Concentric and Eccentric Remodelling of the Left Ventricle and Its Association to Function in the Male Athletes Heart: An Exploratory Study

Aims To compare (1) conventional left ventricular (LV) functional parameters, (2) LV peak strain and strain rate and (3) LV temporal strain and strain rate curves in age, ethnicity and sport-matched athletes with concentric, eccentric and normal LV geometry.Methods Forty-five male athletes were categorised according to LV geometry including concentric remodelling/hypertrophy (CON), eccentric hypertrophy (ECC) or normal (NORM). Athletes were evaluated using conventional echocardiography and myocardial speck tracking, allowing the assessment of myocardial strain and strain rate; as well as twist mechanics. Results Concentric remodelling was associated with an increased ejection fraction (EF) compared to normal geometry athletes (64% (48-78%) and 56% (50-65%), respectively; p < 0.04). No differences in peak myocardial strain or strain rate were present between LV geometry groups including global longitudinal strain (GLS; CON -16.9% (-14.9-20.6%); ECC -17.9% (-13.0-22.1%); NORM -16.9% (-12.8-19.4%)), global circumferential strain (GCS; CON -18.1% (-13.5-24.5%); ECC -18.7% (-15.6-22.4%); NORM -18.0% (-13.5-19.7%)), global radial strain (GRS; CON 42.2% (30.3-70.5%); ECC 50.0% (39.2-60.0%); NORM 40.6 (29.9-57.0%)) and twist (CON 14.9° (3.7-25.3°); ECC 12.5° (6.3-20.8°); NORM 13.2° (8.8-24.2°)). Concentric and eccentric remodelling was associated with alterations in temporal myocardial strain and strain rate as compared to normal geometry athletes. Conclusion Physiological concentric and eccentric remodelling in the athletes heart is generally associated with normal LV function; with concentric remodelling associated with an increased EF. Physiological concentric and eccentric remodelling in the athletes heart has no effect on peak myocardial strain but superior deformation and untwisting is unmasked when assessing the temporal distribution

Reduced Cardiovascular Reserve in Chronic Kidney Failure: A Matched Cohort Study

Background: Patients with chronic kidney failure (CKF) experience impaired functional cardiovascular reserve with reduced oxygen consumption at peak exercise (Vo2peak). No studies have examined whether this is related to impaired cardiovascular compliance as a consequence of loss of adaptive structural alterations, resulting from chronic uremia or hypertension. Study Design: Prospective matched-cohort study. Setting & Participants: We assessed CKF in parallel with patients with essential hypertension but without cardiovascular disease. Patients with CKF were either scheduled for kidney transplantation or transplant waitlisted. 80 patients with CKF and 80 with essential hypertension matched in age, sex, and body mass index were evaluated. 61 patients with CKF (76.3%) were dialysis dependent. Predictor: CKF versus essential hypertension without cardiovascular disease. Measurements & Outcomes: Vo2peak was measured during maximal exercise testing. 2-dimensional echocardiography and arterial applanation tonometry were performed prior to exercise testing. To evaluate for the difference in Vo2peak between study groups, statistically significant predictors of Vo2peak in multiple regression models were additionally assessed by fitting models comprising the interaction term of patient group with the predictor variable of interest. Results: Vo2peak was significantly lower in patients with CKF than those with essential hypertension (18.8 vs 24.5 mL/min·kg; P < 0.001). Independent predictors of Vo2peak for CKF included left ventricular (LV) filling pressure (E/mean e′; unstandardized regression coefficient: change in Vo2peak [in mL/min·kg] per 1-unit change of variable = −5.1) and pulse wave velocity (−4.0); in essential hypertension, these were LV mass index (0.2), LV end-diastolic volume index (0.4), peak heart rate (0.2), and pulse wave velocity (−8.8). The interaction effect of Vo2peak between patient groups with LV mass index (P < 0.001), LV end-diastolic volume index (P < 0.001), and peak heart rate (P < 0.01) were significantly stronger in the hypertension group, whereby higher values led to greater Vo2peak. Limitations: Skeletal muscle strength was not assessed. Conclusion: This study suggests that maladaptive LV changes, as well as blunted chronotropic response, are important mechanistic factors resulting in reduced cardiovascular reserve in patients with CKF, beyond predominantly vascular changes associated with hypertension

British Society of Echocardiography guideline for the transthoracic echocardiographic assessment of cardiac amyloidosis

