The pulmonary manifestations of left heart failure

Under pressure: pulmonary hypertension associated with left heart disease

Pulmonary hypertension (PH) associated with left heart disease (PH-LHD) is the most common type of PH, but its natural history is not well understood. PH-LHD is diagnosed by right heart catheterisation with a mean pulmonary arterial pressure ≥25 mmHg and a pulmonary capillary wedge pressure >15 mmHg. The primary causes of PH-LHD are left ventricular dysfunction of systolic and diastolic origin, and valvular disease. Prognosis is poor and survival rates are low. Limited progress has been made towards specific therapies for PH-LHD, and management focuses on addressing the underlying cause of the disease with supportive therapies, surgery and pharmacological treatments. Clinical trials of therapies for pulmonary arterial hypertension in patients with PH-LHD have thus far been limited and have provided disappointing or conflicting results. Robust, long-term clinical studies in appropriate target populations have the potential to improve the outlook for patients with PH-LHD. Herein, we discuss the knowledge gaps in our understanding of PH-LHD, and describe the current unmet needs and challenges that are faced by clinicians when identifying and managing patients with this disease.

Pulmonary hypertension due to left heart disease is associated with multiple unmet medical needshttp://ow.ly/TFET8

Beneficial Effects of Qili Qiangxin Capsule on Lung Structural Remodeling in Ischemic Heart Failure via TGF-β1/Smad3 Pathway

Qili qiangxin (QL) capsule is a traditional Chinese medicine that is widely used for the treatment of patients with chronic heart failure (CHF) of all etiologies, although the exact mechanisms of action remain unclear. CHF leads to pulmonary vascular remodelling and thickening of the alveolar-capillary barrier that may be important mechanisms in the poor clinical outcome in patients with end-stage heart failure. We examined whether QL could improve lung injury in ischemic CHF by reducing lung remodeling. Rats with myocardial infarct received QL (1.0 g/kg/day) for 4 weeks. Echocardiographic and morphometric measurements were obtained followed by echocardiography, histological staining, and immunohistochemical analysis of lung sections. CHF caused significant lung structural remodeling evidenced by collagen deposition and thickening of the alveolar septa after myocardial infarct that were greatly improved by QL. Lung weight increased after infarct with no evidence of pulmonary edema and was normalized by QL. QL also reduced lung transforming growth factor-β1 (TGF-β1), p-Smad3, tumor necrosis factor-α (TNF-α), and Toll-like receptor-4 (TLR4) expression. Thus, QL reduces lung remodeling associated with CHF, mainly by suppressing the TGF-β1/Smad3 signaling pathway. The mechanism may also involve inhibition of TLR4 intracellular signaling.

Lung function in pulmonary hypertension

Breathlessness is a common symptom in pulmonary hypertension (PH) and an important cause of morbidity. Though this has been attributed to the well described pulmonary vascular abnormalities and subsequent cardiac remodelling, changes in the airways of these patients have also been reported and may contribute to symptoms. Our understanding of these airway abnormalities is poor with conflicting findings in many studies. The present review evaluates these studies for the major PH groups. In addition we describe the role of cardiopulmonary exercise testing in the assessment of pulmonary arterial hypertension (PAH) by evaluating cardiopulmonary interaction during exercise. As yet, the reasons for the abnormalities in lung function are unclear, but potential causes and the possible role of inflammation are discussed. Future research is required to provide a better understanding of this to help improve the management of these patients.

Pulmonary Hypertension and Cardiopulmonary Exercise in Heart Failure

In heart failure (HF), pulmonary hypertension (PH) is initially associated with a rise in the left ventricular filling pressure. PH is defined by pulmonary hemodynamic measurements including pulmonary capillary wedge pressure, mean pulmonary arterial pressure and pulmonary vascular resistance. Eventually, PH in HF may become more of a reactive process. Although the mechanism of the reactive PH development is not clearly understood, vascular dysfunction induced by remodeling, vasoactive substances and genetic variation appear to contribute significantly to this form of PH. Noninvasive cardiopulmonary exercise testing has been extensively utilized to assess disease severity in HF patients. It provides integrated information that is dependent on cardiopulmonary hemodynamics, lung mechanics, breathing pattern and strategy. In this review, we will discuss the mechanisms of PH development in HF and how noninvasive gas exchange measures obtained with submaximal exercise are influenced by PH in this population.

The effects of oxygen induced pulmonary vasoconstriction on bedside measurement of pulmonary gas exchange

In patients with respiratory failure measurements of pulmonary gas exchange are of importance. The bedside automatic lung parameter estimator (ALPE) of pulmonary gas exchange is based on changes in inspired oxygen (FiO2) assuming that these changes do not affect pulmonary circulation. This assumption is investigated in this study. Forty-two out of 65 patients undergoing coronary artery bypass grafting (CABG) had measurements of mean pulmonary arterial pressure (MPAP), cardiac output and pulmonary capillary wedge pressure thus enabling the calculation of pulmonary vascular resistance (PVR) at each FiO2 level. The research version of ALPE was used and FiO2 was step-wise reduced a median of 0.20 and ultimately returned towards baseline values, allowing 6-8 min' steady state period at each of 4-6 levels before recording the oxygen saturation (SpO2). FiO2 reduction led to median decrease in SpO2 from 99 to 92 %, an increase in MPAP of 4 mmHg and an increase in PVR of 36 dyn s cm(-5). Changes were immediately reversed on returning FiO2 towards baseline. In this study changes in MPAP and PVR are small and immediately reversible consistent with small changes in pulmonary gas exchange. This indicates that mild deoxygenation induced pulmonary vasoconstriction does not have significant influences on the ALPE parameters in patients after CABG.

