Prehospital ABC (Age, Bystander and Cardiogram) scoring system to predict neurological outcomes of cardiopulmonary arrest on arrival: post hoc analysis of a multicentre prospective observational study.

BACKGROUND: There is currently limited evidence to guide prehospital identification of patients with cardiopulmonary arrest on arrival (CPAOA) to hospital who have potentially favourable neurological function. This study aimed to develop a simple scoring system that can be determined at the contact point with emergency medical services to predict neurological outcomes. METHODS: We analysed data from patients with CPAOA using a regional Japanese database (SOS-KANTO), from January 2012 to March 2013. Patients were randomly assigned into derivation and validation cohorts. Favourable neurological outcomes were defined as cerebral performance category 1 or 2. We developed a new scoring system using logistic regression analysis with the following predictors: age, no-flow time, initial cardiac rhythm and arrest place. The model was internally validated by assessing discrimination and calibration. RESULTS: Among 4907 patients in the derivation cohort and 4908 patients in the validation cohort, the probabilities of favourable outcome were 0.9% and 0.8%, respectively. In the derivation cohort, age ≤70 years (OR 5.11; 95% CI 2.35 to 11.14), no-flow time ≤5 min (OR 4.06; 95% CI 2.06 to 8.01) and ventricular tachycardia or fibrillation as initial cardiac rhythm (OR 6.66; 95% CI 3.45 to 12.88) were identified as predictors of favourable outcome. The ABC score consisting of Age, information from Bystander and Cardiogram was created. The areas under the receiver operating characteristic curves of this score were 0.863 in the derivation and 0.885 in the validation cohorts. Positive likelihood ratios were 6.15 and 6.39 in patients with scores >2 points and were 11.06 and 17.75 in those with 3 points. CONCLUSION: The ABC score showed good accuracy for predicting favourable neurological outcomes in patients with CPAOA. This simple scoring system could potentially be used to select patients for extracorporeal cardiopulmonary resuscitation and minimise low-flow time.

Detection of arrhythmogenic substrate within QRS complex in patients with cardiac sarcoidosis using wavelet-transformed ECG.

Signal-averaged electrocardiography (SAECG) has been known to be useful for prediction of lethal ventricular arrhythmias (VA). However, this technique has limitations in patients with intraventricular conduction disturbance (IVCD), which is common in cardiac sarcoidosis (CS). Meanwhile, wavelet-transformed ECG (WTECG) has been reported to be useful for detecting arrhythmogenic substrate hidden within QRS complex. The objective of this study was to assess the utility of WTECG for detecting arrhythmogenic substrate in patients with CS. Forty-four CS patients including 18 patients with VA were retrospectively investigated. The parameters on the signal-averaged electrocardiography (SAECG) and the power of frequency components on WTECG were compared between VA group and non-VA group. Eighteen patients have VA (VT: n = 17, VF: n = 1). LP were detected in 17 in VA group and 24 in non-VA group. WTECG showed that high-frequency components (HFC; 80-150 Hz) were developed in VA group. Peak power value at 150 Hz (P150) was significantly higher in VA group than that in non-VA group (442.9 ± 160.2 vs 316.7 ± 100.8, p = 0.006). The receiver operating characteristic (ROC) curve analysis showed an optimal cutoff point of 336 of P150 for detecting patients with VA, with 82.4% sensitivity, 61.5% specificity, and area under the curve of 0.74 (95% confidence interval [CI] 0.59-0.89). WTECG may be useful for detecting CS patients who are prone to VA.

The ABC (Age, Bystander, and Cardiogram) score for predicting neurological outcomes of cardiac arrests without pre-hospital return of spontaneous circulation: A nationwide population-based study.

