Hemodynamic changes as a diagnostic tool in acute heart failure--a pilot study

The Impact of Noninvasive Ventilator Assisted Ventilation Nursing Combined with Mechanical Vibration on the Level of Heart Failure Indexes in ICU Patients with Acute Heart Failure

The acute attack of acute heart failure or the continuous deterioration of cardiac function leads to a series of changes such as reduced cardiac contractility, increased cardiac load, and a sudden drop of acute cardiac output, which eventually cause pulmonary circulation congestion and acute dyspnea due to acute pulmonary congestion. To observe the impact of noninvasive ventilator-assisted ventilation nursing combined with mechanical vibration on the level of heart failure indexes in intensive care unit (ICU) patients with acute heart failure, 120 patients with acute heart failure who were treated in the ICU ward of our hospital from September 2018 to March 2021 were selected, and the qualified subjects were divided into two groups according to the 1 : 1 principle by a simple random method. 120 patients were given conventional symptomatic treatment and noninvasive ventilator-assisted ventilation. The control group received conventional nursing intervention, and the observation group was given noninvasive ventilator-assisted ventilation nursing and mechanical vibration intervention. The respiratory system indexes, heart rate, blood pressure, central venous pressure, N-terminal B-type natriuretic peptide precursor (NT-proBNP), cardiac troponin T (cTnT), and cardiac function indexes of the two groups of patients are recorded, and the prognosis of the two groups is compared. After intervention, the partial pressure of oxygen (PaO2) and blood oxygen saturation (SpO2) in the two groups were higher than those before intervention, while the partial pressure of carbon dioxide (PaCO2), respiration (RR), heart rate, blood pressure, and central venous pressure were lower than those before intervention (P < 0.05). Compared with the control group, PaO2, SpO2, systolic blood pressure, diastolic blood pressure, and central venous pressure of the observation group after intervention were significantly higher, while PaCO2, RR, and heart rate were significantly lower (P < 0.05). Compared with the control group, the LVEF of the observation group after intervention was significantly higher, while NT-proBNP, cTnT, LVESD, and LVEDD were markedly lower (P < 0.05). The ventilation time and ICU hospitalization time in the observation group were shorter than those in the control group, and the pulmonary infection rate was lower than in the control group. The remission time of infection in patients with pulmonary infection was shorter than that in the control group. When comparing the 28d mortality rate with the control group, the difference was not statistically significant (P > 0.05). Noninvasive ventilator-assisted ventilation nursing combined with mechanical vibration can improve hypoxemia symptoms and heart function, stabilize hemodynamics, shorten the course of disease and reduce the occurrence of lung infections for those patients with acute heart failure in the ICU.

Value of nitroglycerin test in the diagnosis of heart failure in emergency department patients with undifferentiated dyspnea

Background

Rapid diagnosis of heart failure (HF) in acutely dyspneic patients can be challenging for emergency department (ED) physicians.

Hypothesis

Cardiac output (CO) change with sublingual nitroglycerin (NTG) could be helpful in the diagnosis of HF in patients with acute undifferentiated dyspnea.

Materials and Methods

A prospective study of patients >18 years admitted to the ED for acute dyspnea. Using thoracic bioimpedance, we measured CO change at baseline and after sublingual administration of 0.6 mg of NTG. HF was defined on the basis of clinical examination, pro‐brain natriuretic peptide levels, and echocardiographic findings. Diagnostic performance of delta CO was calculated by sensitivity, specificity, likelihood ratio and receiver operating characteristic (ROC) curve.

Results

This study included 184 patients with mean age of 64 years. Baseline CO was comparable between the HF group and the non‐HF group. At its best cutoff (29%), delta CO showed good accuracy in the diagnosis of HF with a sensitivity, specificity, positive and negative likelihood ratios of 80%, 44%, 57%, and 66% respectively. Area under ROC curve was 0.701 [95% CI 0.636–0.760]. The decrease of CO with sublingual NTG was significantly higher in patients with HFpEF compared with those with HFrEF. Multivariate analysis, showed that delta CO was an independent factor associated with HF diagnosis [OR 0.19 (95% CI 0.11–0.29); p < .001].

