COVID-19 vaccines in adult cancer patients with solid tumours undergoing active treatment: Seropositivity and safety. A prospective observational study in Italy

INTRODUCTION

Patients with cancer are presumed a frail group at high risk of contracting coronavirus disease (COVID-19), and vaccination represents a cornerstone in addressing the COVID-19 pandemic. However, data on COVID-19 vaccination in cancer patients are fragmentary and poor.

METHODS

An observational study was conducted to evaluate the seropositivity rate and safety of a two-dose regimen of the BNT162b2 or messenger RNA-1273 vaccine in adult patients with solid cancer undergoing active anticancer treatment or whose treatment had been terminated within 6 months of the start of the study. The control group was composed of healthy volunteers. Serum samples were evaluated for SARS-COV-2 antibodies before vaccinations and 2-6 weeks after the administration of the second vaccine dose. Primary end-point: seropositivity rate. Secondary end-points: safety, factors influencing seroconversion, IgG titers of patients versus healthy volunteers, COVID-19 infection.

RESULTS

Between 20th March 2021 and 12th June 2021, 293 consecutive patients with cancer-solid tumours underwent a program of COVID-19 vaccinations; of these, 2 patients refused vaccination, 13 patients did not receive the second dose of the vaccine because of cancer progression, and 21 patients had COVID-19 antibodies at baseline and were excluded. The 257 evaluable patients had a median age of 65 years (range 28-86), 66.15% with metastatic disease. Primary end-point: seropositivity rate in patients was 75.88% versus 100% in the control group. Secondary end-points: no Grade 3-4 side-effects, no COVID-19 infections were reported. Patients median IgG titer was significantly lower than in the control group; male sex and active anticancer therapy influenced negative seroconversion. BNT162b2 or messenger RNA-1273 vaccines were immunogenic in cancer patients, showing good safety profile.

Efficacy of Osteopathic Manipulative Treatment on postural control in Parkinsonian patients with Pisa syndrome: A pilot randomized placebo-controlled trial

BACKGROUND

Pisa syndrome (PS) is a clinical condition frequently associated with Parkinson's disease (PD). It is characterized by a trunk lateral flexion higher than 10 degrees and reversible when lying. One pathophysiological hypothesis is the altered verticality perception, due to a somatosensory impairment. Osteopathic Manipulative Treatment (OMT) manages fascial-system alterations, linked to somatic dysfunctions. Fascial system showed to be implicated in proprioceptive sensibility.

OBJECTIVE

The aim of the study was to assess OMT efficacy on postural control in PD-PS patients by stabilometry.

METHODS

In this single-blinded trial we studied 24 PD-PS patients, 12 of whom were randomly assigned to receive a multidisciplinary physical therapy protocol (MIRT) and sham OMT, while the other 12 received four OMT plus MIRT, for one month. The primary endpoint was the eye closed sway area assessment after the intervention. Evaluation of trunk lateral flexion (TLF) with DIERS formetrics was also performed.

RESULTS

At one month, the sway area of the OMT group significantly decreased compared to placebo (mean delta OMT - 326.00±491.24 mm2, p = 0.01). In the experimental group TLF showed a mean inclination reduction of 3.33 degrees after treatment (p = 0.044, mean d = 0.54). Moreover, a significant positive association between delta ECSA and delta TLF was observed (p = 0.04, r = 0.46).

DISCUSSION

Among PD-PS patients, MIRT plus OMT showed preliminary evidence of postural control and TLF improvement, compared to the control group.

Effects of zoledronic acid and dexamethasone on early phases of socket healing after tooth extraction in rats: A preliminary macroscopic and microscopic quantitative study

Background

The exact pathogenesis of medication-related osteonecrosis of the jaw (MRONJ) is still unknown. The aim of this paper was to investigate the effects of zoledronic acid and dexamethasone on the early phases of socket healing in rats subjected to tooth extractions.

Material and Methods

Thirty male Sprague-Dawley rats were divided into 2 groups: pharmacologically treated group (T, n=20) and non-pharmacologically treated group (C, n=10). T group rats received 0.1 mg/Kg of zoledronic acid (ZOL) and 1 mg/Kg of dexamethasone (DEX) three times a week for 10 consecutive weeks. C group rats were infused with vehicle. After 9 weeks from the first infusion, first maxillary molars were extracted in each of the rats. Quantitative macroscopic and microscopic analysis was performed to evaluate socket healing 8 days after extraction.

Results

Pharmacologically treated rats showed significant inhibition of bone remodeling. Connective tissue/alveolar bone ratio, osteoclast number and woven bone deposition were significantly reduced in group T compared to group C. Conversely, the proportion of necrotic bone was higher in group T compared to group C (0.8% and 0.3%, respectively. P=0.031). ZOL plus DEX do not cause gross effects on socket healing at a macroscopic level.

Conclusions

Our findings confirmed that exposure to ZOL plus DEX impairs alveolar wound repair. Inhibition of osteoclastic resorption of socket walls after tooth extraction and the inability to dispose of the necrotic bone may be considered the initial steps of MRONJ onset.

Key words:Medication-related osteonecrosis of the jaw, zoledronic acid, dexamethasone, tooth extraction, rat.

Effectiveness of Rotigotine plus intensive and goal-based rehabilitation versus Rotigotine alone in "de-novo" Parkinsonian subjects: a randomized controlled trial with 18-month follow-up

Background

Dopamine Replacement Therapy (DRT) represents the most effective treatment for Parkinson’s disease (PD). Nevertheless, several symptoms are unresponsive to treatment and its long-term use leads to serious side effects. To optimize the pharmacological management of PD, dopamine-agonists are often prescribed to “de-novo” patients. Moreover, several studies have shown the effectiveness and the synergic effect of rehabilitation in treating PD.

Objective

To evaluate the synergism between DRT and rehabilitation in treating PD, by investigating the short and the long-term effectiveness of a multidisciplinary, intensive and goal-based rehabilitation treatment (MIRT) in a group of patients treated with Rotigotine.

Materials and methods

In this multicenter, single blinded, parallel-group, 1:1 allocation ratio, randomized, non-inferiority trial, 36 “de-novo” PD patients were evaluated along 18 months: 17 were treated with Rotigotine plus MIRT; 19 were treated with Rotigotine alone (R). The primary outcome measure was the total score of Unified Parkinson’s Disease Rating Scale (UPDRS). The secondary outcomes included the UPDRS sub-sections II and III (UPDRS II-III), the 6-Minute Walk Test (6MWT), the Timed Up and Go Test (TUG) and the amount of Rotigotine. Patients were evaluated at baseline (T0), 6 months (T1), 1 year (T2), and at 18 months (T3).

Results

No differences in UPDRS scores in the two groups (total score, III part and II part, p = 0.48, p = 0.90 and p = 0.40, respectively) were found in the time course. Conversely, a greater improvement in Rotigotine + MIRT group was observed for 6MWT (p < 0.0001) and TUG (p = 0.03). Along time, the dosage of Rotigotine was higher in patients who did not undergo MIRT, at all observation times following T0.

Conclusions

Over the course of 18 months, the effectiveness of the combined treatment (Rotigotine + MIRT) on the patients’ global clinical status, evaluated with total UPDRS, was not inferior to that of the pharmacological treatment with Rotigotine alone. Importantly, rehabilitation allowed patients to gain better motor performances with lower DRT dosage.

Additional predictive value of nutritional status in the prognostic assessment of heart failure patients

BACKGROUND AND AIMS

Nutritional status (NS) is not routinely assessed in HF. We sought to evaluate whether NS may be additive to a comprehensive pre-discharge evaluation based on a clinical score that includes BMI (MAGGIC) and on an index of functional capacity (six minute walking test, 6mWT) in HF patients.