Aim: We previously proposed the ABC score to predict the neurological outcomes of cardiac arrest without prehospital return of spontaneous circulation (ROSC). Using nationwide population-based data, this study aimed to validate the ABC score through various resuscitation guideline periods. Methods: We analysed cases with cardiac arrest due to internal causes and failure to achieve prehospital ROSC in the All-Japan Utstein Registry. Patients from the 2007-2009, 2012-2014, and 2017-2019 periods were classified into the 2005, 2010, and 2015 guideline groups, respectively. Neurological outcomes were assessed using cerebral performance categories (CPCs) one month after the cardiac arrest. We defined CPC 1-2 as a favourable outcome. We evaluated the test characteristics of the ABC score, which could range from 0 to 3. Results: Among the 162,710, 186,228, and 190,794 patients in the 2005, 2010, and 2015 guideline groups, 0.7%, 0.8%, and 0.9% of the patients had CPC 1-2, respectively. The proportions of CPC 1-2 were 2.9%, 3.6%, and 4.6% in patients with ABC scores of 2 and were 9.5%, 13.3%, and 16.8% in patients with ABC scores of 3, respectively. Among patients with ABC scores of 0, 0.2%, 0.1%, and 0.2%, all had CPC 1-2, respectively. The areas under the receiver operating characteristic curves for the ABC score were 0.798, 0.822, and 0.828, respectively. Conclusions: The ABC score had acceptable discrimination for neurological outcomes in patients without prehospital ROSC in the three guideline periods.

Ascites Caused by Intestinal Anisakiasis: A Case Report and Literature Review.

Anisakiasis is a parasitic infection affecting the human gastrointestinal tract. It is caused by the consumption of contaminated, raw or inadequately cooked fish or squid, which is typically used for making sushi and sashimi. Most cases involve gastric anisakiasis, whereas intestinal anisakiasis is rare. This report describes the case of a 63-year-old Japanese woman with a history of raw fish consumption who presented with acute-onset abdominal pain and vomiting. Abdominal computed tomography (CT) demonstrated thickened small bowel loops and ascites on the liver surface. The patient was admitted for supportive care. On the second day of hospitalization, contrast-enhanced abdominal CT revealed that the ascites had moved from the liver surface to the pouch of Douglas. On the fifth day of hospitalization, the patient was discharged with a substantial improvement in abdominal pain. Five days after the discharge, her eosinophil count was elevated, and parasitic disease was therefore suspected. Anti-Anisakis IgG/A and IgE (RAST) antibody levels were elevated, confirming the diagnosis of intestinal anisakiasis. A review of 51 reported cases of intestinal anisakiasis suggests that the presence of ascites and measurement of anti-Anisakis antibody titers are helpful for diagnosis in cases presenting with nonspecific abdominal symptoms after consumption of raw or undercooked fish.

A Case of Fever, Impaired Consciousness, and Psychosis Caused by Nitrous Oxide Abuse and Misdiagnosed as Acute Meningitis.

Nitrous oxide (N2O) is readily available, and its abuse for recreational purposes has become a social problem. In Japan, where N2O is strictly prohibited for non-medical use, abuse is often overlooked due to a lack of experience in the field. N2O abuse causes various long-term symptoms, including vitamin B12 deficiency, myelopathy, myeloneuropathy, subacute combined degeneration, mood changes, and psychosis. The diagnosis of N2O abuse is difficult due to the compound's short half-life and rapid elimination through the lungs. This report describes a case of fever and impaired consciousness in a patient with a history of N2O abuse.

Long-Term Electrocardiographic Follow-Up of a Patient with Light-Chain Cardiac Amyloidosis.

Amyloid light-chain (AL) cardiac amyloidosis can cause restrictive cardiomyopathy, which has a poor prognosis. Although electrocardiography (ECG) is useful for its diagnosis and management, there are few reports on the long-term follow-up of electrocardiographic changes in affected patients. The present patient was a 62-year-old woman who visited our hospital for assessment of palpitations and lower leg edema. A chest radiograph showed cardiac enlargement, and ECG revealed sinus rhythm, first-degree atrioventricular block, low QRS voltage in the limb leads and a pseudo-myocardial infarction pattern in the precordial leads. Echocardiography revealed left ventricular hypertrophy with systolic and diastolic dysfunction. Immunoelectrophoresis demonstrated M-protein (IgGλ), and bone marrow biopsy suggested IgGλ-type plasmacytoma. Myocardial biopsy findings were compatible with cardiac amyloidosis. On the basis of these findings, we diagnosed AL cardiac amyloidosis. Melphalan-prednisolone (MP) therapy was started in conjunction with treatment for non-sustained ventricular tachycardia and congestive heart failure. Two years and 4 months later, the sinus rhythm converted to atrial tachycardia. At a follow-up examination at 4 years and 8 months, right branch block appeared. After that, intraventricular conduction worsened, and the low voltage in the limb leads was not observed. Seven years after diagnosis, she was hospitalized for treatment of pneumonia and heart failure with tachycardia. On the seventh day of hospitalization, heart rhythm changed to atrial stand-still with escaped ventricular rhythm and she died of cardiac arrest. These ECG changes are valuable information regarding the pathophysiological changes that occur in AL cardiac amyloidosis.

