Fast Optical Investigation of Cardiac Electrophysiology by Parallel Detection in Multiwell Plates

Current techniques for fast characterization of cardiac electrophysiology employ optical technologies to control and monitor action potential features of single cells or cellular monolayers placed in multiwell plates. High-speed investigation capacities are commonly achieved by serially analyzing well after well employing fully automated fluorescence microscopes. Here, we describe an alternative cost-effective optical approach (MULTIPLE) that exploits high-power LED arrays to globally illuminate a culture plate and an sCMOS sensor for parallel detection of the fluorescence coming from multiple wells. MULTIPLE combines optical detection of action potentials using a red-shifted voltage-sensitive fluorescent dye (di-4-ANBDQPQ) with optical stimulation, employing optogenetic actuators, to ensure excitation of cardiomyocytes at constant rates. MULTIPLE was first characterized in terms of interwell uniformity of the illumination intensity and optical detection performance. Then, it was applied for probing action potential features in HL-1 cells (i.e., mouse atrial myocyte-like cells) stably expressing the blue light-activatable cation channel CheRiff. Under proper stimulation conditions, we were able to accurately measure action potential dynamics across a 24-well plate with variability across the whole plate of the order of 10%. The capability of MULTIPLE to detect action potential changes across a 24-well plate was demonstrated employing the selective K _v 11.1 channel blocker (E-4031), in a dose titration experiment. Finally, action potential recordings were performed in spontaneous beating human induced pluripotent stem cell derived cardiomyocytes following pharmacological manipulation of their beating frequency. We believe that the simplicity of the presented optical scheme represents a valid complement to sophisticated and expensive state-of-the-art optical systems for high-throughput cardiac electrophysiological investigations.

Management of patients presenting with haemoptysis to a Tertiary Care Italian Emergency Department: the Florence Haemoptysis Score (FLHASc)

We analysed the clinical features and diagnostic workup of patients presenting with haemoptysis to an Italian teaching hospital to derive an easy-to-use clinical score to guide risk stratification and initial management in the emergency department (ED). We retrospectively reviewed clinical records of consecutive patients with haemoptysis over 1 year. A pre-specified set of variables, including demographic data, vital signs, type of expectorate (pure blood vs. blood-streaked sputum), comorbidities, and diagnostic tests and treatments was originally registered. The primary outcome was a composite of any of the following: death from any cause, invasive or non-invasive ventilation, Intensive Care Unit admission, blood transfusions or invasive haemostatic procedures. We investigated associations between the pre-specified clinical variables and the primary outcome using a logistic regression analysis. Finally, we derived a score (the Florence Haemoptysis Score, FLHASc) giving a proportional weight to each variable according to the Odds Ratios (OR). We included 197 patients with a median age of 60 years. The first radiological study was a plain chest X-ray in 128 patients (65%). For 33 (17%) patients, a chest computer tomography (CT scan) was the first radiological study. The most common diagnosis was lung malignancy (19% of cases). The diagnosis remained undetermined in one-third of patients. The primary outcome was met by 11.2% of the study population. Systolic blood pressure <100 mmHg (OR 9.7), a history of malignancy (OR 3), the expectoration of pure blood (OR 2.8), and more than 2 episodes of haemoptysis in the prior 24 h (OR 2.5) are found as independent predictors of the primary outcome. The FLHASc ranges from 0 to 6 with a prognostic accuracy of 78% (IC 95%, 68-88%). The primary outcome incidence is 2.4% (IC 95%, 0.2-8.2%) in patients with a FLHASc equal to zero (n = 85, 43%) versus 13.4% (IC 95% 7.8-21.1%) in patients with a FLHASc > 0 (p < 0.01). Among patients with a FLHASc equal to zero, a negative chest X-ray study identifies patients who may be safely discharged. Patients who presented to the ED with haemoptysis experience a heterogeneous management. We derive a simple clinical prognostic score that may rationalize their diagnostic workup.

