than in those without MI (31.8% vs 6.3%, p=0.001). Compared with the non-MI group, patients with MI were more likely to have acute coronary syndromes at the time of index procedure (81.8% vs 56.8%, p=0.02). CONCLUSION: Clinical in-stent restenosis can frequently present as MI and such patients are more likely to have an aggressive angiographic pattern of restenosis. Renal failure and acute coronary syndromes at the initial procedure are associated with MI.

Analysis of unknown primary carcinomas metastatic to the neck: diagnosis, treatment, and outcomes.

Metastatic squamous cell carcinoma presenting in the neck from an unknown primary site represetns 2% to 6% of head and neck cancers. Optimal management of these cases remains controversial and continues to evolve with experience. We performed a retrospective analysis involving patients treated for unknown primary squamous cell carcinomas with metastases to cervical lymph nodes who presented to either the University of Kentucky or the Veterans Affairs Hospital of Lexington, Kentucky, from 1990 to 2000. Thirty-five out of 173 patients met inclusion criteria for carcinoma of unknown primary. The following data subsets were analyzed: age, gender, smoking and alcohol use, family history, diagnostic studies performed, radiation dose, surgical intervention, number and location of pathologic nodes, presence or absence of extracapsular extension, time between surgery and radiation, disease-specific and overall survival, response to treatment, emergence of a primary tumor, and duration of follow-up. Overall and disease-specific survivals were analyzed using, the Kaplan-Meier method and the log-rank test was used to assess differences in survival curves. The actuarial 5-year overall and disease-specific survival of all patients in this study was 54% and 63%, respectively. At 10 years, the overall survival declined to 37% with a disease-specific survival rate of 49%. The 5-year survival rates stratified by nodal stage were 80% for N1 patients, 64.7% for N2, 55.6% for N3, and 0% for any M disease. These rates declined to 60% for N1, 52.9% for N2, 11.1% for N3, and 0% for any M disease at 10 years (p<.0001). The presence of extracapsular spread, increased number of positive lymph nodes, and eventual discovery of a primary tumor did not significantly decrease survival in this series. The mean follow-up period for patients in this study was 54.8 months. We continue to refine our diagnostic and treatment strategies in this group of patients in an effort to improve long-term survival and reduce patient morbidity.

Rheolytic thrombectomy for thromboembolic occlusion of the internal carotid artery complicating coronary intervention.

Stroke associated with percutaneous coronary intervention (PCI) is an infrequent, but devastating complication. Intra-arterial thrombolysis has been used with limited success, but there are no widely accepted strategies for acute ischemic stroke during PCI. We report a case in which the AngioJet rheolytic thrombectomy device was used in an attempt to re-establish patency of an occluded internal carotid artery in the setting of an acute stroke caused by thromboembolization from the right coronary artery during PCI.

The acetabular reamer: a unique tool for anterior iliac crest bone graft harvesting.

Bone grafting is often required in craniofacial reconstruction. Morselized corticocancellous bone grafts are particularly useful in applications such as filling and contouring irregular bony defects. Obtaining grafts of this consistency by traditional methods is difficult. An efficient harvesting method that can produce such grafting material in clinically useful quantities is needed. We report the use of a mechanical acetabular reamer for the purpose of harvesting a bone graft from the iliac crest.

Paradoxical embolism in the left main coronary artery: diagnosis by transesophageal echocardiography.

We describe a patient with a paradoxical coronary embolism diagnosed by transesophageal echocardiography. The patient developed a stroke followed by a myocardial infarction. Coronary angiography showed an obstruction of the left main coronary artery. Transesophageal echocardiography showed the mechanism of the neurologic and cardiac events to be a paradoxical embolism. Emergency surgical retrieval of the thrombus lodged in the left main coronary ostium and of a separate thrombus traversing a patent foramen ovale was performed. To our knowledge, direct visualization of the paradoxical coronary embolism by echocardiography has not been reported previously. We discuss mechanisms responsible for paradoxical coronary embolism and review the literature pertaining to this condition.