Effect of corticosteroid therapy on ventricular arrhythmias in patients with cardiac sarcoidosis.

BACKGROUND: Ventricular arrhythmias are one of the main causes of sudden death in cardiac sarcoidosis (CS). Little is known about the efficacy of corticosteroid therapy for ventricular arrhythmias in CS. METHODS: Thirty-one CS patients presenting premature ventricular contractions (PVCs, ≥300/day) were investigated. Fourteen patients had nonsustained ventricular tachycardia (NSVT). All of patients were treated with corticosteroid, and the initial dosage is 30 mg/day of prednisone, which was tapered over a period of 6 months to a maintenance dosage of 10 mg/day. Twenty-four hour Holter monitoring, signal averaged electrocardiography (SAECG), echocardiography, gallium-67 scintigraphy, serum angiotensin converting enzyme (ACE) and plasma B-type natriuretic peptide (BNP) concentrations were assessed before and after corticosteroid therapy. RESULTS: As a whole, there were no significant differences in the number of PVCs and in the prevalence of NSVT before and after steroid therapy. However, the less advanced LV dysfunction patients (EF ≥ 35%, n = 17) showed significant reduction in the number of PVCs (from 1820 ± 2969 to 742 ± 1425, P = 0.048) and in the prevalence of NSVT (from 41 to 6%, p = 0.039). Late potentials on SAECG were abolished in 3 patients. The less advanced LV dysfunction group showed a significantly higher prevalence of gallium-67 uptake compared with the advanced LV dysfunction group (EF < 35 %, n = 14). In the advanced LV dysfunction patients, there were no significant differences in these parameters. CONCLUSIONS: Corticosteroid therapy may be effective for ventricular arrhythmias in the early stage, but less effective in the late stage.

A new approach for the comparison of conduction abnormality between arrhythmogenic right ventricular cardiomyopathy/dysplasia and Brugada syndrome.

BACKGROUND: Right ventricular outflow tract ventricular tachycardia (RVOT-VT), arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/ARVD), and Brugada syndrome (BrS) were characterized by arrhythmias originating in the right ventricle, and the pathophysiologic mechanism underlying these arrhythmias has not been fully understood. METHODS: This study consisted of 40 subjects, including 20 patients with RVOT-VT, 10 patients with BrS, and 10 ARVD patients. The parameters on the signal-averaged electrocardiography (ECG) and the frequency components recorded from the wavelet-transformed ECG were compared between the three groups. Late potentials were positive in none of the patients with RVOT-VT, seven of the patients with BrS, and all of ARVD patients. RESULTS: In Brugada and ARVD patients, the power of high-frequency components (80-150 Hz) was developed to a greater extent than in RVOT-VT patients. In the power analysis of the high-frequency components between BrS and ARVD, the frequency showing the greatest power was significantly higher in ARVD patients than that in BrS patients (145.4 ± 27.9 Hz vs 81.7 ± 19.9 Hz, P < 0.01). CONCLUSIONS: High-frequency components were developed in ARVD and BrS, but not in RVOT-VT. The frequency levels showing high power by wavelet analysis obviously differ between ARVD and BrS. Wavelet analysis may provide new insight into unsolved mechanisms in arrhythmogenic right heart disease.

Detection of prior myocardial infarction patients prone to malignant ventricular arrhythmias using wavelet transform analysis.