Conclusions

Our study showed that CO change with sublingual nitroglycerin is a simple tool that may be helpful for the diagnosis of HF in ED patients with undifferentiated dyspnea.

Value of DYnamicVariation of impedance cardiac output in the diagnosis of heart failure in emergency department patients with undifferentiated dyspnea

AIM OF STUDY

Cardiac output (CO) responses to acute changes in body position and Valsalva maneuver (VM) were proposed to assess cardiac contractile reserve. We investigated the value of sitting position (SP), leg raising (LR), and VM for identifying heart failure (HF) in patients with undifferentiated dyspnea.

MATERIALS AND METHODS

It is a prospective study including patients over 18 years old admitted to the emergency department (ED) for dyspnea. Bioimpedance CO was measured at baseline, under SP, LR, and VM. HF diagnosis was based on clinical assessment, serum levels of brain natriuretic peptide (BNP) and echocardiography findings. Study population was divided into patients with heart failure (HF group) and patients without HF (non-HF group). Diagnostic performance of CO change under the three maneuvers was calculated by sensitivity, specificity, likelihood ratio and receiver operating characteristic (ROC) curve.

RESULTS

290 patients were enrolled in the study. The final diagnosis was dyspnea due to congestive heart failure in 147 patients (50.7%). CO change with VM was the most accurate exam in identifying congestive heart failure as the cause of dyspnea with a sensitivity, specificity, positive and negative likelihood ratios of 79%, 60%, 1.97, and 0.36 respectively. Area under ROC curve was 0.62(95% CI, 0.55-0.69), 0.63(95% CI, 0.56-0.69), and 0.70(95% CI, 0.64-0.76) respectively for SP, LR, and VM. In a multivariate analysis, CO change with VM, but not with SP or LR, carried independent diagnostic value (p < 0.001).

CONCLUSION

the diagnosis of HF can be aided with use of analyzing the effect of VM on non-invasively measured CO among patients admitted to the ED with undifferentiated dyspnea. Diagnostic yield of SP and LR was poor.

Does Intraoperative Diuretic Therapy Affect the Thoracic Fluid Content and Clinical Outcome in Patients Undergoing Mitral Valve Surgery?

Pulmonary congestion is inevitable in valvular heart disease. The condition worsens when a patient undergoes cardiopulmonary bypass (CPB). Thoracic fluid content (TFC) is an indicator of total volume status of lung in health and disease. We hypothesize that intraoperative diuretic therapy can improve the hemodynamic and clinical outcome in patients undergoing mitral valve surgery by decreasing TFC as measured by impedance cardiography (ICG).

Sixty adult patients with critical mitral stenosis scheduled for mitral valve surgery divided into diuretic (Gr D, n = 30) and control (Gr C, n = 30) group. One mg/kg of furosemide was administered before CPB to Gr D and similar volume of normal saline to Gr C. Hemodynamic and TFC measurements were done by index of contractility (ICON), NICOM monitor at baseline, before anesthesia induction (T1), post skin closure (T2), postoperatively at 6th hour (T3), 24th hour (T4), and 48th hour (T5). The duration of mechanical ventilation (hour), intensive care unit stay (day) and inotropic score was significantly higher in Gr C (5.29 ± 1.4 vs. 2.15 ± 1.1; p = 0.001; 2.11 ± 0.64 vs. 1.67 ± 0.57, p = 0.002; 9 ± 5.4 vs. 5.8 ± 3.2, p = 0.05), respectively. Three patients in Gr C developed respiratory complication during their course of hospital stay. The baseline TFC value was comparable (p = 0.08). In Gr C. it gradually increased over time and never reached the baseline value, whereas in Gr D, there was slight increase in TFC till 6th postoperative hour and it came below the baseline value at 48th hour. A significantly higher TFC value in Gr C in comparison with Gr D from 6th to 48th postoperative hour (p = 0.005, 0.000, and 0.005, respectively) was observed.

