Transient Attenuation Research Articles

Diagnostic accuracy of MDCT in differentiating gallbladder cancer from acute and xanthogranulomatous cholecystitis

ObjectiveTo determine the diagnostic accuracy of multi-detector CT (MDCT) for differentiating gallbladder cancer from acute and xanthogranulomatous cholecystitis using previously described imaging features. MethodsIn this IRB approved HIPAA-compliant retrospective cohort study, contrast-enhanced MDCT of histologically confirmed acute cholecystitis (n = 17), xanthogranulomatous cholecystitis (n = 25), and gallbladder cancer (n = 18) were reviewed independently by three abdominal radiologists blinded to outcome. The primary outcome was the diagnostic accuracy of MDCT for the differentiation of gallbladder cancer from cholecystitis (acute and xanthogranulomatous) using various imaging parameters. Kappa (κ) statistics and two-way mixed-model single-measure intra-class correlation statistics (ICC) were calculated for each imaging feature and the final radiologic diagnosis. ResultsInter-rater agreement was moderate to substantial (κ = 0.43–0.70), sensitivity 0.67–0.78, specificity 0.22–0.33 and the positive likelihood ratio was 4.28–8.56 for the differentiation of gallbladder cancer from benign gallbladder pathology. Only three imaging findings: disrupted gallbladder mucosa (κ = 0.68), intraluminal gallstones (κ = 0.66), and gallbladder wall thickness (ICC = 0.63) had substantial inter-rater agreement. The following had slight or no agreement: intramural hypoattenuating nodules (κ = 0.17), transient hepatic attenuation differences (κ = 0.14), gallbladder wall calcification (κ = −0.01), gallbladder wall enhancement (κ = 0.18), and omental or mesenteric invasion (κ = 0.08). In the final multivariate model, the following were significant predictors useful in making or excluding diagnosis of gallbladder cancer: focal gallbladder wall thickening (p = 0.003, OR: 13.09 [95% CI: 2.40–71.48]), pericholecystic “fat stranding” (p = 0.018, OR: 0.10 [95% CI: 0.01–0.66]), and maximum short axis lymph node diameter (p = 0.043, OR: 1.18 [95% CI: 1.00–1.38]). ConclusionMDCT has moderate sensitivity, poor specificity, and moderate-to-substantial inter-rater repeatability for the differentiation of gallbladder cancer from acute and xanthogranulomatous cholecystitis.

Representation of Transient Processes on a Hyperplane Using Examples from Electrical Engineering

Vector representation of transient processes on a plane with two coordinate systems makes it possible to visualize all the parameters of transient oscillations, namely, amplitude, frequency, phase, and attenuation. On a complex plane with two coordinate systems, the origin of the vector is determined by the damping factor and the cyclic frequency and is set on the scale of axes of the complex frequency plane, while the length and the phase of the vector are set on the scale of complex amplitude. Such a representation significantly improves visualization of processes and, consequently, increases the informativeness of the research. The use of the hypervector representation of transients is illustrated by various examples. When analyzing the functioning of an automatic excitation controller (AEC) in certification tests, the vector representation of transient processes clearly demonstrates the effect of the AEC and allows one to quantitatively control the effect of channel stabilization on oscillation modes. The vector representation of the dominant oscillations in various implementations of the circuits reveals the most extreme situations for which it is necessary to test the AEC tuning for a specific station. Investigation of the vectors of the voltage-frequency oscillation measured at different points of the system makes it possible to localize the source of low-frequency oscillations.

Method to mix tea with honey and use of transient light attenuation as an indicator of homogeneity

We built a magnetic stirrer to mix tea and honey and developed a method to determine the homogeneity of the mixture based on the variation of light intensity of a laser beam with time due to its scattering by the mixture. The addressed problem was that of mixing tea and honey as fast as possible with a power limitation of one single 1.5 V battery, following the statement of Problem 15 of the 9th International Physicists’ Tournament. The influence of temperature and honey concentration on the total time of mixing was studied through the performance of several experiments reported here. In the best configuration of parameters, the total mixture occurs in less than 2 s, while in the worst configuration, the time necessary reaches 10 s. Results validate the magnetic stirrer as a proper device for mixing tea with honey and light attenuation as an excellent physical property for investigating the homogeneity of the mixture of the honey in tea. Supplementary investigations were made exploring the influence of adding sugar and or a slice of lemon to the tea.

