A case of meningoencephalitis caused by multisystem inflammatory syndrome in adult SARS-CoV-2 infection

A 37-year-old woman was hospitalized with fever and consciousness disturbance. She showed systemic inflammation with stress cardiomyopathy. Brain computed tomography showed diffuse brain edema. Cerebrospinal fluid (CSF) findings revealed markedly elevated cerebrospinal fluid pressure with pleocytosis, elevated protein, and elevated interleukin 6. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nicking enzyme amplification reaction test using a nasopharyngeal swab was positive, and the patient was diagnosed with SARS-CoV-2 infection. From the negative result of the CSF SARS-CoV-2 polymerase chain reaction test and no findings of bacterial or viral infection, we diagnosed meningoencephalitis by multisystem inflammation syndrome in adults (MIS-A). Intravenous methylprednisolone pulse therapy improved her symptoms and brain edema. There have been no cases of MIS-A with meningoencephalitis, and no initial treatment strategy has been established, especially in emergency cases of suspected MIS-A. The present case suggested Early intravenous methylprednisolone pulse with anti-coronaviral therapies after the exclusion of bacterial infection would be useful in suspected MIS-A with emergent meningoencephalitis cases.

Fatal Community-Acquired Clostridioides difficile Infection as a Cause of Listeria Meningitis: A Case Report

A 77-year-old woman with a history of total gastrectomy was transferred to our hospital with complaints of fever and consciousness disturbance for five days. She had fever and consciousness disturbance with positive meningeal signs. Laboratory findings indicated an elevated inflammatory response and hypoalbuminemia, and computed tomography (CT) of the body indicated intestinal gas retention and mild ascites. Cerebrospinal fluid analysis revealed pleocytosis with elevated protein levels and a diagnosis of Listeria meningitis was made. Treatment with ampicillin/sulbactam was started, and her fever and consciousness disturbance resolved on day 2. However, on day 3, her fever and conscious disturbance deteriorated, and she went into shock subsequently. Laboratory findings revealed deteriorated inflammatory response and hypoalbuminemia. Body CT showed an obvious distended bowel loop and intestinal edema. A stool culture revealed positive Clostridioides difficile toxin B, and we diagnosed her with Clostridioides difficile infection (CDI). Although intravenous metronidazole was initiated, she died due to prolonged hypovolemic shock. We considered she had community-acquired CDI because her CDI emerged immediately after the initiation of antibiotics, symptom deterioration within 48 hours of admission, and abnormal abdominal CT findings at admission. Listeria meningitis can develop based on community-acquired CDI. Because CDI can have a very rapid and fatal course and is sometimes complicated by other infectious diseases, clinicians should pay attention to this complication.

Successful Recanalization by Intravenous Thrombolysis in a Patient With Calcified Cerebral Emboli With Major Vessel Occlusion: A Case Report

A 69-year-old man, with a history of left superficial temporal artery-middle cerebral artery bypass due to cerebral infarction by left internal carotid artery occlusion, was hospitalized with acute right hemispatial neglect and left hemiparesis. Diffusion-weighted imaging showed a high-intensity lesion in the right insular cortex. Although there seemed to be no arterial occlusion in magnetic resonance angiography (MRA), non-contrast computed tomography (CT) on admission showed calcification in the right Sylvian fissure. As hyperacute ischemic stroke within 4.5 hours after onset, we used an intravenous recombinant tissue plasminogen activator, and his symptoms improved. Follow-up MRA revealed recanalization of the right M2 branches with distal migration of calcification. Although calcification was identified on non-contrast CT in the initial assessment, the diagnosis of middle cerebral artery occlusion was missed. Therefore, arterial occlusion should be considered when calcification is observed in the brain sulcus. This case also illustrated that intravenous thrombolysis may be effective even in calcified cerebral emboli with major vessel occlusion.

Enteral tube nutrition for geriatric post-stroke dysphagia evaluation (ENGE) score to evaluate the risk of dysphagia after acute ischemic stroke

BACKGROUND

Post-stroke dysphagia (PSD) is a common complication after stroke. Early PSD prediction is essential for patient stratification for intensive oral intake rehabilitation. We aimed to develop a PSD prediction score using clinical data obtained at admission.

METHODS

We examined consecutive patients with acute ischemic stroke between 2018 and 2019. The dysphagia status 14 days after admission was assessed using the Functional Oral Intake Scale (FOIS). PSD was defined as FOIS 1-3, which represents tube-dependent nutrition. Using multivariable logistic regression analysis, we constructed the Enteral tube Nutrition for Geriatric post-stroke dysphagia Evaluation (ENGE) score. The discriminative performance of the ENGE score was analyzed by receiver operating curve analysis. The reproducibility of the ENGE score was validated using patient data in 2020.

RESULTS

PSD developed in 84 of 488 patients (median age 78 years; 57% males). The ENGE score ranged from 0 to 6, with 1 point assigned for older age (≥78 years), 1 for high premorbid modified Rankin Scale (mRS) (≥1), 3 for high NIHSS score (≥12), and 1 for low serum albumin (<3.0 mg/dl). The area under the curve (AUC) of the ENGE score for discriminating PSD was 0.88 (95% confidence interval [CI] 0.83-0.92), and a score of 3 or more had a higher positive likelihood ratio. In the validation cohort, the AUC of the ENGE score for PSD was 0.85 (95% CI 0.78-0.91), which was similar to the derivation cohort (p = 0.491).

CONCLUSIONS

The ENGE score predicts severe PSD after acute ischemic stroke with good reproducibility.

Harboring Cnm-expressing Streptococcus mutans in the oral cavity relates to both deep and lobar cerebral microbleeds

BACKGROUND

Cerebral microbleeds (CMBs) influence long-term prognoses of stroke patients. Streptococcus mutans expressing the collagen-binding protein Cnm induces cerebrovascular inflammation, impairing blood brain barrier integrity and causing cerebral bleeding. Here, we examine the association of Cnm-positive S. mutans with CMBs.

METHODS

Acute stroke patients were selected from a single-center registry database. Oral carriage of Cnm-positive or Cnm-negative S. mutans was determined using polymerase chain reaction assays. The associations of Cnm-positive S. mutans with CMB number and specifically the presence of >10 CMBs were examined using quasi-Poisson and logistic regression models, respectively.

RESULTS

This study included 3154 stroke patients, of which 428 patients (median [interquartile range] age, 73.0 [63.0-81.0] years; 269 men [62.9%]) underwent oral bacterial examinations. In total, 326 patients harbored S. mutans. After excluding four patients without imaging data, we compared patients with Cnm-positive (n = 72) and Cnm-negative (n = 250) S. mutans. Harboring Cnm-positive S. mutans was independently associated with the presence of >10 CMBs (adjusted odds ratio 2.20 [1.18-4.10]) and higher numbers of deep and lobar CMBs (adjusted risk ratio 1.61 [1.14-2.27] for deep; 5.14 [2.78-9.51] for lobar), but not infratentorial CMBs, after adjusting for age, sex, hypertension, stroke type, National Institutes of Health Stroke Scale score, and cerebral amyloid angiopathy.

CONCLUSIONS

Harboring Cnm-positive S. mutans was independently associated with a higher number of CMBs in deep and lobar locations. Reducing Cnm-positive S. mutans in the oral cavity may serve as a novel therapeutic approach for stroke.

Eustachian Valve-Enhanced Paradoxical Cerebral Embolism: A Case Report

Cryptogenic stroke includes many suspicious embolic causes that do not fulfill the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification criteria. Atrial fibrillation (AF) is one of the major hidden causes of cryptogenic stroke, and an implantable loop recorder (ILR) is widely used for detecting AF. Herein, we report a case of paradoxical cerebral embolism due to a large Eustachian valve with large PFO under no molecular complete remission (CR) of acute monocytic leukemia (AMoL). A 75-year-old man arrived at our emergency room because of aphasia and right hemiparesis. He had a history of two cryptogenic strokes and implanted ILR. Magnetic resonance imaging showed left middle cerebral artery occlusion with slight acute ischemic lesion. The red clot was retrieved by mechanical thrombectomy, and complete recanalization was achieved. We checked ILR, but there was no AF. Transesophageal echocardiography revealed a large patent foramen ovale (PFO) and the large Eustachian valve in the right atrium. Although obvious deep vein thrombosis (DVT) was not detected in venous ultrasonography of the lower extremities, Wilms' tumor 1 messenger ribonucleic acid (WT1mRNA) expression level was high, and AMoL was considered to be not in molecular CR, suggesting a high risk of thrombosis to the large Eustachian valve. From large PFO and no molecular CR of AMoL, we diagnosed him with paradoxical cerebral embolism. Ruling out of AF by ILR and other etiologies, such as aortic or carotid atherosclerosis and pulmonary shunt, also supported the diagnosis of paradoxical cerebral embolism. Even in the absence of obvious DVT, paradoxical cerebral embolism should be considered in cases of a large Eustachian valve and PFO with a hypercoagulable state.

Geriatric nutrition risk index predicts prolonged post-stroke dysphagia in acute ischemic stroke

BACKGROUND

Post-stroke dysphagia (PSD) is a common complication after stroke. Malnutrition inhibits stroke recovery and is associated with stroke mortality. However, no studies have investigated the effects of nutritional state at admission on prolonged PSD.