METHODS AND RESULTS

The CONUT (Controlling Nutritional Status) score (including serum albumin level, total cholesterol and lymphocyte count) was computed in 466 consecutive patients (mean age 61 ± 11 years, NYHA class 2.6 ± 0.6, LVEF 34 ± 11%, BMI 27.2 ± 4.5) who had pre-discharge MAGGIC and 6MWT. The endpoint was all-cause mortality. Mild or moderate undernourishment was present in 54% of patients with no differences across BMI strata. The 12-month event rate was 7.7%. Deceased patients had a more compromised NS (CONUT 2.8 ± 1.5 vs 1.7 ± 1.3, p < 0.0001), and a more advanced HF (MAGGIC 28.2 ± 6.0 vs 22.0 ± 6.6, p < 0.0001; 6MWT 311.1 ± 102.2 vs. 408.9 ± 95.9 m, p < 0.0001). The 12-month mortality rate varied from 4% for well-nourished to 11% for undernourished patients (p = 0.008). At univariate analysis, the CONUT was predictive for all-cause mortality with a Hazard Ratio of 1.701 [95% CI 1.363-2.122], p < 0.0001. Multivariable analysis showed that the CONUT significantly added to the combination of MAGGIC and 6MWT and improved predictive discrimination and risk classification (c-index 0.82 [95% CI 0.75-0.88], integrated discrimination improvement 0.028 [95% CI 0.015-0.081]).

CONCLUSIONS

In HF patients assessment of NS, significantly improves prediction of 12-month mortality on top of the information provided by clinical evaluation and functional capacity and should be incorporated in the overall assessment of HF patients.

Ontogenetic allometry in the foot size of Oligoryzomys flavescens (Waterhouse, 1837) (Rodentia, Sigmodontinae)

Ontogenetic allometry is the study of how the size or shape of certain structures changes over the course of an animal's development. In this study, using Huxley's formula of allometric growth (1932), we assessed the changes in the rate of growth of the feet size of the sigmodontine rodent Oligoryzomys flavescens during its ontogeny and compared differences between males and females. We find evidence of a change of polarity during the ontogenetic development of the species, with the presence of positive allometry during pregnancy and negative allometry in adulthood. Moreover, we note the presence of sexual dimorphism in the size of the feet, in which males of the species have a higher rate of growth than females. This growth pattern is positively related to escape from predators in childhood in both sexes and, in adulthood, provides a higher encounter rate of females by males, due to the larger displacement of the latter. We suggest that both the forces of natural selection and sexual selection have acted to shape the evolution of foot size in this species.

Localized 100 Hz vibration improves function and reduces upper limb spasticity: a double-blind controlled study

BACKGROUND

Physical modalities such as vibration has been suggested as possible non-pharmacological way to control spasticity.

AIMS

The hypotheses tested were: 1) can a selective vibration of the upper limb flexor antagonist, triceps brachii, reduce the spasticity of the flexor biceps brachii muscle; 2) is its association with physiotherapy better than physiotherapy alone in reducing spasticity and improving function, 3) can this possible effect last for longer than the stimulation period.

DESIGN

Randomized double-blind study.

SETTING

Rehabilitation Institute, inward patients.

POPULATION

Thirty hemiplegic patients affected by upper limb spasticity.

METHOD

(VIB + PT) group received physiotherapy plus vibration by means of a pneumatic vibrator applied over the belly of the triceps brachii of the spastic side (contact surface 2 cm2; frequency 100 Hz; amplitude 2 mm; mean pressure 250 mBar). (SHAM + PT) group received physiotherapy and sham vibration. Both groups had 60 minutes of physiotherapy (Kabat techniques) for 5 days a week (from Monday to Friday) for 2 weeks.

MAIN OUTCOME MEASURE

Ashworth modified scale for spasticity and robot-aided motor tasks changes for functional modifications were evaluated before starting treatment (T0), 48 hours after the fifth session (T1) and 48 hours after the last session (T2).

RESULTS

Fisher's exact test showed a statistically significant greater improvements in the (VIB + PT) group (P=0.0001) compared to in the (SHAM + PT) group after 1 week, as well as after 2 weeks of treatment (P=0.0078) at the Ashworth scale.

CONCLUSION

1) 100 Hz vibration applied to the triceps brachii of a spastic upper limb in association with physiotherapy is able to reduce the spasticity of the flexor agonist, biceps brachii; 2) this association is better than physiotherapy alone in controlling spasticity and improving function; 3) this clinically perceivable reduction of spasticity and function improvement extends (for at least 48 hours) beyond the period of application of the vibration, supporting its possible role in the rehabilitation of spastic hemiplegia.

CLINICAL REHABILITATION IMPACT

100 Hz antagonist muscle vibration, a non-pharmacological treatment, can help physiotherapy to reduce flexors spasticity and improve functions in the rehabilitation of upper limb spasticity.

Pain and electrophysiological parameters are improved by combined 830-1064 high-intensity LASER in symptomatic carpal tunnel syndrome versus Transcutaneous Electrical Nerve Stimulation. A randomized controlled study

AIM

The aim of the study was to compare LASER versus transcutaneous electrical nerve stimulation (TENS) in reducing pain and paraesthesia; and in improving motor and sensory median nerve conduction parameters in mild to moderate carpal tunnel syndrome (CTS).

DESIGN

Randomised blinded pilot study. Patients and staff administered treatments and outcome measures were blinded.

SETTING

Outpatient; Research and Care Rehabilitation Institute.

PARTICIPANTS

Twenty CTS symptomatic patients.

INTERVENTIONS

Fifteen sessions of: 1) 100 Hz TENS (30 minutes; rectangular waves; 80 ms width, intensity below muscle contraction); 2) combined 830-1064 nm LASER (radiating dose: 250 J cm-2 delivered to the skin overlying the course of the median nerve at the wrist for 100 s at 25 W (18 W [1064 nm] + 7 W [830 nm]) via a fiber-optic probe with a spot size of ~1 cm2). Outcome measures. Visual analogue scale (VAS) for pain and paresthesia; median nerve distal motor latency and sensory nerve conduction velocity.

RESULTS

LASER improved both positive and negative sensory symptoms. TENS induced clinical improvement but this was not statistically significant and was limited to pain reduction. LASER but not TENS favourably modified the neurophysiological parameters.

CONCLUSION

High-intensity combined LASER wavelengths of 830 nm and 1064 nm, which produce a better transparency with less scattering and a high energy transfer, are better than TENS in improving both pain and paraesthesia as well as neurophysiological parameters in CTS.

Idiopathic retroperitoneal fibrosis: clinicopathologic features and differential diagnosis

Idiopathic retroperitoneal fibrosis (IRF) is a rare disease often causing obstructive uropathy. We evaluated the clinicopathologic features of 24 patients with IRF to characterize the histopathology of the disease and to provide a framework for the differential diagnosis with other retroperitoneal fibrosing conditions. Retroperitoneal specimens were analyzed by light and electron microscopy and by immunohistochemistry. Most patients presented with abdominal/lumbar pain, constitutional symptoms, and high acute-phase reactants. Overall, 20 had ureteral involvement and 13 developed acute renal failure. The retroperitoneal tissue consisted of a fibrous component and a chronic inflammatory infiltrate with the former characterized by myofibroblasts within a type-I collagen matrix. The infiltrate displayed perivascular and diffuse patterns containing lymphocytes, macrophages, plasma cells, and eosinophils. The perivascular aggregates had a central core of CD20(+) cells and a mantle of CD3(+) cells in equal proportions. In the areas of diffuse infiltrate, CD3(+) cells outnumbered the CD20(+) cells. Most plasma cells were positive for the IgG4 isotype. Small vessel vasculitis was found in the specimens of 11 patients. Our study indicates that a sclerotic background with myofibroblasts associated with a diffuse and perivascular infiltrate mainly consisting of T and B lymphocytes may be a pathological hallmark of IRF.

An integrated approach based on uniform quantization for the evaluation of complexity of short-term heart period variability: Application to 24 h Holter recordings in healthy and heart failure humans

We propose an integrated approach based on uniform quantization over a small number of levels for the evaluation and characterization of complexity of a process. This approach integrates information-domain analysis based on entropy rate, local nonlinear prediction, and pattern classification based on symbolic analysis. Normalized and non-normalized indexes quantifying complexity over short data sequences ( approximately 300 samples) are derived. This approach provides a rule for deciding the optimal length of the patterns that may be worth considering and some suggestions about possible strategies to group patterns into a smaller number of families. The approach is applied to 24 h Holter recordings of heart period variability derived from 12 normal (NO) subjects and 13 heart failure (HF) patients. We found that: (i) in NO subjects the normalized indexes suggest a larger complexity during the nighttime than during the daytime; (ii) this difference may be lost if non-normalized indexes are utilized; (iii) the circadian pattern in the normalized indexes is lost in HF patients; (iv) in HF patients the loss of the day-night variation in the normalized indexes is related to a tendency of complexity to increase during the daytime and to decrease during the nighttime; (v) the most likely length L of the most informative patterns ranges from 2 to 4; (vi) in NO subjects classification of patterns with L=3 indicates that stable patterns (i.e., those with no variations) are more present during the daytime, while highly variable patterns (i.e., those with two unlike variations) are more frequent during the nighttime; (vii) during the daytime in HF patients, the percentage of highly variable patterns increases with respect to NO subjects, while during the nighttime, the percentage of patterns with one or two like variations decreases.

