In vivo human cardiac shortening and lengthening velocity is region-dependent and not coupled with heart rate

New Findings •What is the central question of this study? Regulation of cardiac function is typically achieved by changes in heart rate (HR) and cardiac shortening velocity (strain rate; SR), but their interdependence in vivo remains poorly understood. •What is the main finding and its importance? Using resistance exercise to increase heart rate and arterial resistance physiologically in humans and measuring regional cardiac SR (at the base and apex), we found that HR and SR were not strictly coupled because SR at the base and apex responded differently, despite the same HR. Importantly, our data show that the region-averaged ‘longitudinal’ SR, which is currently popular in the clinical setting, markedly underestimates the contribution of the apex. The fundamental importance of cardiac shortening and lengthening velocity (i.e. strain rate; SR) has been demonstrated in vitro. Currently, the interdependence between in vivo SR and HR is poorly understood because studies have typically assessed region-averaged ‘longitudinal’ strain rate, which is likely to underestimate the apical contribution, and have used non-physiological interventions that may also have been influenced by multicollinearity caused by concomitant reductions in arterial resistance. Resistance exercise acutely raises HR, blood pressure and arterial resistance and transiently disassociates these cardiovascular factors following exercise. Therefore, we measured SR, HR, blood pressure and arterial resistance in nine healthy men (aged 20 ± 1 years) immediately before, during and after double-leg-press exercise at 30 and 60% of maximal strength. Resistance exercise caused a disproportionate SR response at the left ventricular base and apex (interaction effect, P < 0.05). Consequently, associations between HR and regional peak SR were inconsistent and mostly very weak (r2 = 0.0004–0.24). Likewise, the areas under the curve for systolic and diastolic SR and their relationship with systolic and diastolic duration were variable and weak. Importantly, region-averaged ‘longitudinal’ SR was identical to basal SR, thus, markedly underestimating the apical contribution. In conclusion, in vivo HR and SR are not strictly coupled in healthy humans, which is explained by the region-specific responses of SR that are not captured by ‘longitudinal SR’. This novel observation emphasizes the independent role of in vivo SR in overall cardiac function during stress and may cause a ‘revival’ of SR as a marker of regional left ventricular (dys)function

Heart failure with preserved ejection fraction according to the HFA-PEFF score in COVID-19 patients: clinical correlates and echocardiographic findings

Aims: Viral-induced cardiac inflammation can induce heart failure with preserved ejection fraction (HFpEF)-like syndromes. COVID-19 can lead to myocardial damage and vascular injury. We hypothesised that COVID-19 patients frequently develop a HFpEF-like syndrome, and designed this study to explore this. Methods and results: Cardiac function was assessed in 64 consecutive, hospitalized, and clinically stable COVID-19 patients from April-November 2020 with left ventricular ejection fraction (LVEF) ≥50% (age 56 ± 19 years, females: 31%, severe COVID-19 disease: 69%). To investigate likelihood of HFpEF presence, we used the HFA-PEFF score. A low (0-1 points), intermediate (2-4 points), and high (5-6 points) HFA-PEFF score was observed in 42%, 33%, and 25% of patients, respectively. In comparison, 64 subjects of similar age, sex, and comorbidity status without COVID-19 showed these scores in 30%, 66%, and 4%, respectively (between groups: P = 0.0002). High HFA-PEFF scores were more frequent in COVID-19 patients than controls (25% vs. 4%, P = 0.001). In COVID-19 patients, the HFA-PEFF score significantly correlated with age, estimated glomerular filtration rate, high-sensitivity troponin T (hsTnT), haemoglobin, QTc interval, LVEF, mitral E/A ratio, and H2 FPEF score (all P < 0.05). In multivariate, ordinal regression analyses, higher age and hsTnT were significant predictors of increased HFA-PEFF scores. Patients with myocardial injury (hsTnT ≥14 ng/L: 31%) vs. patients without myocardial injury, showed higher HFA-PEFF scores [median 5 (interquartile range 3-6) vs. 1 (0-3), P < 0.001] and more often showed left ventricular diastolic dysfunction (75% vs. 27%, P < 0.001). Conclusion: Hospitalized COVID-19 patients frequently show high likelihood of presence of HFpEF that is associated with cardiac structural and functional alterations, and myocardial injury. Detailed cardiac assessments including echocardiographic determination of left ventricular diastolic function and biomarkers should become routine in the care of hospitalized COVID-19 patients