METHODS

We retrospectively analyzed ischemic stroke patients in our institute from January 2018 to December 2020. Swallowing function was assessed using the Food Oral Intake Scale; prolonged PSD was defined as levels 1-3 at 14 days after admission. The Geriatric Nutritional Risk Index (GNRI) was used to assess nutritional risks, which were classified as follows: >98, no nutritional risk; 92-98, mild nutritional risk; 82-92, moderate nutritional risk; and <82, severe nutritional risk. The association between GNRI and prolonged PSD was assessed.

RESULTS

Of 580 patients (median age, 81 years; male, 53%), prolonged PSD was detected in 117 patients. Patients with severe dysphagia had older age, higher pre-stroke modified Rankin Scale score, lower GNRI, and higher National Institutes of Health Stroke Scale score. Logistic regression analysis revealed that lower GNRI was independently associated with prolonged PSD (continuous value; adjusted odds ratio [OR] 1.03, 95% confidence interval [CI] 1.00-1.05). In addition, when "severe" and "moderate" nutritional risk was analyzed as a single class, moderate or severe nutritional risk (GNRI < 92) was independently associated with prolonged PSD (adjusted OR 2.50, 95% CI 1.29-4.87), compared with no nutritional risk patients (GNRI > 98).

CONCLUSIONS

In acute ischemic stroke, lower GNRI at admission was independently associated with prolonged PSD, suggesting that GNRI at admission might identify patients at risk of prolonged PSD.

P-wave terminal force in lead V1 and atrial fibrillation burden in cryptogenic stroke with implantable loop recorders

Implantable loop recorders (ILRs) are useful for the detection of atrial fibrillation (AF) in patients with cryptogenic stroke (CS). P-wave terminal force in lead V₁ (PTFV₁) is associated with AF detection; however, data on the association between PTFV₁ and AF detection using ILRs in patients with CS are limited. Consecutive patients with CS with implanted ILRs from September 2016 to September 2020 at eight hospitals in Japan were studied. PTFV₁ was calculated by 12-lead ECG before ILRs implantation. An abnormal PTFV₁ was defined as ≥ 4.0 mV × ms. The AF burden was calculated as a proportion based on the duration of AF to the total monitoring period. The outcomes included AF detection and large AF burden, which was defined as ≥ 0.5% of the overall AF burden. Of 321 patients (median age, 71 years; male, 62%), AF was detected in 106 patients (33%) during the median follow-up period of 636 days (interquartile range [IQR], 436-860 days). The median time from ILRs implantation to AF detection was 73 days (IQR, 14-299 days). An abnormal PTFV₁ was independently associated with AF detection (adjusted hazard ratio, 1.71; 95% confidence interval [CI], 1.00-2.90). An abnormal PTFV₁ was also independently associated with a large AF burden (adjusted odds ratio, 4.70; 95% CI, 2.50-8.80). In patients with CS with implanted ILRs, an abnormal PTFV₁ is associated with both AF detection and a large AF burden.Clinical Trial Registration Information: UMIN Clinical Trials Registry 000044366.

A Case Report of Deep Cerebral Venous Thrombosis Presenting Unilateral Lesion: The Association of Asymmetric Venous Outflow and Unilateral Lesion

A 60-year-old man was admitted to our hospital due to progressive aphasia and right hemiparesis. Brain magnetic resonance imaging showed the left thalamus and basal ganglia lesion. Digital subtraction angiography showed the vein of Galen and straight sinus occlusion, suggesting cerebral venous thrombosis. Since his left transverse sinus was hypoplastic, his left deep cerebral lesion was due to the left deep cerebral vein congestion by the asymmetrical venous outflow. After anticoagulant therapy, his symptom and unilateral lesion improved. Clinicians should consider the vein of Galen and straight sinus thrombosis even in unilateral deep cerebral lesions.

Abstract WP102: Side-to-side Relative Reduction In End-diastolic Velocity Of The Common Carotid Artery For Emergent Discrimination Of Anterior Circulation Large Vessel Occlusion

Introduction: Side-to-side relative reduction in end-diastolic velocity (EDV) of the common carotid artery (CCA) may discriminate ipsilateral anterior circulation large vessel occlusion (LVO), which will contribute faster patient triage for reperfusion therapy. We evaluated the discriminative accuracy of this simple sonographic index for anterior circulation LVO in acute stroke population, including intracerebral hemorrhage (ICH).

Methods: Among patients with acute stroke admitted to our institute between 2016-2018, those who underwent both carotid ultrasonography and head MRA or CTA within 24 hours after last known normal time were reviewed. Relative EDV reduction was calculated as a ratio by dividing the CCA EDV lower side by the EDV higher side. Anterior circulation LVO was defined as occlusion of the internal carotid artery (ICA) or M1 segment of the middle cerebral artery on the lower EDV side. Discriminative performance of relative EDV reduction for anterior circulation LVO was assessed by receiver operating characteristics analysis.

Results: A total of 688 patients (411 males; median age 77 years; 87 with anterior circulation LVO) were analyzed. When compared to no occlusion, value of relative EDV reduction was remarkably lower in ICA occlusion, followed by that in M1 occlusion (Figure). Area under the curve (AUC) of relative EDV reduction for ICA occlusion was 0.96 (95% confidence interval [CI] 0.94-0.99) with an appropriate cut-off value of 0.50 (sensitivity 94%, specificity 94%). When the discrimination target was set to anterior circulation LVO, the AUC was 0.78 (95% CI 0.72-0.85) with an appropriate cut-off value of 0.67 (sensitivity 69%, specificity 83%). At this cut-point, 51% of patients with M1 occlusion was classified as false negative.

Conclusions: The discriminative performance of the relative CCA EDV reduction in acute stroke population was excellent for ICA occlusion and acceptable for anterior circulation LVO.

Abstract WP191: Post Stroke Dysphagia Prediction Score In Acute Ischemic Stroke In Japan

Background and Purpose: Post stroke dysphagia (PSD) is a common complication after stroke. The earlier prediction of PSD is essential for patient stratification for intensive rehabilitation, but there was no scoring system for predicting PSD. We aimed to develop the PSD prediction score.

Methods: We examined consecutive patients with acute ischemic stroke between 2018-2020. Patients with in-hospital-death were excluded. Dysphagia state was assessed using food oral intake scale (FOIS) score at hospital discharge. PSD was defined as FOIS 1-3, which represent tube-dependent nutrition. For the assessment of reproducibility of PSD score, patients were divided into derivation and validation cohort. Using the derivation cohort, PSD score was developed from associated factors to discriminate PSD by logistic regression analysis. Discriminative performance was analyzed by receiver operating curve (ROC) analysis. Reproducibility of PSD score was validated using the validation cohort.

Results: Among 795 patients (median 77 years; male, 57%), 556 (70%) patients were assigned as derivation cohort and 239 (30%) patients were assigned as validation cohort. In the derivation cohort, older age (≥85 years), low BMI (≦18.5 kg/m 2 for aged <70 years and ≦ 20 kg/m 2 for aged ≥70 years), high NIHSS score (≥16), and low serum albumin (≦3.0 mg/dl) were associated with PSD (Table). PSD score were ranged from 0 to 6 from these factors (Table). Area under the curve (AUC) of PSD score for PSD was 0.83 (95% confidence interval [CI] 0.78-0.88) with an appropriate cut-off value of 2 (sensitivity, 69%; specificity, 88%). In the validation cohort, the AUC of PSD score for PSD was 0.78 (95% CI 0.70-0.86), which was not significantly different in the AUC of the derivation cohort (AUC; 0.83 vs 0.78, p=0.30).

Conclusions: In acute ischemic stroke population, the discriminative performance of PSD score had acceptable for diagnosing PSD.

Sequential detection rates of intramural hematoma for diagnosing spontaneous intracranial artery dissection

BACKGROUND AND PURPOSE

Spontaneous intracranial artery dissection (IAD) can be definitively diagnosed by detecting intramural hematoma (IMH) on arterial wall imaging. However, evidence of a time-dependent natural history for the development of radiological findings is lacking. Therefore, this study aimed to determine when imaging detects IAD.

METHODS

We obtained data from our cohort databases between March 2011 and August 2018 on consecutive patients who had definite, probable, or possible IAD based on the multidisciplinary expert consensus criteria. We assessed IMH on initial and follow-up high-resolution three-dimensional T1-weighted imaging (HR-3D-T1WI). We retrospectively investigated the association between IMH detection and days from symptom onset to initial HR-3D-T1WI and compared the IMH detection rate with other definitive diagnostic arterial dissection findings.

RESULTS

We analyzed 106 patients (mean age = 51 ± 13 years, 31 women) with at least initial HR-3D-T1WI data. The final diagnoses were definite, probable, and possible IAD in 83, 18, and 5 patients, respectively. IMHs were observed in 63 patients (59%, 95% confidence interval [CI] = 49%-69%). Overall IMH detection rate was 55% (95% CI = 45%-64%), 20% (95% CI = 3%-60%), 40% (95% CI = 21%-64%), and 50% (95% CI = 37%-63%) on the initial HR-3D-T1WI and Days 3, 7, and 13, respectively. Among 68 patients evaluated with digital subtraction angiography and HR-3D-T1WI, IMH was confirmed more frequently than other definitive diagnostic arterial dissection findings.

