Effects of Ischemic Reperfusion Injury and Remote Conditioning on Passive Leg Raising-Induced Brachial-Artery Dilation.

OBJECTIVES: Passive leg raising (PLR) has been proposed to assess arterial vasodilator reserve and possibly endothelial function. Since endothelial function is sensitive to ischemic-reperfusion (I-R) injury, we determined the effects of I-R injury and ischemic conditioning on PLR-induced brachial-artery dilation (BAD), i.e. PLR-BAD. METHODS: We induced PLR-BAD before and after ipsilateral arm I-R injury (7.5 min of occlusion) in 20 healthy males aged 29 ± 6 years. The protocol was repeated in combination with remote conditioning stimuli (3 × 30 s of contralateral arm occlusions). RESULTS: PLR resulted in significant BAD (3.85%, p < 0.001) before but not after prolonged ischemia (0.25%, p = 0.38). I-R injury, along with either preischemic or postischemic conditioning restored the PLR-BAD response (before: 3.11%, p < 0.001 and after: 3.74%, p < 0.001). CONCLUSIONS: I-R injury blunts the BAD induced by PLR. Remote pre- and postconditioning restore this response. These findings are similar to those previously reported using hyperemia and ultrasound to assess BAD.

Diastolic function improves after resolution of takotsubo cardiomyopathy.

BACKGROUND: Takotsubo cardiomyopathy (TTC) is a condition of reversible left ventricular (LV) systolic dysfunction. However, the diastolic function (DF) manifestations of TTC have not been widely investigated. We performed a bicentric study with retrospective analysis of DF in patients with TTC, during onset and at follow-up. METHODS: Twenty-eight patients with TTC (64 ± 10 years, F 24) were included. All underwent echocardiograms acutely and at the recovery phase (average three months later). Diastolic and systolic function parameters were recorded, including E-wave velocity (E), A-wave velocity, E/A ratio, relaxation (e') and contractility (S') based on tissue Doppler velocities of the mitral annuli, ejection fraction (EF), left atrial (LA) size and DF stages. RESULTS: Recovery, including the mean difference with 95% confidence interval, was associated with tending improvement (i.e. uncorrected significance) in E [13 cm s(-1) (-24, -2·3), P = 0·02] and in E/A ratio [0·2 (-0·41, -0·02), P = 0·04], as well as significant improvement (after multiple comparison correction) in mean e' [2·0 cm s(-1) (-3·3, -1·2), P<0·001] and in A-wave duration [29 ms (-46·7, -12·7), P = 0·002]. LA area tended to decrease during recovery [-2 cm² (0·33, 2·4), P = 0·01]. Improvement in DF stages was significant between the phases (21% versus 58% defined as normal DF, P = 0·016). Improvement in LVEF correlated with improvement in mean e' (r = 0·52, P = 0·02). CONCLUSIONS: TTC is associated with an acute impairment of conventional DF variables, which improves during recovery. DF recovery seems to occur in parallel with systolic recovery in patients with TTC.

Left ventricular systolic function in sickle cell anemia: a meta-analysis.

BACKGROUND: We sought to evaluate whether patients with sickle cell anemia (SCA) have left ventricular (LV) systolic dysfunction. METHODS AND RESULTS: We conducted a Medline, Embase, Ebscohost, and Google scholar literature search articles published before April 2010. All studies that compared any measure of LV function (eg, ejection fraction [EF], fractional shortening [FS], or cardiac index [CI]) between normal control subjects and SCA (hemoglobin SS) patients were included. Among 57 studies that qualified for review, 19 studies including 841 SCA patients and 554 control subjects met the inclusion criteria. There were no significant differences in either LVEF (Hedge g = 0.15; 95% confidence interval -0.84 to 1.14; P = .76) or FS (P = .28) between SCA patients and control subjects. CI was significantly higher (P < .001) and LV end-systolic stress-volume index (load independent) was significantly lower (P < .001) in SCA patients. All LV systolic measures inversely correlated with age (all P < .001). LV end-systolic and -diastolic dimensions were significantly higher in SCA patients and increased with age. CONCLUSIONS: SCA patients have similar load-dependent but lower load-independent measures of LV systolic function than control subjects. SCA is associated with LV dilation. LV structural and functional abnormalities appear to be age dependent with progressive LV dilation and impairment over time.