The ICON had a gradual improvement from 12th over 48th postoperative hour in Gr D in comparison to Gr C. The systemic vascular resistance index was decreased over time in Gr C, whereas in Gr D there was a mild fall at the end of surgery and it came back to near the baseline value at 48th postoperative hour. A continuous decrease in DO2 I except at 6th postoperative hour was seen in Gr C, whereas it remained near the baseline value in Gr D.

Linear regression analysis showed significant direct correlation of TFC with intraoperative fluid balance (r = 0.524, p = 0.001), cumulative fluid balance (r = 0.680, p = 0.000) and both peak and mean airway pressure (r = 0.436, p = 0.001 and r = 0.548, p = 0.001, respectively).

We concluded that TFC is clearly influenced by intraoperative diuretic therapy. A decrease in TFC has an association with better hemodynamic parameters that could find interesting clinical applications in the decision, whether or not to include a diuretic as a routine therapy during intraoperative management in valve surgery patients.

Should we overcome the resistance to bioelectrical impedance in heart failure?

INTRODUCTION

Heart failure is associated with increased neurohormonal activation that results in changes in body composition including volume overload and the loss of skeletal muscle, body fat, and bone density. Bioelectrical impedance measures body composition based on the conduction of electrical current through body fluids.

AREAS COVERED

The PubMed and Scopus databases were reviewed up to the third week of June 2020. Cross-sectional studies, retrospective observational studies, prospective observational studies, and randomized controlled trials have examined numerous bioelectrical impedance monitoring strategies to guide the diagnosis, prognosis, and treatment of heart failure. These monitoring strategies include intrathoracic impedance, lung impedance, bioelectrical impedance vector analysis, leg bioelectrical impedance, and thoracic bioreactance.

EXPERT COMMENTARY

Based on the current evidence, more studies are needed to validate bioelectrical impedance in heart failure. Lung impedance appears to be useful for guiding heart failure treatment in patients with ST-elevation myocardial infarction and improving outcomes in outpatients with heart failure. Furthermore, bioelectrical impedance has potential as a noninvasive, quantitative heart failure variable for population-based research.

Complex assessment of patients with decompensated heart failure: The clinical value of impedance cardiography and N-terminal pro-brain natriuretic peptide

BACKGROUND

Acute decompensated heart failure (ADHF) is a serious clinical problem and a condition requiring immediate diagnostics, supporting the therapeutic decision adequate to the specific ADHF mechanism. N-terminal pro-brain natriuretic peptide (NT-proBNP) is an established biochemical marker of heart failure, strongly related to hemodynamic status. Impedance cardiography (ICG) provides non-invasive hemodynamic assessment that can be performed immediately at the bedside and revealed to be useful diagnostic tool in some clinical settings in cardiology.

OBJECTIVES

The aim of this study was to evaluate the usefulness of ICG in the admission diagnostics and monitoring the effects of treatment in patients hospitalized due to ADHF, with special emphasis on its relation to NT-proBNP.

METHODS

This study enrolled 102 patients, aged over 18 years, hospitalized due to ADHF. The subjects underwent detailed clinical assessment, including ICG and NT-proBNP at admission and at discharge day.

RESULTS

Among all analyzed ICG parameters thoracic fluid content (TFC), a marker of chest overload, was the most significantly correlated with NT-proBNP level (R = 0.46; p = 0.000001). In comparison with patients with low thoracic fluid content (TFC ≤ 35/kΩ), those with higher TFC values (>35/kΩ) exhibited a greater severity of symptoms (NYHA functional class); higher NT-proBNP levels; lower left ventricular ejection fraction (LVEF), stroke index (SI), and cardiac index (CI); as well as significantly higher systemic vascular resistance index (SVRI). These TFC-based subgroups showed no significant differences in terms of heart rate (HR), systolic blood pressure (SBP), or diastolic blood pressure (DBP).

CONCLUSIONS

The evaluation of hemodynamic parameters, especially TFC, seems to be a worthwhile addition to standard diagnostics, both at the stage of hospital admission and while monitoring the effects of treatment. Impedance cardiography is a useful method in evaluating individual hemodynamic profiles in patients with ADHF.