CONCLUSIONS

The overall IMH detection rate on HR-3D-T1WI was >50% and peaked in 1-2 weeks. IMH was a frequently detectable finding for the diagnosis of IAD compared to other radiological findings.

Uremic Encephalopathy Presenting with Unilateral Destructive Leukoencephalopathy Successfully Treated with Hemodialysis

An 81-year-old woman was hospitalized with progressive consciousness disturbance. Blood tests showed acidemia with severe renal dysfunction, and a cerebral spinal fluid (CSF) test showed pleocytosis with myelin basic protein (MBP) elevation. Brain magnetic resonance imaging showed unilaterally dominant subcortical white matter lesions with lentiform fork sign on T2-weighted imaging. After initiating hemodialysis, her consciousness disturbance and white matter lesions improved, suggesting uremic encephalopathy (UE). Unilaterally dominant leukoencephalopathy and high pleocytosis with MBP elevation in CSF are less common than previously identified characteristics of UE. When unilateral leukoencephalopathy occurs in patients with renal failure, UE should be considered.

Abstract WMP71: Sequential Detection Rates Of Intramural Hematoma For Diagnosing Spontaneous Intracranial Artery Dissection

Introduction: Spontaneous intracranial artery dissection (IAD) can be diagnosed with the detection of intramural hematoma (IMH). We previously reported that high-resolution 3-dimensional T1-weighted magnetic resonance imaging (HR-3D-T1WI) is useful to detect IMH. Limited evidence is available regarding sequential detection rates of IMH and appropriate timing of the detection.

Methods: We retrieved data on consecutive patients from our prospective cohort databases from March 2011 to August 2018 who had definite, probable, or possible IAD based on the multidisciplinary expert consensus criteria. We detected IMH on initial and follow-up HR-3D-T1WI. We explored the association between detection of IMH and days from symptom onset to initial or follow-up HR-3D-T1WI.

Results: A total of 104 patients (mean age 51 ± 13; 30 female; 68 patients, definite IAD; 31 patients; probable IAD, 5 patients; possible IAD) with at least initial HR-3D-T1WI data were included in the analysis. Clinical diagnoses included ischemic stroke (46%), subarachnoid hemorrhage (6%), transient ischemic attack (2%), and head or neck pain alone (46%). Age, Sex, vascular risk factors and modified Rankin Scale at 3 months were comparable between patients with IMH and without. Among them, follow-up HR-3D-T1WI was performed in 54 patients (52%). IMH was observed in 61 patients, 59% of all and 90% of definite IAD. The median days from symptom onset to initial or follow-up HR-3D-T1WI were 11 (interquartile range[IQR] 8–15) and 29 (IQR 19–57) days, respectively. The median days from symptom onset to first IMH detection were 12 (IQR range 8–17). The detection rate of IMH on initial HR-3D-T1WI was 55% overall, reaching 20% on day 3, 40% on day 7, and 50% on day 8–12 ( Figure ). Of the 23 patients who did not have an IMH on the initial HR-3D-T1WI, 4 (17%) had an IMH detected on the follow-up imaging.

Conclusion: The detection rate of IMH on HR-3D-T1WI was approximately 60%, which reached the maximum in 1-2 weeks.

Abstract TP217: Potential Utility Of Magnetocardiogram For Patients With Embolic Stroke Of Undetermined Source

Background: The magnetocardiogram (MCG) is a promising medical tool for detecting and visualizing abnormal cardiac electrical activation in cardiovascular disease patients. MCG has higher spatial resolution than the electrocardiogram (ECG) because the magnetic field is not distorted by flow through tissues. Taking advantage of these features, MCG has been applied for studying arrhythmia, such as atrial fibrillation (AF) and long-QT syndrome. Paroxysmal AF is the most common sources of thromboembolism for ESUS. Since factors that reflect left atrial overload (LAO) are independent predictors of paroxysmal AF, evaluation of these factors in ESUS patients is essential to improve their prognosis. We aimed to investigate the potential utility of MCG in ESUS patients for evaluation of the factors that reflect LAO.

Methods: ESUS patients who underwent MCG (MC-6400 MCG system with 64 magnetic sensors) in our hospital were enrolled between September 2018 and July 2021. The peak P-wave magnitude of the right atrium segment and the left atrium segment on the MCG (MCG-RA, MCG-LA) were measured. Subsequently, the ratio of peak magnitude of the LA segment to that of the RA segment (MCG-LA/RA) was used to evaluate LAO. Other factors that reflect LAO, such as PAC frequency on Holter monitoring, LAD in transthoracic echocardiography (TTE), serum level of brain natriuretic peptide, left ventricular ejection fraction (LVEF) in TTE, and P-wave terminal force in lead V1 (PTFV1) on ECG were also evaluated.

Results: Fifty-two ESUS patients with a mean age of 67.9±14.3 years (females, 42%) were included. The mean MCV-RA and MCG-LA were 7.70±12.82 and 4.50±7.74 pico-Tesla, respectively. The mean MCG-LA/RA was 0.66±0.31. The MCG-LA/RA was significantly correlated with the PAC frequency (r=0.293, p=0.039), although either MCG-RA or MCG-LA was not correlated. Also, the MCG-LA/RA ratio was significantly correlated with LAD (r=0.301, p=0.03) but not with brain natriuretic peptide (r= 0.25, p= 0.09), LVEF (r= -0.06, p= 0.654), or PTFV1 (r= 0.02, p=0.91).

Conclusion: This is the first study that evaluated the relationship of the MCG-LA/RA ratio with factors that reflect LAO in ESUS patients. These results suggest that the MCG-LA/RA ratio is a novel biomarker for LAO in ESUS patients.

Postprandial cerebral infarction

Some neurological diseases are accompanied by autonomic dysfunction. Postprandial hypotension (PPH) is one disorder accompanied by autonomic dysfunction. Although the major symptoms of PPH are fall and syncope, PPH is sometimes overlooked because of its non-specific symptoms, such as dizziness, nausea, and light-headedness. Because PPH could result in decreased cerebral perfusion pressure accompanied by a decrease in blood pressure, PPH may be linked to the risk of hemodynamic stroke or transient ischemic events, especially in patients with chronic cerebral large vessel occlusion/stenosis. Whether chronic cerebral large vessel occlusion or stenosis causes symptomatic ischemic events depends on the patient's compensatory collateral circulation and cerebral vasoreactivity. Therefore, we hypothesized that cerebral blood flow assessment could be essential for stratifying patients at high risk of postprandial cerebral infarction. However, there have been few reports on the association between cerebral blood flow and the occurrence of postprandial cerebral infarction. In a literature review, we identified seven cases of postprandial cerebral infarction. Postprandial cerebral infarction occurs in patients with chronic cerebral large vessel occlusion/stenosis accompanied by cerebral blood flow reduction. Non-pharmacotherapeutic and pharmacotherapeutic approaches could improve postprandial cerebral infarction; however, one patient with poor compensatory collateral circulation and reduced cerebral vasoreactivity experienced recurrent symptomatic episodes even with sufficient medical treatment and needed extracranial-intracranial bypass surgery. Physicians should be aware of PPH as it can complicate neurological disorders. Long-term blood pressure monitoring for the detection of PPH and cerebral blood flow assessment is needed in patients with cerebral large vessel occlusion/stenosis to prevent postprandial cerebral infarction.

Left Ventricular Abnormality and Covert Atrial Fibrillation in Embolic Stroke of Undetermined Source

Aims: The relationship between left ventricular (LV) function and AF detection in embolic stroke of undetermined source (ESUS) patients with insertable cardiac monitors (ICMs) remains unclear. We investigated the association between LV function and AF detection in patients with ESUS after ICMs implantation.

Methods: We enrolled patients with ESUS who underwent ICMs implantation from September 2016 to September 2020 using a single-center, prospective registry. LV systolic and diastolic functions were assessed on precordial echocardiography by LV fractional shortening (LVFS) and average E/e’, respectively. Associations between characteristics of LV function and detection of AF by ICMs were analyzed.

Results: Participants comprised 101 patients (median age, 74 years; male, 62%). During a median follow-up period of 442 days (interquartile range (IQR), 202–770 days), AF was detected in 24 patients (24%). Median duration from ICMs implantation to AF detection was 71 days (IQR, 13–150 days). When LVFS and E/e’ were dichotomized by cutoff value, each of low LVFS (＜35.5%; adjusted hazard ratio (HR), 4.77; 95% confidence interval (CI), 1.77–12.9) and high E/e’ (≥ 8.65; adjusted HR, 4.56; 95%CI, 1.17–17.7) were independently associated with AF detection after adjusting for age and sex. When patients were divided into four groups according to dichotomized LVFS and E/e’, the combination of low LVFS and high E/e’ was independently associated with AF.

Conclusions: In patients with ESUS after ICMs implantation, the LV characteristics of low LVFS and high E/e’ were associated with AF detection.

