De Lorenzo A; Da Silva CL; Castro Souza FC; De Souza Leao Lima R

Physiological Research [Physiol Res] 2018 Jul 25. Date of Electronic Publication: 2018 Jul 25.

This study investigated the value of oxygen (O(2)) pulse curves obtained during cardiopulmonary exercise testing (CPET) for the diagnosis of coronary artery disease (CAD). Forty patients with known coronary anatomy (35.0 % normal, 27.0 % single-vessel and 38.0 % multivessel CAD) underwent CPET with radiotracer injection at peak exercise, followed by myocardial scintigraphy. O(2) pulse curves were classified as: A-normal, B-probably normal (normal slope with low peak value); C-probably abnormal (flat, with low peak value); or D- definitely abnormal (descending slope). Sensitivity, specificity, positive and negative predictive values of the O(2) pulse curve pattern (A or B vs. C or D) for the diagnosis of CAD were, respectively, 38.5 %, 81.3 %, 76.9 %, and 44.8 %. The concordance rate between the abnormal O2 pulse curve pattern and ischemia in myocardial scintigraphy was 38.1 %. Age and the extent of scintigraphic perfusion defect, but not the abnormal O(2) pulse curve patterns (B or C or both combined) were independently associated with CAD. In conclusion, the O(2) pulse curve pattern has low diagnostic performance for the diagnosis of obstructive CAD, and the abnormal curve pattern was not associated with myocardial ischemia defined by scintigraphy.

Fornasiero A; Savoldelli A; Skafidas S; Stella F; Bortolan L; Boccia G;
Zignoli A; Schena F; Mourot L; Pellegrini B;

European Journal Of Applied Physiology [Eur J Appl Physiol] 2018 Jul 26. Date of Electronic Publication: 2018 Jul 26.

Purpose: This study investigated the effects of acute hypoxic exposure on post-exercise cardiac autonomic modulation following maximal cardiopulmonary exercise testing (CPET).
Methods: Thirteen healthy men performed CPET and recovery in normoxia (N) and normobaric hypoxia (H) (FiO2 = 13.4%, ≈ 3500 m). Post-exercise cardiac autonomic modulation was assessed during recovery (300 s) through the analysis of fast-phase and slow-phase heart rate recovery (HRR) and heart rate variability (HRV) indices.
Results: Both short-term, T30 (mean difference (MD) 60.0 s, 95% CI 18.2-101.8, p = 0.009, ES 1.01), and long-term, HRRt (MD 21.7 s, 95% CI 4.1-39.3, p = 0.020, ES 0.64), time constants of HRR were higher in H. Fast-phase (30 and 60 s) and slow-phase (300 s) HRR indices were reduced in H either when expressed in bpm or in percentage of HRpeak (p < 0.05). Chronotropic reserve recovery was lower in H than in N at 30 s (MD - 3.77%, 95% CI - 7.06 to - 0.49, p = 0.028, ES - 0.80) and at 60 s (MD - 7.23%, 95% CI - 11.45 to - 3.01, p = 0.003, ES - 0.81), but not at 300 s (p = 0.436). Concurrently, Ln-RMSSD was reduced in H at 60 and 90 s (p < 0.01) but not at other time points during recovery (p > 0.05).
Conclusions: Affected fast-phase, slow-phase HRR and HRV indices suggested delayed parasympathetic reactivation and sympathetic withdrawal after maximal exercise in hypoxia. However, a similar cardiac autonomic recovery was re-established within 5 min after exercise cessation. These findings have several implications in cardiac autonomic recovery interpretation and in HR assessment in response to high-intensity hypoxic exercise.

Bekfani T; Pellicori P; Morris D; Valentova M; Sandek A; Doehner W; Cleland JG;
Lainscak M; Schulze PC; Anker SD; von Haehling S;

Clinical Research In Cardiology: Official Journal Of The German Cardiac Society [Clin Res Cardiol] 2018 Jul 26. Date of Electronic Publication: 2018 Jul 26.