Assessing Extracellular Volume in Hemodialysis Patients Using Intradialytic Blood Pressure Slopes

BACKGROUND/AIMS

Extracellular volume (ECV) overload is a mortality risk factor in hemodialysis patients, but no standard approach exists to objectively assess this clinically. We aimed to quantify relationships between slopes of repeated intradialytic blood pressure (BP) measurements and ECV.

METHODS

In a cross-sectional study of 71 hemodialysis patients, we calculated BP slopes from all intradialytic measurements using Gaussian regression. We measured extracellular and total body water (TBW) with bioimpedance spectroscopy. We analyzed unconditional and conditional associations between BP slope and volume metrics with mixed linear models and sensitivity analyses using non-linear intradialytic BP trajectory.

RESULTS

Mean systolic intradialytic BP slope (IBPS) was -0.06 (0.1) mm Hg/min. Post-dialysis extracellular water (ECW)/weight was the volume metric mostly strongly associated with slope (r = 0.34, p = 0.007 for unconditional analysis; β = 1.45, p = 0.001 for conditional analysis). Among subjects with post-dialysis systolic BP ≥130 mm Hg, the association strengthened (r = 0.40, p = 0.006; β = 1.42, p = 0.003). ECV was more strongly associated with the BP slope than with pre-dialysis, post-dialysis, or delta systolic BP (r = -0.07, 0.19, 0.28; p = 0.6, 0.1, 0.03). In nonlinear models, BP trajectory also had the strongest association with post-dialysis ECW/body weight (p < 0.001).

CONCLUSIONS

In hypertensive hemodialysis patients, measurements of ECV excess are more strongly associated with IBPSs than with pre-dialysis, post-dialysis, or change in systolic BP. Among varying volume metrics, post-dialysis ECW/weight has the strongest association with these slopes. Determining IBPS is a novel method to optimize clinical assessment of ECV in hemodialysis patients.

Considerations for initial therapy in the treatment of acute heart failure

The diagnosis of patients presenting to the emergency department with acute heart failure (AHF) is challenging due to the similarity of AHF symptoms to other conditions such as chronic obstructive pulmonary disease and pneumonia. Additionally, because AHF is most common in an older population, the presentation of coexistent pathologies further increases the challenge of making an accurate diagnosis and selecting the most appropriate treatment. Delays in the diagnosis and treatment of AHF can result in worse outcomes and higher healthcare costs. Rapid initiation of treatment is thus necessary for optimal disease management. Early treatment decisions for patients with AHF can be guided by risk-stratification models based on initial clinical data, including blood pressure, levels of troponin, blood urea nitrogen, serum creatinine, B-type natriuretic peptide, and ultrasound. In this review, we discuss methods for differentiating high-risk and low-risk patients and provide guidance on how treatment decisions can be informed by risk-level assessment. Through the use of these approaches, emergency physicians can play an important role in improving patient management, preventing unnecessary hospitalizations, and lowering healthcare costs. This review differs from others published recently on the topic of treating AHF by providing a detailed examination of the clinical utility of diagnostic tools for the differentiation of dyspneic patients such as bedside ultrasound, hemodynamic changes, and interrogation of implantable cardiac devices. In addition, our clinical guidance on considerations for initial pharmacologic therapy in the undifferentiated patient is provided. It is crucial for emergency physicians to achieve an early diagnosis of AHF and initiate therapy in order to reduce morbidity, mortality, and healthcare costs.

Passive leg raising performed before a spontaneous breathing trial predicts weaning-induced cardiac dysfunction

PURPOSE

Weaning-induced cardiac dysfunction is more likely to occur if the heart does not tolerate the changes in loading conditions induced by spontaneous breathing trial (SBT). We hypothesized that the presence of cardiac preload independence before an SBT is associated with weaning failure related to cardiac dysfunction.

METHODS

We included 30 patients after a first failed 1-h T-tube SBT who had a transpulmonary thermodilution already in place. Preload independence [no increase in the pulse contour analysis-derived cardiac index ≥10 % during passive leg raising (PLR)] was assessed before the second SBT. Failure of the SBT related to cardiac dysfunction was defined by an increase in pulmonary artery occlusion pressure above 18 mmHg at the end of the SBT associated with clinical intolerance.