Abstract P715: Vertebral Artery Occlusive Dissection Score in Acute Ischemic Stroke

Background and purpose: The discrimination of vertebral artery (VA) occlusive dissection from other etiologies is critical for acute stroke management but sometimes difficult. We aimed to assess the factors associated with VA occlusive dissection and develop the discrimination score.

Methods: We examined consecutive patients with acute posterior ischemic stroke due to unilateral VA occlusion from our prospective stroke registry between 2012 and 2019. Unilateral VA occlusion was confirmed by magnetic resonance angiography and cervical ultrasonography. The diagnosis of VA dissection was based on the magnetic resonance imaging or digital subtraction angiography. Dissection score was developed from associated factors to discriminate VA occlusive dissection by logistic regression analysis. Discriminative performance was analyzed by receiver operating curve (ROC) analysis.

Results: Consecutive 84 patients (70±13 years; male, 77%) involved 16 (19%) with VA occlusive dissection. On logistic regression analysis, each of younger age ( ≤ 70 years), absence of hypertension, absence of dyslipidemia, head or neck pain, medullary infarction and non-dominance side VA occlusion were significantly associated with VA occlusive dissection (Table). Dissection score was created with these factors by assigning respective points based on the corresponding regression coefficients, and the score were ranged from 0 to 9 (Table). High discriminative performance for VA occlusive dissection was observed (area under the curve: 0.91) and optimal cut-off value was 5 or more (accuracy, 79%; sensitivity, 94%; specificity, 75%).

Conclusions: In patients with acute posterior ischemic stroke due to unilateral VA occlusion, dissection score had high discriminative performance for diagnosing VA dissection.

Abstract P9: Mid-Regional Pro-Adrenomedullin as a Novel Biomarker of Transient Ischemic Attack

Background: Transient ischemic attack (TIA) is often a warning sign for ischemic stroke within a couple of months and should be treated as an emergency disease. However, the symptoms often disappear within a few hours, making the diagnosis of TIA difficult. The peptide hormone adrenomedullin (AM) increases during the acute phase of ischemic stroke because AM is produced by vascular endothelial cells as a biological defense mechanism against hypoxia and oxidative stress during cerebral ischemia. Therefore, we hypothesized that the blood levels of mid-regional pro-adrenomedullin (MR-pro-AM), half-life of which is several hours and much longer than AM, in patients with TIA could be a useful biomarker for the diagnosis of TIA.

Method: We retrospectively compared the blood levels of MR-pro-AM using stored peripheral blood samples of the TIA cohort within 14 days from onset in the National Cerebral and Cardiovascular Center from April 1, 2016 to March 30, 2019, and those of the population-based cohort of the Kyoto Prefectural University of Medicine.

Results: The TIA cohort (n = 39) was significantly older (73 vs. 58 years old) and showed higher frequency of cerebrovascular risk factors and higher levels of MR-pro-AM (0.584 vs. 0.418 nmol/l) than the population-based cohort (n = 1298). The MR-pro-AM level was significantly associated with TIA: odds ratio (OR) per 0.1 nmol/l MR-pro-AM increment was 2.8 (95% confidence interval (CI) = 2.2-3.6) in univariable analysis and 1.5 (95% CI = 1.1-2.1) in multivariable analysis with sex, age, chronic kidney disease and cerebrovascular risk factors as covariates. The cutoff value of MR-pro-AM was 0.523 nmol/l based on receiver operating characteristic curve analysis for TIA, with a sensitivity of 69% and a specificity of 88% (area under the curve = 0.78). Moreover, the model with the blood level of MR-pro-AM in addition to the prediction model the ABCD 2 score predicted TIA more accurately (net reclassification improvement = 1.14, p < 0.001). The MR-pro-AM level was found significantly higher in the TIA cohort than the population-based cohort after propensity score-matching (0.665 vs. 0.525 nmol/l, p = 0.047).

Conclusion: MR-pro-AM may be a promising diagnostic biomarker for TIA.

Oral Carriage of Streptococcus mutans Harboring the cnm Gene Relates to an Increased Incidence of Cerebral Microbleeds

Supplemental Digital Content is available in the text.

Cerebral microbleeds (CMB) are associated with stroke and cognitive impairment. We previously reported a high prevalence of CMB in people with Streptococcus mutans expressing Cnm, a collagen-binding protein in the oral cavity. S.mutans is a major pathogen responsible for dental caries. Repeated challenge with S.mutans harboring the cnm gene encoding Cnm induced cerebral bleeding in stroke-prone spontaneously hypertensive rats. The purpose of this longitudinal study is to examine the relationship of cnm-positive S.mutans to the development of CMB.

Postprandial cerebral infarction resolved by extracranial-intracranial bypass surgery

A 51-year-old man with type 2 diabetes mellitus was admitted with a 2-month history of repeated episodes of transient aphasia and right hemiparesis after food intake. His blood pressure (BP) fell when the neurological deficits developed. The fall in BP after each meal was confirmed by 24-h ambulatory blood pressure monitoring (ABPM), which established the diagnosis of postprandial hypotension (PPH). Diffusion-weighted magnetic resonance imaging of the brain showed multiple high-intensity lesions at the borderzone between the anterior and middle cerebral artery (MCA) territories in the left hemisphere. Digital subtraction angiography showed tapered occlusion at the origin of the left internal carotid artery (ICA). Despite sufficient antiplatelet therapy and medication for PPH, the transient symptoms remained. Positron emission tomography scanning using H₂¹⁵O showed decreased cerebral blood flow with increased oxygen extraction fraction in the left MCA territory. As the symptomatic left ICA occlusion was intractable, an extracranial-intracranial (EC-IC) bypass surgery was conducted without any perioperative complications. Although PPH remained, cerebrovascular ischemic events including repeated transient ischemic attack disappeared for 2 months after surgery. The coincidence of stroke with ABPM-proved transient hypotension suggested that the brain infarcts were caused by hemodynamic changes related to PPH co-existent with the chronic left ICA occlusion. ABPM is useful in evaluating hemodynamic infarcts associated with BP fluctuation, and should be considered for patients with chronic ICA occlusion. In addition, EC-IC bypass may be a treatment option for symptomatic chronic ICA occlusion due to PPH.

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This case illustrates recurrent hemodynamic ischemic stroke caused by internal carotid artery occlusion with postprandial hypotension.

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Ambulatory blood pressure monitoring is useful in evaluating hemodynamic infarcts associated with blood pressure fluctuation.

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Extracranial-intracranial bypass is an option for cases with symptomatic chronic internal carotid artery occlusion due to postprandial hypotension.

Bilateral carotid artery dissection due to Eagle syndrome in a patient with vascular Ehlers-Danlos syndrome: a case report

BACKGROUND

Patients with vascular Ehlers-Danlos syndrome (EDS) occasionally suffer from arterial dissection. Eagle syndrome, which is caused by an elongated styloid process and also causes arterial dissection, is difficult to diagnose and could sometimes be overlooked. Little is known of the coexistence of these two diseases, and treatment strategy is not established. Here, we present a case of bilateral internal carotid artery (ICA) dissection due to Eagle syndrome in a patient with vascular EDS.

CASE PRESENTATION

A 30-year-old man was admitted to our hospital because of sudden onset of mild sensory disturbance in his left limbs. He had a history of Ehlers-Danlos syndrome (EDS) and also had left cervical internal carotid artery (ICA) dissection 3 years before. Diffusion-weighted imaging showed acute cerebral infarcts in the right hemisphere. Cervical computed tomography angiography (CTA) revealed the right ICA narrowing at the cervical portion in addition to the previous left cervical ICA dissection. Cervical magnetic resonance imaging (MRI) revealed double-lumen and intramural hematoma at the narrowing portion of the right cervical ICA, which indicates arterial dissection. CT also revealed bilateral elongated styloid processes which are close to each side of cervical ICA. We diagnosed him as bilateral ICA dissection due to bilateral Eagle syndrome. Considering vascular complications due to vascular EDS, we performed closer follow-up with transoral carotid ultrasonography (TOCU). In 4 months, his right ICA dissection gradually improved without stroke recurrence or deterioration of dissection.

CONCLUSIONS

Since patients with vascular EDS easily develop arterial dissection, Eagle syndrome may be overlooked. Clinicians should consider Eagle syndrome in the case of vascular EDS with extracranial ICA dissection and close follow-up should be prioritized in cases of Eagle syndrome with vascular EDS.

Abstract TP331: The Effect of Intradialytic Blood Pressure Variability Prior to Intracerebral Hemorrhage on Outcomes

Introduction: Increased blood pressure variability (BPV) during chronic hemodialysis (HD) is associated with cardiovascular event and all-cause mortality. However, it is largely unknown whether pre-admission intradialytic BPV affects functional outcomes in patients with acute intracerebral hemorrhage (ICH).