These guidelines form an update of the BSE guideline protocol for the assessment of restrictive cardiomyopathy (Knight et al. in Echo Res Prac, 2013). Since the original recommendations were conceived in 2013, there has been an exponential rise in the diagnosis of cardiac amyloidosis fuelled by increased clinician awareness, improvements in cardiovascular imaging as well as the availability of new and effective disease modifying therapies. The initial diagnosis of cardiac amyloidosis can be challenging and is often not clear-cut on the basis of echocardiography, which for most patients presenting with heart failure symptoms remains the first-line imaging test. The role of a specialist echocardiographer will be to raise the suspicion of cardiac amyloidosis when appropriate, but the formal diagnosis of amyloid sub-type invariably requires further downstream testing. This document seeks to provide a focused review of the literature on echocardiography in cardiac amyloidosis highlighting its important role in the diagnosis, prognosis and screening of at risk individuals, before concluding with a suggested minimum data set, for use as an aide memoire when reporting

Left and right ventricular longitudinal strain-volume/area relationships in elite athletes.

We propose a novel ultrasound approach with the primary aim of establishing the temporal relationship of structure and function in athletes of varying sporting demographics. 92 male athletes were studied [Group IA, (low static-low dynamic) (n = 20); Group IC, (low static-high dynamic) (n = 25); Group IIIA, (high static-low dynamic) (n = 21); Group IIIC, (high static-high dynamic) (n = 26)]. Conventional echocardiography of both the left ventricles (LV) and right ventricles (RV) was undertaken. An assessment of simultaneous longitudinal strain and LV volume/RV area was provided. Data was presented as derived strain for % end diastolic volume/area. Athletes in group IC and IIIC had larger LV end diastolic volumes compared to athletes in groups IA and IIIA (50 ± 6 and 54 ± 8 ml/(m(2))(1.5) versus 42 ± 7 and 43 ± 2 ml/(m(2))(1.5) respectively). Group IIIC also had significantly larger mean wall thickness (MWT) compared to all groups. Athletes from group IIIC required greater longitudinal strain for any given % volume which correlated to MWT (r = 0.4, p < 0.0001). Findings were similar in the RV with the exception that group IIIC athletes required lower strain for any given % area. There are physiological differences between athletes with the largest LV and RV in athletes from group IIIC. These athletes also have greater resting longitudinal contribution to volume change in the LV which, in part, is related to an increased wall thickness. A lower longitudinal contribution to area change in the RV is also apparent in these athletes

Speckle Tracking Echocardiography for the Assessment of the Athlete's Heart: Is It Ready for Daily Practice?

PURPOSE OF REVIEW: To describe the use of speckle tracking echocardiography (STE) in the biventricular assessment of athletes' heart (AH). Can STE aid differential diagnosis during pre-participation cardiac screening (PCS) of athletes? RECENT FINDINGS: Data from recent patient, population and athlete studies suggest potential discriminatory value of STE, alongside standard echocardiographic measurements, in the early detection of clinically relevant systolic dysfunction. STE can also contribute to subsequent prognosis and risk stratification. Despite some heterogeneity in STE data in athletes, left ventricular global longitudinal strain (GLS) and right ventricular longitudinal strain (RV ɛ) indices can add to differential diagnostic protocols in PCS. STE should be used in addition to standard echocardiographic tools and be conducted by an experienced operator with significant knowledge of the AH. Other indices, including left ventricular circumferential strain and twist, may provide insight, but further research in clinical and athletic populations is warranted. This review also raises the potential role for STE measures performed during exercise as well as in serial follow-up as a method to improve diagnostic yield

Long-Lasting Control of Anopheles arabiensis by a Single Spray Application of Micro-encapsulated Pirimiphos-methyl (Actellic(R) 300 CS).