Strain and strain rate parametric imaging. A new method for post processing to 3-/4-dimensional images from three standard apical planes. Preliminary data on feasibility, artefact and regional dyssynergy visualisation

BACKGROUND: We describe a method for 3-/4D reconstruction of tissue Doppler data from three standard apical planes, post processing to derived data of strain rate / strain and parametric colour imaging of the data. The data can be displayed as M-mode arrays from all six walls, Bull's eye projection and a 3D surface figure that can be scrolled and rotated. Numerical data and waveforms can be re-extracted. METHODS: Feasibility was tested by Strain Rate Imaging in 6 normal subjects and 6 patients with acute myocardial infarction. Reverberation artefacts and dyssynergy was identified by colour images. End systolic strain, peak systolic and mid systolic strain rate were measured. RESULTS: Infarcts were visualised in all patients by colour imaging of mid systolic strain rate, end systolic strain and post systolic shortening by strain rate. Reverberation artefacts were visible in 3 of 6 normals, and 2 of 6 patients, and were identified both on bull's eye and M-mode display, but influenced quantitative measurement. Peak systolic strain rate was in controls minimum -1.11, maximum -0.89 and in patients minimum -1.66, maximum 0.02 (p = 0.04). Mid systolic strain rate and end systolic strain did not separate the groups significantly. CONCLUSION: 3-/4D reconstruction and colour display is feasible, allowing quick visual identification of infarcts and artefacts, as well as extension of area of post systolic shortening. Strain rate is better suited to colour parametric display than strain

Flow propagation velocity is not a simple index of diastolic function in early filling. A comparative study of early diastolic strain rate and strain rate propagation, flow and flow propagation in normal and reduced diastolic function

BACKGROUND: Strain Rate Imaging shows the filling phases of the left ventricle to consist of a wave of myocardial stretching, propagating from base to apex. The propagation velocity of the strain rate wave is reduced in delayed relaxation. This study examined the relation between the propagation velocity of strain rate in the myocardium and the propagation velocity of flow during early filling. METHODS: 12 normal subjects and 13 patients with treated hypertension and normal systolic function were studied. Patients and controls differed significantly in diastolic early mitral flow measurements, peak early diastolic tissue velocity and peak early diastolic strain rate, showing delayed relaxation in the patient group. There were no significant differences in EF or diastolic diameter. RESULTS: Strain rate propagation velocity was reduced in the patient group while flow propagation velocity was increased. There was a negative correlation (R = -0.57) between strain rate propagation and deceleration time of the mitral flow E-wave (R = -0.51) and between strain rate propagation and flow propagation velocity and there was a positive correlation (R = 0.67) between the ratio between peak mitral flow velocity / strain rate propagation velocity and flow propagation velocity. CONCLUSION: The present study shows strain rate propagation to be a measure of filling time, but flow propagation to be a function of both flow velocity and strain rate propagation. Thus flow propagation is not a simple index of diastolic function in delayed relaxation

Relevance of tissue Doppler in the quantification of stress echocardiography for the detection of myocardial ischemia in clinical practice

In the present article we review the main published data on the application of Tissue Doppler Imaging (TDI) to stress echocardiography for the detection of myocardial ischemia. TDI has been applied to stress echocardiography in order to overcome the limitations of visual analysis for myocardial ischemia. The introduction of a new technology for clinical routine use should pass through the different phases of scientific assessment from feasibility studies to large multicenter studies, from efficacy to effectiveness studies. Nonetheless the pro-technology bias plays a major role in medicine and expensive and sophisticated techniques are accepted before their real usefulness and incremental value to the available ones is assessed. Apparently, TDI is not exempted by this approach : its applications are not substantiated by strong and sound results. Nonetheless, conventional stress echocardiography for myocardial ischemia detection is heavily criticized on the basis of its subjectivity. Stress echocardiography has a long lasting history and the evidence collected over 20 years positioned it as an established tool for the detection and prognostication of coronary artery disease. The quantitative assessment of myocardial ischemia remains a scientific challenge and a clinical goal but time has not come for these newer ultrasonographic techniques which should be restricted to research laboratories

Assessment of atrial regional and global electromechanical function by tissue velocity echocardiography: a feasibility study on healthy individuals