Methods: We examined consecutive patients with acute spontaneous ICH who had received HD from our prospective stroke registry between January 2012 and March 2019. Patients with premorbid modified Rankin Scale (mRS) score of 5 and patients who could not be obtained either pre-admission or post-admission blood pressure were excluded from the study. Pre-admission intradialytic BPV was quantified by systolic blood pressure successive variation (SBP-SV) from the last pre-admission dialysis record prior to ICH. Post-admission BPV during initial 24 hours was also quantified using SBP-SV. The clinical outcomes were hematoma expansion and unfavorable outcome at 3-months (mRS score of 5 to 6).

Results: Of 54 ICH patients who had received HD, 45 patients were analyzed (median age, 68 years; male, 64%; non-lobar ICH, 93 %).Unfavorable outcome was observed in 26 (58%) patients.Increased pre-admission intradialytic SBP-SV was associated with only post-admission SBP-SV, but not associated with National Institute of Health Stroke Scale (NIHSS) score, hematoma volume, or hematoma expansion.In univariate analysis, both of pre- and post-admission SBP-SV were associated with unfavorable outcome. In analysis adjusting for age, NIHSS score, and hematoma volume, pre-admission SBP-SV (per SD; odds ratio, 3.70; 95% confidence interval, 1.01-13.6) was associated with unfavorable outcome, while post-admission SBP-SV was not independently associated with unfavorable outcome.

Conclusions: In ICH patients who had received chronic HD, pre-admission intradialytic BPV was independently associated with unfavorable outcome after ICH, suggesting that BP control during HD may be a therapeutic target for avoiding further neurological aggravation even once ICH has occurred.

Abstract WMP100: Excessive Blood Pressure Reduction Increases the Risk of Acute Kidney Injury After Intracerebral Hemorrhage

Background: Elevated blood pressure (BP) in the first 24 hours of admission of acute intracerebral hemorrhage (ICH) has been the focus of intensive therapeutic investigation, although early intensive BP lowering addresses a concern about development of acute kidney injury (AKI). However, it is unclear as to the effect of BP measure including the absolute BP reduction and increased BP variability on AKI in patients with acute ICH.

Methods: We retrieved data of consecutive patients with acute ICH from our prospective stroke registry between July 2015 and August 2017. We excluded patients with preexisting end-stage renal disease or in-hospital death within 24 hours. The primary outcome was AKI within 7days after admission defined using the AKI Network criteria. We recorded BP on emergency department arrival and for every 1 hour from 1 to 24 hours after admission (25 measurements). We measured mean systolic BP (SBP) and maximum minus minimum SBP within both 12 hours and 24 hours, and also quantified SBP variabilities (SBPV) including standard deviation, coefficient of variation, successive variation, and average real variability.

Results: Among 361 patients with ICH (age 72.7±12.8, male 55%, non-lobar 76%), 31 (9%) developed AKI. For all SBP measure, the 12-hour SBP reduction was associated with the increased risk of AKI in multivariable analysis (odds ratio [per10 mmHg increase] 1.30; 95% CI 1.10-1.35). There was no significant association between the SBP variability and risk of AKI. The area under the receiver operating characteristic curve of the 12-hour SBP reduction for predicting AKI was 0.75. The association between the 12-hour SBP reduction and AKI was not modified by preexisting chronic kidney disease (interaction P=0.40).

Conclusion: Early BP reduction in the first 12 hours of admission contributed to the risk of AKI in acute ICH. This may have clinical implication to avoid excess absolute BP reduction in patients with acute ICH.

Abstract 157: High Systolic Blood Pressure Variability After Successful Reperfusion Therapy in Acute Ischemic Stroke Predicts Unfavorable Outcomes

Introduction: There has been increasing evidence that higher systolic blood pressure variability (SBPV) is related to unfavorable outcomes in patients with stroke. We explored the relation between SBPV and clinical outcomes after reperfusion therapy; intravenous thrombolysis (IVT) and endovascular therapy (EVT).

Methods: We retrieved data of consecutive patients with acute ischemic stroke (AIS) treated with reperfusion therapy from our prospective stroke registry between October 2005 and December 2018. We calculated the following five SBPV during 24 hours after IVT or EVT; mean, standard deviation (SD), coefficient of variation (CV), successive variation (SV), and average real variability (ARV). Clinical outcomes included unfavorable outcomes as modified Rankin Scale (mRS) score 3-6 at 3 months and symptomatic intracranial hemorrhage (sICH) as any hemorrhage with neurological deterioration of 4 points of more on the National Institute of Health Stroke Scale (NIHSS). Successful reperfusion was indicated with early neurological improvements of 4 points of more on the NIHSS after IVT alone or Thrombolysis in Cerebral Infarction scores of 2b or 3 after EVT alone or EVT combined with IVT.

Results: Among 933 patients with premorbid mRS scores of 0-1 (72±12 years; 316 women), 426 patients with unfavorable outcomes and 35 patients with sICH were observed. In adjusted analyses, all measures of SBPV but CV were related to unfavorable outcomes, while all measures of SBPV but mean SBP were related to sICH. In 566 patients with successful reperfusion, 228 patients with unfavorable outcomes and 10 patients with sICH were observed. In adjusted analyses, all measures of SBPV but mean SBP were positively related to unfavorable outcomes, while no measures of SBPV were independently related to sICH (table).

Conclusion: High SBPV after successful reperfusion therapy contributed to unfavorable outcomes, suggesting high SBPV after reperfusion therapy might need more attention.

Balloon-like Mobile Plaque in the Innominate Artery: Ultrasonographic and Pathological Perspectives of Repetitive Embolism

Mobile plaque in the innominate artery is extremely rare and difficult to diagnose, especially in its acute stage. Its diagnosis is often delayed in many cases, resulting in delayed treatment and poor prognosis. Herein, we report the case of a 69-year-old patient with multiple cerebral infarction only in the right internal carotid artery and vertebrobasilar territories. No embolic sources were found until arterial ultrasonography detected a large balloon-like mobile plaque in the IA. Mobile plaque consisted of high-and low-echoic components and showed balloon-like plaque. Despite sufficient antiplatelet therapy, recurrence of cerebral embolism could not be prevented. IA replacement was eventually performed by cardiac surgeons. Pathological examinations showed that organized mobile plaque could have existed previously and acute thrombi, generated after the atheromatous plaque rupture caused by the mechanical burden of organized mobile plaque, could expand along with the organized mobile plaque and caused balloon-like plaque and related with repeated embolism. The IA should be explored immediately in cases of repetitive right-sided cerebral embolisms to prevent further recurrence.

Clinical and Radiological Characteristics of Intracranial Artery Dissection Using Recently Proposed Diagnostic Criteria

BACKGROUND

Data on the clinical and radiological characteristics of intracranial artery dissection (IAD) have remained limited. Our purpose was to reveal the clinical and radiological characteristics of IAD according to diagnostic criteria for IAD as recently reported by a group of international experts.

METHODS

Patients were retrospectively enrolled using a prospective single-center stroke registry between 2011 and 2016. Baseline characteristics and radiological findings including conventional magnetic resonance imaging (MRI) sequences, magnetic resonance angiography (MRA), high-resolution 3-dimensional T1-weighted imaging (HR-3D-T1WI), and digital subtraction angiography were reviewed. We performed statistical comparisons to determine which findings from which modalities are useful.

RESULTS

We identified 118 patients with suspected artery dissection, with 64 patients (median age, 51 [interquartile range, 45-56) years; 16 women) finally meeting the criteria for definite (n = 47), probable (n = 15), or possible (n = 2) idiopathic IAD. Ischemic stroke alone was found in 31 patients (48%) on admission. There were 36 patients (56%) suffering from hypertension and 39 (61%) with smoking history. The vertebral artery alone was the most affected in 42 patients (66%). Intramural hematoma (IMH) was more frequently detected on HR-3D-T1WI than on conventional MRI/MRA (odds ratio, 4.72; 95% confidence interval, 1.71-13.00). In 54 patients (84%), the modified Rankin Scale score after 3 months was 0-1.

CONCLUSIONS

Male dominance and age at IAD onset were similar to previous studies, and more than half had hypertension and smoking history. We confirmed that HR-3D-T1WI is useful for detecting IMH in the diagnostic criteria.

Focal Segmental Glomerulosclerosis Associated with Chronic Progressive External Ophthalmoplegia and Mitochondrial DNA A3243G Mutation

Focal segmental glomerulosclerosis (FSGS) is caused by various etiologies, with mitochondrial dysfunction being one of the causes. FSGS is known to be associated with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS), which is a subclass of mitochondrial disease. However, it has rarely been reported in other mitochondrial disease subclasses. Here, we reported a 20-year-old man diagnosed with FSGS associated with chronic progressive external ophthalmoplegia (CPEO) due to mitochondrial DNA (mtDNA) 3243A>G mutation. He presented with left ptosis, short stature, mild sensorineural deafness, and cardiac conduction block. A renal biopsy sample showed segmental sclerosis and adhesions between capillaries and Bowman's capsule, indicating FSGS. Electron microscopy demonstrated abnormal aggregated mitochondria in podocytes, and the basement membrane and epithelial cells of Bowman's capsule. Skeletal muscle biopsy also showed accumulation of abnormal mitochondria. mtDNA analysis identified heteroplasmic mtDNA 3243A>G mutation with no large-scale deletions. From these findings, we diagnosed the case as CPEO with multi-organ involvement including FSGS. Our report demonstrates that CPEO, as well as MELAS, can be associated with FSGS. Because mitochondrial disease presents with a variety of clinical symptoms, atypical cases with non-classical manifestations are observed. Thus, mitochondrial disease should be considered as an underlying cause of FSGS with systemic manifestations even with atypical phenotypes.

