A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was 'Does tranexamic acid stop haemoptysis'? Altogether 49 papers were found using the reported search strategy, of which 13 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. This consisted of one systematic review including a meta-analysis of two double-blind randomized controlled trials (RCTs), the two RCTs, one cohort study, two case-series and seven case reports. Main outcomes included bleeding time, bleeding volume and occurrence of thromboembolic complications after start of treatment. Based on results from the meta-analysis, no difference in remission of bleeding within 1 week was found between tranexamic acid (TA) and placebo groups (odds ratio 1.56, 95% CI: 0.44-5.46). However, overall bleeding time was significantly shorter for the TA group (weighted mean difference -19.47, 95% CI: -26.90, -12.03 h). In one RCT, TA reduced both the duration and the volume of bleeding compared with patients receiving placebo (both P < 0.0005). However, the other RCT failed to find a difference in bleeding time (P = 0.2). In these studies, no patient suffered from thromboembolic complications. Two case reports, however, describe development of pulmonary embolism during TA treatment. Several case reports on the use of TA for treatment of haemoptysis secondary to cystic fibrosis were found. In general, they suggest that TA may be a useful and well-tolerated medication for the treatment of intractable haemoptysis in this patient group. We conclude that limited research on the use of TA for treatment of haemoptysis exists. As aetiology of haemoptysis as well as length of treatment, dosage and form of TA administration varied between the studies, strong recommendations are difficult to give. Current best evidence, however, indicates that TA may reduce both the duration and volume of bleeding, with low risk of short-term thromboembolic complications, in patients with haemoptysis.

This study investigates how tissue Doppler imaging (TDI) and speckle tracking echocardiography (STE) describe regional myocardial deformation during controlled reductions of left anterior descending (LAD) coronary artery perfusion pressure. In eight anesthetized pigs, a shunt with constrictor was installed from the brachiocephalic artery to the LAD. Data were obtained with open shunt, followed by four degrees of stenosis (S1-S4) of increasing severity: S1, ∼15%; S2, ∼35%; S3, ∼50%; and S4, ∼60% reductions of LAD perfusion pressure. At each situation, microspheres for perfusion measurements were injected and left ventricular (LV) short- and long-axis cineloops were recorded. In the anterior wall, radial, circumferential, and longitudinal one-layer STE strain, one-layer radial TDI strain, and three-layer radial TDI and STE strain were measured. LV peak mean rotation was measured at six equidistant levels from apex to base (in 7 pigs). LV torsion was calculated from end-systolic mean rotation. With open shunt, three-layer TDI analysis showed a transmural strain gradient with no perfusion gradient. Perfusion, one-layer TDI strain, and strain in the mid- and subendocardium from three-layer TDI were reduced at S2 (P < 0.05). STE strain was not affected until S3 (P < 0.05). Peak mean rotation, increasing toward the apex, decreased at the three apical levels at S4 (P < 0.05). LV torsion did not decrease (P = 0.26). In conclusion, TDI strain detected dysfunction already with minor changes in global hemodynamics, whereas STE strain was first reduced with moderate changes. LV peak mean rotation was not reduced until severe reduction of LAD perfusion pressure, but remained increasingly counterclockwise toward the apex. LV torsion remained unaffected by ischemia.

Noninvasive measurements of myocardial strain and strain rate by speckle tracking echocardiography correlate to cardiac contractile state but also to load, which may weaken their value as indices of inotropy. In a porcine model, we investigated the influence of acute dynamic preload reductions on left ventricular strain and strain rate and their relation to the pressure-conductance catheter-derived preload recruitable stroke work (PRSW) and peak positive first derivative of left ventricular pressure (LV-dP/dtmax). Speckle tracking strain and strain rate in the longitudinal, circumferential, and radial directions were measured during acute dynamic reductions of end-diastolic volume during three different myocardial inotropic states. Both strain and strain rate were sensitive to unloading of the left ventricle (P < 0.001), but the load dependency for strain rate was modest compared with strain. Changes in longitudinal and circumferential strain correlated more strongly to changes in end-diastolic volume (r = -0.86 and r = -0.72) than did radial strain (r = 0.35). Longitudinal, circumferential, and radial strain significantly correlated with LV-dP/dtmax (r = -0.53, r = -0.46, and r = 0.86), whereas only radial strain correlated with PRSW (r = 0.55). Strain rate in the longitudinal, circumferential and radial direction significantly correlated with both PRSW (r = -0.64, r = -0.58, and r = 0.74) and LV-dP/dtmax (r = -0.95, r = -0.70, and r = 0.85). In conclusion, the speckle tracking echocardiography-derived strain rate is more robust to dynamic ventricular unloading than strain. Longitudinal and circumferential strain could not predict load-independent contractility. Strain rates, and especially in the radial direction, are good predictors of preload-independent inotropic markers derived from conductance catheter.

