Hemodynamics Of Pulmonary Circulation Research Articles

Right heart status in patients with COVID-19: a literature review

The COVID-19 pandemic has placed unprecedented strain on healthcare worldwide. Considering that the main pathophysiological processes causing the severe and extremely severe course of the disease are COVID-19-associated pneumonia and hypercoagulation, the hemodynamics of pulmonary circulation and the right heart was of particular concern. Echocardiography has become the main method for assessing the condition of the right heart in COVID-19 patients, owing to its availability and speed of the investigation. However, echocardiographic assessment of the right heart is challenging, and data in the available literature are conflicting. The functioning of the right parts of the heart regarding normality and in conditions of COVID-19 infection is shown. The results of studies aimed at assessing the structural, hemodynamic, and functional parameters of the right heart during the acute course of the disease and in the long-term period — from a month to a year — were studied. Currently, there is no consensus on the effect of COVID-19 on the condition of the right side of the heart in the long term and, accordingly, further monitoring of patients who have had COVID-19, especially severe and extremely severe cases, is required.

Endothelial Function Correlates With Pulmonary Pressures in Subjects With Clinically Suspected Pulmonary Hypertension

BackgroundImpaired pulmonary circulation hemodynamics are characteristic of pulmonary hypertension. We therefore sought to evaluate possible correlations between endothelial function non-invasively assessed by flow-mediated dilation (FMD) and hemodynamic parameters at right heart catheterization (RHC) in patients with clinically suspected pulmonary hypertension. MethodsConsecutive outpatients with suspected PH were enrolled in the study. In all patients, endothelial function was assessed by FMD and hemodynamic parameters (pulmonary artery pressure (PAP), pulmonary vascular resistances (PVR)) were derived by RHC. ResultsNinety-five consecutive patients with suspected pulmonary hypertension were enrolled in the study (mean age 63±13 years, 58% male) and included in the analysis. FMD values were significantly correlated with systolic (s)PAP levels (r=-0.29, P=0.016); correlation with pulmonary vascular resistance values was of borderline significance (r=-0.21, p=0.78).After multivariable regression analysis including age, gender, TAPSE and peak tricuspid regurgitation velocity (peak-TVR), and FMD, the latter remained significantly correlated with sPAP values (B=-47, p=0.02). After classifying patients according to median levels of peak TRV and FMD into 3 groups (neither, either, or both impaired), progressively increased levels of sPAP, mPAP and PVR were found (P for trend <0.001 in all cases). ConclusionsFMD values were inversely related with sPAP levels in a small population of patients with clinically suspected PH. In combination with peak TRV levels, FMD values non-invasively assessed were predictive of increased sPAP, mPAP, and PVR.

ACE2 gene polymorphisms are associated with elevated pulmonary artery pressure in congenital heart diseases

BackgroundsAngiotensin converting enzyme 2 (ACE2) polymorphisms are related to the occurrence and prognosis of cardiovascular disease. However, whether ACE2 polymorphisms also affect pulmonary circulation in congenital heart disease (CHD) remains unclear. Thus, we investigated the relationship between ACE2 single nucleotide polymorphism (SNPs) and pulmonary circulation in CHD patients of Chinese Han ethnicity. MethodsEnrolled CHD patients (n = 367) underwent gene sequencing of ACE2 SNPs rs2074192, rs2285666, and rs2106809. Patients with pulmonary hypertension were further examined for detailed hemodynamics. ResultsFemale heterozygous patients had worse pulmonary circulation hemodynamic parameters compared to those of homozygotes. Female CHD patients with the CCA (OR = 0.53, 95% CI: 0.32–0.88) or CCG (OR = 0.59, 95% CI: 0.35–0.99) haplotype had a lower risk of elevated pulmonary artery pressure. ConclusionIn female CHD patients, ACE2 SNPs are related to pulmonary circulation hemodynamics. Female CHD patients with the CCA and CCG haplotype had a lower risk of pulmonary hypertension.

Pulse Wave Analysis Predicts Invasive Hemodynamics in Pre-Capillary Pulmonary Hypertension.