Duplex Sonography of Vertebral Arteries for Evaluation of Patients with Acute Vertigo

We evaluated the role of vertebral artery extracranial color-coded duplex sonography (VAECCS) in predicting vertebrobasilar stroke in consecutive patients presenting to the emergency department with vertigo of suspected ischemic origin. The final diagnosis was established by a panel of experts consisting of an emergency physician, a neurologist, and an otoneurologist. Vertebrobasilar stroke was diagnosed when an acute brain ischemic lesion congruent with symptoms was detected by neuroimaging during the index visit or a stroke was diagnosed within a 3-mo period after emergency department presentation. Among 126 patients, 28 (22%) were diagnosed with vertebrobasilar stroke. Fifteen (75%) of 20 patients with abnormal VAECCS results and 13 (12%) of 106 with normal VAECCS results had a final diagnosis of vertebrobasilar stroke. The sensitivity and specificity of VAECCS were 53.6% and 94.9%, respectively. Detecting an abnormal flow pattern at VAECCS significantly increased the risk of vertebrobasilar stroke (odds ratio = 21.5). The flow patterns most frequently related to vertebrobasilar stroke were absence of flow and high resistance pattern velocity (odds ratio = 9.3 and 22.7, respectively). VAECCS predicts vertebrobasilar stroke and could be a useful bedside screening tool in patients with vertigo.

Can non-invasive ventilation modify central venous pressure? Comparison between invasive measurement and ultrasonographic evaluation

Central venous pressure (CVP) is primarily measured to assess intravascular volume status and heart preload. In clinical practice, the measuring device most commonly used in emergency departments and intensive care units, is an electronic transducer that interconnects a central venous catheter (CVC) with a monitoring system. Non-invasive ventilation (NIV) consists in a breathing support that supplies a positive pressure in airways through a mask or a cask though not using an endotracheal prosthesis. In emergency settings, non-invasive ultrasonography evaluation of CVP, and hence of intravascular volume status entail the measurement by a subxiphoid approach of inferior vena cava diameter and its variations in relation to respiratory activity. In the literature, there are many studies analyzing the ability to estimate CVP through ultrasonography, rating inspiratory and expiratory vena cava diameters and their ratio, defined as inferior vena cava collapsibility index (IVC-CI). At the same time, the effects of invasive mechanical ventilation on blood volume and the correlation during ventilation between hemodynamic invasive measurement of CVP and inferior vena cava diameters have already been demonstrated. Nevertheless, there are no available data regarding the hemodynamic effects of NIV and the potential correlations during this kind of ventilation between invasive and non-invasive CVP measurements. Therefore, this study aims to understand whether there exists or not an interrelationship between the values of CVP assessed invasively through a CVC and non-invasively through the IVC-CI in patients with severe respiratory distress, and above all to evaluate if these means of assessment can be influenced using NIV.

Differential Diagnosis of Vertigo in the Emergency Department: A Prospective Validation Study of the STANDING Algorithm

Objective

We investigated the reliability and accuracy of a bedside diagnostic algorithm for patients presenting with vertigo/unsteadiness to the emergency department.

Methods

We enrolled consecutive adult patients presenting with vertigo/unsteadiness at a tertiary hospital. STANDING, the acronym for the four-step algorithm we have previously described, based on nystagmus observation and well-known diagnostic maneuvers includes (1) the discrimination between SponTAneous and positional nystagmus, (2) the evaluation of the Nystagmus Direction, (3) the head Impulse test, and (4) the evaluation of equilibrium (staNdinG). Reliability of each step was analyzed by Fleiss’ K calculation. The reference standard (central vertigo) was a composite of brain disease including stroke, demyelinating disease, neoplasm, or other brain disease diagnosed by initial imaging or during 3-month follow-up.

Results

Three hundred and fifty-two patients were included. The incidence of central vertigo was 11.4% [95% confidence interval (CI) 8.2–15.2%]. The leading cause was ischemic stroke (70%). The STANDING showed a good reliability (overall Fleiss K 0.83), the second step showing the highest (0.95), and the third step the lowest (0.74) agreement. The overall accuracy of the algorithm was 88% (95% CI 85–88%), showing high sensitivity (95%, 95% CI 83–99%) and specificity (87%, 95% CI 85–87%), very high-negative predictive value (99%, 95% CI 97–100%), and a positive predictive value of 48% (95% CI 41–50%) for central vertigo.