Long-term monitoring of sleep apnea at home in heart failure patients: preliminary results from the HHH study

Sleep apnea is very common in patients with chronic heart failure (CHF) and has important implications in terms of morbidity, mortality and clinical management. Home respiratory telemonitoring might constitute a potential low-cost, widely-applicable alternative to traditional polysomnography in the evaluation and long-term monitoring of breathing disorders in these patients. In this paper we briefly describe the technological infrastructure and present preliminary results of the European Community multicountry trial HHH (Home or Hospital in Heart Failure), which is currently testing a novel system for home telemonitoring of cardiorespiratory signals in CHF patients. The recording and transmitting devices are suitable to be self-managed by the patient. We give a detailed report on the prevalence of nocturnal respiratory disorders at the beginning of the one-year follow-up and on their persistency over the following recordings (one per month). These preliminary findings clearly indicate that intermittent home telemonitoring of respiratory signals based on patient's self-management is feasible in CHF patients and the compliance is high. Reported statistics unambiguously confirm the high prevalence of nocturnal breathing disorders in these patients and clearly show that this phenomenon tends to persist over time.

[Function recovery in patients with knee arthroplasty: role of proprioceptive rehabilitation]

This study evaluates the outcome of proprioceptive rehabilitation in 18 patients who underwent knee joint prosthetic replacement using the dynamic electronic plate Pro-kin_machine. The proprioceptive performance was determined by having the patients trace a set of three outlines (horizontal, vertical and circular) using the foot of the operated limb. The measures of outcome parameters were: 1) time taken to do the test; 2) score of accuracy of the test measured in percentage. Tests were performed on admission, half way through rehabilitation and on discharge. Each patient had 15 sittings of physiotherapy. Our results demonstrate a significant improvement of both parameters at the end of the treatment. After prosthetic knee joint replacement, not only is it important to re-establish mechanical stability but also dynamic stability. The latter can be achieved through active virtual taping by the stabilizer muscles. Prompt management of instability of the joint in the rehabilitation phase is extremely important in the re-activating of the control mechanisms that are compromised by the surgical operation.

Noninvasive measurement of blood pressure variability: accuracy of the Finometer monitor and comparison with the Finapres device

To assess the accuracy of spectral indices of arterial pressure variability and baroreflex sensitivity obtained from beat-by-beat noninvasive blood pressure recordings by the Finometer device, we compared these measures with those obtained from intra-arterial recordings. The performance of the Finometer was also compared to the traditional Finapres device. In 19 cardiac disease patients, including myocardial infarction, heart failure and cardiac transplant, we estimated the power of systolic and diastolic pressures in the VLF (0.01-0.04 Hz), LF (0.04-0.15 Hz) and HF (0.15-0.45 Hz) bands and computed absolute and percentage errors relative to intra-arterial brachial pressure. We also computed the characteristic frequency of each band (i.e. the barycentric frequency of spectral components identified in the band). The variability of systolic pressure in the VLF and LF bands was markedly overestimated by both the Finometer and Finapres (p < 0.01), with percentage median errors of respectively 130% and 103% (Finometer), and 134% and 78% (Finapres). The HF power was substantially unchanged using the Finometer and reduced using the Finapres (-28%, p < 0.05). The limits of agreement between noninvasive and invasive spectral measurements were wide. Linear system analysis showed that most (>80%) of the power of noninvasive signals was linearly related to the power of the invasive signal. The characteristic frequency of each band was substantially preserved in both noninvasive signals. The results for diastolic pressure were similar, but the Finapres errors in the VLF and LF bands were lower. Baroreflex sensitivity was significantly underestimated by both devices (Finometer: -31%, Finapres: -24%). Despite previous studies having shown that brachial artery waveform reconstruction performed by the Finometer has improved the accuracy of blood pressure measurement compared to the Finapres device, measurement of blood pressure variability in cardiac disease patients provides worse results in most spectral parameters and a better accuracy only in the HF band of systolic pressure.

Effect of paced breathing on ventilatory and cardiovascular variability parameters during short-term investigations of autonomic function

Paced breathing (PB) around 0.25 Hz has been advocated as a means to avoid confounding and to standardize measurements in short-term investigations of autonomic cardiovascular regulation. Controversy remains, however, as to whether it causes any alteration in autonomic control. We addressed this issue in 40 supine, middle-aged, healthy volunteers by assessing the changes induced by PB (0.25 Hz for 8 min) on 1) ventilatory parameters, 2) the indexes of autonomic control of cardiovascular function, and 3) the spectral indexes of cardiovascular variability. Subjects were grouped into group 1 (n = 31), if spontaneous breathing was regular and within the high-frequency (HF) band (0.15-0.45 Hz), or group 2 (n = 9), if it was irregular or slow (< 0.15 Hz). In both groups, PB was accompanied by an increase in minute ventilation (both groups, P < 0.01), whereas tidal volume increased only in group 1 (P = 0.0003). End-tidal CO2 decreased by [median (lower quartile, upper quartile)] -0.2 (-0.5, -0.1)% (group 1, P < 0.0001) and -0.6 (-0.8, -0.5)% (group 2, P = 0.008). Mean R-R interval and systolic and diastolic pressure remained remarkably stable (all P > or = 0.13, both groups). No significant changes were observed in spectral indexes of R-R and pressure variability (all P > or = 0.12, measured only in group 1 to avoid confounding), except in the HF power of pressure signals, which significantly increased (all P < 0.05) in association with increased tidal volume. In conclusion, PB at 0.25 Hz causes a slight hyperventilation and does not affect traditional indexes of autonomic control or, in subjects with spontaneous breathing in the HF band, most relevant spectral indexes of cardiovascular variability. These findings support the notion that PB does not alter cardiovascular autonomic regulation compared with spontaneous breathing.

Leave-one-out prediction error of systolic arterial pressure time series under paced breathing

In this paper, we consider systolic arterial pressure time series from healthy subjects and chronic heart failure patients, undergoing paced respiration, and show that different physiological states and pathological conditions may be characterized in terms of predictability of time series signals from the underlying biological system. We model time series by the regularized least-squares approach and quantify predictability by the leave-one-out error. We find that the entrainment mechanism connected to paced breath, that renders the arterial blood pressure signal more regular and thus more predictable, is less effective in patients, and this effect correlates with the seriousness of the heart failure. Using a Gaussian kernel, so that all orders of nonlinearity are taken into account, the leave-one-out error separates controls from patients (probability less than 10(-7)), and alive patients from patients for whom cardiac death occurred (probability less than 0.01).

Phase shifts of synchronized oscillators and the systolic-diastolic blood pressure relation

We study the phase-synchronization properties of systolic and diastolic arterial pressure in healthy subjects. We find that delays in the oscillatory components of the time series depend on the frequency bands that are considered, in particular we find a change of sign in the phase shift going from the very low frequency band to the high frequency band. This behavior should reflect a collective behavior of a system of nonlinear interacting elementary oscillators. We prove that some models describing such systems, e.g., the Winfree and the Kuramoto models, offer a clue to this phenomenon. For these theoretical models there is a linear relationship between phase shifts and the difference of natural frequencies of oscillators and a change of sign in the phase shift naturally emerges.

Long- and short-time analysis of heartbeat sequences: correlation with mortality risk in congestive heart failure patients

We analyze RR heartbeat sequences with a dynamic model that satisfactorily reproduces both the long- and the short-time statistical properties of heart beating. These properties are expressed quantitatively by means of two significant parameters, the scaling delta concerning the asymptotic effects of long-range correlation, and the quantity 1-pi establishing the amount of uncorrelated fluctuations. We find a correlation between the position in the phase space (delta, pi) of patients with congestive heart failure and their mortality risk.

Left atrial function: bridge to central and hormonal determinants of exercise capacity in patients with chronic heart failure

The stroke volume response to exercise is a critical determinant in meeting peripheral metabolic demands in patients with chronic hear failure. The Left atrium, by its position, is important in coupling right and left ventricles, to left preload reserve and to modulate sympathetic activity. We performed this study to investigate the relationship between exercise capacity and diastolic and systolic left atrium function in patients with chronic heart failure.