Aims: This study investigates whether subendocardial ischemia can be detected by measuring multilayer radial systolic strain from epicardial tissue Doppler imaging. Methods:In 10 anesthetized open-chest pigs an extracorporeal shunt from the proximal brachiocephalic to the left anterior descending coronary artery was constricted in steps. Color microsphere injections and short axis Tissue Velocity Imaging (TVI) recordings were performed with open shunt, with a non-significant stenosis, and with 2 steps of shunt flow reduction.Results: With open shunt and no transmural flow gradient, there was a gradient of peak ejection strain with high values subendocardially for both 4 and 2 layer measurements. For 2 layer measurement strain was 56.0 AE 10.5% subendocardially and 22.0 AE 5.2% subepicardially. A non-significant stenosis, not altering transmural flow distribution, reduced strain to 40.3 AE 5.4% in the endocardial half-layer. With reduced shunt flow resulting in subendocardial ischemia, peak ejection strain decreased further, primarily in inner wall layers, and postsystolic strain became evident. At severe stenosis (52.4 AE 1.8% shunt flow reduction) strain was reduced to 3.8 AE 3.6% in the subendocardium and 0.0 AE 2.6% in the subepicardium. Conclusion: Evaluation of myocardial function with multilayer radial systolic strain has a potential for detecting subendocardial ischemia.

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We have demonstrated that it is feasible to measure radial velocity, strain rate and strain in up to three individual layers in young healthy humans, and the diagnostic potentials should be tested on patient groups.

Objective: Myocardial dysfunction after reperfusion can be a clinical problem in the early postoperative phase after on-pump cardiac surgery. The aim was, in an experimental setting, to investigate if administration of the b-adrenergic receptor blocker esmolol prior to cross-clamping for 80 min with cold oxygenated blood cardioplegia would improve myocardial protection and early postoperative function. Methods: Twenty-four anaesthetised pigs were randomly allocated into one of two equally sized groups and put on mild hypothermic cardiopulmonary bypass. Esmolol 1 mg kg À1 or saline was administered into the arterial line 4 min prior to aortic cross-clamp. Cardiac arrest during 80 min of cross-clamp was obtained with repeated antegrade cold oxygenated blood cardioplegia; the pigs were weaned from bypass following a standardised protocol. Left ventricular global and regional myocardial function and tissue blood flow were evaluated with conductance catheter, echocardiography and coloured microspheres at baseline and at 1, 2 and 3 h after declamping. Four animals did not fulfil the protocol and were excluded. Results: No significant differences between groups could be demonstrated for left ventricular global and local function and tissue blood flow at baseline. At 1 h after declamping the slope of preload recruitable stroke work (PRSW slope ) averaged 73.7 AE 12.7 mmHg (SD) in controls and 72.7 AE 11.1 mmHg in esmolol-treated animals. In controls PRSW slope decreased to 62.1 AE 11.0 and 58.4 AE 12.7 mmHg after 2 and 3 h, respectively ( p < 0.005 vs 1 h for both). In the esmolol-treated animals PRSW slope remained unchanged at 72.0 AE 11.4 and 73.7 AE 12.9 mmHg at 2 and 3 h after declamp and were significantly higher ( p < 0.025 and <0.001) than the corresponding values in the control group. The slope of the end systolic pressure volume relationship did not differ between groups at 1 and 2 h after declamp, but were 1.85 AE 0.86 and 2.51 AE 0.96 mmHg ml À1 in controls and in esmolol-treated animals, respectively, after 3 h ( p < 0.025). Conclusions: Esmolol administered prior to cold oxygenated cardioplegic arrest alleviates left ventricular dysfunction in the early hours after cardiopulmonary bypass. #

Esmolol added to blood cardioplegia preserved systolic cardiac function during the first 3 hours after reperfusion in a porcine model with 100 minutes of cardioplegic arrest.