Factors associated with B-lines after exposure to hypobaric hypoxia

AIMS

Increased extravascular lung water (EVLW) is seen as B-lines on chest ultrasonography. In lowlanders ascending to altitude the time course, relationship with the patient's clinical status and factors affecting B-lines are still unclear. The aim was to monitor B-lines, clinical status and N-terminal B-type natriuretic peptide (NT-proBNP) during exposure to high altitude.

METHODS AND RESULTS

Chest ultrasonography, blood samples, cardiovascular parameters, and signs and symptoms of high altitude pulmonary oedema (HAPE) were prospectively assessed in 19 participants at baseline and after ascent to 3830 m (9, 24, 48, 72 h, and 8 days) by blinded investigators. Potential confounding factors (e.g. altitude variations, physical effort) were minimized. Generalized estimating equations were used to analyse factors associated with B-lines. B-lines changed with exposure to altitude (P = 0.006) in a parabolic-like pattern within the first 72 h; 10 of 18 participants (55.6%) had >5 B-lines at 24 h. B-lines were correlated with the number of signs and symptoms (partial coefficient = 0.372, P = 0.001). B-lines were associated with time (P = 0.038), sex (P = 0.013), and SpO2 (P = 0.042), but not with NT-proBNP (P = 0.546). The participant with a clinical diagnosis of HAPE had 23 B-lines.

CONCLUSION

B-lines during exposure to altitude seem to reflect the individual response to hypobaric hypoxia and represent clinically relevant alterations at high altitude, also in patients with HAPE. Similar to previous studies, our results support a non-cardiogenic aetiology of B-lines.

Pulmonary Oedema-Therapeutic Targets

Pulmonary oedema (PO) is a common manifestation of acute heart failure (AHF) and is associated with a high-acuity presentation and with poor in-hospital outcomes. The clinical picture of PO is dominated by signs of pulmonary congestion, and its pathogenesis has been attributed predominantly to an imbalance in Starling forces across the alveolar-capillary barrier. However, recent studies have demonstrated that PO formation and resolution is critically regulated by active endothelial and alveolar signalling. PO represents a medical emergency and treatment should be individually tailored to the urgency of the presentation and acute haemodynamic characteristics. Although, the majority of patients admitted with PO rapidly improve as result of conventional intravenous (IV) therapies, treatment of PO remains largely opinion based as there is a general lack of good evidence to guide therapy. Furthermore, none of these therapies showed simultaneous benefit for symptomatic relief, haemodynamic improvement, increased survival and end-organ protection. Future research is required to develop innovative pharmacotherapies capable of relieving congestion while simultaneously preventing end-organ damage.

Pathophysiology and clinical relevance of pulmonary remodelling in pulmonary hypertension due to left heart diseases

Pulmonary hypertension (PH) in left heart disease, classified as group II, is the most common form of PH that occurs in approximately 60% of cases of reduced and preserved left ventricular ejection fraction. Although relatively much is known about hemodynamic stages (passive or reactive) and their consequences on the right ventricle (RV) there is no consensus on the best hemodynamic definition of group II PH. In addition, the main pathways that lead to lung capillary injury and impaired biology of small artery remodelling processes are largely unknown. Typical lung manifestations of an increased pulmonary pressure and progressive RV-pulmonary circulation uncoupling are an abnormal alveolar capillary gas diffusion, impaired lung mechanics (restriction), and exercise ventilation inefficiency. Of several classes of pulmonary vasodilators currently clinically available, oral phosphodiesterase 5 inhibition, because of its strong selectivity for targeting the cyclic guanosine monophosphate pathway in the pulmonary circulation, is increasingly emerging as an attractive opportunity to reach hemodynamic benefits, reverse capillary injury, and RV remodelling, and improve functional capacity. Guanylate cyclase stimulators offer an additional intriguing opportunity but the lack of selectivity and systemic effects might preclude some of the anticipated benefits on the pulmonary circulation. Future trials will determine whether new routes of pharmacologic strategy aimed at targeting lung structural and vascular remodelling might affect morbidity and mortality in left heart disease populations. We believe that this therapeutic goal rather than a pure hemodynamic effect might ultimately emerge as an important challenge for the clinician.

Pulmonary effects of chronic elevation in microvascular pressure differ between hypertension and myocardial infarct induced heart failure

BACKGROUND

Chronic heart failure (CHF) following coronary artery ligation and myocardial infarction in the rat leads to a homeostatic reduction in surface tension with associated alveolar type II cell hyperplasia and increased surfactant content, which functionally compensates for pulmonary collagen deposition and increased tissue stiffness. To differentiate the effects on lung remodelling of the sudden rise in pulmonary microvascular pressure (Pmv) with myocardial infarction from its consequent chronic elevation, we examined a hypertensive model of CHF.

METHODS

Cardiopulmonary outcomes due to chronic pulmonary capillary hypertension were assessed at six and 15 weeks following abdominal aortic banding (AAB) in the rat.

RESULTS

At six weeks post-surgery, despite significantly elevated left ventricular end-diastolic pressure, myocardial hypertrophy and increased left ventricular internal circumference in AAB rats compared with sham operated controls (p≤0.003), lung weights and tissue composition remained unchanged, and lung compliance was normal. At 15 weeks post-surgery increased lung oedema was evident in AAB rats (p=0.002) without decreased lung compliance or evidence of tissue remodelling.

CONCLUSION

Despite chronically elevated Pmv, comparable to that resulting from past myocardial infarction (LVEDP>19mmHg), there is no evidence of pulmonary remodelling in the AAB model of CHF.

Lung Ultrasound Predicts Well Extravascular Lung Water but Is of Limited Usefulness in the Prediction of Wedge Pressure

Background:

Pulmonary congestion is indicated at lung ultrasound by detection of B-lines, but correlation of these ultrasound signs with pulmonary artery occlusion pressure (PAOP) and extravascular lung water (EVLW) still remains to be further explored. The aim of the study was to assess whether B-lines, and eventually a combination with left ventricular ejection fraction (LVEF) assessment, are useful to differentiate low/high PAOP and EVLW in critically ill patients.