METHODS

We considered 128 consecutive patients with severe chronic heart failure (EF < 35%) due to ischemic or idiopathic dilated cardiomyopathy. Cardiac output, right atrial pressure, pulmonary artery pressures and mean pulmonary wedge pressure (A, X, V, Y wedge pressures) were determined during right cardiac catheterization. By Echocardiography evaluation, we measured atrial pressures and volume during early and late left atrial systolic filling and we calculated left atrial chamber stiffness by this equation P = A*eKV1. (P = left atrial pressure; A = elastic constant (mmHg*ml); e = the base of the natural logarithm; V1 = left atrial volume (ml); K = left atrial chamber stiffness constant (ml-1) = ln (V/X)/(maximal--minimal left atrial volumes)). All patients performed cardiopulmonary exercise test with modified Noughton protocol. Plasma norepinephrine and Atrial natriuretic factor levels were determined.

RESULTS

Maximal and minimal left atrial volumes were inversely related to oxygen consumption (r = -.44, p < .001; r = -.61, p < .001). At rest, no differences were found in plasma norepinephrine concentrations (309 +/- 152 pg/ml vs 309 +/- 394 pg/ml; p = ns) and systemic vascular resistance (1706 +/- 435 vs 1771 +/- 524 dynes/cm sec-5; p = ns) in patients with large or normal left atrial volumes. During exercise the chronotropic response increased less in patients with large atrial volumes (56 +/- 13 vs 45 +/- 14; p = .001). The left atrial chamber stiffness constant was inversely related to peak oxygen consumption and exercise time. Patients with different chamber stiffness showed statistical difference in peak VO2 (16 +/- 4 vs 11 +/- 3 ml/kg/min; p = .0001). Left atrial ejection fraction was directly related to peak oxygen consumption (r = 0.55), but the most strongly correlation was with atrial filling fraction (r = .67).

CONCLUSIONS

This study demonstrates a strong relationship between left atrial function and exercise capacity in patients with chronic heart failure.

RESP-24: a computer program for the investigation of 24-h breathing abnormalities in heart failure patients

In this paper, we describe a computer program (RESP-24) specifically devised to assess the prevalence and characteristics of breathing disorders in ambulant chronic heart failure patients during the overall 24 h period. The system works on a single channel respiratory signal (RS) recorded through a Holter-like portable device. In the pre-processing stage RESP-24 removes noise, baseline drift and motion artefacts from the RS using a non-linear filter, enhances respiratory frequency components through high-pass filtering and derives an instantaneous tidal volume (ITV) signal. The core processing is devoted to the identification and classification of the breathing pattern into periodic breathing (PB), normal breathing or non-classifiable breathing using a 60 s segmentation, and to the identification and estimation of apnea and hypopnea events. Sustained episodes of PB are detected by cross analysis of both the spectral content and time behavior of the ITV signal. User-friendly interactive facilities allow all the results of the automatic analysis procedure to be edited. The final report provides a set of standard and non-standard parameters quantifying breathing abnormalities during the 24 h period, the night-time and the day-time, including the apnea/hypopnea index, the apnea index, the total time spent in apnea or in hypopnea and the prevalence of non-apneic and apneic PB. The accuracy of these measurements was appraised on a data set of 14 recordings, by comparing them with those provided by a trained analyst. The mean and standard deviation of the error of the automatic procedure were below respectively 6 and 8% of the reference value for all parameters considered and the mean total classification accuracy was 92%. In most cases, the individual error was <12%. We conclude that measurements provided automatically by the RESP-24 software are suitable for screening purposes and clinical trials, although a preventive check of signal quality should be recommended.

New criteria for estimating baroreflex sensitivity using the transfer function method

Computer simulations were carried out to appraise three new criteria for the estimation of baroreflex sensitivity (BRS) using the transfer function method. The major goal was to identify a computation procedure able to overcome the intrinsic limitations of the classical coherence criterion. Four representative shapes of the gain function and three different average gains (2, 5 and 8 ms(mmHg)(-1) in the low-frequency (LF) band (0.04-0.15Hz) were considered. The signal-to-noise ratio was made to vary so that the peak coherence in the LF band changed from 0.15 to 0.9. All simulation parameters were derived from previous observations in healthy subjects and heart disease patients. The error of the estimated gain function was obtained from its confidence interval. BRS was computed as average gain in the LF band: (a) including in the average only those points having error < or = threshold (criterion 1, C1); (b) calculating the mean error in the band and accepting BRS measurements only when this error was < or = threshold (criterion 2, C2); (c) including in the average all points, regardless of the error (criterion 3, C3). The three criteria were compared in terms of measurability (percentage of measured BRS) and accuracy (bias and SD of BRS). Using C1 and C2, measurability dropped to 10% when the peak coherence in the LF band decreased, respectively, to 0.18-0.41 and to 0.26-0.53, depending on the shape and strength of the gain. In this condition (lower bound of measurability), worst bias and SD (average gain: 8 ms(mmHg)(-1)) were, respectively, 0.8 ms(mmHg)(-1) and 3.3ms(mmHg)(-1) (C1), and 0.1 ms(mmHg)(-1) and 1.0 ms(mmHg)(-1) (C2). C3, by definition, always ensured 100% measurability and showed bias and SD comparable with, or even lower than, C1 and C2, within the common range of measurable BRS. In the extreme condition of 0.15 coherence, bias and SD were, respectively, 1.7 ms(mmHg)(-1) and 2.3ms(mmHg)(-1) (average gain: 8ms(mmHg)(-1)). Hence, error checking (C1 and C2) dramatically reduced measurability and did not improve accuracy of BRS measurements compared with performing no error check (C3). In conditions of low signal-to-noise ratio and/or impaired baroreflex gain, leading to markedly reduced coherence, the simple average of the gain function in the LF band allows BRS to be estimated with accuracy adequate for clinical purposes.

Echo-Doppler mitral flow monitoring: an operative tool to evaluate day-to-day tolerance to and effectiveness of beta-adrenergic blocking agent therapy in patients with chronic heart failure

OBJECTIVES

The goals of this study were: 1) to assess the predictive value of baseline mitral flow pattern (MFP) and its changes after loading manipulations as regards tolerance to and effectiveness of beta-adrenergic blocking agent treatment in patients with chronic heart failure (CHF); and 2) to analyze the prognostic implications of chronic MFP modifications after beta-blocker treatment.

BACKGROUND

In patients with CHF, carvedilol therapy induces clinical and hemodynamic improvements. Individual management, clinical effectiveness and prognostic implications, however, remain unclear. The MFP changes induced by loading manipulations provide independent prognostic information.

METHODS

Echo-Doppler was performed at baseline and after loading manipulations in 116 consecutive patients with CHF (left ventricular ejection fraction: 25 +/- 7%); 54 patients with a baseline restrictive MFP were given nitroprusside infusion; 62 patients with a baseline nonrestrictive MFP performed passive leg lifting. According to changes in MFP, we identified four groups: 17 with irreversible restrictive MFP (Irr-rMFP), 37 with reversible restrictive MFP (Rev-rMFP), 12 with unstable nonrestrictive MFP (Un-nrMFP) and 50 with stable nonrestrictive MFP (Sta-nrMFP). Carvedilol therapy (44 +/- 27 mg) was administered blind to results of loading maneuvers. After six months, MFP was reassessed and patients reclassified according to chronic MFP changes. During follow-up, tolerance to and effectiveness of treatment and major cardiac events (death, readmission and urgent transplantation) were considered.

RESULTS

Changes of MFP after loading manipulations were more accurate than baseline MFP in predicting both tolerance to (p < 0.01) and effectiveness of (p < 0.05) carvedilol. After 26 +/- 14 months of follow-up, cardiac events had occurred in 23/102 patients (23%). The event rate in patients with chronic Irr-rMFP or Un-nrMFP was markedly higher than it was in those with Rev-rMFP or Sta-nrMFP.

CONCLUSIONS

In our patients, tolerance to and effectiveness of carvedilol was predicted better by echo-Doppler MFP changes after loading manipulations than by baseline MFP. Chronic changes of MFP after therapy are strong predictors of major cardiac events.

[Correlation between computed tomography and isokinesis in patients with reconstructive surgery of anterior cruciate ligament of the knee]

AIM

The aim of this study was to correlate the length (measured by computed tomography) of the anterior cruciate neoligament following knee surgery with the time required by the flexors-extensors of the knee to reach isokinesis (measured using an isokinetic method).