Ventricular tachycardia (VT) and ventricular fibrillation (VF) leading to sudden cardiac death remains responsible for significant mortality in patients with prior myocardial infarction (MI). The study population consisted of 50 normal controls and 50 patients with prior MI. The MI subjects were divided into 3 groups: VT/VF (-) group; 25 patients without ventricular tachyarrhythmia, VT group; 13 patients with sustained VT, and VF group; 12 patients with resuscitated VF. The parameters on the signal-averaged ECG and the frequency components recorded from the wavelet-transformed ECG were compared. The high-frequency components (HFC; 80-150 Hz) were developed in the MI group to a greater extent than those in the control group. Among the MI patients, the HFC were more developed in the VT and VF groups than in the VT/VF (-) group. In the VF group, the positive rate of LP was 50%. Meanwhile, when the peak power value at 150 Hz > 300 was defined as abnormal, the HFC was detected in 13 (100%) patients in the VT group and 12 (91.7%) in the VF group. The sensitivity of the abnormal HFC in identifying patients with VT/VF was higher than that of SAECG (96% versus 72%), although the specificity remained similar (68.5% versus 64.3%). Abnormal HFC recorded from the wavelet-transformed ECG may be a novel factor in detecting patients who are prone to VT/VF.

Detection of arrhythmogenic substrates in prior myocardial infarction patients with complete right bundle branch block QRS using wavelet-transformed ECG.

BACKGROUND: It is important to follow up patients surviving acute myocardial infarction (MI), to detect the presence of any life-threatening arrhythmias. Various non-invasive examinations, such as signal-averaged ECG (SAECG), have been reported to predict the fatal ventricular tachycardia (VT); however, these conventional methods have limitations in detecting VT occurring in patients with complete right bundle branch block (CRBBB) QRS. Wavelet transform has been increasingly reported as a superior time-frequency analysis on the surface ECG in detecting abnormal high-frequency components (HFCs), thus suggesting abnormal myocardial conductions; however, it remains unclear whether wavelet-transformed ECG (WTECG) is useful in patients with CRBBB. OBJECTIVE: The purpose of this study is to assess the predictive value of WTECG for detecting arrhythmogenic substrates in MI patients with CRBBB. METHODS: Both the WTECG and SAECG were evaluated in 22 subjects with CRBBB, including 10 subjects without cardiovascular diseases (control group), 7 prior MI patients without VT (Non-VT group), and 5 prior MI patients with sustained VT (VT group). A 12-lead ECG (10 kHz sampling) was recorded and the representative QRS complex (300 ms) was transformed at a frequency range of 40-280 Hz using the Gabor function as the analyzing wavelet. In the power curve along a time course, the percentages of the peak power values at each frequency (60, 80, 120, 150, and 200 Hz) in the corresponding power values at 40 Hz (P60/40, P80/40, P120/40, P150/40, and P200/40, respectively) were calculated. 'The power percentages (P120/40, P150/40, or P200/40) > or =50%' was defined as an abnormal HFC (AHFC), and the number of the leads in which an AHFC was detected (NL-AHFC) of 8 leads (I, aV(F), V1-V6) was counted for comparison of the two MI groups. RESULTS: There was no significant difference among the three groups in the SAECG recording. The power percentages of HFCs (P120/40, P150/40, and P200/40) in Non-VT group were significantly higher than those in control group (48.2 +/- 36.5 vs. 30.6 +/- 7.7, P<0.001; 47.8 +/- 35.5 vs. 26.9 +/- 7.1, P<0.001; 47.3 +/- 39.4 vs. 24.9 +/- 7.6, P<0.001; respectively). NL-AHFC (P150/40) in VT group significantly increased more than in Non-VT group (3.2 +/- 0.4 vs. 1.4 +/- 0.8, P=0.001). When 'NL-AHFC (P150/40) > or =3' was defined as abnormal, the sensitivity, specificity, positive and negative predictive values for detection of VT in MI patients with CRBBB was 100, 85.7, 83.3, and 100%, respectively. CONCLUSION: WTECG might be a novel non-invasive method to detect arrhythmogenic substrates in MI patients with CRBBB.

Serum Hepcidin-25 Levels Reflect the Presence of Bacteremia in Patients with Systemic Inflammatory Response Syndrome.