Effect of sensory attenuation on cortical movement-related oscillations.

This study examined the impact of induced sensory deficits on cortical, movement-related oscillations measured using electroencephalography (EEG). We hypothesized that EEG patterns in healthy subjects with induced sensory reduction would be comparable to EEG found after chronic loss of sensory feedback. EEG signals from 64 scalp locations were measured from 10 healthy subjects. Participants dorsiflexed their ankle after prolonged vibration of the tibialis anterior (TA). Beta band time frequency decompositions were calculated using wavelets and compared across conditions. Changes in patterns of movement-related brain activity were observed following attenuation of sensory feedback. A significant decrease in beta power of event-related synchronization was associated with simple ankle dorsiflexion after prolonged vibration of the TA. Attenuation of sensory feedback in young, healthy subjects led to a corresponding decrease in beta band synchronization. This temporary change in beta oscillations suggests that these modulations are a mechanism for sensorimotor integration. The loss of sensory feedback found in spinal cord injury patients contributes to changes in EEG signals underlying motor commands. Similar alterations in cortical signals in healthy subjects with reduced sensory feedback implies these changes reflect normal sensorimotor integration after reduced sensory input rather than brain plasticity. NEW & NOTEWORTHY Transient attenuation of sensory afferents in young, healthy adults led to similar changes in brain activity found previously in volunteers with incomplete spinal cord injury. Beta band power associated with ankle movement in these controls was attenuated after prolonged vibration of the tibialis anterior. Evoked potential measurements suggest that prolonged vibration reduces phasing across trials as the mechanism behind this attenuation of cortical activity.

Upgraded Microwave Radio Thermometer Input Unit for Remote Temperature Measurement of a Biological Object

A modernized input unit of a microwave radio thermometer designed for the study of biological media is described. In this unit, a coupler is applied on the connected transmission lines. A part of the high-frequency signal of the noise generator branches from the main channel into the working arms of the secondary channel with different coefficients of transient attenuation, whose difference determines the range of measurements. Modeling the coupler parameters enables the creation of radio thermometers with specified measurement ranges.

A Comprehensive Approach to Hepatic Vascular Disease.

The liver has a complex vascular supply, which involves the inflow of oxygenated blood through the hepatic artery (systemic circulation) and deoxygenated blood through the portal vein (portal circulation), as well as the outflow of deoxygenated blood through the hepatic veins to the inferior vena cava. A spectrum of vascular variants can involve the liver. Some of these variants may result in areas of enhancement that can mimic more serious pathologic conditions. In this article, the authors discuss a spectrum of variants and pathologic conditions that may involve the liver vasculature. These include variants, anomalies, and diseases involving the portal vein, such as rudimentary portal vein, thrombosis, cavernous transformation, thrombotic angiitis, thrombophlebitis, transient hepatic attenuation difference or transient hepatic intensity difference, portal venous aneurysm, and portal vein gas. The hepatic artery can be involved by various diseases, including thrombosis, stenosis, and aneurysm or pseudoaneurysm. Unusual "third inflow" sources of venous inflow are also discussed, including aberrant right gastric vein, aberrant left gastric vein, epigastric-paraumbilical veins, and cholecystic vein. A spectrum of variants and diseases involving the inferior vena cava and hepatic veins, including thrombosis, Budd-Chiari syndrome, veno-occlusive disease, stenosis, torsion, congestive hepatopathy, and peliosis hepatis, are discussed. Vascular shunts are illustrated, including portosystemic shunts (intra- and extrahepatic), arterioportal shunt, shunts of hereditary hemorrhagic telangiectasia, and acquired arteriovenous fistula. Familiarity with the pathogenesis and imaging features of these vascular entities can aid radiologic diagnoses and guide appropriate patient management. ©RSNA, 2017.