BACKGROUND: The appropriate evaluation of atrial electrical function is only possible by means of invasive electrophysiology techniques, which are expensive and therefore not suitable for widespread use. Mechanical atrial function is mainly determined from atrial volumes and volume-derived indices that are load-dependent, time-consuming and difficult to reproduce because they are observer-dependent. AIMS: To assess the feasibility of tissue velocity echocardiography (TVE) to evaluate atrial electromechanical function in young, healthy volunteers. SUBJECTS AND METHODS: We studied 37 healthy individuals: 28 men and nine women with a mean age of 29 years (range 20–47). Standard two-dimensional (2-D) and Doppler echocardiograms with superimposed TVE images were performed. Standard echocardiographic images were digitized during three consecutive cardiac cycles in cine-loop format for off-line analysis. Several indices of regional atrial electrical and mechanical function were derived from both 2-D and TVE modalities. RESULTS: Some TVE-derived variables indirectly reflected the atrial electrical activation that follows the known activation process as revealed by invasive electrophysiology. Regionally, the atrium shows an upward movement of its walls at the region near the atrio-ventricular ring with a reduction of this movement towards the upper levels of the atrial walls. The atrial mechanical function as assessed by several TVE-derived indices was quite similar in all left atrium (LA) walls. However, all such indices were higher in the right (RA) than the LA. There were no correlations between the 2-D- and TVE-derived variables expressing atrial mechanical function. Values of measurement error and repeatability were good for atrial mechanical function, but only acceptable for atrial electrical function. CONCLUSION: TVE may provide a simple, easy to obtain, reproducible, repeatable and potentially clinically useful tool for quantifying atrial electromechanical function

Hand grip strength in patients with advanced cancer: a prospective study

BACKGROUND: Hand grip strength (HGS) is a widely used functional test for the assessment of strength and functional status in patients with cancer, in particular with cancer cachexia. The aim was to prospectively evaluate the prognostic value of HGS in patients with mostly advanced cancer with and without cachexia and to establish reference values for a European-based population. METHODS: In this prospective study, 333 patients with cancer (85% stage III/IV) and 65 healthy controls of similar age and sex were enrolled. None of the study participants had significant cardiovascular disease or active infection at baseline. Repetitive HGS assessment was performed using a hand dynamometer to measure the maximal HGS (kilograms). Presence of cancer cachexia was defined when patients had ≥5% weight loss within 6 months or when body mass index was <20.0 kg/m(2) with ≥2% weight loss (Fearon's criteria). Cox proportional hazard analyses were performed to assess the relationship of maximal HGS to all-cause mortality and to determine cut-offs for HGS with the best predictive power. We also assessed associations with additional relevant clinical and functional outcome measures at baseline, including anthropometric measures, physical function (Karnofsky Performance Status and Eastern Cooperative of Oncology Group), physical activity (4-m gait speed test and 6-min walk test), patient-reported outcomes (EQ-5D-5L and Visual Analogue Scale appetite/pain) and nutrition status (Mini Nutritional Assessment). RESULTS: The mean age was 60 ± 14 years; 163 (51%) were female, and 148 (44%) had cachexia at baseline. Patients with cancer showed 18% lower HGS than healthy controls (31.2 ± 11.9 vs. 37.9 ± 11.6 kg, P < 0.001). Patients with cancer cachexia had 16% lower HGS than those without cachexia (28.3 ± 10.1 vs. 33.6 ± 12.3 kg, P < 0.001). Patients with cancer were followed for a mean of 17 months (range 6-50), and 182 (55%) patients died during follow-up (2-year mortality rate 53%) (95% confidence interval 48-59%). Reduced maximal HGS was associated with increased mortality (per -5 kg; hazard ratio [HR] 1.19; 1.10-1.28; P < 0.0001; independently of age, sex, cancer stage, cancer entity and presence of cachexia). HGS was also a predictor of mortality in patients with cachexia (per -5 kg; HR 1.20; 1.08-1.33; P = 0.001) and without cachexia (per -5 kg; HR 1.18; 1.04-1.34; P = 0.010). The cut-off for maximal HGS with the best predictive power for poor survival was <25.1 kg for females (sensitivity 54%, specificity 63%) and <40.2 kg for males (sensitivity 69%, specificity 68%). CONCLUSIONS: Reduced maximal HGS was associated with higher all-cause mortality, reduced overall functional status and decreased physical performance in patients with mostly advanced cancer. Similar results were found for patients with and without cancer cachexia

Patient-reported ability to walk 4 m and to wash: New clinical endpoints and predictors of survival in patients with pre-terminal cancer