[Ebstein's anomaly associated with left ventricular dysfunction: a case report]

A 66-year-old man presented with Ebstein's anomaly associated with left ventricular dysfunction. He had been followed since 40 years of age for cardiomegaly and arrhythmia, and experienced episodes of orthopnea at the age of 64. He was referred to our hospital in April 1997 because of lower extremity edema. Physical examination revealed dilated external jugular vein, tenderness of the right hypocondorium, and lower extremity edema. Electrocardiography confirmed atrial fibrillation. Transthoracic echocardiography revealed bilateral atrial and ventricular dilation, and paradoxical septal movement. The apical four-chamber view demonstrated 15 mm apical displacement of the septal leaflet. Color Doppler echocardiography revealed moderate tricuspid regurgitation. Transesophageal echocardiography revealed low echoic and hypoplastic tricuspid valve. Left ventriculography showed diffuse hypokinesis, and the ejection fraction was 49%. The coronary artery was normal. Atrial septal defect was not detected. Diffuse fibrosis, which may be found in the hearts of patients with Ebstein's anomaly at autopsy may have been responsible for the left ventricular depressed systolic function in this patient.

[Left ventricular wall motion dynamics of asymmetric septal hypertrophy: assessment by intramyocardial pulsed Doppler echocardiography]

Apical pulsed Doppler tissue imaging can be used to assess the function of regional myocardium. We hypothesized that septal dysfunction might be clarified in the hypertrophic cardiomyopathy (asymmetric septal hypertrophy) by this method. Twenty-one patients with asymmetric septal hypertrophy (mean age 54.8 +/- 11 years) and age-matched 24 normal subjects (52.4 +/- 8 years) were studied. The E/A ratio measured by mitral inflow Doppler was not different between the groups (1.1 vs 1.2). E wave velocities of the septum were significantly decreased in the hypertrophy group compared to the control group (4.0 +/- 1.5 vs 8.1 +/- 2.2 cm/sec), and A wave velocities were increased in the hypertrophic septum, resulting in a significantly lower E/A ratio (0.5 +/- 0.3) compared to the E/A ratio (0.9 +/- 0.3) of the normal septum. Deceleration time of the E wave and isovolumic relaxation time were significantly prolonged in the thick septum compared to the normal septum (136 +/- 51 vs 107 +/- 28 msec, 91 +/- 36 vs 63 +/- 19 msec, respectively). In conclusion, asymmetric septal hypertrophy was characterized by diastolic dysfunction of the thickened septum. Intramyocardial pulsed Doppler echocardiography can detect regional myocardial dysfunction earlier than the mitral inflow Doppler method.

Chronic total occlusion of the left main coronary artery

We report 3 patients with chronic total occlusion of the left main coronary artery, which is considered to be very rare. In all three cases, coronary arteriograms showed a total occlusion of the left main coronary artery with good collaterals from the intact right coronary arteries. All of the patients underwent successful coronary artery bypass surgery; two of the cases were followed up for more than 10 years after the surgery. The Japanese literature is reviewed, and a comparison of foreign and Japanese cases is discussed.

Negative inotropic effect of adrenomedullin in isolated adult rabbit cardiac ventricular myocytes

BACKGROUND

Adrenomedullin (AM) is a potent vasodilator peptide. AM-induced vasodilatation is mediated by an increase of NO as well as cAMP. Both AM and binding sites for this peptide have been found in cardiac tissue, indicating the possible existence of an autocrine or paracrine system of AM in the heart.

METHODS AND RESULTS

Myocytes were isolated by use of retrograde coronary perfusion with physiological solution containing collagenase and hyaluronidase from adult rabbit ventricles. Contraction of cardiac myocytes was traced with a video motion detector, and [Ca2+]i was measured with indo 1 at 37 degrees C. The Ica was measured with a whole-cell patch clamp at 23 degrees C. AM and calcitonin gene-related peptide (CGRP), another member of the same peptide family, showed a concentration-dependent negative inotropic effect (10(-7) mol/L AM: contraction amplitude, 64 +/- 7% of control; [Ca2+]i, 52 +/- 5% of control; n = 10; 10(-6) mol/L CGRP: contraction amplitude, 64 +/- 25%; [Ca2+]i, 70 +/- 3%; n = 5; mean +/- SD). Ica was decreased to 60 +/- 39% by superfusion with AM after the cessation of NG-monomethyl-L-arginine (L-NMMA), an NO synthase inhibitor. Pretreatment with L-NMMA (10 mumol/L) abolished the negative inotropic effect of AM, whereas switching from AM+L-NMMA to AM+L-arginine (1 mmol/L) restored it. Superfusion with 8-bromo-cGMP also showed a negative inotropic effect. AM significantly increased the intracellular content of cGMP, a second messenger of NO, but not that of cAMP. AM (10 nmol/L) blunted the effect of 1 mumol/L forskolin.

CONCLUSIONS

AM has a negative inotropic effect and decreased both [Ca2+]i and Ica, with these effects being at least party mediated via the L-arginine-NO pathway in adult rabbit ventricular myocytes.

Survival of metabolically inhibited ventricular myocytes is enhanced by inhibition of rigor and SR Ca2+ cycling

During severe ATP depletion, sarcolemmal rupture resulting from rigor- and/or Ca(2+)-induced myofilament force development is considered to be an important cause of irreversible cell injury. Recent experiments in our laboratory demonstrated that during prolonged metabolic inhibition (MI) in adult rabbit ventricular myocytes, in which rigor was prevented by exposure to 30 mM 2,3-butanedione monoxime (BDM), cyclic uptake and release of cystolic Ca2+ occurred and was associated with strong phasic contractions. To investigate the relative contribution of this sarcoplasmic reticulum Ca2+ cycling and associated force development to energy depletion injury, the effects of BDM together with 7 mM caffeine were examined in isolated rabbit ventricular myocytes subjected to MI with 2 mM NaCN and 20 mM 2-deoxyglucose (2-DG). During 90 min of MI with CN and 2-DG, no cells retained a rod shape in the absence of BDM or caffeine. In the presence of both 30 mM BDM and 7 mM caffeine during MI, preservation of rod morphology was enhanced, and 52 +/- 6.2% of cells retained a rod shape 48 h after metabolic inhibition and had normal ATP content and resting membrane potential. Both systolic and diastolic functions of cells that survived MI, however, were impaired. We conclude that exposure to caffeine together with BDM markedly enhances survival of myocytes during severe prolonged ATP depletion. After recovery, these isolated myocytes show some characteristics of stunning.

Ca(2+)-growth coupling in angiotensin II-induced hypertrophy in cultured rat cardiac cells

OBJECTIVES

There remain some controversies about the effect of angiotensin II on intracellular Ca2+ concentration ([Ca2+]i) in cardiac myocytes. The aim of this study was to investigate different roles of intracellular Ca2+ in the responses to angiotensin II between cardiac myocytes and nonmyocytes.

METHODS

Primary cultures of neonatal rat cardiac myocytes and nonmyocytes were prepared. [Ca2+]i was measured with indo-1. Cellular growth was assayed by [3H]thymidine uptake, RNA content, [3H]phenylalanine incorporation and protein content. Induction of immediate-early gene was examined by Northern blot analysis.

RESULTS

In myocytes, angiotensin II decreased [Ca2+]i transients, induced c-fos mRNA, and accelerated hypertrophy. These effects were completely suppressed by AT1 receptor blockade or protein kinase C inhibition. After chelation of extracellular Ca2+, angiotensin II caused no change in [Ca2+]i or no induction of c-fos in myocytes. Phorbol 12-myristate 13-acetate also decreased [Ca2+]i transients, caused c-fos induction, and provoked hypertrophy in myocytes. In nonmyocytes, angiotensin II increased [Ca2+]i transiently, induced c-fos mRNA and hypertrophy. These effects of angiotensin II were not fully abolished by protein kinase C inhibition. Extracellular Ca2+ chelation did not completely inhibit the effects of angiotensin II on [Ca2+]i or c-fos induction in nonmyocytes. Phorbol 12-myristate 13-acetate did not affect [Ca2+]i or cellular growth in nonmyocytes but did cause c-fos induction.

CONCLUSIONS

These results suggest that angiotensin II induces cellular hypertrophy and immediate-early genes through the activation of protein kinase C in myocytes, although angiotensin II decreases [Ca2+]i transients via this signaling pathway. Induction by angiotensin II of hypertrophy and immediate-early genes in nonmyocytes may be in part mediated by a transient increase in [Ca2+]i which acts synergistically with protein kinase C activation.

