Associations between heart rate variability and maximal fat oxidation in two different cohorts of healthy sedentary adults

Background and aimsResting heart rate variability (HRV) and maximal fat oxidation (MFO) during exercise are both considered as a noninvasive biomarkers for early detection of cardiovascular risk factors. Thus, this study aimed to analyze the relationship between resting HRV parameters and MFO during exercise, and the intensity of exercise that elicit MFO (Fat_max) in healthy sedentary adults.Methods and resultsA total of 103 healthy young adults (22.2 ± 2.3 years old, 67% female; from the ACTIBATE cohort) and 67 healthy middle-aged adults (53.1 ± 5.0 years old, 52% female; from the FIT-AGEING cohort) were included in this cross-sectional study. HRV was assessed using a Polar RS800CX heart rate monitor, while MFO and Fat_max were determined during a graded exercise treadmill test using indirect calorimetry. No significant associations were observed for healthy young adults (standardized β coefficients ranged from ?0.063 to 0.094, and all P ≥ 0.347) and for middle-aged adults (standardized β coefficients ranged from ?0.234 to 0.090, and all P ≥ 0.056). Nevertheless, only a weak association was observed between one HRV parameter in time-domain (the percentage of R-R intervals that shows a difference higher than 50 ms [pNN50]) and MFO in the cohort of middle-aged adults (β coefficient = ?0.279, and P = 0.033).ConclusionThe results of this study suggest that resting HRV parameters are not associated with MFO and Fat_max during exercise in two independent cohorts of healthy sedentary young and middle-aged adults, respectively.     

Outcomes of coronary artery bypass grafting in patients with heart failure with a midrange ejection fraction

BackgroundCoronary artery bypass grafting (CABG) improves survival in patients with heart failure and severely reduced left ventricular systolic function (LVEF). Limited data exist regarding adverse cardiovascular event rates after CABG in patients with heart failure with midrange ejection fraction (HFmrEF; LVEF > 40% and < 55%).MethodsWe analyzed data on isolated CABG patients from the Veterans Affairs national database (2010-2019). We stratified patients into control (normal LVEF and no heart failure), HFmrEF, and heart failure with reduced LVEF (HFrEF) groups. We compared all-cause mortality and heart failure hospitalization rates between groups with a Cox model and recurrent events analysis, respectively.ResultsIn 6533 veterans, HFmrEF and HFrEF was present in 1715 (26.3%) and 566 (8.6%) respectively; the control group had 4252 (65.1%) patients. HFrEF patients were more likely to have diabetes mellitus (59%), insulin therapy (36%), and previous myocardial infarction (31%). Anemia was more prevalent in patients with HFrEF (49%) as was a lower serum albumin (mean, 3.6 mg/dL). Compared with the control group, a higher risk of death was observed in the HFmrEF (hazard ratio [HR], 1.3 [1.2-1.5)] and HFrEF (HR, 1.5 [1.2-1.7]) groups. HFmrEF patients had the higher risk of myocardial infarction (subdistribution HR, 1.2 [1-1.6]; P = .04). Risk of heart failure hospitalization was higher in patients with HFmrEF (HR, 4.1 [3.5-4.7]) and patients with HFrEF (HR, 7.2 [6.2-8.5]).ConclusionsHeart failure with midrange ejection fraction negatively affects survival after CABG. These patients also experience higher rates myocardial infarction and heart failure hospitalization.     

Pump Speed Optimization in Patients Implanted With the HeartMate 3 Device

Background

Pump speed optimization in patients implanted with a ventricular assist device represents a major challenge during the follow-up period. We present our findings on whether combined invasive hemodynamic ramp tests and cardiopulmonary exercise testing (CPX) can help optimize patient management.

丙泊酚复合瑞芬太尼喉罩全麻的效果分析与研究

目的 探讨丙泊酚复合瑞芬太尼喉罩全身麻醉(全麻)的效果。方法 62例腹腔镜、泌尿科、骨科、肛肠科、妇科等手术治疗的患者,随机分为实验组和对照组,每组31例。对照组采用常规气管插管静脉复合全麻,实验组给予靶控输注丙泊酚复合瑞芬太尼喉罩全麻。比较两组患者插入喉罩(插管)、插管1 min、插管3 min、拔出喉罩(拔管)1 min、拔管3 min时心率(HR)和平均动脉压(MAP)水平;不良反应发生情况、麻醉效果;全麻起效时间、维持全麻时间、术后苏醒时间。结果 实验组插管时、插管1 min、插管3 min、拔管1 min、拔管3 min的HR水平分别为(77.52±6.36)、(73.26±5.56)、(72.01±4.69)、(75.35±7.63)、(72.34±6.79)次/min,均低于对照组的(92.34±7.85)、(87.97±5.25)、(78.85±5.20)、(95.69±9.21)、(85.63±7.43)次/min,差异均具有统计学意义(P<0.05)。实验组插管时、插管1 min、插管3 min、拔管1 min、拔管3 min的MAP水平分别为(90.25±6.73)、(87.65±7.98)、(88.79±7.65)、(88.09±5.61)、(88.52±5.16)mm Hg(1 mm Hg=0.133 kPa),均低于对照组的(109.51±7.85)、(103.27±12.43)、(102.52±8.21)、(106.74±7.68)、(104.62±7.71)mm Hg,差异均具有统计学意义(P<0.05)。实验组不良反应发生率3.23%低于对照组的19.35%,差异具有统计学意义(P<0.05)。实验组麻醉总有效率96.77%均高于对照组的80.65%,差异均具有统计学意义(P<0.05)。实验组全麻起效、维持全麻、术后苏醒时间分别为(1.61±0.23)、(100.59±6.72)、(17.99±3.52)min,均短于对照组的(2.93±0.41)、(123.61±7.85)、(36.87±4.16)min,差异均具有统计学意义(P<0.05)。结论 针对腹腔镜等手术患者应用丙泊酚复合瑞芬太尼喉罩全麻对血液动力学影响小,不良反应发生率低,麻醉效果良好,降低对机体损伤,值得推广应用。