Background: The prevalence of iron deficiency (ID) in outpatients with heart failure with preserved ejection fraction (HFpEF) and its relation to exercise capacity and quality of life (QoL) is unknown.
Methods: 190 symptomatic outpatients with HFpEF (LVEF 58 ± 7%; age 71 ± 9 years; NYHA 2.4 ± 0.5; BMI 31 ± 6 kg/m2) were enrolled as part of SICA-HF in Germany, England and Slovenia. ID was defined as ferritin < 100 or 100-299 µg/L with transferrin saturation (TSAT) < 20%. Anemia was defined as Hb < 13 g/dL in men, < 12 g/dL in women. Low ferritin-ID was defined as ferritin < 100 µg/L. Patients were divided into 3 groups according to E/e’ at echocardiography: E/e’ ≤ 8; E/e’ 9-14; E/e’ ≥ 15. All patients underwent echocardiography, cardiopulmonary exercise test (CPX), 6-min walk test (6-MWT), and QoL assessment using the EQ5D questionnaire.
Results: Overall, 111 patients (58.4%) showed ID with 89 having low ferritin-ID (46.84%). 78 (41.1%) patients had isolated ID without anemia and 54 patients showed anemia (28.4%). ID was more prevalent in patients with more severe diastolic dysfunction: E/e’ ≤ 8: 44.8% vs. E/e’: 9-14: 53.2% vs. E/e’ ≥ 15: 86.5% (p = 0.0004). Patients with ID performed worse during the 6MWT (420 ± 137 vs. 344 ± 124 m; p = 0.008) and had worse exercise time in CPX (645 ± 168 vs. 538 ± 178 s, p = 0.03). Patients with low ferritin-ID had lower QoL compared to those without ID (p = 0.03).
Conclusion: ID is a frequent co-morbidity in HFpEF and is associated with reduced exercise capacity and QoL. Its prevalence increases with increasing severity of diastolic dysfunction.

Engeroff T; Füzéki E; Vogt L; Fleckenstein J; Schwarz S; Matura S; Pilatus U; Deichmann R;
Hellweg R; Pantel J; Banzer W;

Neuroscience [Neuroscience] 2018 Aug 02. Date of Electronic Publication: 2018 Aug 02.

The aim of this cross-sectional study was to determine the associations of objectively assessed habitual physical activity and physical performance with brain plasticity outcomes and brain derived neurotrophic factor (BDNF) levels in cognitively healthy older adults. Physical performance was analyzed based on cardiopulmonary exercise testing data and accelerometer based physical activity was analyzed as total activity counts, sedentary time, light physical activity and moderate to vigorous physical activity. Brain plasticity outcomes included magnetic resonance spectroscopy (MRS) based markers, quantitative imaging based hippocampal volume and BDNF serum levels. The association between physical performance and hippocampal volume was strongly influenced by participants’ education, sex, age and BMI. Confounder controlled correlation revealed significant associations of brain plasticity outcomes with physical activity but not with performance. MRS based adenosine-triphosphate to phosphocreatine and glycerophosphocholine to phosphocreatine ratios were significantly associated with accelerometer total activity counts. BDNF was detrimentally associated with sedentary time but beneficially related to accelerometer total activity counts and moderate to vigorous physical activity. Exceeding the current moderate to vigorous physical activity recommendations led to significantly higher BDNF levels. Our results indicate that regular physical activity might be beneficial for preserving brain plasticity in higher age. In this study these associations were not mediated significantly by physical performance. Overall physical activity and exceeding current moderate to vigorous physical activity recommendations were positively associated with BDNF. Sedentary behavior, however, seems to be negatively related to neurotrophic factor bioavailability in the elderly.

Bramley P; Bristol, UK. Brown J;

British Journal Of Anaesthesia [Br J Anaesth] 2018 Aug; Vol. 121 (2), pp. 496-497. Date of Electronic Publication: 2018 May 30.

NO ABSTRACT AVAILABLE. LETTER

Wallen MP; Woodward AJ; Hall A; Skinner TL; Coombes JS; Macdonald GA;

Transplantation [Transplantation] 2018 Jul 13. Date of Electronic Publication: 2018 Jul 13.

Background: Patients with advanced liver disease are at increased risk of infection and other complications. A significant proportion of patients also have poor fitness and low muscle mass. The primary aim of this study was to investigate if cardiorespiratory fitness and body composition are risk factors for sepsis and other complications of advanced liver disease.
Methods: Patients being listed for liver transplantation underwent cardiopulmonary exercise testing to determine ventilatory threshold (VT). Computed tomography was used to measure skeletal muscle and subcutaneous and visceral adipose tissue indexes. All unplanned hospital admissions, deaths or delistings prior to transplantation were recorded.
Results: Eighty-two patients [aged 55.1 (50.6-59.4) years, median (interquartile range); male 87%] achieved a median VT of 11.7 (9.7-13.4) mL[BULLET OPERATOR]kg[BULLET OPERATOR]min. Their median MELD-Na score was 18 (14-22); and 37 had hepatocellular carcinoma. There were 50 admissions in 31 patients; with 16 admissions for sepsis in 13 patients. Patients with sepsis had a significantly lower VT [sepsis 9.5 (7.8-11.9), no sepsis 11.8 (10.5-13.8) mL[BULLET OPERATOR]kg[BULLET OPERATOR]min; P=0.003]. No body composition variables correlated with sepsis, nor were there any significant associations between VT and unplanned admissions for other indications. Multivariate logistic regression demonstrated that VT was independently associated with a diagnosis of sepsis (P=0.03). Poisson regression revealed that VT was a significant predictor for the number of septic episodes (P=0.02); independent of age, MELD-Na score, hepatocellular carcinoma diagnosis, presence of ascites, and beta-blocker use.
Conclusion: Poor cardiorespiratory fitness is an independent risk factor for the development of sepsis in advanced liver disease.

