No abstract

Background-The dynamics of systolic and diastolic strains and torsional mechanics of the left ventricle (LV) and their relation to diastolic filling never have been evaluated at various exercise intensities. Methods and Results-Speckle tracking echocardiography was performed in 20 healthy sedentary subjects at rest and during a progressive submaximal exercise test at 20%, 30%, and 40% of maximal aerobic power. LV twist increased progressively with exercise intensity (10.5Ϯ3.2 to 15.8Ϯ4.5°; PϽ0.001), whereas longitudinal strain remained unchanged after the first workload, underlining the key role of torsional reserve in systolic-diastolic coupling during exercise. The increase in diastolic untwisting (Ϫ88.7Ϯ34.2 to Ϫ182.9Ϯ53.5 deg ⅐ s Ϫ1 ; PϽ0.01) was correlated to enhanced systolic twist (Rϭ0.61; PϽ0.001), and its magnitude of increase was significantly higher compared to diastolic longitudinal and circumferential strain rates (119Ϯ64% versus 65Ϯ44% and 57Ϯ24%, respectively), emphasizing its contribution to diastolic filling. The timing of peak untwisting and the chronology of diastolic mechanical events were unchanged during effort. Untwisting was driven mainly by apical rotation and determined mitral opening and isovolumic relaxation time (Rϭ0.47 and 0.61, respectively; PϽ0.001), whereas basal rotation and longitudinal and circumferential diastolic strain rates were major determinants of increased early diastolic filling (Rϭ0.64, 0.79, and 0.81, respectively; PϽ0.001). Conclusions-The use of speckle tracking echocardiography gives new insights into physiological adaptive LV mechanics during incremental exercise in healthy subjects, underlining the key role of torsional mechanics. It might be useful to better understand the mechanisms of diastolic dysfunction and exercise intolerance in various pathological conditions. (Circ Cardiovasc Imaging. 2010;3:586-594.)

Background-Numerous studies have reported evidence of cardiac injury associated with transient left ventricular (LV) systolic and diastolic dysfunction after prolonged and strenuous exercise. We used 2D ultrasound speckle tracking imaging to evaluate the effect of an ultralong-duration exercise on LV regional strains and torsion. We speculated that systolic dysfunction after exercise is associated with depressed LV strains and torsion, and diastolic dysfunction results from decreased and delayed untwisting, a key factor of LV suction and early filling. Methods and Results-Twenty-three triathletes underwent conventional and speckle tracking imaging echocardiography at rest before and immediately after an ultralong distance triathlon. Measurements included LV longitudinal, circumferential and radial strains, LV rotations, and LV torsion. After the race, LV systolic dysfunction was characterized by a decrease in LV longitudinal, radial, and circumferential strains, especially for apical radial strains (44.6Ϯ15.1% versus 31.1Ϯ13.8%, PϽ0.001). Peak torsion was slightly decreased (8.3Ϯ5.1°versus 6.4Ϯ3.9°, respectively, Pϭ0.09) and significantly delayed (91Ϯ18% versus 128Ϯ31% of systolic duration, PϽ0.001) beside end-ejection. Peak untwisting was also depressed and delayed beside isovolumic relaxation. Conclusions-This study documented major alterations in cardiac strains and torsion after an ultralong distance triathlon.LV systolic strains were depressed but not delayed, whereas twisting was decreased and delayed. This altered pattern hampered the rapid untwisting during isovolumic relaxation phase, reducing LV diastolic suction and early filling.

Diastolic asynchrony is weakly correlated with QRS duration, is more frequent than systolic asynchrony, and may be observed alone. Diastolic asynchrony is less improved by CRT than systolic. Persistent diastolic asynchrony may explain some cases of lack of improvement after CRT despite good systolic resynchronization.

PurposeTo investigate preoperative ocular risk factors and indications for secondary intraocular lens (IOL) implantation and compare postoperative complications, visual and refractive outcomes in a tertiary referral center.MethodsPatients older than 14 years that underwent secondary IOL implantation and had a minimum follow-up of 3 months were enrolled in this retrospective case series. Preoperative ocular risk factors, indications for surgery, postoperative complications, and visual and refractive outcomes including prediction error (PE) and absolute error (AE) were evaluated. IOLs were fixated in following positions: anterior chamber (AC), retropupillary iris-claw (IC), sulcus, and capsular bag or sclera.ResultsOne-hundred eighty-two eyes of 174 patients with mean follow-up of 17 ± 13.6 months were evaluated. Leading cause for surgery was IOL dislocation (75%), followed by secondary aphakia (19%) and IOL opacifications (6%). Previous vitrectomy was the major preoperative ocular risk factor (43%). Mean corrected distance visual acuity improved from preoperative 0.68 ± 0.55 to 0.42 ± 0.31LogMAR by the last follow-up (p = 0.001). PE and AE differed highly depending on the indication for surgery (p = 0.041 and p = 0.008, respectively) and the IOL fixation (p = 0.011 and p = 0.028, respectively), with IC-IOLs showing the lowest PE and AE. Postoperative AC-hemorrhage occurred mainly after IC-IOLs (p = 0.003), and postoperative hypotony was significantly higher in eyes with previous uveitis (p = 0.026).ConclusionsPrevious vitrectomy seems to be a major underreported risk factor in eyes that undergo secondary IOL implantation. Refractive outcomes depend on indication for surgery and fixation type, with retropupillary IC-IOLs providing the best refractive results, though not statistically significant compared to other IOL positions.

Gómez, Ana M., Iris Schuster, Jérémy Fauconnier, Jü rgen Prestle, Gerd Hasenfuss, and Sylvain Richard. FKBP12.6 overexpression decreases Ca 2ϩ spark amplitude but enhances [Ca 2ϩ ]i transient in rat cardiac myocytes.

No abstract

Mild-to-moderate obesity in prepubertal boys without insulin resistance is associated with impaired endothelial function and blunted muscle perfusion response to local dynamic exercise without alteration of vascular smooth muscle reactivity.