MATERIAL AND METHODS

Twenty-five patients (all males, median age 25.4 years), who had undergone surgical repair of the anterior cruciate ligament (ACL), were assessed by computed axial tomography (CT) and isokinetic tests a mean of 6.3 months after their operation. The following isokinetic parameters were calculated: time to reach isokinesis in flexion, time to reach isokinesis in extension, flexion strength, and extension strength. Mean values were calculated from all the values recorded during the test cycles performed. The CT examinations, after lateral scanograms, were carried out with 1 mm contiguous axial scans parallel to the tibial plate. It was possible to assess the integrity of the neoligament which was measured from a section of the tibial plate above the tibial cartilage to its insertion in the intercondylar furrow.

RESULTS

As expected, all the values recorded from the healthy knee were significantly different from those recorded on the operated side. As far as concerns analysis of any correlations, there were good correlations between the time to reach isokinesis in extension and the length of the ACL both on the operated side (r=.62) and the healthy side (r=.69), whereas the correlations between the length of the ACL and all other measurements were moderate or very weak (from 0.44 to 0.03).

DISCUSSION AND CONCLUSIONS

That the isokinetic measurements show an increased time for the extensor muscles of the operated knee to reach isokinesis is related to altered biomechanics of the passage of the tibia from a posterior translaction position to one of an anterior translaction that is, to anterior displacement of the tibia during extension of the knee, which leads to the prolonged time. The correlation between this time and the length of the ACL, as measured by CT, offers the possibility of being able to monitor the outcome of cruciate ligament repair periodically during various phases of rehabilitation treatment and of only using control CT examinations if there are any complications and/or problems.

Chronic infusion of dobutamine and nitroprusside in patients with end-stage heart failure awaiting heart transplantation: safety and clinical outcome

BACKGROUND

in patients with severe heart failure additional therapeutic support with intravenous inotropic or vasodilator drugs is frequently employed in an attempt to obtain hemodynamic and clinical control. No data comparing the use and efficacy of chronic intravenous inotropic and vasodilator therapy in patients with advanced heart failure are available.

AIMS

we evaluated, in a group of patients with advanced heart failure undergoing chronic infusion with dobutamine or nitroprusside, in addition to optimized oral therapy, (1) the safety of chronic infusion, (2) the efficacy of both drugs in managing unloading therapy and (3) clinical outcome of the two therapeutic strategies.

METHODS

one hundred and thirteen patients receiving optimized oral therapy, in functional class III/IV with symptoms and signs of refractory heart failure and requiring additional pharmacological support with either intravenous dobutamine or nitroprusside were evaluated. Clinical and therapeutic management and clinical outcome of the two groups were considered.

RESULTS

dobutamine was administered for 12 h/day for 20+/-23 days at a dosage of 7+/-3 microg/kg/min to 43 patients. The mean dose of nitroprusside was 0.76+/-0.99 microg/kg/min. The mean duration of use of this drug, administered as a 12-h/day infusion was 22+/-38 days. Nitroprusside infusion allowed greater doses of short-term ACE-inhibitors to be used compared to pre-infusion (ACE-inhibitor dose: 55+/-30 mg/day vs. 127+/-30 mg/day P<0.0001) and during dobutamine infusion (ACE-inhibitor dose: 85+/-47 mg/day vs. 127+/-30 mg/day P<0.002). Nitroprusside unlike dobutamine significantly improved the NYHA functional class. Of the 113 patients, 109 (97%) had a cardiac event during a mean follow-up of 337+/-264 days. Forty-four patients required hospitalization for worsening congestive heart failure, 45/113 (39%) patients died during the follow-up and 27/113 (24%) patients had a heart transplant in status one. Hospitalization, because of worsening heart failure was less frequent in the nitroprusside than in the dobutamine subgroup [29/51 (57%) vs. 19/22 (86%) P<0.02]. The overall mortality was 28% (20/70) in the nitroprusside group and 58% (25/43) in the dobutamine group (odds ratio 0.33 CI 0.16 to 0.73 P<0.006). In the group treated with nitroprusside, heart transplantation in status one was performed in 16/33 patients (48%), while in the dobutamine group this was done in 11/14 patients (78%) (odds ratio 0.25 CI 0.06-1.02 P<0.06). There was a significant reduction in the combined end-point of mortality/heart transplantation in status one in patients treated with nitroprusside compared to those treated with dobutamine (36/70 (51%) vs. 36/43 (84%) - (odds ratio 0.34 CI 0.14-0.80 P<0.01). The incidence of adverse events in the patients treated with nitroprusside was similar to that in those treated with dobutamine (20% vs. 17% P=ns).

CONCLUSIONS

for patients awaiting heart transplantation chronic intermittent nitroprusside infusions are more effective and safer than dobutamine in relieving symptoms, facilitating unloading therapy management and improving survival. Whether chronic intermittent infusion of nitroprusside could represent a feasible medical strategy in out-patients with severe heart failure remains to be investigated.

[Rehabilitation day-hospital of the heart failure unit: structure and functions]

Chronic heart failure has emerged as an important public health problem. The consequent increase in the sanitary services has induced an increased consumption of financial resources and conditioned the need to investigate new sanitary models that guarantee, by integrating the inpatient and outpatient health care delivery, the continuity of health assistance. Cardiac rehabilitation in the context of a day-hospital Heart Failure Unit allows for the organization of a rehabilitation program including various health approaches aimed at guaranteeing a multidisciplinary program and the relief continuity. This article describes the experience developed in the Heart Failure Unit of Montescano.

Reliability of transfer function estimates in cardiovascular variability analysis

Transfer function (TF) analysis is a widely diffused technique in the assessment of the relationship between short-term cardiovascular variability signals, particularly blood pressure, heart rate and respiration. To guarantee the reliability of the estimates, a conventional threshold of 0.5 on the magnitude squared coherence (MSC) is commonly used, although (i) other analysis parameters play a role and (ii) lower values of MSC are frequently unavoidable in physiological systems. In this study, computer simulations are performed to assess the dependency of the bias and standard deviation (SD) of TF estimates on record length (RL), spectral window bandwidth (Bw) and MSC; to evaluate the accuracy of theoretical expressions for the computation of the confidence interval (CI) of the estimates; and to assess, in some representative situations, how faithfully observed TF shapes reproduce the underlying true functions in conditions of very low MSC. The accuracy of TF estimates increases non-linearly with increasing RL, and the benefit over 7 min is small. Using this RL, the relative bias for the TF modulus is < 10% for MSC > 0.2. Estimates of TF phase are unbiased. The SD of both the modulus and phase increases linearly as the MSC decrease to 0.4 and then, for lower MSC, increases markedly with nonlinear behaviour. Bw= 0.03Hz appears to be most suitable to reduce the error, preserving spectral resolution. CIs for the TF phase are highly reliable, whereas those for the modulus tend to be slightly narrower than the nominal value at high coherence values. Major features of the TF shape appear to be preserved in simulations with very low MSC. The major problem in TF estimation is the sharp increase in the variability of the measurements as the coherence decreases towards the lowest values. The combination of RL > or = 420s and Bw= 0.03Hz should be suggested in short-term cardiovascular variability studies. Although basic features of the true TF can be recovered even when the MSC is < 0.5, much greater values can be necessary when accurate point estimates are needed. Theoretical expressions for the computation of confidence intervals of the TF are adequate for practical purposes.