Numerical analysis of multicomponent responses of surface-hole transient electromagnetic method

We calculate the multicomponent responses of surface-hole transient electromagnetic method. The methods and models are unsuitable as geoelectric models of conductive surrounding rocks because they are based on regular local targets. We also propose a calculation and analysis scheme based on numerical simulations of the subsurface transient electromagnetic fields. In the modeling of the electromagnetic fields, the forward modeling simulations are performed by using the finite-difference time-domain method and the discrete image method, which combines the Gaver–Stehfest inverse Laplace transform with the Prony method to solve the initial electromagnetic fields. The precision in the iterative computations is ensured by using the transmission boundary conditions. For the response analysis, we customize geoelectric models consisting of near-borehole targets and conductive wall rocks and implement forward modeling simulations. The observed electric fields are converted into induced electromotive force responses using multicomponent observation devices. By comparing the transient electric fields and multicomponent responses under different conditions, we suggest that the multicomponent-induced electromotive force responses are related to the horizontal and vertical gradient variations of the transient electric field at different times. The characteristics of the response are determined by the varying the subsurface transient electromagnetic fields, i.e., diffusion, attenuation and distortion, under different conditions as well as the electromagnetic fields at the observation positions. The calculation and analysis scheme of the response consider the surrounding rocks and the anomalous field of the local targets. It therefore can account for the geological data better than conventional transient field response analysis of local targets.

Covering the Cover

Covering the Cover

A Calculation Method for the Nonlinear Crowbar Circuit of DFIG Wind Generation based on Frequency Domain Analysis

The ride-through control of a doubly-fed induction generator (DFIG) for the voltage sags on wind farms utilizing crowbar circuits by which the rotor side converter (RSC) is disabled has being reported in many literatures. An analysis and calculation of the transient current when the RSC is switched off are of significance for carrying out the low voltage ride through (LVRT) of a DFIG. The mathematical derivation is highlighted in this paper. The zero-state and zero-input responses of the transient current in the frequency domain through a Laplace transformation are investigated, and the transient components in the time domain are achieved. With the characteristics worked out from the linear resolving without modeling simplification, the selection of the resistance in the linear crowbar circuit and the value conversion from a linear circuit to a nonlinear one is proposed to setup the attenuation rate. In terms of grid code requirements, the theoretical analysis for the time constant of the transient components attenuation insures the controllability when the excitation of the RSC is resumed and it guarantees the reserved time for the response of the reactive power compensation. Simulations are executed in MATLAB/SIMPOWER and experiments are carried out to validate the theoretical analysis. They indicate that the calculation method is effective for selection of the resistance in a crowbar circuit for LVRT operations.

32. BAEPs and their application in monitoring the auditory pathway

We discuss cases with cerebellopontine angle surgery and intraoperative monitoring with auditory evoked potentials. The aim of neuromonitoring is to provide the surgical team with an additional instrument to assess the functional state of the hearing pathway with objective neurophysiological criteria, during surgery near the eighth cranial nerve. Changes in latency, amplitude or total loss of the responses during a neurovascular decompression of the trigeminal nerve, can be avoided by the surgeon modifying the surgical technique. Monitoring is challenging in chronic lesions with poor basal studies. In cases of acoustic neuroma with preserved, but low voltage potentials, the outcome is good. In other cases, latency increments and transient amplitude attenuation, with normalization at the end of surgery, the postoperative results were good with hearing preservation. The relationship between intraoperative auditory evoked potentials changes and eighth nerve integrity with hearing preservation, are consistent with patient prognosis.

Letter Regarding Article, "Electrocardiogram in a Patient with Takotsubo Syndrome and Cardiogenic Shock"

I read with interest the paper by Yoo et al.,1) published in the March, 2016 issue of the Journal, about the 41-year-old previously healthy woman, who suffered Takotsubo syndrome (TTS) complicated by cardiogenic shock, necessitating resuscitation and invasive supportive means of extra-corporeal membrane oxygenation, with eventual full recovery of her heart function. The patient's first electrocardiogram (ECG) (Fig. 1A) recorded on her 2nd visit to the hospital, showed low QRS complexes, in keeping with a recent report,2),3) associating transient attenuation of the ECG QRS complexes (attQRS) and TTS. It is difficult to compare this ECG with the one recorded 1month after discharge (Fig. 1B), since the upper panel of the figure has half of the height of the lower panel, but it appears that there was decrease in QRS voltage in all ECG leads of the admission ECG. This transient attQRS has been attributed to myocardial edema (ME),2) as diagnosed by cardiac magnetic resonance imaging (cMRI).4),5) Unfortunately there was no cMRI in this case, early during the clinical course corresponding to the ECG in Fig. 1A, but much later, a month after admission,1) which of course showed no ME. I will be grateful to the authors if they provide us with information about subsequent ECGs during the patient's follow-up, or ECGs recorded before her admission with TTS (unlikely in a previous healthy young woman), regarding the amplitude of the QRS complexes in those ECGs, in comparison with the ECG of Fig. 1A. Fig. 1 Electrocardiographic findings revealed sinus tachycardia with ST segment elevation in precordial leads at initial admission (A) and normalized ST segment on follow up electrocardiogram at 1 month after discharge (B).