RESULTS

Fifty-seven SBTs were analyzed. The SBT failed in 46 cases. Overall, 31 failed SBTs were associated with weaning-induced cardiac dysfunction. During PLR, the cardiac index did not change in cases of failed SBTs with cardiac dysfunction, whereas it significantly increased in the other cases: 4 % (interquartile range, IQR 0-5) vs. 12 % (IQR 11-15), respectively. If PLR did not increase the cardiac index by more than 10 % before the SBT, the occurrence of SBT failure related to cardiac dysfunction was predicted with a sensitivity of 97 % [95 % confidence interval (CI) 83-100], specificity of 81 % (95 % CI 61-93) and area under the receiver-operating characteristic curve of 0.88 (95 % CI 0.78-0.98).

CONCLUSIONS

Preload independence assessed by a negative PLR test performed before an SBT predicts weaning failure related to cardiac dysfunction.

Noninvasive assessment of acute dyspnea in the ED

Background:

We compared the ability of noninvasive measurements of cardiac output (CO) and thoracic fluid content (TFC) and their change in response to orthostatic challenges to diagnose acute decompensate heart failure (ADHF) from non-ADHF causes of acute dyspnea in patients in the ED.

Methods:

Forty-five patients > 44 years old presenting in the ED with dyspnea were studied. CO and TFC were monitored with a NICOM bioreactance device. CO and TFC were measured continuously while each patient was sitting, supine, and during a passive leg-raising maneuver (3 min each); the maximal values during each maneuver were reported. Orthostatic challenges were repeated 2 h into treatment. One patient was excluded because of intolerance to the supine position. Diagnoses obtained with the hemodynamic measurements were compared with ED diagnoses and with two expert physicians by chart review (used as gold standard diagnosis); both groups were blinded to CO and TFC values. Patient’s treatment, ED disposition, hospital length of stay, and subjective dyspnea (Borg scale) were also recorded.

Results:

Sixteen of 44 patients received a diagnosis of ADHF and 28 received a diagnosis of non-ADHF by the experts. Baseline TFC was higher in patients with ADHF (P = .001). Fifteen patients were treated for ADHF, and their Borg scale values decreased at 2 h (P < .05). TFC threshold of 78.8 had a receiver operator characteristic area under the curve of 0.81 (76% sensitivity, 71% specificity) for ADHF. Both ADHF and non-ADHF groups were similar in their increased CO from baseline to PLR and supine. Pre- and posttreatment measurements were similar.

Conclusions:

Baseline TFC can discriminate patients with ADHF from non-ADHF dyspnea in the ED.

Reduced thoracic fluid content in early-stage primary biliary cirrhosis that associates with impaired cardiac inotropy

Primary biliary cirrhosis (PBC) is a chronic liver disease characterized by cholestasis. Recent MRI studies have confirmed the presence of cardiac abnormalities in noncirrhotic PBC patients. However, cardiorespiratory consequences of these abnormalities have not been explored. Thoracic fluid content (TFC) is a noninvasive bioelectrical impedance measure of the electrical conductivity of the chest cavity. We explored TFC and its relationship with cardiac contractility parameters in early-stage PBC patients, compared with chronic liver disease and community controls. TFC was measured in early-stage PBC (noncirrhotic; n = 78), nonalcoholic fatty liver disease (n = 23), and primary sclerosing cholangitis (n = 18) and in a community control population (n = 78). Myocardial contractility was measured as index of contractility, acceleration index, cardiac index, stroke index, left ventricular ejection time, and left ventricular work index. We also measured total arterial compliance and the Heather Index (HI; cardiac inotropy). The PBC group had significantly lower TFC compared with controls and the chronic liver disease groups (P < 0.0001). There was an association between increasing TFC and markers of cardiac function (cardiac index, stroke index, end-diastolic index, index of contractility, and acceleration index), together with indicators of cardiac inotropy and total arterial compliance. Multivariate analysis confirmed that the only parameter that independently associated with TFC was the marker of cardiac inotropy HI (P = 0.037; β 0.5). This study has confirmed that TFC is reduced in those with PBC, that this is specific to PBC, and that it associates independently with markers of cardiac inotropy.