Assessment of baroreflex sensitivity in patients with preserved and impaired left ventricular function by means of the Valsalva manoeuvre and the phenylephrine test

The purpose of the present study was to assess the agreement between measurements of baroreflex sensitivity (BRS) obtained by the Valsalva manoeuvre and by the phenylephrine test in patients with previous myocardial infarction and different degrees of left ventricular dysfunction. Patients with a previous myocardial infarction were enrolled consecutively into two groups according to their left ventricular ejection fraction (LVEF): <or=40% (n=52) or >40% (n=52). All patients underwent BRS assessment by the phenylephrine technique (Phe-BRS) and by the Valsalva manoeuvre, with the latter using both the overshoot part of phase IV (Ov-VM-BRS) and the whole of phase IV (IV-VM-BRS). The linear association between methods was assessed by correlation analysis and the agreement was evaluated by computing the bias and the limits of agreement. IV-VM-BRS and Ov-VM-BRS could not be computed in 26% and 39% of patients respectively. For both indices a much higher percentage of non-computable Valsalva manoeuvre slopes was found in the group of patients with LVEF <or=40%. Phe-BRS was significantly lower in patients with non-computable Valsalva manoeuvre slopes; 55% and 59% of patients with non-computable Ov-VM-BRS and IV-VM-BRS respectively had a markedly depressed Phe-BRS (i.e. <3 ms/mmHg, as defined by the ATRAMI study). On comparing Phe-BRS and Ov-VM-BRS in patients with LVEF <or=40%, we obtained the following results: r=0.75 (P<0.001), bias=0.5 ms/mmHg (P=0.5) and limits of agreement from -6.7 to 7.8 ms/mmHg. In patients with LVEF >40% the results were: r=0.91 (P<0.001), bias=0.1 ms/mmHg (P=0.84) and limits of agreement from -4.8 to 5 ms/mmHg. When comparing Phe-BRS and IV-VM-BRS, we found r=0.67 (P=0.001), bias=-1.5 ms/mmHg (P=0.06) and limits of agreement from -8.8 to 5.7 ms/mmHg in the group of patients with LVEF <or=40%; and r=0.66 (P<0.001), bias=-3.1 ms/mmHg (P<0.001) and limits of agreement from -12.1 to 5.9 ms/mmHg in the group of patients with LVEF >40%. Dichotomizing Ov-VM-BRS, the best cut-off value to identify patients with a Phe-BRS of <3 ms/mmHg was found to be 7 ms/mmHg, giving 100% sensitivity and 69% specificity. In conclusion, estimation of BRS by the Valsalva manoeuvre in post-myocardial infarction patients is limited by a large number of non-measurable results. When computable, measurements are well correlated with those obtained by Phe-BRS, but, because of large limits of agreement, the two methods cannot be used interchangeably. If used as a screening test for risk stratification, the Valsalva manoeuvre could reduce by about one-third the need for phenylephrine injection.

Periodic breathing in heart failure patients: testing the hypothesis of instability of the chemoreflex loop

In this study, we applied time- and frequency-domain signal processing techniques to the analysis of respiratory and arterial O(2) saturation (Sa(O(2))) oscillations during nonapneic periodic breathing (PB) in 37 supine awake chronic heart failure patients. O(2) was administered to eight of them at 3 l/min. Instantaneous tidal volume and instantaneous minute ventilation (IMV) signals were obtained from the lung volume signal. The main objectives were to verify 1) whether the timing relationship between IMV and Sa(O(2)) was consistent with modeling predictions derived from the instability hypothesis of PB and 2) whether O(2) administration, by decreasing loop gain and increasing O(2) stores, would have increased system stability reducing or abolishing the ventilatory oscillation. PB was centered around 0.021 Hz, whereas respiratory rate was centered around 0.33 Hz and was almost stable between hyperventilation and hypopnea. The average phase shift between IMV and Sa(O(2)) at the PB frequency was 205 degrees (95% confidence interval 198-212 degrees). In 12 of 37 patients in whom we measured the pure circulatory delay, the predicted lung-to-ear delay was 28.8 +/- 5.2 s and the corresponding observed delay was 30.9 +/- 8.8 s (P = 0.13). In seven of eight patients, O(2) administration abolished PB (in the eighth patient, Sa(O(2)) did not increase). These results show a remarkable consistency between theoretical expectations derived from the instability hypothesis and experimental observations and clearly indicate that a condition of loss of stability in the chemical feedback control of ventilation might play a determinant role in the genesis of PB in awake chronic heart failure patients.

Reproducibility of the six-minute walking test in chronic heart failure patients

The six-minute walking test (WT) is used in trials and clinical practice as an easy tool to evaluate the functional capacity of chronic heart failure (CHF) patients. As WT measurements are highly variable both between and within individuals, this study aims at assessing the contribution of the different sources of variation and estimating the reproducibility of the test. A statistical model describing WT measurements as a function of fixed and random effects is proposed and its parameters estimated. We considered 202 stable CHF patients who performed two baseline WTs separated by a 30 minute rest; 49 of them repeated the two tests 3 months later (follow-up control). They had no changes in therapy or major clinical events. Another 31 subjects performed two baseline tests separated by 24 hours. Collected data were analysed using a mixed model methodology. There was no significant difference between measurements taken 30 minutes and 24 hours apart (p = 0.99). A trend effect of 17 (1.4) m (mean (SE)) was consistently found between duplicate tests (p < 0.001). REML estimates of variance components were: 5189 (674) for subject differences in the error-free value; 1280 (304) for subject differences in spontaneous clinical evolution between baseline and follow-up control, and 266 (23) for the within-subject error. Hence, the standard error of measurement was 16.3 m, namely 4 per cent of the average WT performance (403 m) in this sample. The intraclass correlation coefficient was 0.96. We conclude that WT measurements are characterized by good intrasubject reproducibility and excellent reliability. When follow-up studies > or = 3 months are performed, unpredictable changes in individual walking performance due to spontaneous clinical evolution are to be expected. Their clinical significance, however, is not known.

Nonselective beta-adrenergic blocking agent, carvedilol, improves arterial baroflex gain and heart rate variability in patients with stable chronic heart failure

OBJECTIVES

The purpose of this study was to investigate in a case-controlled study whether carvedilol increased baroreflex sensitivity and heart rate variability (HRV).

BACKGROUND

In chronic heart failure (CHF), beta-adrenergic blockade improves symptoms and ventricular function and may favorably affect prognosis. Although beta-blockade therapy is supposed to decrease myocardial adrenergic activity, data on restoration of autonomic balance to the heart and, particularly, on vagal reflexes are limited.

METHODS

Nineteen consecutive patients with moderate, stable CHF (age 54 +/- 7 years, New York Heart Association [NYHA] class II to III, left ventricular ejection fraction [LVEF] 24 +/- 6%), treated with optimized conventional medical therapy, received carvedilol treatment. Controls with CHF were selected from our database on the basis of the following matching criteria: age +/- 3 years, same NYHA class, LVEF +/- 3%, pulmonary wedge pressure +/- 3 mm Hg, peak volume of oxygen +/- 3 ml/kg/min, same therapy. All patients underwent analysis of baroreflex sensitivity (phenylephrine method) and of HRV (24-h Holter recording) at baseline and after six months.

RESULTS

Beta-blockade therapy was associated with a significant improvement in symptoms (NYHA class 2.1 +/- 0.4 vs. 1.8 +/- 0.5, p < 0.01), systolic and diastolic function (LVEF 23 +/- 7 vs. 28 +/- 9%, p < 0.01; pulmonary wedge pressure 17 +/- 8 vs. 14 +/- 7 mm Hg, p < 0.05) and mitral regurgitation area (7.0 +/- 5.1 vs. 3.6 +/- 3.0 cm2, p < 0.01). No significant differences were observed in either clinical or hemodynamic indexes in control patients. Phenylephrine method increased significantly after carvedilol (from 3.7 +/- 3.4 to 7.1 +/- 4.9 ms/mm Hg, p < 0.01) as well as RR interval (from 791 +/- 113 to 894 +/- 110 ms, p < 0.001), 24-h standard deviation of normal RR interval and root mean square of successive differences (from 56 +/- 17 to 80 +/- 28 ms and from 12 +/- 7 to 18 +/- 9 ms, all p < 0.05), while all parameters remained unmodified in controls. During a mean follow-up of 19 +/- 8 months a reduced number of cardiac events (death plus heart transplantation, 58% vs. 31%) occurred in those patients receiving beta-blockade.

CONCLUSIONS

Besides the well-known effects on ventricular function, treatment with carvedilol in CHF restores both autonomic balance and the ability to increase reflex vagal activity. This protective mechanism may contribute to the beneficial effect of beta-blockade treatment on prognosis in CHF.

Non-invasive estimation of right atrial pressure by combined Doppler echocardiographic measurements of the inferior vena cava in patients with congestive heart failure

BACKGROUND

In patients with congestive heart failure, evaluation of right atrial pressure (RAP) provides useful therapeutic, functional and prognostic information. The aim of this study was to investigate whether a combination of inferior vena cava variables measured by Doppler echocardiography could provide a reliable non-invasive estimate of RAP.