We tested the hypothesis that non-invasive pulse wave analysis (PWA)-derived systemic circulation variables can predict invasive hemodynamics of pulmonary circulation and the indicator of right heart function, N-terminal pro-brain natriuretic peptide (NT-proBNP), in patients with precapillary pulmonary hypertension (PH). This prospective study enrolled patients with group 1 and 4 PH who had complete PWA, NT-proBNP, and hemodynamics data. Risk assessment-based "hemodynamic score (HS)" and principal component analysis-based PWA variable grouping were determined/performed. Models of hierarchical multiple linear regression (HMLR) and receiver operating characteristic (ROC) curves were used to determine the relationships of PWA variables with HS and NT-proBNP and to predict the latter parameters. Fifty-three PWAs were included. PWA variables were classified into 4 eigenvalue principal components (representing 90% configuration). Univariate analysis showed that left ventricular ejection time (LVET) was significantly negatively associated with HS and NT-proBNP levels. HMLR analysis showed that LVET was still significantly, negatively, and independently associated with HS (B = -0.006 [-0.010~-0.001]) and NT-proBNP (B = -13.47 [-21.20~-5.73]). ROC curve analysis showed that LVET > 306.9 msec and > 313.2 msec predicted the low-risk group of HS (AUC: 0.802; p = 0.001; sensitivity: 100%; and specificity: 59%) and low-to-intermediate risk levels of NT-proBNP (AUC: 0.831; p < 0.001; sensitivity: 100%; and specificity: 59%). The non-invasive PWA parameter, LVET, is an independent predictor of invasive right heart HS and NT-proBNP levels; it may serve as a novel biomarker of right ventricular function in patients with pre-capillary PH.

Early signs of disorders of cardiovascular biomechanics

Aim a comprehensive study of disorders of the biomechanics of blood circulation for early diagnostics of atherosclerosis.&#x0D; Material and methods. The study included 120 people having one of the following risk factors for cardiovascular diseases: smoking, hypertension, Type 1 or Type 2 diabetes. All subjects underwent computer-assisted rheopulmonography, rheovasography, apexcardiography, and direct sphygmography of the major arteries. The functioning of the heart, the arterial wall, the vascular bed of the pulmonary and systemic circulation was evaluated.&#x0D; Results. Smoking patients mainly had violations of the pulmonary circulation hemodynamics and the biomechanics of the arterial wall of the peripheral arteries due, obviously, to direct damage by nicotine. In patients with arterial hypertension, there was an increase in the work of the myocardium, obviously as a result of the formation of a hyperkinetic type of blood circulation in this disease. Patients with type 1 and type 2 diabetes mellitus were characterized primarily by the development of systolic-diastolic vascular dysfunction, which may be a predictor of the development of angiopathies in the future. In addition, the study of the kinetics of the major arteries revealed violations of the biomechanics of the wall of all vessels under study with risk factors for atherosclerosis. At the same time, it should be noted that more pronounced changes were found in the distal arteries of the muscular type than in the arteries of the muscular-elastic type, which is obviously associated with hemodynamic overloads experienced by peripheral vessels, both as a result of the hydraulic shock that occurs with hyperkinetic type of blood circulation, and the effect of hydrodynamic forces on the vessel wall under the influence of gravity.&#x0D; Conclusion. Each factor contributes to the development of disorders of cardiovascular biomechanics and hemodynamics. It is necessary to consider changes in the biomechanics of the heart and vascular bed as early manifestations of the circulatory system malfunction with present risk factors for cardiovascular diseases.

Features of hemodynamics of pulmonary circulation during the diving reflex

The adaptive cardiovascular reactions of the human diving reflex were studied. The diving reflex was activated by submerging a face in cold water under laboratory conditions. Forty volunteers (aged 18–24) were examined. ECG, arterial blood pressure (ABP) and central blood flow were recorded by the impedance rheography method in resting state, during diving simulation (DS) and after apnea. During DS there is a statistically significant decrease in the dicrotic index (DCI), which reflects a decrease in the resistive vessel tone and as well as diastolic index (DSI), characterizing lung perfusion. A comparison of the latent periods (LP) of an increase in ABP and a drop in DCI showed that a decrease in pulmonary vascular tone develops faster than ABP begins to increase. The LP for lowering DCI is from 0.6 to 10 s; for an increase in ABP — from 6 to 30 s. A short LP for DCI and the absence of a correlation between a decrease in ABP and DCI suggests that a decrease in pulmonary vascular tone during DS occurs reflexively and independently of a change in ABP.