Stationary and Transient Heat Conduction in Multilayer Non-Homogeneous Stratigraphy

The tendency to speed up the building process and reduce its capital costs is bringing to the increased use of semi-finished products in constructions. One frequent characteristic of those elements is the use of non-homogeneous layers of materials, possibly affecting their thermal properties. In addition to this, the gradual increase in the thickness of insulation layers in buildings is also shifting the focus from the heating loads to the cooling loads, especially for hot climates such as southern Europe, raising the necessity to evaluate the transient properties of construction elements, alongside with the most common stationary properties. The aim of this paper is to correctly evaluate both stationary and transient heat conduction properties of strongly non-homogeneous multi-layered constructions and evaluate the impact of the non-homogeneities. The evaluation of those properties are based on the definitions detailed in the EN ISO 13786 directive, for dynamic thermal characteristics, and in the EN ISO 6946 directive, for stationary thermal characteristics. The stationary thermal transmittance is the parameter considered for the stationary analyses; for transient analyses transient thermal transmittance, time shift and attenuation factor are evaluated. The methodology provided inside the respective directives is applied in order to estimate the parameters. Following, a finite elements model is implemented in the COMSOL Multiphysics software and the same properties are calculated through a finite element analysis performed based on the conditions detailed in the physical definitions of those properties in the respective directives. Each parameter assessed based on the respective directives, EN ISO 13786 and EN ISO 6946, is then compared with the results of the finite elements analyses. Based on those comparisons the impact of the non-homogeneities in the construction for the calculation of its thermal properties are evaluated and conclusions on their relevance in the identification of the thermal properties are given, also the ability of describing non- homogeneous constructions through the directive's methodology is discussed.

Acoustic Estimation of Resonance Frequency and Sonodestruction of SonoVue Microbubbles

AbstractAcoustic properties of ultrasound (US) contrast agent microbubbles (MB) highly influence sonoporation efficiency and intracellular drug and gene delivery. In this study we propose an acoustic method to monitor passive and excited MBs in a real time. MB monitoring system consisted of two separate transducers. The first transducer delivered over an interval of 1 s US pulses (1 MHz, 1% duty cycle, 100 Hz repetition frequency) with stepwise increased peak negative pressure (PNP), while the second one continuously monitored acoustic response of SonoVue MBs. Pulse echo signals were processed according to the substitution method to calculate attenuation coefficient spectra and loss of amplitude. During US exposure at 50–100 kPa PNP we observed a temporal increase in loss of amplitude which coincided with the US delivery. Transient increase in loss of amplitude vanished at higher PNP values. At higher PNP values loss of amplitude decreased during the US exposure indicating MB sonodestruction. Analysis of transient attenuation spectra revealed that attenuation coefficient was maximal at 1.5 MHz frequency which is consistent with resonance frequency of SonoVue MB. The method allows evaluation of the of resonance frequency of MB, onset and kinetics of MB sonodestruction.

The Suppression of Beta Oscillations in the Primate Supplementary Motor Complex Reflects a Volatile State During the Updating of Action Sequences

The medial motor areas play crucial but flexible roles in the temporal organizations of multiple movements. The beta oscillation of local field potentials is the predominant oscillatory activity in the motor areas, but the manner in which increases and decreases in beta power contribute to updating of multiple action plans is not yet fully understood. In the present study, beta and high-gamma activities in the supplementary motor area (SMA) and pre-SMA of monkeys were analyzed during performance of a bimanual motor sequence task that required updating and maintenance of the memory of action sequences. Beta power was attenuated during early delay periods of updating trials but was increased during maintenance trials, while there was a reciprocal increase in high-gamma power during updating trials. Moreover, transient attenuation of beta power during maintenance trials resulted in the erroneous selection of an action sequence. Therefore, it was concluded that the suppression of beta power during the early delay period reflects volatility of neural representation of the action sequence. This neural representation would be properly updated to the appropriate instructed action sequence via increases in high-gamma power in updating trials whereas it would be erroneously updated without the appropriate updating signal in maintenance trials.

Suppression of hyperinsulinaemia in growing female mice provides long-term protection against obesity.