METHODS

One hundred consecutive patients with severe congestive heart failure (ejection fraction 24 +/- 6%) due to dilated cardiomyopathy were evaluated by simultaneous Doppler echocardiography and hemodynamic studies. RAP, end-expiratory (IVCDmax) and end-inspiratory (IVCDmin) diameters of the inferior vena cava, its collapse index [CIIVC = (IVCDmax - IVCDmin/IVCDmax)*100] and systolic fraction of forward inferior vena cava flow were measured and correlated by both single and multilinear regression analysis. The accuracy of generated equations was tested in a separate testing group of 61 patients at baseline and a subgroup of 20 patients after loading manipulations, prospectively studied in the same methodological setting.

RESULTS

All Doppler echocardiographic variables were correlated with RAP. The IVCDmin showed the strongest correlation (r = 0.84, p < 0.0001). Stepwise regression analysis identified two equations for predicting RAP: 1) RAP = (6.4*IVCDmin + 0.04*CIIVC - 2) (r = 0.82, p < 0.0001, SEE 1.7 mmHg) in all patients, and 2) RAP = (4.9*IVCDmin + 0.01*CIIVC - 0.2) (r = 0.92, p < 0.0001, SEE 1.2 mmHg) in patients without tricuspid regurgitation. In the testing group estimated and measured RAP was strongly correlated at baseline (r = 0.95, SEE 1.3 mmHg, p < 0.00001) and after loading manipulations (r = 0.96, SEE 1.2 mmHg, p < 0.00001). The agreement between invasive and non-invasive measurements of RAP in identifying patients with normal (< or = 5 mmHg), moderately increased (< 5 RAP < 10 mmHg) and markedly increased (> or = 10 mmHg) RAP was 81 or 93% using equation 1 or 2, respectively.

CONCLUSIONS

Our results provide evidence that in patients with congestive heart failure indices derived from Doppler measurements of the inferior vena cava can be used to produce an accurate, strong and non-invasive estimate of RAP. This is another example of the usefulness of Doppler echocardiography in evaluating hemodynamic profile and its changes in patients with congestive heart failure. Echocardiographic assessment of the inferior vena cava should be included in the evaluation of patients with congestive heart failure.

Comparison between invasive and non-invasive measurements of baroreflex sensitivity; implications for studies on risk stratification after a myocardial infarction

AIMS

The ATRAMI (Autonomic Tone and Reflexes After Myocardial Infarction) study has proved the independent prognostic value of baroreflex sensitivity. A limitation of the traditional method of estimating baroreflex sensitivity by phenylephrine, is the need to monitor intra-arterial blood pressure. Our objective was to establish whether this invasive method of monitoring could be superseded by non-invasive methods, such as the Finapres device.

METHODS AND RESULTS

Patients with three repeated invasive and non-invasive baroreflex sensitivity measurements were selected from the ATRAMI database (n = 454). The mean of these measurements was taken as the baroreflex sensitivity estimate. The repeatability of both methods (standard deviation of the three measurements) decreased with increasing baroreflex sensitivity. There was no constant bias between invasive and non-invasive measurements (0. 22+/-2.2 ms. mmHg(-1), P = 0.42). The linear correlation was very high (r = 0.91, P < 0.01). The normalized 95% limits of agreement were -0.5 and 0.52. On survival analysis, invasive and non-invasive baroreflex sensitivity gave similar prognostic information (likelihood ratio: 155.6 (P = 0.007) and 155.0 (P = 0.006); risk ratio: 0.79 and 0.81, respectively). According to the ATRAMI cut-off points, 85% of patients were classified concordantly by the two methods. None of the patients at high (low) risk with the invasive method were classified as low (high) risk class by the non-invasive method.

CONCLUSION

Despite wide limits of agreement, invasive and non-invasive baroreflex sensitivity measurements are highly correlated and provide equivalent prognostic information.

Effect of beta-blockade on the premature ventricular beats/heart rate relation and heart rate variability in patients with coronary heart disease and severe ventricular arrhythmias

We examined the effects of beta-blockers on the associations between heart rate and number of premature ventricular beats (PVBs) and on heart rate variability and myocardial ischemia in patients with coronary heart disease. After 2 weeks of run-in placebo treatment, 18 patients with coronary artery disease were randomized to a 7-day treatment with either propranolol (40 mg) three times a day or placebo. During run-in and after 7 days of treatment, patients underwent 24-hour Holter monitoring and exercise tests. We analyzed the 24-hour Holter recordings with customized software that computes the correlation between heart rate and occurrence of PVBs. We also computed spectral measures of heart rate variability on the same recordings. Propranolol caused a significant decrease in the log-transformed total number of PVBs recorded over 24 hours and during the day. The number of PVBs was much lower during the night than during the day both after placebo and after propranolol. There were no differences between the two treatments. During the day, there was a positive correlation between heart rate and the number of PVBs in all 18 patients. The mean correlation coefficients between heart rate and number of PVBs increased significantly after propranolol treatment both during the 24-hour monitoring (p < 0.05) and during the day (p < 0.05). The night-recorded correlation coefficients between heart rate and number of PVBs were not significantly different in the placebo versus propranolol group. Propranolol significantly increased the total power during the day. Placebo caused a significant decrease in the low-frequency band (LF) and a significant increase in the high-frequency band (HF) during the night compared with the day. During the day, propranolol significantly reduced LF power and increased HF power, with respect to placebo. After propranolol treatment, the values of LF and HF power during the day were comparable to those recorded at night. The LF/HF ratio decreased significantly after propranolol treatment with respect to placebo in the day and became similar to that recorded during sleep. Propranolol significantly reduced heart rate and systolic blood pressure at rest and at peak exercise and reduced signs of myocardial ischemia. Propranolol administration reduces PVBs in patients with coronary artery disease and severe ventricular arrhythmias possibly through an improvement of cardiac autonomic regulation and through anti-ischemic effects, antiarrhythmic effects, or both.

Invasive and non-invasive determinants of pulmonary hypertension in patients with chronic heart failure

BACKGROUND

In patients with chronic heart failure, pulmonary hypertension is an important predictive marker of adverse outcome. Its invasive and non-invasive determinants have not been evaluated.

OBJECTIVE

This study was performed to evaluate hemodynamic determinants of pulmonary hypertension in chronic heart failure and to compare the predictive value of Doppler indices with that of invasively measured hemodynamic indices.

METHODS

Right heart catheterization and transthoracic echo-Doppler were simultaneously performed in 259 consecutive patients with chronic heart failure (ejection fraction 24% +/- 7%) who were in sinus rhythm and receiving optimized medical therapy. Systolic pulmonary artery pressure (sPAP), cardiac index, transpulmonary gradient pressure, and pulmonary wedge pressure (PWP) were measured invasively. Left atrial and ventricular systolic and diastolic volumes, the ratio of maximal early to late diastolic filling velocities (E/A ratio), deceleration time (DT) and atrial filling fraction (AFF) of transmitral flow, systolic fraction of forward pulmonary venous flow (SFpvf), and mitral regurgitation were quantified by echo-Doppler.

RESULTS

Patients with pulmonary hypertension had greater left atrial systolic and diastolic dysfunction, more left ventricular diastolic abnormalities, and greater hemodynamic impairment. The correlations between systolic left ventricular indices, mitral regurgitation, and sPAP were generally poor. Among invasive and non-invasive measurements, PWP (r = 0.89, p < 0.0001) and SFpvf (r = -0.68, p < 0.0001) showed the strongest correlation with sPAP. When we compared all patients with those without mitral regurgitation, the correlations between E/A ratio (r = 0.56 vs r = 0. 74, p < 0.002), SFpvf (r = -0.68 vs r = -0.84, p < 0.03), and systolic pulmonary artery pressure were significantly stronger. Multivariate analysis revealed that PWP was the strongest invasive independent predictor of systolic pulmonary artery pressure in patients with (R(2) = 0.87, p < 0.0001) and without (R(2) = 0.90, p < 0.0001) mitral regurgitation. A PWP > or= 18 mm Hg (odds ratio [95% CL], 142 (41-570) was strongly associated with systolic pulmonary hypertension. Among non-invasive variables DT, SFpvf, and AFF were identified as independent predictors of sPAP in patients with (R(2) = 0.56, p < 0.0001) and without (R(2) = 0.78, p < 0.0001) mitral regurgitation. A DT < 130 (odds ratio [95% CL], 3.5 (1.3-8.5), SFfvp < 40% (odds ratio [95% CL], 333 (41-1,007), and AFF < 30% (odds ratio [95% CL], 2 (1.3-7) most strongly predicted systolic pulmonary hypertension.

