Erling Aarsæther

Left ventricular size determines tissue Doppler-derived longitudinal strain and strain rate

AIMS Tissue Doppler-derived indices of strain (epsilon) and strain rate (SR) have been developed to assess regional cardiac function. However, the effect of left ventricular (LV) size on epsilon and SR has not been studied in depth. The aim of this study was to assess to what extent heart size influence epsilon or SR. METHODS AND RESULTS In 21 anaesthetized pigs ranging from 12.5 to 70.0 kg, tissue Doppler-derived epsilon and SR, and haemodynamic parameters, were assessed during controlled heart rates and different loading conditions. dP/dt did not correlate to pig weight, suggesting constant contractility during growth. Longitudinal epsilon and SR were significantly higher in smaller compared with larger hearts. The hyperbolic correlation between pigs weight and epsilon and SR was r(2)=0.621 and 0.372, respectively, both P<0.0001. Afterload elevation induced a reduction in longitudinal epsilon (from -24.2+/-3.2 to -12.1+/-5.5%, P=0.001) and SR (from -2.3+/-0.8 to -1.3+/-2.4 s(-1), P=0.034), whereas increasing preload increased epsilon (from -26.4+/-10.3 to -38.1+/-14.3%, P=0.006) and SR (from -2.3+/-0.9 to -4.22+/-1.8 s(-1), P=0.002). CONCLUSION Longitudinal epsilon and SR decrease with increasing LV dimensions in spite of an unaltered contractility. These results show and confirm that heart size influences epsilon and SR, which are highly load-dependent parameters.

Enhanced Recovery After Surgery: Are We Ready, and Can We Afford Not to Implement These Pathways for Patients Undergoing Radical Cystectomy?

Enhanced recovery after surgery (ERAS) for radical cystectomy seems logical, but our study has shown a paucity in the level of clinical evidence. As part of the ERAS Society, we welcome global collaboration to collect evidence that will improve patient outcomes.

The influence of frame rate on two-dimensional speckle-tracking strain measurements: a study on silico-simulated models and images recorded in patients

AIMS Ultrasound-derived myocardial strain can render valuable diagnostic and prognostic information. However, acquisition settings can have an important impact on the measurements. Frame rate (i.e. temporal resolution) seems to be of particular importance. The aim of this study was to find the optimal range of frame rates needed for most accurate and reproducible 2D strain measurements using a 2D speckle-tracking software package. METHODS AND RESULTS Synthetic two dimensional (2D) ultrasound grey-scale images of the left ventricle (LV) were generated in which the strain in longitudinal, circumferential, and radial direction were precisely known from the underlying kinematic LV model. Four different models were generated at frame rates between 20 and 110 Hz. The resulting images were repeatedly analysed. Results of the synthetic data were validated in 66 patients, where long- and short-axis recordings at different frame rates were analysed. In simulated data, accurate strain estimates could be achieved at >30 frames per cycle (FpC) for longitudinal and circumferential strains. Lower FpC underestimated strain systematically. Radial strain estimates were less accurate and less reproducible. Patient strain displayed the same plateaus as in the synthetic models. Higher noise and the presence of artefacts in patient data were followed by higher measurement variability. CONCLUSION Standard machine settings with a FR of 50-60 Hz allow correct assessment of peak global longitudinal and circumferential strain. Correct definition of the region of interest within the myocardium as well as the reduction of noise and artefacts seem to be of highest importance for accurate 2D strain estimation.

Cardioprotective effect of pretreatment with b-glucan in coronary artery bypass grafting

Background. β-glucan pretreatment has been shown to attenuate inflammatory response and to protect against ischemia-reperfusion injury in animal studies. The aims of the present study were to examine the safety of pretreatment with β-1,3/1,6-glucan in patients scheduled for coronary artery bypass grafting (CABG), and to investigate whether β-1,3/1,6-glucan pretreatment could suppress inflammatory response and protect against ischemia-reperfusion injury following CABG. Methods. Twenty one patients scheduled for CABG were assigned to oral β-1,3/1,6-glucan 700 mg (Group 1) or 1 400 mg (Group 2) five consecutive days before surgery and were compared with a control group (Group 3). Blood samples were drawn preoperatively and on the first, third and fifth postoperative day for analysis of acute-phase reactants, hematology, cytokines and myocardial enzymes. Results. The study drug was well tolerated. Creatine kinase isoenzyme MB was significantly lower in Group 2 compared with controls on the first postoperative day (p = 0.028). Mean change in cardiac troponin T was lower in Group 2 compared with controls (p = 0.028). Conclusions. β-1,3/1,6-glucan pretreatment is safe in patients undergoing CABG and may protect against ischemia reperfusion injury following CABG.