Pyrethroid-resistant mosquitoes are an increasing threat to malaria vector control. The Global Plan for Insecticide Resistance Management (GPIRM) recommends rotation of non-pyrethroid insecticides for indoor residual spraying (IRS). The options from other classes are limited. The carbamate bendiocarb and the organophosphate pirimiphos-methyl (p-methyl) emulsifiable concentrate (EC) have a short residual duration of action, resulting in increased costs due to multiple spray cycles, and user fatigue. Encapsulation (CS) technology was used to extend the residual performance of p-methyl. Two novel p-methyl CS formulations were evaluated alongside the existing EC in laboratory bioassays and experimental hut trials in Tanzania between 2008-2010. Bioassays were carried out monthly on sprayed substrates of mud, concrete, plywood, and palm thatch to assess residual activity. Experimental huts were used to assess efficacy against wild free-flying Anopheles arabiensis, in terms of insecticide-induced mortality and blood-feeding inhibition. In laboratory bioassays of An. arabiensis and Culex quinquefasciatus both CS formulations produced high rates of mortality for significantly longer than the EC formulation on all substrates. On mud, the best performing CS killed >80% of An. arabiensis for five months and >50% for eight months, compared with one and two months, respectively, for the EC. In monthly bioassays of experimental hut walls the EC was ineffective shortly after spraying, while the best CS formulation killed more than 80% of An. arabiensis for five months on mud, and seven months on concrete. In experimental huts both CS and EC formulations killed high proportions of free-flying wild An. arabiensis for up to 12 months after spraying. There was no significant difference between treatments. All treatments provided considerable personal protection, with blood-feeding inhibition ranging from 9-49% over time. The long residual performance of p-methyl CS was consistent in bioassays and experimental huts. The CS outperformed the EC in laboratory and hut bioassays but the EC longevity in huts was unexpected. Long-lasting p-methyl CS formulations should be more effective than both p-methyl EC and bendiocarb considering a single spray could be sufficient for annual malaria control. IRS with p-methyl 300 CS is a timely addition to the limited portfolio of long-lasting residual insecticides

The Impact of Pyrethroid Resistance on the Efficacy of Insecticide-Treated Bed Nets against African Anopheline Mosquitoes: Systematic Review and Meta-Analysis

Background Pyrethroid insecticide-treated bed nets (ITNs) help contribute to reducing malaria deaths in Africa, but their efficacy is threatened by insecticide resistance in some malaria mosquito vectors. We therefore assessed the evidence that resistance is attenuating the effect of ITNs on entomological outcomes. Methods and Findings We included laboratory and field studies of African malaria vectors that measured resistance at the time of the study and used World Health Organization–recommended impregnation regimens. We reported mosquito mortality, blood feeding, induced exophily (premature exit of mosquitoes from the hut), deterrence, time to 50% or 95% knock-down, and percentage knock-down at 60 min. Publications were searched from 1 January 1980 to 31 December 2013 using MEDLINE, Cochrane Central Register of Controlled Trials, Science Citation Index Expanded, Social Sciences Citation Index, African Index Medicus, and CAB Abstracts. We stratified studies into three levels of insecticide resistance, and ITNs were compared with untreated bed nets (UTNs) using the risk difference (RD). Heterogeneity was explored visually and statistically. Included were 36 laboratory and 24 field studies, reported in 25 records. Studies tested and reported resistance inconsistently. Based on the meta-analytic results, the difference in mosquito mortality risk for ITNs compared to UTNs was lower in higher resistance categories. However, mortality risk was significantly higher for ITNs compared to UTNs regardless of resistance. For cone tests: low resistance, risk difference (RD) 0.86 (95% CI 0.72 to 1.01); moderate resistance, RD 0.71 (95% CI 0.53 to 0.88); high resistance, RD 0.56 (95% CI 0.17 to 0.95). For tunnel tests: low resistance, RD 0.74 (95% CI 0.61 to 0.87); moderate resistance, RD 0.50 (95% CI 0.40 to 0.60); high resistance, RD 0.39 (95% CI 0.24 to 0.54). For hut studies: low resistance, RD 0.56 (95% CI 0.43 to 0.68); moderate resistance, RD 0.39 (95% CI 0.16 to 0.61); high resistance, RD 0.35 (95% CI 0.27 to 0.43). However, with the exception of the moderate resistance category for tunnel tests, there was extremely high heterogeneity across studies in each resistance category (chi-squared test, p<0.00001, I2 varied from 95% to 100%). Conclusions This meta-analysis found that ITNs are more effective than UTNs regardless of resistance. There appears to be a relationship between resistance and the RD for mosquito mortality in laboratory and field studies. However, the substantive heterogeneity in the studies' results and design may mask the true relationship between resistance and the RD, and the results need to be interpreted with caution. Our analysis suggests the potential for cumulative meta-analysis in entomological trials, but further field research in this area will require specialists in the field to work together to improve the quality of trials, and to standardise designs, assessment, and reporting of both resistance and entomological outcomes