Methods:

The authors enrolled 73 patients requiring invasive monitoring from the intensive care unit of four university-affiliated hospitals. Forty-one patients underwent PAOP measurement by pulmonary artery catheterization and 32 patients had EVLW measured by transpulmonary thermodilution method. Lung and cardiac ultrasound examinations focused to the evaluation of B-lines and gross estimation of LVEF were performed. The absence of diffuse B-lines (A-pattern) versus the pattern showing prevalent B-lines (B-pattern) and the combination with normal or impaired LVEF were correlated with cutoff levels of PAOP and EVLW.

Results:

PAOP of 18 mmHg or less was predicted by the A-pattern with 85.7% sensitivity (95% CI, 70.5 to 94.1%) and 40.0% specificity (CI, 25.4 to 56.4%), whereas EVLW 10 ml/kg or less with 81.0% sensitivity (CI, 62.6 to 91.9%) and 90.9% specificity (CI, 74.2 to 97.7%). The combination of A-pattern with normal LVEF increased sensitivity to 100% (CI, 84.5 to 100%) and specificity to 72.7% (CI, 52.0 to 87.2%) for the prediction of PAOP 18 mmHg or less.

Conclusions:

B-lines allow good prediction of pulmonary congestion indicated by EVLW, whereas are of limited usefulness for the prediction of hemodynamic congestion indicated by PAOP. Combining B-lines with estimation of LVEF at transthoracic ultrasound may improve the prediction of PAOP.

Lung capillary injury and repair in left heart disease: a new target for therapy?

The lungs are the primary organs affected in LHD (left heart disease). Increased left atrial pressure leads to pulmonary alveolar–capillary stress failure, resulting in cycles of alveolar wall injury and repair. The reparative process causes the proliferation of MYFs (myofibroblasts) with fibrosis and extracellular matrix deposition, resulting in thickening of the alveolar wall. Although the resultant reduction in vascular permeability is initially protective against pulmonary oedema, the process becomes maladaptive causing a restrictive lung syndrome with impaired gas exchange. This pathological process may also contribute to PH (pulmonary hypertension) due to LHD. Few clinical trials have specifically evaluated lung structural remodelling and the effect of related therapies in LHD. Currently approved treatment for chronic HF (heart failure) may have direct beneficial effects on lung structural remodelling. In the future, novel therapies specifically targeting the remodelling processes may potentially be utilized. In the present review, we summarize data supporting the clinical importance and pathophysiological mechanisms of lung structural remodelling in LHD and propose that this pathophysiological process should be explored further in pre-clinical studies and future therapeutic trials.

A woman with breathlessness: a practical approach to diagnosis and management

Worsening breathless in a patient with severe chronic obstructive pulmonary disease (COPD) is a common diagnostic and management challenge in primary care. A systematic approach to history-taking and examination combined with targeted investigation of pulmonary, cardiovascular, thromboembolic and systemic causes is essential if co-morbidities are to be identified and managed. Distinguishing between heart failure and COPD is a particular challenge as symptoms and signs overlap. In low and middle income countries additional priorities are the detection of infections such as tuberculosis and human immunodeficiency virus (HIV). Clinicians need to be alert to the possibility of atypical presentations (such as pain-free variants of angina) and less common conditions (including chronic thromboembolic pulmonary hypertension) in order not to overlook important potentially treatable conditions.

Pulmonary production of osteopontin in humans: effects of left ventricular systolic dysfunction and cardiopulmonary bypass

BACKGROUND

We evaluated pulmonary production of osteopontin (OPN) in left ventricular systolic dysfunction (LVSD) and after cardiopulmonary bypass surgery (CPB). OPN is a phosphoglycoprotein involved in inflammation and remodeling. In subjects with LVSD, plasma OPN correlates with prognosis but its origin is unknown. We hypothesized that the lungs produce OPN and that this could be affected by LVSD and CPB.

METHODS AND RESULTS

Subjects with (n = 57; left ventricular ejection fraction [LVEF] 32 ± 8%) and without (n = 63; LVEF 59 ± 7%) LVSD were studied during CPB. Arterial and venous OPN plasma levels were determined. Arterial and venous OPN levels were higher in LVSD (P = .0290). For both groups, levels dropped 1 hour after surgery and nearly doubled 24 hours after (P < .0001 vs basal). Notably, there was a significant positive arteriovenous gradient with arterial levels higher than venous levels. Arteriovenous differences were statistically significant at baseline (P = .0120) and 1 hour (P < .0001) but not at 24 hours (P = .0649). Arterial levels in heart failure correlated inversely with renal function (P = .016) and positively with mean pulmonary pressure (P = .028), heart rate (P = .036), and C-reactive protein (P = .047).

CONCLUSIONS

There is production of circulating OPN by the lungs, unaffected by LVSD or CPB. This likely represents an overflow from local lung production and does not contribute to increased levels in LVSD or after CPB.

Abl kinases are required for vascular function, Tie2 expression, and angiopoietin-1-mediated survival

Endothelial dysfunction is associated with diverse cardiovascular pathologies. Here, we show a previously unappreciated role for the Abelson (Abl) family kinases (Abl and Arg) in endothelial function and the regulation of angiogenic factor pathways important for vascular homeostasis. Endothelial Abl deletion in Arg-null mice led to late-stage embryonic and perinatal lethality, with mutant mice displaying focal loss of vasculature and tissue necrosis. Loss of Abl kinases led to increased endothelial cell apoptosis both in vitro and in vivo, contributing to vascular dysfunction, infarction, and tissue damage. Mechanistically, we identify a unique dual role for Abl kinases in the regulation of angiopoietin/Tie2 protein kinase signaling. Endothelial Abl kinases modulate Tie2 expression and angiopoietin-1-mediated endothelial cell survival. These findings reveal a critical requirement for the Abl kinases in vascular development and function, which may have important implications for the clinical use of Abl kinase inhibitors.