Mechanisms of adrenomedullin-induced vasodilation in the rat kidney

To explore the mechanisms of adrenomedullin-induced vasorelaxation, we tested the effects of adrenomedullin on renal function in rats in vivo and measured the release of endothelium-derived nitric oxide from isolated perfused rat kidney (using a chemiluminescence assay) and the diameters of the glomerular arterioles in the hydronephrotic kidney. Adrenomedullin decreased blood pressure in a dose-dependent manner (3 nmol/kg: -29 +/- 2% [SEM]; P < .01) and slightly increased the glomerular filtration rate and urinary sodium excretion (+108%; P < .05). These changes were associated with significant increases in urinary excretion of cyclic AMP (+54%; P < .05). Adrenomedullin decreased renal vascular resistance (10(-7) mol/L adrenomedullin: -41 +/- 2%; P < .001) and increased release of nitric oxide (+5.1 +/- 0.7 fmol/min per gram kidney weight; P < .001) in the isolated kidney. This increase in nitric oxide release was abolished by the inhibitor NG-monomethyl-L-arginine, and it also reversed the decrease in renal vascular resistance seen with adrenomedullin. Renal responses of deoxycorticosterone acetate-salt hypertensive rats to adrenomedullin were significantly smaller than those of control rats for both release of nitric oxide (10(-7) mol/L adrenomedullin: +0.8 +/- 0.2 fmol/min per gram kidney weight; P < .01 versus control) and renal vasodilation (-28 +/- 6%; P < .05). Videomicroscopic analysis revealed that adrenomedullin increased the diameters of both afferent and efferent arterioles (3 nmol/kg: +11%; P < .05). Thus, adrenomedullin-induced renal vasodilation is partially endothelium dependent and is attenuated in deoxycorticosterone acetate-salt hypertension, probably due to endothelial damage.

Effects of angiotensin II on intracellular Ca2+ and pH in isolated beating rabbit hearts and myocytes loaded with the indicator indo-1

1. Angiotensin II increases myocardial contractility in several species, including the rabbit and man. However, it is controversial whether the predominant mechanism is an increase in free cytosolic [Ca2+]i or a change in myofilament Ca2+ sensitivity. To address this question, we infused angiotensin II in isolated perfused rabbit hearts loaded with the Ca2+ indicator indo-1 AM and measured changes in beat-to-beat surface transients of the Ca2+i-sensitive 400:500 nm ratio and left ventricular contractility. The effects of angiotensin II were compared with the response to a Ca(2+)-dependent increase in the inotropic state produced by a change in the perfusate [Ca2+] from 0.9 to 3.6 nM. 2. In the isolated beating heart, an increase in perfusate [Ca2+] caused an increase in left ventricular pressure +dP/dt in association with an increase in peak systolic [Ca2+]i. Angiotensin II perfusion caused a similar increase in left ventricular +dP/dt in the absence of any increase in peak systolic [Ca2+]i. 3. To exclude any contribution of non-myocyte sources of Ca(2+)-sensitive fluorescence which may be present in the intact heart, we also compared the effects of angiotensin II and a change in superfusate [Ca2+] in collagenase-dissociated paced adult rabbit ventricular myocytes loaded with indo-1 AM. In the isolated rabbit myocytes a change in perfusate [Ca2+] from 0.9 to 3.6 mM caused an increase in peak systolic cell shortening coincident with an increase in peak systolic [Ca2+]i. In contrast, angiotensin II caused a similar increase in peak systolic cell shortening whereas there was no increase in peak systolic [Ca2+]i. There was also no change in inward Ca2+ current (ICa) in response to angiotensin II. 4. To investigate further the mechanism of the positive inotropic action of angiotensin II, its effects on intracellular pH were studied in isolated rabbit myocytes loaded with the fluorescent H+ probe SNARF 1. These experiments demonstrated that angiotensin II induced a 0.2 pH unit increase coincident with the development of a positive inotropic effect in isolated rabbit myocytes. 5. In summary, angiotensin II has a direct positive inotropic effect in beating rabbit hearts and in isolated paced rabbit myocytes. These experiments provide support for the hypothesis that the predominant mechanism is not an increase in free cytosolic Ca2+ but is due in part to an increase in myofilament Ca2+ sensitivity due to intracellular alkalosis.

Effect of 2,3-butanedione monoxime on myocyte resting force during prolonged metabolic inhibition

The chemical phosphatase 2,3-butanedione monoxime (BDM) has been reported to inhibit both Ca(2+)-induced myofilament force development and rigor due to ATP depletion. However, during prolonged hypoxia in cultured ventricular myocytes BDM delays but does not prevent a marked increase in resting force. To investigate the mechanisms involved we measured the effects of BDM on intracellular Ca2+ concentration ([Ca2+]i; indo 1), force development (video motion detector), and ATP contents (luciferase assay) in cultured embryonic chick ventricular myocytes and adult rabbit ventricular myocytes subjected to prolonged metabolic inhibition with 1 mM NaCN and 20 mM 2-deoxyglucose. In the absence of metabolic inhibition, 20 mM BDM depressed force development even when [Ca2+]i was markedly elevated by exposure to zero-Na solution or 10 mM caffeine in chick cells, and 30 mM BDM completely inhibited Ca(2+)-induced force development in rabbit myocytes. During metabolic inhibition, 20 mM BDM delayed the onset of an increase in resting force (from 5.44 +/- 0.87 to 13.67 +/- 1.34 min in chick myocytes; from 19.13 +/- 2.23 to 32.43 +/- 3.30 min in rabbit myocytes, means +/- SE, n = 8-9). However, the rates of ATP depletion and rise in [Ca2+]i after metabolic inhibition were not altered by BDM. In the presence of BDM, during prolonged metabolic inhibition in both chick and rabbit myocytes, abrupt spontaneous or evoked alterations in [Ca2+]i were associated with corresponding changes in force. During the initial increase in resting force induced by metabolic inhibition, exposure to BDM caused a partial transient relaxation. We conclude that the delayed increase in resting force during metabolic inhibition in the presence of BDM is due to redevelopment of Ca2+ sensitivity of the myofilaments in the presence of an increased [Ca2+]i as a consequence of severe ATP depletion, whereas in the absence of BDM the more rapidly developing increase in resting force during metabolic inhibition is initially due to a rise in [Ca2+]i followed by development of rigor.

Variable effects of endothelin-1 on [Ca2+]i transients, pHi, and contraction in ventricular myocytes

We examined the effects of endothelin-1 (ET-1) on intracellular free calcium concentration ([Ca2+]i) transients, intracellular pH (pHi), and cell contraction in both embryonic and neonatal as well as in adult ventricular myocytes. Exposure of chick ventricular myocytes to ET-1 (10 nM) significantly decreased both peak systolic and end-diastolic [Ca2+]i (from 949 +/- 43 to 628 +/- 59 nM and from 230 +/- 13 to 162 +/- 8 nM, respectively; P < 0.05, n = 12). The amplitude of cell contraction was also decreased during exposure to 10 nM ET-1 (81.7 +/- 1.2% of control, P < 0.01, n = 12). Exposure to 10 nM ET-1 slightly decreased pHi (-0.055 +/- 0.020 U; P < 0.05). Exposure of cultured neonatal rat ventricular myocytes to ET-1 (10 nM) produced similar effects. Responses of adult rabbit ventricular myocytes to ET-1 were dramatically different from those of embryonic or neonatal ventricular myocytes. Exposure to 10 nM ET-1 increased the amplitude of cell contraction to 159 +/- 32% of control (P < 0.01) without an increase in [Ca2+]i transients. ET-1 also increased pHi (+0.081 +/- 0.047 U; P < 0.01). These results indicate that ET-1 produces a negative inotropic effect by decreasing [Ca2+]i transients and induces a slight intracellular acidosis in immature ventricular myocytes. However, ET-1 causes a positive inotropic effect in adult ventricular myocytes via an intracellular alkalinization, rather than by an increase in the [Ca2+]i transient. Thus the response of myocytes to vasoactive peptides may vary with development and/or species.

ATP depletion causes a reversible decrease in Na+ pump density in cultured ventricular myocytes

To examine factors contributing to impaired K+ homeostasis induced by prolonged but sublethal ATP depletion, we subjected cultured chick ventricular myocytes to metabolic inhibition with 20 mM 2-deoxy-D-glucose plus 1 mM NaCN for 2 h and then allowed myocytes to recover for 5 days in medium containing 6% fetal calf serum (FCS) or in hormone-supplemented serum-free medium. We measured spontaneous contractions (with a video motion detector), K+ content, K+ uptake, membrane potential, and Na+ pump density ([3H]ouabain binding). Exposure to metabolic inhibition for 2 h caused an acute decrease in Na+ pump site density [8.2 +/- 1.1 to 3.8 +/- 0.8 (SE) pmol/mg protein; n = 9, P < 0.02]. Compared with control cells (no metabolic inhibition, cultured for 5 days in serum-free medium), Na+ pump density remained depressed in cells recovered from metabolic inhibition in serum-free medium (3.0 +/- 0.7 pmol/mg), and this was associated with persistently depressed K+ uptake (54% of control), K+ content (67% of control), and membrane depolarization (-19 +/- 2 mV), a significant decrease in cell number (79% of control), and failure to resume spontaneous contractions. Exposure of cells inhibited for 2 h to culture medium containing 6% FCS resulted in a return of Na+ pump site density toward normal levels by 5 days, associated with recovery of K+ uptake and K+ content, preservation of cell number, and resumption of contraction.(ABSTRACT TRUNCATED AT 250 WORDS)