Aims/hypothesisHyperinsulinaemia is associated with obesity but its causal role in the onset of obesity remains controversial. In this study, we tested the hypothesis that transient attenuation of diet-induced insulin hypersecretion in young mice can provide sustained protection against obesity throughout adult life.MethodsUsing ‘genetically humanised’ mice lacking both alleles of rodent-specific Ins1, we compared mice heterozygous for the ancestral insulin gene Ins2 with Ins2+/+ controls. Female Ins1−/−:Ins2+/− and Ins1−/−:Ins2+/+ littermates were fed chow or high-fat diet (HFD). Insulin secretion, metabolic health variables and body mass/composition were tracked for over 1 year. We examined islet function and adipose transcript levels of adipogenic, lipogenic and lipolytic genes at two time points.ResultsIn control Ins1−/−:Ins2+/+ mice, HFD resulted in elevated fasting and glucose-stimulated insulin secretion between 8 weeks and 27 weeks of age. Hyperinsulinaemia was reduced by nearly 50% in Ins1−/−:Ins2+/− mice during this period, without lasting adverse effects on glucose homeostasis. This corresponded with attenuated weight gain and adiposity. White adipose tissue from Ins1−/−:Ins2+/− mice had fewer large lipid droplets, although transcriptional changes were not detected. Importantly, Ins1−/−:Ins2+/− mice remained lighter than Ins1−/−:Ins2+/+ littermates despite reaching an equivalent degree of hyperinsulinaemia on HFD by 52 weeks.Conclusions/interpretationThese data demonstrate that attenuation of hyperinsulinaemia in young, growing female mice provides a long-lasting protection against obesity. This protection persists despite a late-onset emergence of hyperinsulinaemia in HFD-fed Ins1−/−:Ins2+/− mice. Given the evolutionary conserved roles of insulin, it is possible that suppressing hyperinsulinaemia early in life may have far-reaching consequences on obesity in full-grown adult humans.Electronic supplementary materialThe online version of this article (doi:10.1007/s00125-015-3676-7) contains peer-reviewed but unedited supplementary material, which is available to authorised users.

Optimization of translation profiles enhances protein expression and solubility.

mRNA is translated with a non-uniform speed that actively coordinates co-translational folding of protein domains. Using structure-based homology we identified the structural domains in epoxide hydrolases (EHs) and introduced slow-translating codons to delineate the translation of single domains. These changes in translation speed dramatically improved the solubility of two EHs of metagenomic origin in Escherichia coli. Conversely, the importance of transient attenuation for the folding, and consequently solubility, of EH was evidenced with a member of the EH family from Agrobacterium radiobacter, which partitions in the soluble fraction when expressed in E. coli. Synonymous substitutions of codons shaping the slow-transiting regions to fast-translating codons render this protein insoluble. Furthermore, we show that low protein yield can be enhanced by decreasing the free folding energy of the initial 5’-coding region, which can disrupt mRNA secondary structure and enhance ribosomal loading. This study provides direct experimental evidence that mRNA is not a mere messenger for translation of codons into amino acids but bears an additional layer of information for folding, solubility and expression level of the encoded protein. Furthermore, it provides a general frame on how to modulate and fine-tune gene expression of a target protein.

Xanthogranulomatous cholecystitis: diagnostic performance of US, CT, and MRI for differentiation from gallbladder carcinoma.

The purpose of this study is to evaluate the diagnostic performance of HRUS, CT, and MRI for differentiating xanthogranulomatous cholecystitis (XGC) from gallbladder (GB) cancer. Patients with surgically proven XGC (n=40) and GB cancer (n=44), who had undergone at least one HRUS (n=43), CT (n=82), or MRI (n=34) examination between 2000 and 2012, were included. Two radiologists retrospectively graded the likelihood of XGC or GB cancer using a 5-point confidence scale; they also assessed the imaging features. Statistical analyses were performed using ROC, ANOVA, and Fisher's exact test. Diagnostic performance of MRI was better than HRUS for differentiating XGC from GB cancer (AUCs=0.867 and 0.911 vs. AUCs=0.818 and 0.86). However, HRUS showed a better performance than CT (AUCs=0.818 and 0.86 vs. AUCs=0.806 and 0.84) with moderate to excellent agreement (κ=0.48-0.83). Statistically common findings for XGC included non-focal thickening, smooth GB wall, presence of intramural nodules, type I enhancement of wall, transient hepatic attenuation difference, and continuity of mucosa (p<0.05). Co-existence of gallstones (OR=16.5), non-focal thickening (OR=14.7), and collapsed lumen (OR=13.0) on HRUS, and type I enhancement on CT (OR=3.52) were independently associated with XGC (p<0.05). Although MRI showed a better performance than both HRUS and CT, HRUS showed a better performance than CT. The co-existence of gallstones, non-focal thickening, and collapsed lumen on HRUS was independently associated with XGC.