Heart failure and chronic obstructive pulmonary disease: the challenges facing physicians and health services

Pulmonary disease is common in patients with heart failure, through shared risk factors and pathophysiological mechanisms. Adverse pulmonary vascular remodelling and chronic systemic inflammation characterize both diseases. Concurrent chronic obstructive pulmonary disease presents diagnostic and therapeutic challenges, and is associated with increased morbidity and mortality. The cornerstones of therapy are beta-blockers and beta-agonists, whose pharmacological properties are diametrically opposed. Each disease is implicated in exacerbations of the other condition, greatly increasing hospitalizations and associated health care costs. Such multimorbidity is a key challenge for health-care systems oriented towards the treatment of individual diseases. Early identification and treatment of cardiopulmonary disease may alleviate this burden. However, diagnostic and therapeutic strategies require further validation in patients with both conditions.

Diagnosing heart failure among acutely dyspneic patients with cardiac, inferior vena cava, and lung ultrasonography

BACKGROUND

Rapid diagnosis (dx) of acutely decompensated heart failure (ADHF) may be challenging in the emergency department (ED). Point-of-care ultrasonography (US) allows rapid determination of cardiac function, intravascular volume status, and presence of pulmonary edema. We test the diagnostic test characteristics of these 3 parameters in making the dx of ADHF among acutely dyspneic patients in the ED.

METHODS

This was a prospective observational cohort study at an urban academic ED. Inclusion criteria were as follows: dyspneic patients, at least 18 years old and able to consent, whose differential dx included ADHF. Ultrasonography performed by emergency sonologists evaluated the heart for left ventricular ejection fraction (LVEF), the inferior vena cava for collapsibility index (IVC-CI), and the pleura sampled in each of 8 thoracic regions for presence of B-lines. Cutoff values for ADHF were LVEF less than 45%, IVC-CI less than 20%, and at least 10 B-lines. The US findings were compared with the final dx determined by 2 emergency physicians blinded to the US results.

RESULTS

One hundred one participants were enrolled: 52% male, median age 62 (25%-75% interquartile, 53-91). Forty-four (44%) had a final dx of ADHF. Sensitivity and specificity (including 95% confidence interval) for the presence of ADHF were as follows: 74 (65-90) and 74 (62-85) using LVEF less than 45%, 52 (38-67) and 86 (77-95) using IVC-CI less than 20%, and 70 (52-80) and 75 (64-87) using B-lines at least 10. Using all 3 modalities together, the sensitivity and specificity were 36 (22-51) and 100 (95-100). As a comparison, the sensitivity and specificity of brain natriuretic peptide greater than 500 were 75 (55-89) and 83 (67-92).

CONCLUSION

In this study, US was 100% specific for the dx of ADHF.

Bronchodilator responsiveness in patients with chronic heart failure

OBJECTIVE

The aim of this study was to evaluate the effect of inhaled bronchodilators on pulmonary function and dyspnea in patients with chronic heart failure (HF).

BACKGROUND

Conflicting data exist on whether bronchodilators may improve pulmonary function and dyspnea in patients with chronic HF.

METHODS

In this retrospective observational study we analyzed data of 116 chronic HF outpatients with systolic dysfunction who underwent spirometry and Borg dyspnea measurements before and after inhalation of 400 μg salbutamol and 80 μg ipratropium. Patients with chronic obstructive pulmonary disease (COPD) or asthma were excluded.

RESULTS

Bronchodilators fully reversed airway obstruction (AO) in 25 of 64 (39.1%) patients with pre-bronchodilator AO. All spirometric measurements, except for forced vital and inspiratory capacities, improved significantly post-bronchodilation. Absolute and percent improvements in forced expiratory volume in 1 s (FEV1) were more pronounced in patients with persistent AO post-bronchodilation compared to those without AO (0.19 ± 0.18 L and 8.4 ± 7.3% versus 0.11 ± 0.12 L and 4.3 ± 4.0%, p < 0.05). Significant bronchodilator responsiveness of FEV1 (>200 mL and >12%) was noted in 12.1% and was more frequent in patients with persistent AO and fully reversible AO than in those without AO (23.1% and 16.0% versus 1.9%, p < 0.05). We measured a small, albeit significant improvement in dyspnea (0.7 ± 1.2 versus 0.9 ± 1.3, p = 0.002).

CONCLUSIONS

Inhaled bronchodilators may have an additional role in the management of patients with chronic HF because of their potential to improve pulmonary function, especially in those with AO. The clinical usefulness and possible adverse events of bronchodilators need to be further established.

Cardiac asthma

Cardiac dyspnea, especially if present only with exercise, is often confused with asthma and exercise-induced bronchospasm. Cardiac dyspnea or asthma is the consequence of pulmonary edema due to pulmonary venous hypertension and not due to asthmatic bronchoconstriction. In overt, acute congestive heart failure, the diagnosis may be readily made by history and physical examination and pertinent laboratory and imaging data.

Prevention of airway hyperresponsiveness induced by left ventricular dysfunction in rats

Background

The effectiveness of strategies for treatment of the altered static lung volume and against the development of bronchial hyperreactivity (BHR) following a left ventricular dysfunction (LVD) induced by myocardial ischaemia was investigated in a rat model of sustained postcapillary pulmonary hypertension.