Conclusion

Using the STANDING algorithm, non-sub-specialists achieved good reliability and high accuracy in excluding stroke and other threatening causes of vertigo/unsteadiness.

Point-of-Care Ultrasonography for Evaluation of Acute Dyspnea in the ED

BACKGROUND

Acute dyspnea is a common symptom in the ED. The standard approach to dyspnea often relies on radiologic and laboratory results, causing excessive delay before adequate therapy is started. Use of an integrated point-of-care ultrasonography (PoCUS) approach can shorten the time needed to formulate a diagnosis, while maintaining an acceptable safety profile.

METHODS

Consecutive adult patients presenting with dyspnea and admitted after ED evaluation were prospectively enrolled. The gold standard was the final diagnosis assessed by two expert reviewers. Two physicians independently evaluated the patient; a sonographer performed an ultrasound evaluation of the lung, heart, and inferior vena cava, while the treating physician requested traditional tests as needed. Time needed to formulate the ultrasound and the ED diagnoses was recorded and compared. Accuracy and concordance of the ultrasound and the ED diagnoses were calculated.

RESULTS

A total of 2,683 patients were enrolled. The average time needed to formulate the ultrasound diagnosis was significantly lower than that required for ED diagnosis (24 ± 10 min vs 186 ± 72 min; P = .025). The ultrasound and the ED diagnoses showed good overall concordance (κ = 0.71). There were no statistically significant differences in the accuracy of PoCUS and the standard ED evaluation for the diagnosis of acute coronary syndrome, pneumonia, pleural effusion, pericardial effusion, pneumothorax, and dyspnea from other causes. PoCUS was significantly more sensitive for the diagnosis of heart failure, whereas a standard ED evaluation performed better in the diagnosis of COPD/asthma and pulmonary embolism.

CONCLUSIONS

PoCUS represents a feasible and reliable diagnostic approach to the patient with dyspnea, allowing a reduction in time to diagnosis. This protocol could help to stratify patients who should undergo a more detailed evaluation.

Chest Abdominal-Focused Assessment Sonography for Trauma during the primary survey in the Emergency Department: the CA-FAST protocol

PURPOSE

To evaluate the feasibility of a new protocol, Chest Abdominal-Focused Assessment Sonography for Trauma (CA-FAST), during the primary survey and to estimate its diagnostic accuracy when compared with thoracoabdominal computed tomography (CT) scan.

METHODS

A prospective accuracy study was performed from November 2012 to November 2013 at the Emergency Department. Only adult trauma patients who underwent a CA-FAST examination prior to a thoracoabdominal CT scan were enrolled. In addition to standard patterns detected by Extended-FAST (E-FAST) such as pneumothorax (PTX), hemothorax (HTX), pericardial and intraabdominal effusion, CA-FAST protocol also included the research of lung contusions (LCs).

RESULTS

Six hundred and one patients were enrolled. The mean time for protocol execution was 7 ± 3 min. Chest ultrasonography showed the following results (all p < 0.001): LCs sensitivity 59 %, specificity 98 %, positive predictive value (PPV) 92 %, negative predictive value (NPV) 86 %, accuracy 87 %; PTX sensitivity 84 %, specificity 98 %, PPV 93 %, NPV 95 %, accuracy 95 %; HTX sensitivity 82 %, specificity 97 %, PPV 87 %, NPV 95 %, accuracy 94 %. The standard 4-views FAST examination showed a diagnostic accuracy of 91 % with a sensitivity of 75 %, specificity of 96 %, PPV of 81 % and NPV of 94 %.