Contributions of [Ca2+]i, [Pi]i, and pHi to altered diastolic myocyte tone during partial metabolic inhibition

Ischemia may cause increased or decreased distensibility of the left ventricle, but the cellular mechanisms involved have not been clarified. We examined the possible contributions of changes in intracellular inorganic phosphate, pH, and Ca2+ concentrations to altered diastolic function in cultured myocytes subjected to partial metabolic inhibition. Paced cultured embryonic chick and adult rabbit ventricular myocytes superfused with 20 mM 2-deoxyglucose (2DG) exhibited an increase in end-diastolic intracellular free calcium concentration ([Ca2+]i) and an upward shift in end-diastolic cell position. These results indicate that glycolytic blockade increases diastolic and systolic calcium in paced ventricular myocytes, and that this elevated diastolic calcium influences the extent of diastolic relaxation. In contrast, paced ventricular myocytes superfused with 1 mM cyanide (CN) exhibited a similar increase in end-diastolic [Ca2+]i but a decrease in end-diastolic cell position and amplitude of motion. Although changes in ATP contents were similar in both groups (2DG, -29.9%; CN, -40.1%), alterations of intracellular pH and inorganic phosphate concentrations were different. In 2DG-treated cells, pHi did not decrease significantly (7.18 +/- 0.04 to 7.12 +/- 0.11, n = 14) but in the CN group it decreased markedly within 6 min (7.18 +/- 0.04 to 6.76 +/- 0.11, n = 11, P less than 0.01). Intracellular inorganic phosphate decreased slightly in the 2DG group (-14.8%, NS) but increased in cells exposed to CN (45.7%, P less than 0.02). We conclude that while a prominent increase in diastolic [Ca2+]i occurs in rapidly paced ventricular myocytes exposed to either inhibitors of glycolysis or oxidative phosphorylation, the effects of this increase in [Ca2+]i on diastolic distensibility may be influenced by intracellular accumulation of metabolites that decrease the sensitivity of myofilament to [Ca2+]i.

Lysophosphatidylcholine increases cytosolic calcium in ventricular myocytes by direct action on the sarcolemma

Lysophosphatidylcholine (LPC) accumulates in myocardial tissues during ischemia, and has toxic effects which may contribute to the arrhythmias and relaxation abnormalities that occur during acute ischemia. These effects of LPC may be mediated in part by calcium overload. To test this hypothesis, spontaneously contracting cultured embryonic chick ventricular myocytes were superfused with various concentrations of LPC (10, 50 and 100 microM) while effects on contractile motion (video motion detector) and changes in free intracellular calcium ion concentration ([Ca2+]i indo-1 fluorescence) were determined. At concentrations greater than or equal to 10 microM, a dose-related, time-dependent effect occurred after exposure to LPC, consisting of the development of contracture and marked elevation of [Ca2+]i. LPC also produced a dose-related, time-dependent inhibition of K+ uptake, indicating there was inhibition of the Na(+)-K+ ATPase Na+ pump. However, the LPC-induced increase in [Ca2+]i was not due to Na+ overload caused by inhibition of the Na(+)-K+ ATPase Na+ pump because superfusion with a zero-Na+ solution did not prevent an increase in [Ca2+]i after LPC exposure; and the increase in [Ca2+]i after exposure to LPC occurred too rapidly to be accounted for by Na+ pump inhibition. Removal of extracellular Ca2+ prevented the rise in [Ca2+]i, after exposure to LPC but treatment with verapamil failed to inhibit the increase in [Ca2+]i induced by LPC. We conclude that LPC produces contracture due to an increase [Ca2+]i. These effects are seen at concentrations of 10 microM and greater, are not due to altered Na(+)-K+ ATPase Na+ pump or calcium channel function, and are probably related to the detergent properties of this amphiphile. There effects may account in part for myocardial dysfunction during ischemia in intact tissue.

Effects of nifedipine on diastolic abnormalities in low-flow and pacing-induced ischemia in isolated rat hearts

An animal experimental model which stimulates human effort angina, especially in terms of diastolic abnormalities, was developed using isovolumically beating perfused rat hearts. Using this model, we studied the effects of nifedipine, a Ca2+ channel blocker, on diastolic properties during pacing-induced ischemia. When the preload of the left ventricle was set at a low level, low-flow ischemia (coronary perfusion pressure of 40 mmHg) plus tachycardia (480 beats/min for 4 min) did not induce an increase in left ventricular end-diastolic pressure (LVEDP). However, with a high preload, low-flow ischemia plus pacing tachycardia induced an increase in LVEDP of 8.4 +/- 5.4 mmHg (p less than 0.01) and a prolongation of the time constant of ventricular pressure decline (6.8 +/- 4.6 msec, p less than 0.05) immediately after pacing tachycardia. Pretreatment with nifedipine (3 x 10(-8) M) prevented the rise in LVEDP induced by pacing tachycardia. Thus, in isolated perfused hearts, diastolic abnormalities similar to those seen in angina pectoris were obtained by low-flow ischemia plus pacing tachycardia. The response to nifedipine suggested that an alteration of Ca2+ movement may play an important role in the increase in left ventricular stiffness under these conditions.

Evidence that binding of Indo-1 to cardiac myocyte protein does not markedly change Kd for Ca2+

Quantitative measurement of [Ca2+]i with the fluorescent Ca(2+)-indicators Indo-1 and Fura-2 is complicated by the possibility that the value of the dissociation constant (Kd) may be influenced by binding to intracellular proteins. We investigated this question in cultured chick ventricular myocytes by use of two different Indo-1 calibration methods. First, the Indo-1 fluorescence ratio (R) (400/500 nm) was measured in beating myocytes loaded by exposure to Indo-1/AM. Then, cells were exposed to the Ca2+ ionophore Br A-23187 and fluorescence ratio was measured in the presence of 500 nM Ca2+ (EGTA-Ca2+ buffer). Subsequently cells were permeabilized to Ca2+ by a 1 min exposure to 25 microM digitonin in the presence of 'zero' Ca2+ (10 mM EGTA) and saturating 1 mM Ca2+ to obtain Rmin, Rmax and beta. We then calculated [Ca2+]i from the formula ([Ca2+]i = Kd [( R - Rmin)/(Rmax - R)]beta). With Kd = 250 nM, calculated systolic [Ca2+]i was 750 +/- 44 nM and diastolic 269 +/- 19 nM (means +/- SEM, n = 16). The R value calculated for an assumed [Ca2+]i = 500 nM using the above formula and digitonin derived constants was very similar to the value measured using Br A-23187 (digitonin, 0.67 +/- 0.03: Br A-23187, 0.66 +/- 0.03, ns). As the Br A-23187 method is independent of the value chosen for Kd, we conclude that the Kd of 250 nM for Indo-1 measured in free solutions closely approximates the Kd for intracellular Indo-1 in these cells, and that therefore the Kd of Indo-1 for Ca2+ does not appear to be markedly affected by binding to proteins or other intracellular molecules.

Forearm venous distensibility in relation to severity of symptoms and hemodynamic data in patients with congestive heart failure

The distensibility of the forearm veins in 24 patients with congestive heart failure was studied by occlusion plethysmography. Relationships between forearm venous distensibility and symptoms, hemodynamic data obtained by right heart catheterization and plasma levels of vasoactive hormones were evaluated. Forearm venous pressure (VP) and volume change (delta V) were measured simultaneously by the venous occlusion technique with strain gauge plethysmography. The relationship between venous pressure and volume change was fitted by the equation VP = c* exp (k* delta V) (r = 0.98 +/- 0.01) and the venous stiffness constant (k) was calculated. Venous volume change at a venous pressure of 20 mmHg (V20) was also measured as another index of venous compliance. The pressure-volume curve of the peripheral veins shifted leftward on the volume axis and the stiffness constant (k) increased as the New York Heart Association functional class grade increased. Mean pulmonary arterial pressure and pulmonary vascular resistance were closely related to k (r = 0.74, p less than 0.001; r = 0.73, p less than 0.001, respectively), and less closely to V20 (r = -0.56, p less than 0.004; r = -0.59, p less than 0.002, respectively). K and V20 were also related to stroke index (r = -0.57, p less than 0.004; r = 0.44, p less than 0.03, respectively) and stroke work index (r = -0.47, p less than 0.02; r = 0.45, p less than 0.03, respectively). K was also related to heart rate (r = 0.55, p less than 0.007), pulmonary capillary wedge pressure (r = 0.54, p less than 0.02), right atrial pressure (r = 0.51, p less than 0.02), cardiac index (r = -0.45, p less than 0.03), and systemic vascular resistance (r = 0.45, p less than 0.03). Both indexes were related to the plasma level of norepinephrine (r = 0.64, p less than 0.008; r = -0.52, p less than 0.04, respectively). We concluded that the venous tone was related to the severity of heart failure, especially to the symptoms, pulmonary arterial pressure and plasma concentration of norepinephrine, and that the venous stiffness constant, k, was a better parameter with which to assess peripheral venous tone.