BACKGROUND: Hepcidin-25 is a key regulatory hormone of iron homeostasis in humans, and its production is greatly upregulated by inflammation as well as iron overload. The aim of this study was to investigate the pathophysiological role of hepcidin-25 in patients with systemic inflammatory response syndrome (SIRS). METHODS: We enrolled 113 consecutive patients (aged 63.4±21, 50 men, 63 women), with 2 or more SIRS criteria, who were admitted to our department of general medicine between August 1, 2015 and August 31, 2017. We measured complete blood cell count and serum levels of hepcidin-25, iron, iron-binding capacity, ferritin, blood urea nitrogen, creatinine, albumin, and C-reactive protein (CRP) on admission. The patients were divided into 3 group: a bacteremia group (27 patients), a culture-negative bacterial infection group (60 patients), and a non-bacterial infection group (26 patients). RESULTS: Hepcidin-25 levels were found to be comparable in terms of SIRS criteria: 162 [2.8-579], 193 [2.24-409], and 180 [89.2-421] ng/mL in patients with 2, 3, and 4 criteria, respectively (P=0.533). However, hepcidin-25 levels were significantly higher in the bacteremia group (209 [56.7-579] ng/mL) than in either the culture-negative bacterial infection group (168 [2.24-418] ng/mL) or the non-bacterial infection group (142 [2.8-409] ng/mL). A significant positive correlation between hepcidin-25 and CRP levels was noted in the bacteremia group (r=0.528, P=0.005) and non-bacterial infection group (r=0.648, P<0.001). Moreover, iron and ferritin levels were significantly lower in the bacteremia group than in the non-bacterial infection group. CONCLUSIONS: Our findings suggest that hepcidin-25 level may reflect the presence of bacteremia as well as the severity of inflammation in patients with SIRS.

Evaluation of the genotoxicity of PM2.5 collected by a high-volume air sampler with impactor.

BACKGROUND: The harmful effects of fine particles with an aerodynamic diameter less than 2.5 µm (PM2.5) on respiratory organs are emphasized in pollution studies because PM2.5 have high deposition rates in the respiratory organs and contain various hazardous compounds. In this study, a sampling method combining a high-volume air sampler (HV) with a PM2.5 impactor was developed for collecting large quantities of PM2.5. The concentrations of elemental carbon (EC), organic carbon (OC), inorganic ions, and polycyclic aromatic hydrocarbons (PAHs) were measured in PM2.5 collected by the high-and low-volume air samplers (LV). RESULTS: Similar results were obtained from the HV and LV methods, with respect to inorganic carbon, organic carbon, sodium ions, ammonium ions, and PAHs with more than four rings. Because of the much larger amount of PM2.5 could be collected by the HV method, the trace constituents, that were difficult to detect by the conventional LV method, were readily detected by the HV method. Furthermore, when the microsuspension method that was modified more sensitive Ames mutagenicity test, was used to test the PM2.5 samples at four sites, mutagenic activities were detected by strains TA100 and TA98. Most of the mutagenic activity was associated with the PM2.5 fraction and mutagenic activity in winter was greater than that in summer. CONCLUSIONS: The HV method produced results similar to those from the conventional LV method with respect to the PM2.5 components present in the atmosphere in relatively high concentrations, but its 40-fold greater flow rate enabled the detection of mutagenic compounds present in only trace concentrations.

Prognostic significance of ventricular late potentials in patients with pulmonary sarcoidosis.