Comparison of pulmonary circulation hemodynamics and respiratory mechanics induced by drowning with equal volume of freshwater and seawater in sheep: a randomized controlled study

To compare the effects of freshwater and seawater drowning on sheep's pulmonary circulation hemodynamics and respiratory mechanics. According to the random number table method, healthy crossbred sheep were divided into freshwater drowning group (n = 12) and seawater drowning group (n = 12). 30 mL/kg of freshwater or seawater was infused respectively through trachea for approximately 5 minutes. Before the drowning, immediately after drowning, and 30, 60, 120 minutes after drowning, the systemic circulation hemodynamic parameters [heart rate (HR), mean arterial pressure (MAP), cardiac output (CO)] were monitored by pulse indicator continuous cardiac output (PiCCO); the respiratory parameters were obtained through the ventilator, including tidal volume (VT), lung compliance (Cdyn), oxygenation index (PaO2/FiO2), peak airway pressure (Ppeak)]; PiCCO and the right heart floating catheter (Swan-Ganz catheter) was used to measure pulmonary hemodynamic parameters [pulmonary systolic pressure (PAS), pulmonary diastolic pressure (PAD), pulmonary artery wedge pressure (PAWP), and extravascular lung water (EVLW)]. The animals were sacrificed at the end of the experiment, and the amount of residual water in the respiratory tract was measured; the pathological changes in the lung tissue were observed by hematoxylin-eosin (HE) staining. (1) Systemic circulation hemodynamics: compared with the values before drowning, HR, MAP, and CO at the time of immediately after drowning in both freshwater and seawater were significantly increased and peaked. In addition, all indicators in the freshwater drowning group were significantly higher than those in the seawater drowning group [HR (bpm): 170.75±1.87 vs. 168.67±2.27, MAP (mmHg, 1 mmHg = 0.133 kPa): 172.92±1.62 vs. 159.42±3.18, CO (L/min): 13.27±0.71 vs. 10.33±0.73, all P < 0.05]. (2) Respiratory parameters: compared with values before drowning, PaO2/FiO2, VT, and Cdyn decreased immediately in both freshwater and seawater drowning groups, Ppeak was significantly increased; in addition, the values in the seawater drowning group were decreased or increased more significantly than freshwater drowning group [PaO2/FiO2 (mmHg): 37.83±1.99 vs. 60.42±5.23, VT (mL): 86.25±7.66 vs. 278.75±9.67, Cdyn (mL/cmH2O): 8.86±0.33 vs. 23.02±0.69, Ppeak (cmH2O, 1 cmH2O = 0.098 kPa): 42.17±2.69 vs. 17.67±1.15, all P < 0.01]. In addition, PaO2/FiO2 in the freshwater drowning group was gradually increased over time, while the seawater group continued to decline. (3) Pulmonary circulation hemodynamic parameters: PAS, PAD, PAWP at the time of immediately after drowning in both freshwater and seawater groups were significantly higher than before drowning; in addition, the freshwater drowning group was significantly higher than the seawater drowning group [PAS (mmHg): 34.58±2.87 vs. 26.75±1.66, PAD (mmHg): 27.25±1.22 vs. 16.75±0.87, PAWP (mmHg): 27.83±1.85 vs. 11.75±1.82, all P < 0.01]. Thereafter, PAS and PAD in the freshwater drowning group gradually decreased, while the parameters in the seawater drown group continued to increase. PAWP gradually decreased after freshwater or seawater drowning, and recovered to pre-drowning levels 120 minutes after drowning and 30 minutes after drowning, respectively. EVLW continued to increase after freshwater drowning, reaching a peak at 30 minutes, and then decreased, until 120 minutes after drowning was still significantly higher than that before drowning (mL/kg: 10.73±1.27 vs. 7.67±0.69, P < 0.01); EVLW could not be measured. (4) Residual water in the respiratory tract: residual water in the freshwater drowning group was significantly less than that in the seawater drowning group (mL: 164.33±25.21 vs. 557.33±45.23, P < 0.01). (5) HE staining: partial alveolar atrophied in the freshwater drowning group, some alveolar spaces were broken, alveolar spaces and alveolar cavity showed a little powdery substance deposition; it was noted that alveolar expanded in the seawater drowning group, alveolar spaces were broken and bleeding and edema were obvious in the interstitial space. The effect of seawater drowning on the respiratory mechanics and pulmonary circulation of animals is more obvious than that of freshwater drowned animals, and the amount of residual water in the respiratory tract is also significantly more than that of freshwater drowned animals.