Weberruss H, Maucher J, Oberhoffer R, Müller J.

Eur J Appl Physiol. 2018 Jan;118(1):205-211. doi: 10.1007/s00421-017-3762-2. Epub
2017 Nov 15.

OBJECTIVE: The body’s adaptation to physical exercise is modulated by sympathetic
and parasympathetic (vagal) branches of the autonomic nervous system (ANS). Heart
rate variability (HRV), the beat-to-beat variation of the heart, is a proxy
measure for ANS activity, whereas blood pressure (BP) is an indicator for
cardiovascular function. Impaired vagal activity and lower BP is already
described after exercise. However, inconsistent results exist about how long
vagal recovery takes and how long post-exercise hypotension persists. Therefore,
the aim of this study was to assess HRV and BP 1 h after maximal cardiopulmonary
exercise testing (CPET).
PATIENTS AND METHODS: HRV (Polar RS800CX), peripheral and central BP
(Mobil-O-Graph®) were prospectively studied in 107 healthy volunteers (47 female,
median age 29.0 years) in supine position, before and 60 min after maximal CPET.
RESULTS: One hour after terminating CPET measures of HRV were still impaired and
post-exercise BP was significantly reduced suggesting an improved vascular
function compared to pre levels. HRV parameters post-exercise were 34.7% (RMSSD),
67.2% (pNN50), 57.2% (HF), and 42.7% (LF) lower compared to pre-exercise levels
(for all p < 0.001). Median reduction in BP was 5 mmHg for systolic BP
(p < 0.001), and 4 mmHg for diastolic BP (p = 0.016) and central systolic
post-exercise (p = 0.005).
CONCLUSIONS: One hour after terminating strenuous exercise, autonomic nervous
regulation seems to be postponed which is reflected in reduced HRV, whereas the
early recovery of the vasculature, post-exercise hypotension, is still preserved
over the recovery period of 1 h.

Li M, Lu Y, Fang C, Zhang X

Echocardiography. 2017 Nov;34(11):1640-1648. doi: 10.1111/echo.13675. Epub 2017
Sep 19.

PURPOSE: Heart failure (HF) is a multifactorial entity that combines derangements
in both systolic and diastolic function. The relationship between systolic and
diastolic function and exercise capacity is not fully understood. We sought to
determine the mechanisms linking cardiac function and exercise tolerance in
patients with HF.
METHODS: One hundred fifty-six subjects with different cardiac function levels
were included in the study. Subjects’ 2D echocardiographic, 3D speckle tracking
echocardiographic, and cardiopulmonary exercise testing (CPET) data were
collected.
RESULT: The amount of untwisting at 25% of the untwist duration (25%Untwist) and
global longitudinal peak systolic strain (GLS) showed the best positive
correlations with peak oxygen uptake (peakVO2 ) (r = .41; P < .001 and r = .32;
P < .001, respectively), while the left ventricular ejection fraction (EF) was
weakly correlated with peakVO2 . The 25%Untwist value was negatively correlated
with the carbon dioxide equivalent slope (VE/VCO2 ) (r = -.49; P < .001). Both
E/e and the left atrium volume index (LA index) exhibited good positive
correlations with VE/VCO2 (r = .39; P < .01 and r = .32; P < .001). In the
multiple regression analysis, the best predictive model for the peakVO2 included
the 25%Untwist, GLS, and E/e, explained 64% of the variation in peakVO2 , with
25%Untwist explaining 17.6% of the variation. Including EF in the model explained
only 3.1% of the variation in peakVO2 . In a multivariable model for VE/VCO2 ,
25%Untwist was the strongest independent predictor, explaining 23% of the
variance in VE/VCO2 .
CONCLUSION: Left ventricular early diastolic function is a modest independent
predictor of aerobic exercise capacity. The 25%Untwist value is a good indicator
of cardiac diastolic function.

S.W. Grant, G.L. Hickey, N.A. Wisely, E.D. Carlson, R.A. Hartley, A.C. Pichel, D. Atkinson, C.N. McCollum