CONCLUSION

According to our results CA-FAST protocol proved to be a rapid bedside method, with good accuracy and high NPV in detection of ultrasonographic patterns suggestive of serious injury in trauma patients; moreover, the additional research of LCs did not cause a delay in the diagnosis. Ultrasonography should be used as initial investigation during the primary survey, sending to further diagnostic studies (CT scan) only those patients not clearly classified.

Comparison of exercise electrocardiogram and exercise echocardiography in intermediate-risk chest pain patients

BACKGROUND

The novel exercise computer-assisted high-frequency QRS analysis (HF/QRS) has demonstrated improved sensitivity and specificity over the conventional ST/electrocardiogram-segment analysis (ST/ECG) in the detection of myocardial ischemia. The aim of the present study was to compare the diagnostic value of the validated exercise echocardiography (ex-Echo) with the novel exercise ECG (ex-ECG) including HF/QRS and ST/ECG analysis.

METHODS

A prospective cohort study was conducted in the emergency department of a tertiary care teaching Hospital. Patients with chest pain (CP), normal resting ECGs, troponins, and echocardiography, labeled as "intermediate-risk" for adverse coronary events, underwent the novel ex-ECG and ex-Echo. An ST-segment depression of at least 2 mV or at least 1 mV when associated with CP was considered as an index of ischemia, as well as a decrease of at least 50% in HF/QRS intensity, or new wall motion abnormalities on ex-Echo. Exclusion criteria were QRS duration of at least 120 milliseconds, poor echo-acoustic window, and inability to exercise. Patients were followed up to 3 months. The end point was the composite of coronary stenoses of 50% or greater at angiography or acute coronary syndrome, revascularization, and cardiovascular death on the 3-month follow-up.

RESULTS

Of 188 patients enrolled, 18 achieved the end point. The novel ex-ECG and ex-Echo showed comparable negative predictive value (97% vs 96%; P = .930); however, sensitivity was 83% vs 61%, respectively (P = .612), and specificity was 64% vs 92%, respectively,(P = .026). The areas on receiver operating characteristic analysis were comparable (ex-ECG: 0.734 [95% confidence interval, or CI, 0.62-0.85] vs ex-Echo: 0.767 [CI, 0.63-0.91]; C statistic, P = .167). On multivariate analysis, both ex-ECG (hazard ratio, 5; CI, 1-20; P = .017) and ex-Echo (HR, 12; CI, 4-40; P < .001) were predictors of the end point.

CONCLUSIONS

In intermediate-risk CP patients, the novel ex-ECG including HF/QRS added to ST/ECG analysis was a valuable diagnostic tool and might be proposed to avoid additional imaging. However, the novel test needs additional study before it can be recommended as a replacement for current techniques.

Prognostic value of emergency physician performed echocardiography in patients with acute pulmonary thromboembolism

INTRODUCTION

Pulmonary embolism (PE) is a life-threatening illness with high morbidity and mortality. Echocardiography (ECG) plays an important role in the early identification of right ventricular (RV) dysfunction, making it a helpful tool in identifying hemodynamically stable patients affected by PE with a higher mortality risk. The purpose of this study was to evaluate if one or more ECG indexes could predict a short-term evolution towards RV dysfunction.

METHODS

We selected all patients consecutively admitted to the Careggi Hospital Emergency Department with the clinical suspicion of PE, confirmed by computed tomography angiography prior to enrollment. Subsequently, properly trained emergency physicians acquired a complete ECG to measure RV morphological and functional indices. For each patient, we recorded if he or she received a fibrinolytic treatment, a surgical embolectomy or heparin therapy during the emergency department (ED) stay. Then, every patient was re-evaluated with ECG, by the same physician, after 1 week in our intensive observation unit and 1 month as outpatient in our ED regional referral center for PE.