Peak longitudinal strain most accurately reflects myocardial segmental viability following acute myocardial infarction - an experimental study in open-chest pigs

BackgroundThe extension and the transmurality of the myocardial infarction are of high predictive value for clinical outcome. The aim of the study was to characterize the ability of longitudinal, circumferential and radial strain measured by 2-dimensional speckle tracking echocardiography (2D-STE) to predict the extent of necrosis in myocardial segments following acute myocardial infarction and to separate transmural necrotic segments from non-transmural necrotic segments in a full 18-segment porcine model.Methods2D-STE strain was assessed in long- and short-axis following myocardial infarction in ten open-chest anesthetized pigs. Strain was defined according to systolic peak values. In segments displaying both negative and positive peaks, only the peak with the highest absolute value was utilized. Necrosis was measured by 2,3,5-triphenyltetrazolium chloride (TTC) staining and expressed as percent of each myocardial segment.ResultsSignificant correlations were found between the extension of necrosis and all measured parameters of myocardial deformation (p < 0.001), but was stronger for longitudinal strain (r2 = 0.52) than circumferential strain (r2 = 0.38) and radial strain (r2 = 0.23). The area under the receiver operator characteristic curve (AUC) for separating transmural necrotic segments (>50% necrosis) from predominantly viable segments (0–50% necrosis) was significantly larger for longitudinal strain (AUC = 0.98, CI = 0.97–1.00) when compared with circumferential strain (AUC = 0.91, CI = 0.84–0.97, p < 0.05) and radial strain (AUC = 0.90, CI = 0.83 – 0.96, p < 0.01), indicating a stronger ability of longitudinal strain to identify segments with transmural necrosis.ConclusionPeak strain values derived from 2D-STE correlate well with the extent of necrosis in myocardial segments following acute myocardial infarction. Longitudinal strain most accurately reflects myocardial segmental viability in this setting.

High Resolution Speckle Tracking Dobutamine Stress Echocardiography Reveals Heterogeneous Responses in Different Myocardial Layers: Implication for Viability Assessments

BACKGROUND Speckle-tracking echocardiography (STE) can be used to quantify wall strain in 3 dimensions and thus has the potential to improve the identification of hypokinetic but viable myocardium on dobutamine stress echocardiography (DSE). However, if different myocardial layers respond heterogeneously, STE-DSE will have to be standardized according to strain dimension and the positioning of the region of interest. Therefore, the aim of this study was to create a high-resolution model for ejection time (ET) strain and tissue flow in 4 myocardial layers at rest, during hypoperfusion, and during dobutamine challenge to assess the ability of STE-DSE to detect deformation and functional improvement in various layers of the myocardium. METHODS In 10 open chest pigs, the left anterior descending coronary artery was constricted to a constant stenosis, resulting in 35% initial flow reduction. Fluorescent microspheres were used to measure tissue flow. High-resolution echocardiography was performed epicardially to calculate ET strain in 4 myocardial layers in the radial, longitudinal, and circumferential directions using speckle-tracking software. Images were obtained at rest, during left anterior descending coronary artery constriction (hypoperfusion), and during a subsequent dobutamine stress period. RESULTS Dobutamine stress at constant coronary stenosis increased flow in all layers. ET strain increased predominantly in the midmyocardial layers in the longitudinal and circumferential directions, whereas subendocardial strain did not improve in either direction. CONCLUSION Dobutamine stress influences ET strain differently in the various axes and layers of the myocardium and only partially in correspondence to tissue flow. Longitudinal and circumferential functional reserve opens the potential for the specific detection of midsubendocardial viable tissue by high-resolution STE.