CONCLUSIONS

The results of this study indicate that in patients with chronic heart failure, venous pulmonary congestion is an important determinant of systolic pulmonary artery hypertension. Hemodynamic and Doppler determinants showed similar predictive power in identifying systolic pulmonary artery hypertension.

Limitations of the computerized laryngeal analyzer (CLA) in the assessment of the swallowing mechanism

This study was devised to assess the repeatability of measurements obtained from the Computerized Laryngeal Analyzer (CLA), a commercial system which monitors global laryngeal activity through a piezoelectric transducer positioned at the level of the thyroid cartilage. Twenty-two healthy subjects (37+/-7 yr) were asked to repeat three consecutive times the deglutition of three types of bolus: dry (saliva only), liquid (10 ml water) and solid (1 cm(3) biscuit). The whole recording session was repeated 4+/-3 days apart. Two parameters were considered: amplitude and duration of the deglutition. Both intra- and inter-sessions repeatability were assessed by the standard error of measurement. The amplitude measurements were often found to be clipped at 100 mV, making duration the only parameter suitable for analysis. The duration was homogenous for the three types of bolus and no trend effect was found either intra- or inter-sessions. Inter-sessions repeatability was significantly lower than the intra-session one (P<0.05). As a practical implication, a change in duration >/=1 s (=65% of the observed mean value) between two separate measurements is required in order to be 95% confident that it is not due to chance alone. We conclude that the observed limitations in the measurements provided by the CLA system, in conjunction with its intrinsic characteristic of providing only an uncalibrated measurement of global laryngeal activity, seriously question the possibility of using the CLA system either as a diagnostic tool or as a substitute of the gold standard method (videofluorography).

Cardiorespiratory interactions during periodic breathing in awake chronic heart failure patients

We applied spectral techniques to the analysis of cardiorespiratory signals [instantaneous lung volume (ILV), instantaneous tidal volume (ITV), arterial O(2) saturation (Sa(O(2))) at the ear, heart rate (HR), systolic (SAP), and diastolic (DAP) arterial pressure] during nonapneic periodic breathing (PB) in 29 awake chronic heart failure (CHF) patients and estimated the timing relationships between respiratory and slow cardiovascular (<0.04 Hz) oscillations. Our aim was 1) to elucidate major mechanisms involved in cardiorespiratory interactions during PB and 2) to test the hypothesis of a central vasomotor origin of PB. All cardiovascular signals were characterized by a dominant (>/=84% of total power) oscillation at the frequency of PB (mean +/- SE: 0.022 +/- 0.0008 Hz), highly coherent (>/=0.89), and delayed with respect to ITV (ITV-HR, 2.4 +/- 0.72 s; ITV-SAP, 6.7 +/- 0.65 s; ITV-DAP, 3.2 +/- 0.61 s; P < 0.01). Sa(O(2)) was highly coherent with (coherence function = 0.96 +/- 0. 009) and almost opposite in phase to ITV. These findings demonstrate the existence of a generalized cardiorespiratory rhythm led by the ventilatory oscillation and suggest that 1) the cyclic increase in inspiratory drive and cardiopulmonary reflexes and 2) mechanical effects of PB-induced changes in intrathoracic pressure are the more likely sources of the HR and blood pressure oscillations, respectively. The timing relationship between ITV and blood pressure signals excludes the possibility that PB represents the effect of a central vasomotor rhythm.

Angiotensin II type 1 receptor blockade prevents cardiac remodeling in bradykinin B(2) receptor knockout mice

Knockout mice (B(2)(-/-)) lacking the bradykinin (BK) B(2) receptor gene develop mild hypertension, cardiac hypertrophy, and myocardial damage. We hypothesized that these effects are due to the hypertrophying and damaging actions of angiotensin II (Ang II) in the absence of the balancing protection of BK. To verify this hypothesis, B(2)(-/-) or wild-type mice (B(2)(+/+)) were administered a nonpeptide antagonist of Ang II type 1 (AT(1)) receptors (A81988) from conception through 180 days of age. Untreated B(2)(+/+) and B(2)(-/-) served as controls. Blood pressure (BP) and heart rate were monitored with the use of tail-cuff plethysmography at regular intervals. Ventricular weights, diameters, wall thickness, chamber volume, and myocardial fibrosis were measured at 40 and 180 days. No differences were observed in BP, heart rate, and cardiac weight and dimensions between treated and untreated B(2)(+/+). The BP of AT(1) antagonist-treated B(2)(-/-) was reduced until 70 days; then, it increased to the levels found in untreated B(2)(-/-). AT(1) receptor blockade resulted in a reduction in left ventricular mass, chamber volume, and wall thickness and abrogated myocardial fibrosis in B(2)(-/-). These results indicate that Ang II is the major factor responsible for ventricular remodeling and myocardial damage in mice with disruption of BK B(2) receptor signaling. The interaction of Ang II and BK appears to be essential for the development of a normal heart.

Dilated and failing cardiomyopathy in bradykinin B(2) receptor knockout mice

BACKGROUND

The activation of B(2) receptors by kinins could exert cardioprotective effects in myocardial ischemia and heart failure.

METHODS AND RESULTS

To test whether the absence of bradykinin B(2) receptors may affect cardiac structure and function, we examined the developmental changes in blood pressure (BP), heart rate, and heart morphology of bradykinin B(2) receptor gene knockout (B(2)(-/-)), heterozygous (B(2)(+/-)), and wild-type (B(2)(+/+)) mice. The BP of B(2)(-/-) mice, which was still normal at 50 days of age, gradually increased, reaching a plateau at 6 months (136+/-3 versus 109+/-1 mm Hg in B(2)(+/+), P<0.01). In B(2)(+/-) mice, BP elevation was delayed. At 40 days, the heart rate was higher (P<0.01) in B(2)(-/-) and B(2)(+/-) than in B(2)(+/+) mice, whereas the left ventricular (LV) weight and chamber volume were similar among groups. Thereafter, the LV growth rate of B(2)(-/-) and B(2)(+/-) mice was accelerated, leading at 360 days to a LV weight-to-body weight ratio that was 9% and 17% higher, respectively, than that of B(2)(+/+) mice. In B(2)(-/-) mice, hypertrophy was associated with a marked chamber dilatation (42% larger than that of B(2)(+/+) mice), an elevation in LV end-diastolic pressure (25+/-3 versus 5+/-1 mm Hg in B(2)(+/+) mice, P<0.01), and reparative fibrosis.

CONCLUSIONS

The disruption of the bradykinin B(2) receptor leads to hypertension, LV remodeling, and functional impairment, implying that kinins are essential for the functional and structural preservation of the heart.

Association between hemodynamic impairment and Cheyne-Stokes respiration and periodic breathing in chronic stable congestive heart failure secondary to ischemic or idiopathic dilated cardiomyopathy

Irregular breathing occurs frequently in patients with congestive heart failure (CHF) both during daytime and nighttime. Many factors are involved in the genesis of these breathing abnormalities, but the role of the hemodynamic impairment remains controversial. This study investigated the relation between worsening ventricular function and the frequency of respiratory disorders in patients with mild to severe CHF. One hundred fifty patients with CHF (mean age 53 +/- 8 years, left ventricular (LV) ejection fraction 26 +/- 7, in New York Heart Association [NYHA] classes II to IV, and who underwent stable therapy for > or =2 weeks) were studied. Analysis of instantaneous lung volume signal and arterial oxygen saturation during awake daytime revealed a normal respiratory pattern in 63 patients, whereas 87 had a persistent alteration of breathing, with a typical Cheyne-Stokes respiration (CSR) in 42 and periodic breathing (PB [oscillation of tidal volumes without apnea]) in 45 patients. Patients with PB and CSR showed a more pronounced hemodynamic impairment with a significantly reduced cardiac index, an increased pulmonary arterial wedge pressure, and a longer lung-to-ear circulation time (LECT) compared with patients with normal respiratory patterns. In a logistic regression model that included all of the variables significantly associated with breathing disorders, cardiac index and LECT emerged as the major determinants of CSR. In those patients with LECT > or =30 seconds (upper quartile) and cardiac index < or =1.9 L/min/m2 (lower quartiles), the incidence of CSR was significantly higher (69%) than in patients with lower LECT and higher cardiac index (14%, p <0.001). In conclusion, abnormalities of breathing activity during daytime are significantly associated with a prolonged circulation time and a more severe impairment of systolic and diastolic LV indexes.