Transient QRS amplitude attenuation is associated with clinical recovery in patients with takotsubo cardiomyopathy

Background/objectivesLow voltage QRS complexes (LQRSV) and amplitude attenuation of QRS voltage (AAQRS) have been described in takotsubo (TC) patients, and postulated as valuable pre-angiographic markers. The aim of this observational study is to evaluate potential diagnostic and prognostic features of QRS amplitude in TC and acute coronary syndrome (ACS) patients. MethodsFifty-eight patients with TC were matched with 58 patients with ACS according to age, gender, and presence or absence of ST elevation at hospital admission. A 12-lead ECG was recorded within 12h after symptoms onset, the day after coronary angiography (CA) and before hospital discharge. When available, ECGs prior and subsequent to the acute event were also collected. ResultsQRS amplitude showed a time related trend, with a first phase characterized by an initial decrease in amplitude in both groups and a second phase, with a progressive recovery of QRS amplitude in TC patients up to pre-event levels, while QRS amplitude in ACS patients remained substantially unchanged from admission onwards. Rise in AAQRS during hospitalization showed a positive linear association with systolic function recovery and both troponin I and CK-MB decrease (all p<0.01) in TC patients. A 20% increase of mean AAQRS from admission is able to predict LVEF recovery and troponin I and CK-MB normalization in TC patients with good sensitivity and specificity. ConclusionsLQRSV and AAQRS are not reliable in differentiating ACS from TC. However, QRS amplitude attenuation in TC is transient, and is linearly associated with systolic function recovery and cardiac biomarkers normalization.

Superior vena kava obstrüksiyonu olan iki hastada geçici hepatik kontrastlanma farklılığı: Bilgisayarlı tomografi bulguları

Radiographic appearances of transient hepatic attenuation differences (THAD) can mimic tumors. THAD can occur as a result of altered hemodynamics of the hepatic blood flow. Tumoral or non-tumoral processes can play role in the etiology. THADs that appear secondary to the obstruction of the superior vena cava are rarely seen. Herein, we present computed tomography findings of two cases with THAD secondary to superior vena cava obstruction

Comment on "Takotsubo Cardiomyopathy: A New Perspective in Asthma".

I read with interest the study by Marmoush et al. [1] about the 80-year-old woman with an exacerbation of her asthma who suffered Takotsubo syndrome (TTS), after using “her rescue albuterol inhaler several times.” As the authors state this is not the first case of an albuterol-triggered TTS, as shown by many similar cases of TTS published as single case reports and series of patients derived from cohorts admitted to the respiratory intensive care unit, treated with a variety of β2-adrenergic agents. I have some thoughts for the authors to consider. (1) The electrocardiogram (ECG) on admission showed complete left bundle branch block (LBBB), which they felt was new, presumably documented by comparison with a previous ECG of the patient; however, the LBBB persisted after recovery from TTS, which is at variance with the transient nature of LBBB in other patients with TTS reported in the literature heretofore, and it is conceivable that the LBBB emerged during the time intervals between the last preadmission ECG and the admission with TTS. (2) Irrespective of this, I wonder whether the authors noted any transient attenuation of amplitude of the ECG QRS complexes of the serial ECGs, from the admission ECG to the tracings recorded during hospitalization, at discharge, and finally at the 3-month outpatient follow-up, in keeping with a recently published new insight about the ECG and TTS [2]. (3) Did this patient have any history of similar excessive use of albuterol during an exacerbation of her asthma, which however did not precipitate similar symptoms or laboratory testing finding to the TTS admission? (4) In reference to the pathophysiologic mechanism(s) which led to TTS in their patient, do the authors feel that at the roots of the TTS attack was the excessive dose of albuterol, impacting directly the cardiomyocytes, or that the externally introduced catecholamine triggered an autonomic adrenergic surge, via the sympathetic nervous system and/or adrenal catecholamine secretion? We need to start delving in such questions if we have any hopes that we will eventually understand the pathophysiological underpinnings of this mysterious affliction.