Methods

Airway resistance (Raw) was identified from the respiratory system input impedance (Zrs) in four groups of rats. End-expiratory lung volume (EELV) was determined plethysmographically, and Zrs was measured under baseline conditions and following iv infusions of 2, 6 or 18 μg/kg/min methacholine. Sham surgery was performed in the rats in Group C, while the left interventricular coronary artery was ligated and Zrs and its changes following identical methacholine challenges were reassessed in the same rats 8 weeks later, during which no treatment was applied (Group I), or the animals were treated daily with a combination of an angiotensin enzyme converter inhibitor and a diuretic (enalapril and furosemide, Group IE), or a calcium channel blocker (diltiazem, Group ID). The equivalent dose of methacholine causing a 100% increase in Raw (ED₅₀) was determined in each group. Diastolic pulmonary arterial pressure (Pap_D) was assessed by introducing a catheter into the pulmonary artery.

Results

The sustained presence of a LVD increased Pap_D in all groups of rats, with variable but significant elevations in Groups I (p = 0.004), ID (p = 0.013) and IE (p = 0.006). A LVD for 8 weeks induced no changes in baseline Raw but elevated the EELV independently of the treatments. In Group I, BHR consistently developed following the LVD, with a significant decrease in ED₅₀ from 10.0 ± 2.5 to 6.9 ± 2.5 μg/kg/min (p = 0.006). The BHR was completely abolished in both Groups ID and IE, with no changes in ED₅₀ (9.5 ± 3.6 vs. 10.7 ± 4.7, p = 0.33 and 10.6 ± 2.1 vs. 9.8 ± 3.5 μg/kg/min p = 0.56, respectively).

Conclusions

These findings suggest that a LVD following coronary ischaemia consistently induces BHR. The more consistent efficacy of both treatment strategies in preventing BHR than in treating the adverse pulmonary vascular consequences suggests the benefit of both calcium channel blockade and ACE inhibition to counteract the airway susceptibility following a LVD.

Transient decrease in PaCO(2) and asymmetric chest wall dynamics in early progressing pneumothorax

PURPOSE

Diagnosis of pneumothorax (PTX) in newborn infants has been reported as late. To explore diagnostic indices for early detection of progressing PTX, and offer explanations for delayed diagnoses.

METHODS

Progressing PTX was created in rabbits (2.3 ± 0.5 kg, n = 7) by injecting 1 ml/min of air into the pleural space. Hemodynamic parameters, tidal volume, EtCO(2), SpO(2), blood gas analyses and chest wall tidal displacements (TDi) on both sides of the chest were recorded.

RESULTS

(Mean ± SD): A decrease in SpO(2) below 90 % was detected only after 46.6 ± 11.3 min in six experiments. In contrary to the expected gradual increase of CO(2), there was a prolonged transient decrease of 14.2 ± 4.5 % in EtCO(2) (p < 0.01), and a similar decrease in PaCO(2) (p < 0.025). EtCO(2) returned back to baseline only after 55.2 ± 24.7 min, and continued to rise thereafter. The decrease in CO(2) was a mirror image of the 14.6 ± 5.3 % increase in tidal volume. The analysis of endotracheal flow and pressure dynamics revealed a paradoxical transient increase in the apparent compliance. Significant decrease in mean arterial blood pressure was observed after 46.2 ± 40.1 min. TDi provided the most sensitive and earliest sign of PTX, decreasing on the PTX side after 16.1 ± 7.2 min. The TDi progressively decreased faster and lower on the PTX side, thus enabling detection of asymmetric ventilation.

CONCLUSIONS

The counterintuitive transient prolonged decrease in CO(2) without changes in SpO(2) may explain the delay in diagnosis of PTX encountered in the clinical environment. An earlier indication of asymmetrically decreased ventilation on the affected side was achieved by monitoring the TDi.

Hemodynamic determinants of dyspnea improvement in acute decompensated heart failure

BACKGROUND

Dyspnea relief constitutes a major treatment goal and a key measure of treatment efficacy in decompensated heart failure. However, there are no data with regard to the relationship between hemodynamic measurements during treatment and dyspnea improvement.

METHODS AND RESULTS

We studied 233 patients assigned to right heart catheterization in the Vasodilation in the Management of Acute Congestive Heart Failure trial. Dyspnea (assessed using a 7-point Likert scale) and hemodynamic parameters were measured simultaneously at 15 and 30 minutes and 1, 2, 3, 6, and 24 hours. Dyspnea relief was defined as moderate or marked improvement. There was a time-dependent association between the reductions in pulmonary capillary wedge pressure (PCWP; 25.4, 24.6, 24.0, 23.5, 23.4, 21.5, and 19.9 mm Hg) and the percentage of patients achieving dyspnea relief (17.7%, 24.6%, 32.2%, 36.2%, 37.8%, 47.4%, and 66.1%, in the respective time points). Multivariable logistic generalized estimating equations modeling demonstrated that reductions of both PCWP and mean pulmonary artery pressure were independently associated with dyspnea relief. Compared with the highest PCWP quartile, the adjusted odds ratios for dyspnea relief were 0.92 (95% confidence interval [CI], 0.67-1.29), 1.07 (95% CI, 0.75-1.55), and 1.80 (95% CI, 1.22-2.65) in the third, second, and first PCWP quartiles, respectively (P(trend)=0.003). Compared with the highest mean pulmonary artery pressure quartile, the adjusted odds ratios for dyspnea relief were 2.0 (95% CI, 1.41-2.82), 2.23 (95% CI, 1.52-3.27), and 2.98 (95% CI, 1.91-4.66) in the third, second, and first mean pulmonary artery pressure quartiles, respectively (P(trend)<0.0001).

CONCLUSIONS

A clinically significant improvement in dyspnea is associated with a reduction in both PCWP and mean pulmonary artery pressure.