BACKGROUND: Early detection of cardiac involvement in sarcoidosis is difficult but essential to achieve optimal treatment. Signal-averaged electrocardiography (SAECG) can detect subtle cardiac electrical abnormalities termed late potentials (LPs) and would be useful for the early diagnosis of cardiac involvement. OBJECTIVE: This study aims to investigate the prognostic significance of LP in patients with pulmonary sarcoidosis. METHODS: We prospectively studied 74 patients with pulmonary sarcoidosis without overt electrocardiographic abnormalities. All participants underwent SAECG, cardiac echocardiography, and 24-hour ambulatory Holter monitoring. Serum angiotensin-converting enzyme and B-type natriuretic peptide levels were also evaluated. We followed these patients for the evaluation of incidence of cardiac events including cardiac death, arrhythmias, and heart failure requiring hospital admission. RESULTS: Of the studied population, 29 patients (39.2%) had detectable LP. During a mean follow-up period of 9.8 years, 8 patients with LPs had cardiovascular events, including development of complete atrioventricular block (n = 4), ventricular tachycardia (n = 2), and heart failure (n = 2). Meanwhile, only 1 of 45 patients without LP developed cardiac event (heart failure). Multivariate analyses revealed that LPs were associated with an increased risk of developing cardiac events (hazard ratio 9.66; 95% confidence interval 1.20-78.01; P = .033) whereas age, sex, serum angiotensin-converting enzyme and B-type natriuretic peptide levels, number of premature ventricular contractions on 24-hour Holter monitoring, and echocardiographic parameters were not associated with subsequent cardiac events. CONCLUSION: SAECG might possibly be useful for the early detection of cardiac sarcoidosis and, if independently validated, could eventually be considered as a screening test for further risk stratification.

High-frequency potentials developed in wavelet-transformed electrocardiogram as a novel indicator for detecting Brugada syndrome.

BACKGROUND: A reliable alternative method for detecting Brugada syndrome is desirable because the diagnosis of Brugada syndrome using 12-lead ECG is not optimal. OBJECTIVES: The purpose of this study was to assess the usefulness of the wavelet-transformed ECG in detecting Brugada syndrome. METHODS: The study consisted of 15 patients with Brugada syndrome and 15 healthy subjects (control group). The parameters on the signal-averaged ECG and the frequency components recorded from the wavelet-transformed ECG were compared between the two groups. Measurements were repeated after pilsicainide infusion in the two groups of patients, after an isoproterenol infusion following pilsicainide injection, and after administration of cilostazol in the group of patients with Brugada syndrome. RESULTS: The positive rate of late potentials was 80% in the Brugada syndrome group and 0% in the control group (P <.01). The high-frequency components (80-150 Hz) were developed in the Brugada syndrome group to a greater extent than in the control group, but the low-frequency components (10-50 Hz) did not differ (mean peak power at 80 Hz; 713 +/- 36 vs 488 +/- 60, P <.001). After pilsicainide injection, high-frequency components significantly increased in both groups. However, after isoproterenol and cilostazol administration, high-frequency components significantly decreased but remained higher than in the control group (80 Hz; 655 +/- 40 vs 488 +/- 60, P <.001). The sensitivity of the development of high-frequency components in detecting Brugada syndrome was higher than that of signal-averaged ECG (100% vs 80%), but specificity remained high and similar (100% for both methods). CONCLUSION: Abnormally high-frequency components recorded from the wavelet-transformed ECG might be a novel factor in detecting Brugada syndrome.

Gymnastic Formation-related Injury to Children in Physical Education.

OBJECTIVE: Current data indicate that the rate of trauma in children during gymnastic formation is increasing, especially while creating a structure with a certain height, such as the human pyramid. The goal of the present study was to clarify the clinical characteristics of these injuries. METHODS: In this single-institution review, all children treated for a gymnastic formation-related injury at Nippon Medical School Hospital from 2013 through 2015 were identified through the institution's registry. The injury mechanism was classified, and injury severity, interventions, and outcome were examined. RESULTS: Eight children were treated for a gymnastic formation-related injury. They were 7 boys and 1 girl aged 10 to 15 years (mean age, 13.1±1.8 years). Neurotrauma ranging from concussion to spinal cord injury without radiographic abnormality occurred in 6 patients (75%). No intracranial hemorrhagic lesions were detected. The Glasgow Coma Scale score on arrival was 15 in all 8 patients, and neurological deficits were present in 1 patient. No patient required surgical intervention. All patients made a full recovery after discharge from the hospital. No patients died. The average follow-up period was 2.1±0.9 weeks. CONCLUSIONS: Neurotrauma is a frequent result of gymnastic formation accidents in children. Healthcare workers and teachers should recognize this type of injury, and public education that targets parents should be introduced.

Clinical significance of pleural effusion in acute aortic dissection.