RESULTS

From 2002 to 2007, 120 consecutive patients affected by PE were evaluated by echocardiography at the Careggi Hospital ED. Nine patients (8%) were treated with thrombolytic therapy. Six died within 1 week and 4 abandoned the study, while the remaining 110 survived and were re-evaluated by ECG after 1 week and 1 month. The majority of the echocardiographic RV indexes improve mostly in the first 7 days: Acceleration Time (AT) from 78±14 ms to 117±14 ms (p<0.001), Diameter of Inferior Vena Cava (DIVC) from 25±6 mm to 19±5 mm (p<0.001), Tricuspid Annular Plane Systolic Excursion (TAPSE) from 16±6 mm to 20±6 mm (p<0.001). Pulmonary Artery Systolic Pressure (PASP) showed a remarkable decrease from 59±26 mmHg to 37±9 mmHg, (p<0.001). The measurements of the transverse diameters of both ventricles and the respective ratio showed a progressive normalization with a reduction of RV diameter, an increase of Left Ventricular (LV) diameter and a decrease of RV/LV ratio over time. To evaluate the RV function, the study population was divided into 3 groups based on the TAPSE and PASP mean values at the admission: Group 1 (68 patients) (TAPSE+/ PASP-), Group 2 (12 patients) (TAPSE-/PASP-), and Group 3 (30 patients) (TAPSE-/PASP+). Greater values of AT, minor RV diameter, greater LV diameter and a lesser RV/LV ratio were associated with a short-term improvement of TAPSE in the Group 2. Instead, in Group 3 the only parameter associated with short-term improvement of TAPSE and PASP was the treatment with thrombolytic therapy (p<0.0001).

CONCLUSION

Greater values of AT, minor RV diameter, greater LV diameter and a lesser RV/LV ratio were associated with a short-term improvement of TAPSE-/PASP- values. Patients with evidence of RV dysfunction (TAPSE-/PASP+), may benefit from thrombolytic therapy to improve a short- term RV function. After 1 month, also a decreased DIVC predicted improved RV function.

Verification of correct central venous catheter placement in the emergency department: comparison between ultrasonography and chest radiography

In 210 consecutive patients undergoing emergency central venous catheterization, we studied whether an ultrasonography examination performed at the bedside by an emergency physician can be an alternative method to chest X-ray study to verify the correct central venous catheter placement, and to identify mechanical complications. A prospective, blinded, observational study was performed, from January 2009 to December 2011, in the emergency department of a university-affiliated teaching hospital. Ultrasonography interpretation was completed during image acquisition; ultrasound scan was performed in 5 ± 3 min, whereas the time interval between chest radiograph request and its final interpretation was 65 ± 74 min p < 0.0001. We found a high concordance between the two diagnostic modalities in the identification of catheter position (Kappa = 82 %, p < 0.0001), and their ability to identify a possible wrong position showed a high correlation (Pearson's r = 0.76 %, p < 0.0001) with a sensitivity of 94 %, a specificity of 89 % for ultrasonography. Regarding the mechanical complications, three iatrogenic pneumothoraces occurred, all were correctly identified by ultrasonography and confirmed by chest radiography (sensitivity 100 %). Our study showed a high correlation between these two modalities to identify possible malpositioning of a catheter resulting from cannulation of central veins, and its complications. The less time required to perform ultrasonography allows earlier use of the catheter for the administration of acute therapies that can be life-saving for the critically ill patients.

Usefulness of chest ultrasonography in detecting pulmonary embolism in patient with chronic obstructive pulmonary disease and chronic renal failure: a case report

We describe the case of a 75-year-old man affected by a chronic obstructive pulmonary disease and chronic renal failure admitted to our emergency department for dyspnea and interscapular stabbing pain. Chest radiography showed diffuse parenchymal consolidation in the lower right lung with bronchiectasis, but the treatment for infection disease did not improve the clinical conditions of the patient. According to Wells score indicating an intermediate risk for pulmonary embolism, we performed a chest ultrasonography that showed ultrasonographic patterns of thromboembolism. Because the presence of chronic renal failure limited the execution of a helical computed tomographic pulmonary angiography, a pulmonary scintigraphy was performed confirming the diagnosis of pulmonary embolism. Our case suggested that chest ultrasonography can be a valuable tool for early detection of pulmonary embolism and to establish immediately an appropriate therapy.