Hemoptysis in children: a single institutional experience

OBJECTIVES

The purpose of this study was to describe a single institutional experience with pediatric diffuse pulmonary hemorrhage, with an emphasis on etiology, clinical course, and outcome.

METHODS

The medical records of pediatric patients admitted to Assaf Harofeh Medical Center between the years 2002 and 2011 because of hemoptysis and pulmonary infiltrates on chest radiographs were retrospectively reviewed.

RESULTS

Sixteen patients were identified. All the participants had respiratory complaints, and bloody cough was the presenting symptom in 11 patients. Twelve patients were admitted to the pediatric intensive care unit: 10 required mechanical ventilation, 9 had diffuse pulmonary infiltrates, and 8 required transfusions of blood products. Eight patients had an infectious disease (1 had tuberculosis). Two patients had severe coagulopathy. Three patients had diffuse bronchiectasis (1 had immunodeficiency). Cardiac failure was identified in 1 patient. Cocaine-induced pulmonary hemorrhage was identified in an adolescent. In 4 infants, the cause of pulmonary hemorrhage was not identified. Bronchoscopy and computed tomography were each performed in 9 patients. Five patients died during the acute phase of the illness because of severe hypoxia and multiorgan failure.

CONCLUSIONS

At our institution, hemoptysis is a rare but potentially life-threatening symptom. The etiology is heterogeneous. Clinical signs and chest radiographs are important for classifying the severity of the disease. Minor hemoptysis with focal findings on chest radiograph has a favorable short-term prognosis, with infectious diseases being involved in most cases.

Left ventricular markers of global dyssynchrony predict limited exercise capacity in heart failure, but not in patients with preserved ejection fraction

BACKGROUND

The aim of this study was to prospectively examine echocardiographic parameters that correlate and predict functional capacity assessed by 6 min walk test (6-MWT) in patients with heart failure (HF), irrespective of ejection fraction (EF).

METHODS

In 147 HF patients (mean age 61 ± 11 years, 50.3% male), a 6-MWT and an echo-Doppler study were performed in the same day. Global LV dyssynchrony was indirectly assessed by total isovolumic time - t-IVT [in s/min; calculated as: 60 - (total ejection time + total filling time)], and Tei index (t-IVT/ejection time). Patients were divided into two groups based on the 6-MWT distance (Group I: ≤ 300 m and Group II: >300 m), and also in two groups according to EF (Group A: LVEF ≥ 45% and Group B: LVEF < 45%).

RESULTS

In the cohort of patients as a whole, the 6-MWT correlated with t-IVT (r = -0.49, p < 0.001) and Tei index (r = -0.43, p < 0.001) but not with any of the other clinical or echocardiographic parameters. Group I had lower hemoglobin level (p = 0.02), lower EF (p = 0.003), larger left atrium (p = 0.02), thicker interventricular septum (p = 0.02), lower A wave (p = 0.01) and lateral wall late diastolic myocardial velocity a' (p = 0.047), longer isovolumic relaxation time (r = 0.003) and longer t-IVT (p = 0.03), compared with Group II. In the patients cohort as a whole, only t-IVT ratio [1.257 (1.071-1.476), p = 0.005], LV EF [0.947 (0.903-0.993), p = 0.02], and E/A ratio [0.553 (0.315-0.972), p = 0.04] independently predicted poor 6-MWT performance (<300 m) in multivariate analysis. None of the echocardiographic measurements predicted exercise tolerance in HFpEF.

CONCLUSION

In patients with HF, the limited exercise capacity, assessed by 6-MWT, is related mostly to severity of global LV dyssynchrony, more than EF or raised filling pressures. The lack of exercise predictors in HFpEF reflects its multifactorial pathophysiology.

Utility of lung ultrasound in predicting pulmonary and cardiac pressures

AIMS

Quantification of linear lung ultrasound (LUS) artefacts (B-lines) represents a novel, non-invasive approach to assess pulmonary congestion. We investigated the relationship between the number of B-lines (vertical artefacts arising from the pleural line) and intracardiac pressures.

METHODS AND RESULTS

Prior to scheduled right heart catheterization (RHC), 100 subjects underwent LUS of eight zones. A reviewer blinded to the haemodynamic data quantified the number of sonographic B-lines. Of 92 subjects who completed RHC, 79 had adequate LUS data of all zones [median age 61 years, 26 women, median left ventricular ejection fraction (LVEF) 58%, 35 with history of heart failure; 22 postcardiac transplantation]. The number of B-lines correlated with measured right atrial (r = 0.32), pulmonary artery diastolic (PADP) (r = 0.34), mean pulmonary artery (mPAP) (r = 0.43), pulmonary artery systolic (PASP) (r = 0.48) pressures, and pulmonary vascular resistance (PVR) (r = 0.51) (P < 0.005 for all), but not with pulmonary capillary wedge pressure. There was a graded association between tertiles of B-line number and increasing PADP, mPAP, PASP, and PVR (P for trend ≤0.001 for all). Each additional B-line was associated with an increase in PASP of 1 mmHg and an increase in PVR of 0.1 Wood units. These associations remained robust after multivariable adjustment (P = 0.002). Assessment of two inferior lateral zones resulted in similar correlations to the eight-zone method.

CONCLUSIONS

Easily obtainable, LUS may be useful in the estimation of right-sided cardiac pressures and PVR. Further evaluation of lung ultrasound as an adjunct to heart failure diagnosis, monitoring, and prognosis is warranted.

Pulmonary hypertension and right ventricular failure in left ventricular systolic dysfunction

PURPOSE OF REVIEW

Pulmonary hypertension and right ventricular failure (RVF) in left ventricular systolic dysfunction (LVSD) is associated with high morbidity and mortality. This review presents an overview of the classification, pathophysiology, natural history, clinical features, prevention and treatment of this common clinical problem with a focus on the most recent studies. Many of the current evidence-based therapeutic agents for pulmonary hypertension in the absence of systolic or diastolic heart failure (e.g. prostaglandins, endothelin antagonists) are not efficacious in pulmonary hypertension with LVSD.