Telemedical technologies in urological cancer care: past, present and future applications

Since the initial development of telegraphy by Sir Charles Wheatstone in 1837 and the telephone by Alexander Graham Bell in 1875, doctors have been able to convey medical information across great distances. The exchange and sharing of medical information has evolved and adapted to suit the vast array of today’s medicine. Early adopters of telemedicine within clinical practice have gained significant health economic benefits. The arrival of wireless connections has further enhanced the possibilities for all clinical work with focus on diagnosis, treatment and management of urological cancers, as highlighted in this article.

Oral β-glucan reduces infarction size and improves regional contractile function in a porcine ischaemia/reperfusion model

OBJECTIVES We previously reported a cardioprotective effect of oral β-glucan in patients who underwent coronary artery bypass grafting. The present study was conducted to determine whether oral β-glucan could reduce myocardial infarction size and whether these changes would be reflected by better preservation of contractile indices measured by speckle tracking echocardiography (STE). METHODS Fourteen pigs were randomized to receive oral β-glucan 50 mg/kg (n = 7) or placebo (control, n = 7) 10 days before they were anaesthetized and subjected to 1 h clamping of the left anterior descending coronary artery followed by reperfusion for 3 h. Longitudinal strain, circumferential strain and radial strain were assessed by STE after 3 h of reperfusion. Infarction size and area at risk were determined by Evans blue and 2,3,5-triphenyltetrazolium chloride staining. RESULTS Pretreatment with β-glucan reduced the infarct area/area at risk ratio by 36% (P < 0.05) and the total necrotic area of the left ventricle by 37% (P < 0.05) compared with controls. Viable myocardium at risk was 30% higher in the β-glucan vs. control group (P < 0.05). Anterior apical strain values for β-glucan vs. control were -4.7 ± 9.4 vs. 5.9 ± 6.1% (P < 0.05) for longitudinal strain, -14.7 ± 6.6 vs. -7.7 ± 4.3 (P < 0.05) for circumferential strain, 15.1 ± 7.7 vs. 7.1 ± 11.8 (ns) for radial strain. CONCLUSIONS Oral β-glucan pretreatment reduces infarction size and improves regional contractile function in a porcine ischaemia/reperfusion model.

Strategies to improve quality of life in bladder cancer patients

Bladder cancer is a heterogeneous disease that includes both tumors with low risk of dissemination as well as highly malignant tumors with a considerable potential to metastasize. The patient’s quality of life is closely related to the management of the disease. The challenge for the urologist is to acknowledge the malignant potential of the cancer and to adjust the approach to the patient accordingly. Patients with low-risk bladder cancer should avoid an exaggerated follow-up, but on the other hand high-risk patients must be sufficiently surveyed to secure that definitive surgical treatment is performed before it’s too late. When the decision to perform a cystectomy has been made, it is crucial that the patient understands the consequences of the surgery as well as the possible options for urinary reconstruction. This review focuses on aspects of bladder cancer management that we believe are vital for the quality of life of these patients.

Contemplating bladder cancer care: can we cut costs and improve quality of care?

Amid the increased focus on cost– effectiveness brought upon us by the recently signed Patient Protection and Affordable Care Act and the emergence of the economic crisis in Europe, an article published in this issue of Expert Review of Anticancer Therapy addresses the pharmaco economic aspects of the most expensive cancer per capita in the USA – bladder cancer [1]. Bladder cancer is a heterogeneous disease that includes indolent urothelial neoplasms confined within the lamina propria of the bladder mucosa, as well as muscle-infiltrating cancers with high risk of spreading to other organs. Although the former and the latter cancer originate from a urothelial cell, their potential for growth and their ability to spread differ profoundly, and consequently there are important differences related to their management and followup. A small, low-grade cancer without concurrent carcinoma in situ confined to the urothelium of the bladder mucosa should be managed by a transurethral resection followed by intravesical chemotherapy and monitored by cystoscopy after 3 and 6 months, and thereafter annually for 5 years [2]. On the other hand, patients suffering from bladder cancer infiltrating the muscle layer should be scheduled for radical cystectomy. Radical cystectomy involves the complete extirpation of the bladder with subsequent deviation of the urine through a cystostoma and typically includes removal of the prostate in men, and the uterus, ovaries and anterior vaginal wall in women. The procedure has a severe impact on urinary function, sexual function, body image and mental health. However, once bladder cancer has infiltrated the underlying muscle, it represents the only treatment option that can offer a cancer-free survival, provided the cancer has not spread outside of the bladder.