BACKGROUND: Maintaining the ability to perform self-care is a critical goal in patients with cancer. We assessed whether the patient-reported ability to walk 4 m and wash oneself predict survival in patients with pre-terminal cancer. METHODS: We performed a prospective observational study on 169 consecutive hospitalized patients with cancer (52% female, 64 ± 12 years) and an estimated 1-12 months prognosis at an academic, inpatient palliative care unit. Patients answered functional questions for 'today', 'last week', and 'last month', performed patient-reported outcomes (PROs), and physical function assessments. RESULTS: Ninety-two (54%) patients reported the ability to independently walk 4 m and 100 (59%) to wash 'today'. The median number of days patients reported the ability to walk 4 m and wash were 6 (IQR 0-7) and 7 (0-7) days ('last week'); and 27 (5-30) and 26 (10-30) days ('last month'). In the last week, 32% of patients were unable to walk 4 m on every day and 10% could walk on 1-3 days; 30% were unable to wash on every day and 10% could wash on 1-3 days. In the last months, 14% of patients were unable to walk 4 m on every day and 10% could only walk on 1-10 days; 12% were unable to wash on every day and 11% could wash on 1-10 days. In patients who could walk 'today' average 4 m gait speed was 0.78 ± 0.28 m/s. Patients who reported impaired walking and washing experienced more symptoms (dyspnoea, exertion, and oedema) and decreased physical function (higher Eastern Cooperative Oncology Group Performance Status, and lower Karnofsky Performance Status and hand-grip strength [unable vs. able to walk 'today': 205 ± 87 vs. 252 ± 78 Newton, P = 0.001; unable vs. able to wash 'today': 204 ± 86 vs. 250 ± 80 Newton, P = 0.001]). During the 27 months of observation, 152 (90%) patients died (median survival 46 days). In multivariable Cox proportional hazards regression analyses, all tested parameters were independent predictors of survival: walking 4 m 'today' (HR 0.63, P = 0.015), 'last week' (per 1 day: HR 0.93, P = 0.011), 'last month' (per 1 day: HR 0.98, P = 0.012), 4 m gait speed (per 1 m/s: HR 0.45, P = 0.002), and washing 'today' (HR 0.67, P = 0.024), 'last week (per 1 day HR 0.94, p=0.019), and 'last month' (per 1 day HR 0.99, P = 0.040). Patients unable to walk and wash experienced the shortest survival and most reduced functional status. CONCLUSIONS: In patients with pre-terminal cancer, the self-reported ability to walk 4 m and wash were independent predictors of survival and associated with decreased functional status

Clinical and prognostic relevance of cardiac wasting in patients with advanced cancer

BACKGROUND: Body wasting in patients with cancer can affect the heart. OBJECTIVES: The frequency, extent, and clinical and prognostic importance of cardiac wasting in cancer patients is unknown. METHODS: This study prospectively enrolled 300 patients with mostly advanced, active cancer but without significant cardiovascular disease or infection. These patients were compared with 60 healthy control subjects and 60 patients with chronic heart failure (ejection fraction <40%) of similar age and sex distribution. RESULTS: Cancer patients presented with lower left ventricular (LV) mass than healthy control subjects or heart failure patients (assessed by transthoracic echocardiography: 177 ± 47 g vs 203 ± 64 g vs 300 ± 71 g, respectively; P < 0.001). LV mass was lowest in cancer patients with cachexia (153 ± 42 g; P < 0.001). Importantly, the presence of low LV mass was independent of previous cardiotoxic anticancer therapy. In 90 cancer patients with a second echocardiogram after 122 ± 71 days, LV mass had declined by 9.3% ± 1.4% (P < 0.001). In cancer patients with cardiac wasting during follow-up, stroke volume decreased (P < 0.001) and resting heart rate increased over time (P = 0.001). During follow-up of on average 16 months, 149 patients died (1-year all-cause mortality 43%; 95% CI: 37%-49%). LV mass and LV mass adjusted for height squared were independent prognostic markers (both P < 0.05). Adjustment of LV mass for body surface area masked the observed survival impact. LV mass below the prognostically relevant cutpoints in cancer was associated with reduced overall functional status and lower physical performance. CONCLUSIONS: Low LV mass is associated with poor functional status and increased all-cause mortality in cancer. These findings provide clinical evidence of cardiac wasting–associated cardiomyopathy in cancer