STUDY OBJECTIVE: To clarify the clinical significance of pleural effusion in the clinical course of acute aortic dissection (AAD). DESIGN: Retrospective clinical series. SETTING: A university hospital. PATIENTS: Fifty-five patients strongly suspected of having AAD because of severe chest or back pain. Patients with obvious ischemic heart disease, lung disease, and pleural disease were excluded. INTERVENTIONS: An additional diagnosis of pleural effusion was made when evident by CT. MEASUREMENTS AND RESULTS: Pleural effusion was detected in 42 of 48 patients (88%) with AAD (mean plus minus SD age, 65 plus minus 12 years; 35 men and 13 women), but in only 1 of 7 patients (14%) who proved not to have AAD (mean age, 74 +/- 10 years; 6 men and 1 woman). Effusion appeared at a mean of 4.5 days after onset of dissection. Thoracentesis performed in six patients showed a bloody effusion in three patients and an exudative effusion in three patients. In the six AAD patients without pleural effusion, four patients underwent surgery within 3 days after onset of dissection. In patients with AAD, effusion was demonstrated on the first CT after hospital admission in 18 patients, and was bilateral in 32 patients. WBC count in blood, serum C-reactive protein concentration, and body temperature were higher in patients with effusion (13,400 +/- 3,600/microL, 18.4 +/- 11.5 mg/dL, and 38.2 +/- 0.7 degrees C) than in those without effusion (10,300 +/- 2,900/microL, 4.5 +/- 4.2 mg/dL, and 37.0 +/- 1.0 degrees C, respectively). CONCLUSIONS: Pleural effusion occurs frequently in patients with AAD, often in association with inflammatory reactions.

Torsade de pointes and sudden death induced by thiopental and isoflurane anesthesia in dogs with cardiac electrical remodeling.

BACKGROUND: Many anesthetic agents are known to have cardiac effects. The effects of pentobarbital, thiopental and isoflurane on dogs with electrical remodeling are lacking. METHODS AND RESULTS: We studied 12 dogs that underwent two anesthesias. First, anesthesia was induced (N=12) with intravenous thiopental (17 mg/kg) induction followed by isoflurane inhalation (1.5%-3% via endotracheal tube). For electrical remodeling, we created complete atrioventricular block (CAVB) and myocardial infarction (MI). In 6 of the 12 dogs we also infused nerve growth factor (NGF) to the right stellate ganglion. All dogs had an implantable cardioverter-defibrillator (ICD) implanted. A second anesthesia was done 66 +/- 20 days later. In 8 of the 12 dogs (6 without NGF), pentobarbital was used as the only anesthetic. In the remaining 4 dogs (all with NGF), 3 received thiopental and 1 received isoflurane. RESULTS: During the first anesthesia, none of 12 dogs had cardiac arrhythmia. During the second anesthesia, none of the 8 dogs that received pentobarbital developed ventricular fibrillation (VF). In contrast, all the dogs receiving either thiopental or isoflurane died of VF within 2 to 3 minutes. QT and P-P intervals before VF were 440 +/- 36 milliseconds and 298 +/- 28 milliseconds, longer and shorter (respectively) than those obtained the day prior to surgery (315 +/- 25 milliseconds, P < 0.001; 330 +/- 22 milliseconds, P < 0.01, respectively). CONCLUSION: Thiopental and isoflurane are not arrhythmogenic in normal dogs and dogs with acute MI and CAVB, but are extremely proarrhythmic in dogs with chronic MI and CAVB. Consistent with the results of in vitro studies, pentobarbital did not induce ventricular arrhythmia in dogs with cardiac electrical remodeling.

The role of approximate entropy in predicting ventricular defibrillation threshold.