RECENT FINDINGS

Recent clinical evidence strongly supports an evolving role for phosphodiesterase type 5 (PDE5) inhibition in patients with pulmonary hypertension and LVSD. Chronic PDE5 inhibition in the short-to-intermediate duration studies to date significantly reduces pulmonary pressures and pulmonary vascular resistance (PVR), effects reverse right ventricle and left ventricle remodeling, improves ventilator efficiency, improves peak exercise capacity and improves quality of life in selected patients with stable, moderately symptomatic LVSD and pulmonary hypertension.

SUMMARY

Although long-term outcome studies are currently lacking, chronic PDE5 inhibition should be considered in carefully selected LVSD patients who manifest persistent significant elevation of pulmonary hypertension or PVR or uncontrolled RVF after aggressive management with all standard current evidence-based LVSD therapies (neurohormonal antagonists, diuretics and cardiac resynchronization in appropriate candidates).

Pulse oximetry in the diagnosis of acute heart failure

INTRODUCTION AND OBJECTIVES

Oxygen saturation by pulse oximetry is commonly used for monitoring critical patients, but its utility as a diagnostic marker of acute heart failure has not been assessed. This study analyzed the diagnostic role of oxygen saturation by pulse oximetry in a series of patients with acute myocardial infarction.

METHODS

In a prospective observational cohort study of 220 consecutive patients with acute myocardial infarction, data collection included baseline oxygen saturation by pulse oximetry (without oxygen), physiologic measurements, Killip class and data from portable chest radiography, recorded at the same hour on each of the first three days after admission. Patients were followed up for one year.

RESULTS

There were 612 assessments. Baseline oxygen saturation by pulse oximetry decreased progressively in relation to the presence and the severity of acute heart failure assessed by Killip classes 1 to 3 (mean: 95, 92 and 85, respectively; P<.001) or by Radiology Score 0 to 4 (95, 94, 92, 89 and 83, respectively; P<.001), with a correlation coefficient of 0.66 and 0.63, respectively. Receiver operating characteristic curves disclosed the cut-off of oxygen saturation by pulse oximetry<93 to have the greatest area, with a sensitivity of 65%, specificity 90%, and overall test accuracy 83%. Patients grouped according to lowest oxygen saturation by pulse oximetry showed significantly different rates of one-year mortality or rehospitalization for heart failure.

CONCLUSIONS

Baseline oxygen saturation by pulse oximetry is useful in establishing the diagnosis and severity of heart failure in acute settings such as myocardial infarction and may have prognostic implications.The diagnosis may be suspected when baseline oxygen saturation by pulse oximetry is <93. Full English text available from:www.revespcardiol.org.

Effective strategies to improve the management of heart failure

The purpose of this article is to provide resources for primary care physicians to manage heart failure as a chronic disease. We review evidence-based interventions that can be adopted in primary care practices to improve adherence to available guidelines for medication use, promotion of self-care behaviors, transitions of care in acute decompensated heart failure, and end of life care. This information will be valuable to primary care providers who care for patients with heart failure in all care settings but is focused on the management of heart failure in the outpatient setting.

Role of aldosterone on lung structural remodelling and right ventricular function in congestive heart failure

Background

The mechanisms of benefit of mineralocorticoid receptors antagonists in congestive heart failure (CHF) are still debated. We hypothesized that aldosterone contributes to pulmonary remodelling and right ventricular (RV) dysfunction associated with CHF by stimulation of lung myofibroblasts (MYFs) proliferation.

Methods

Rats with moderate to large myocardial infarcts (MI) and CHF were studied. Two weeks after MI, spironolactone 100 mg/kg/day (n = 21) or no treatment (n = 24) were given for 3 weeks and compared to sham (n = 8).

Results

Infarct size was similar by ultrasound and pathologic measures in both MI groups.

The MI-untreated group developed important lung remodelling with nearly doubling of dry lung weight (p < 0.01), reduced left ventricular (LV) fractional shortening (16 ± 2% vs. 53 ± 1%; mean ± SEM, p < 0.0001), pulmonary hypertension (RV systolic pressure: 40 ± 3 mmHg vs. 27 ± 1 mmHg, p < 0.01) and RV hypertrophy (RV/(LV + septum): 38 ± 3% vs. 24 ± 1%, p < 0.05). Spironolactone had no effect on these parameters and did not improve LV or RV performance (tricuspid annular plane systolic excursion and RV myocardial performance index) measured by echocardiography. CHF induced a restrictive respiratory syndrome with histological lung fibrosis: this was also unaffected by spironolactone. Finally, isolated lung MYFs did not proliferate after exposure to aldosterone.

Conclusion

Aldosterone does not significantly contribute to pulmonary remodelling and RV dysfunction associated with CHF. Other mechanisms are responsible for the beneficial effects of spironolactone in CHF.

B-type natriuretic peptide in diagnosis of chronic heart failure in copd patients

The influence of chronic heart failure (CHF) on the В-type natriuretic peptide (BNP) level and BNP role in differential diagnosis of dyspnea in COPD and CHF was estimated.