BACKGROUND: The role of myocardial tissue mass on ventricular defibrillation threshold (DFT) is unclear. We hypothesized that changes in tissue mass modulate DFT by changing ventricular fibrillation (VF) wavefront regularity (entropy). METHODS AND RESULTS: The right ventricles (RV) of seven farm pigs were isolated, superfused and perfused through the right coronary artery with oxygenated Tyrode's solution at 37 degrees C. The epicardial surface was stained with the voltage sensitive dye, di-4-ANEPPS, and activation wavefront numbers (AWN) during VF were determined from the optical maps using a CCD camera (96 x 96 pixels over a 3.5 x 3.5 cm area). The RV mass was progressively reduced by sequential cutting of 1 to 2 g of tissue (approximately 12 cuts in total) distal to the perfusion site. After each cut, VF was reinduced, optical maps obtained, and the 50% probability of successful DFT(50) determined using an up-down algorithm. After each cut, the approximate entropy (ApEn) was also computed using 5 seconds of VF data obtained with a bipolar electrode and a pseudo-electrocardiogram. Tissue mass reduction of up to one third of the RV mass (ie, from 48.4 +/- 4.25 g to 34 +/- 4.7 g) caused little or no change in the DFT, ApEn or AWN. However, further progressive reduction of the RV mass near the critical mass of VF resulted in a significant (P < 0.05) progressive decrease in all three measured parameters. DFT energy was reduced by 27% (1.47 +/- 0.34 J vs. 1.02 +/- 0.14 J). There was a significant (P < 0.01) correlation between the DFT and ApEn, which significantly further increased (P < 0.001) near the critical mass. In a separate series of 6 isolated RVs, the ApEn correlated well with the Kolmogorov-Sinai (K-S) entropy, the standard method of calculating entropy. CONCLUSION: Tissue mass reduction significantly reduces DFT when the mass reduction increases VF wavefront regularity.

Downregulation of immunodetectable atrial connexin40 in a canine model of chronic left ventricular myocardial infarction: implications to atrial fibrillation.

BACKGROUND: The substrate(s) for atrial fibrillation associated with chronic left ventricular myocardial infarction remain poorly defined. Since atrial connexin40 has a rapid turnover rate and may cause atrial fibrillation, we hypothesized that chronic left ventricular myocardial infarction downregulates atrial Connexin40 and increases atrial fibrillation vulnerability. METHODS AND RESULTS: The left anterior descending coronary artery was occluded distal to the first diagonal branch in five dogs and studied 7 weeks later. Five dogs with no left anterior descending coronary artery occlusion served as control. Vulnerability to atrial fibrillation was tested by burst atrial stimulation (50 milliseconds for 3 seconds). Atrial fibrillation was induced in all myocardial infarction dogs, lasting from 20 seconds to several minutes. In contrast, only rapid repetitive activity and short-lasting atrial fibrillation (< 5 seconds) could be induced in control dogs. The mean refractory periods of epicardial RA and LA appendages were not significantly different in the two groups. Mean left ventricular myocardial infarction size was 17 +/- 4% of the left ventricle. Histologic analyses showed no signs of atrial ischemic injury or interstitial fibrosis in either group. Atrial myocyte diameter measured at the level of the nuclei of longitudinally sectioned myocytes was not significantly different in the two groups (10.1 +/- 1.2 microm vs. 10.2 +/- 1.2 microm; P = 0.3). Atrial Connexin40 (both left and right atria) in the left ventricular myocardial infarction group was highly heterogeneous and had significantly smaller total area stained than in the control (0.48 +/- 0.09% vs. 0.82 +/- 0.13%; P < 0.01). CONCLUSIONS: Chronic left ventricular myocardial infarction downregulates immunodetectable atrial Connexin40, a property that might contribute to the increased atrial fibrillation vulnerability in this model.

Prognosis of economy class syndrome treated in intensive care unit.

OBJECTIVE: The aim of this study was to clarify the prognosis of economy class syndrome (pulmonary thromboembolism following long distance flight) patients discharged from the intensive care unit. METHOD: Medications, daily activities, recurrence of pulmonary thromboembolism, and quality of life were investigated for an average of 471 days following discharge from the intensive care unit. The information from the patients was obtained by means of a mailed questionnaire or telephone interview. PATIENTS: Ten patients with economy class syndrome were enrolled in this study. Nine were female and one was male (61+/-9 years). RESULTS: In addition to appropriate acute care, additional management was given including the placement of an inferior vena cava filter in 3 patients and a course of oral anticoagulation therapy in 7 patients. None of them died or had recurrence of pulmonary thromboembolism. Four patients took subsequent air flights. No thromboembolic episodes were seen during the follow-up period. CONCLUSION: The long-term prognosis in these patients can be favorable with appropriate management of the acute episode in conjunction with adequate preventive measures.