The resistive and elastic work of breathing during exercise in patients with chronic heart failure

Patients with heart failure (HF) display numerous derangements in ventilatory function, which together serve to increase the work of breathing (W(b)) during exercise. However, the extent to which the resistive and elastic properties of the respiratory system contribute to the higher W(b) in these patients is unknown. We quantified the resistive and elastic W(b) in patients with stable HF (n = 9; New York Heart Association functional class I-II) and healthy control subjects (n = 9) at standardised levels of minute ventilation (V'(E)) during graded exercise. Dynamic lung compliance was systematically lower for a given level of V'(E) in HF patients than controls (p<0.05). HF patients displayed slightly higher levels of inspiratory elastic W(b) with greater amounts of ventilatory constraint and resistive W(b) than control subjects during exercise (p<0.05). Our data indicates that the higher W(b) in HF patients is primarily due to a greater resistive, rather than elastic, load to breathing. The greater resistive W(b) in these patients probably reflects an increased hysteresivity of the airways and lung tissues. The marginally higher inspiratory elastic W(b) observed in HF patients appears related to a combined decrease in the compliances of the lungs and chest wall. The clinical and physiological implications of our findings are discussed.

Acute lung failure

Lung failure is the most common organ failure seen in the intensive care unit. The pathogenesis of acute respiratory failure (ARF) can be classified as (1) neuromuscular in origin, (2) secondary to acute and chronic obstructive airway diseases, (3) alveolar processes such as cardiogenic and noncardiogenic pulmonary edema and pneumonia, and (4) vascular diseases such as acute or chronic pulmonary embolism. This article reviews the more common causes of ARF from each group, including the pathological mechanisms and the principles of critical care management, focusing on the supportive, specific, and adjunctive therapies for each condition.

Respiratory muscle training improves hemodynamics, autonomic function, baroreceptor sensitivity, and respiratory mechanics in rats with heart failure

Respiratory muscle training (RMT) improves functional capacity in chronic heart-failure (HF) patients, but the basis for this improvement remains unclear. We evaluate the effects of RMT on the hemodynamic and autonomic function, arterial baroreflex sensitivity (BRS), and respiratory mechanics in rats with HF. Rats were assigned to one of four groups: sedentary sham (n = 8), trained sham (n = 8), sedentary HF (n = 8), or trained HF (n = 8). Trained animals underwent a RMT protocol (30 min/day, 5 day/wk, 6 wk of breathing through a resistor), whereas sedentary animals did not. In HF rats, RMT had significant effects on several parameters. It reduced left ventricular (LV) end-diastolic pressure (P < 0.01), increased LV systolic pressure (P < 0.01), and reduced right ventricular hypertrophy (P < 0.01) and pulmonary (P < 0.001) and hepatic (P < 0.001) congestion. It also decreased resting heart rate (HR; P < 0.05), indicating a decrease in the sympathetic and an increase in the vagal modulation of HR. There was also an increase in baroreflex gain (P < 0.05). The respiratory system resistance was reduced (P < 0.001), which was associated with the reduction in tissue resistance after RMT (P < 0.01). The respiratory system and tissue elastance (Est) were also reduced by RMT (P < 0.01 and P < 0.05, respectively). Additionally, the quasistatic Est was reduced after RMT (P < 0.01). These findings show that a 6-wk RMT protocol in HF rats promotes an improvement in hemodynamic function, sympathetic and vagal heart modulation, arterial BRS, and respiratory mechanics, all of which are benefits associated with improvements in cardiopulmonary interaction.

Reading chest radiographs in the critically ill (Part II): Radiography of lung pathologies common in the ICU patient

This is part II of two series review of reading chest radiographs in the critically ill. Conventional chest radiography remains the cornerstone of day to day management of the critically ill occasionally supplemented by computed tomography or ultrasound for specific indications. In this second review we discuss radiographic findings of cardiopulmonary disorders common in the intensive care patient and suggest guidelines for interpretation based not only on imaging but also on the pathophysiology and clinical grounds.

Repercussões da cardiomegalia na função pulmonar de indivíduos adultos com insuficiência cardíaca crônica: uma revisão sistemática

Para analisar as repercussões da cardiomegalia sobre a função pulmonar em indivíduos adultos com insuficiência cardíaca (IC) crônica, foram revisados artigos nas bases PUBMED, BIREME, ISI Web of Knowledge e COCHRANE, publicados na última década, estudos observacionais e sem restrição de idioma. Utilizados os descritores "cardiomegaly" e "Respiratory Function Tests", e negada a palavra "exercise". Foram incluídos artigos com IC crônica, de ambos os sexos, entre 19 e 64 anos, incluindo IC congestiva e cardiomiopatia dilatada e excluídos com IC aguda, com avaliações pós-intervenção clínica ou por exercício. Para avaliar a qualidade dos artigos foi utilizada a escala da Agency for Healthcare Research and Quality (AHRQ) e aceitos aqueles com escore>50 pontos (0-100). Foram selecionados cinco artigos do total de 1093 e agrupados por parâmetros relacionados aos fluxos e volumes pulmonares, padrão ventilatório e desempenho muscular. Na AHRQ, dois estudos ficaram na faixa de 50-75% e os demais >75%. Eles apontam para redução da capacidade vital inspiratória (CVI), volume expiratório forçado no 1º segundo (VEF1) e pressão inspiratória máxima (PImáx) em função da cardiomegalia, com discreta redução na relação VEF1/CVI e na capacidade de difusão para monóxido de carbono (DLCO). Portanto, segundo os estudos, a cardiomegalia leva a um padrão respiratório restritivo, com redução do volume alveolar que interfere na DLCO. As correlações mais fortes envolvem a redução da PImáx, CVI e VEF1.

Heart failure and the lung

Heart failure (HF) is a highly prevalent disease that leads to significant morbidity and mortality. There is increasing evidence that the symptoms of HF are exacerbated by its deleterious effects on lung function. HF appears to cause airway obstruction acutely and leads to impaired gas diffusing capacity and pulmonary hypertension in the longer term. It is postulated that this is the result of recurrent episodes of elevated pulmonary capillary pressure leading to pulmonary oedema and pulmonary capillary stress fracture, which produces lung fibrosis. It is likely that impaired lung function impairs the functional status of HF patients and makes them more prone to central sleep apnoea.