P1711 Exploring the full spectrum of right ventricular exercise contractile reserve among health and disease: a prospective clinical and echocardiography observational multicenter study

Abstract Funding Acknowledgements None OnBehalf RIGHT-NET Background Exercise Doppler echocardiography (EDE) has been implemented for applications beyond coronary artery disease detection, but its role in assessing subclinical pulmonary vascular disease and right ventricle (RV) impairment is less clear. The RIGHT heart international NETwork (RIGHT-NET) is a prospective clinical and echocardiography observational multicenter study designed to explore the full spectrum of RV function and non-invasive pulmonary circulation hemodynamics during exercise in a large cohort of subjects, from healthy individuals and elite athletes to patients with overt or at risk of developing pulmonary hypertension (PH). Right ventricular (RV) exercise contractile reserve (RVECR) can be assessed through the ratio between tricuspid annular plane systolic excursion (TAPSE) and systolic pulmonary artery pressure (sPAP) and has proved to provide prognostic value in patients with left heart disease (LHD) and pulmonary arterial hypertension (PAH). Methods We enrolled 1424 patients (age 55.4 ± 15 years old, 44.4% males): 353 healthy controls, 40 athletes, 369 patients with cardiovascular risk factors (CVRF: arterial hypertension and/or diabetes mellitus), 46 with PAH (confirmed by right heart catheterization), 487 with systemic sclerosis (SSc) without overt PH, and 129 with LHD (including coronary artery disease and heart failure with reduced or preserved ejection fraction). All enrolled subjects underwent resting and EDE examinations on a semirecumbent cycle ergometer with an incremental workload of 25 Watts every 2 minutes up to the symptom-limited maximal tolerated workload, according to standardised protocols. Key echocardiographic measurements have been acquired at baseline, at 50 Watts, at peak exercise, and after 5-minutes recovery, including but not limited to RV function (TAPSE) and sPAP. Results In all six groups the ratio TAPSE/sPAP was significantly different at peak exercise compared to rest values (all p &amp;lt; 0.01). At rest, TAPSE/sPAP values were not significantly different among controls, athletes and CVRF patients, whereas during exercise TAPSE/sPAP values were significantly different, with CVRF showing the lowest values (p &amp;lt; 0.0001 vs controls and athletes). Patients with PAH and LHD had the worst RVECR both at rest and at peak exercise (all p &amp;lt; 0.0001 vs the other groups), while SSc groups reported intermediate values, which were lower than controls (p &amp;lt; 0.0001) and athletes (p &amp;lt; 0.0001), but higher than CVRF subjects (p = 0.003). (Figure) Conclusions EDE can non-invasively characterise different dynamic behaviours of the RVECR among healthy subjects, athletes and patients with various pathologic conditions. Whether a thorough EDE assessment of non-invasive hemodynamics, RVECR and coupling may predict later development of manifest PH, clinical deterioration or decreased survival will be further investigated during the ongoing follow-up. Abstract P1711 Figure

In Vitro Hemocompatibility Evaluation of Modified Rotary Left to Right Ventricular Assist Devices in Pulmonary Flow Conditions

Right ventricular failure is a common postoperative com-plication following left ventricular assist device (LVAD) im-plantation. Left ventricular assist devices are adapted for right ventricular assist device (RVAD) support by reducing the right pump speed or restricting the diameter of the outflow graft by “banding.” We sought to conduct in vitro hemocompatibility testing in a pulmonary flow condition for current modification of an LVAD for RVAD support, with a specific aim to provide benchmark values for future RVAD development. Two Heart-Ware HVADs coupled to custom-built blood circulation loops, as RVADs, were tested using human blood (n = 6). The RVADs were either used in reduced speed (1,920 ± 50 RPM) or band-ing conditions (3,050 ± 50 RPM) to mimic healthy pulmonary circulation hemodynamics. Blood from the loop was sampled at 0, 15, 60, 150, and 300 min to investigate the level of he-molysis, red blood cell (RBC) deformability, and the activation and aggregation of platelets. The amount of hemolysis and RBC deformability were significantly increased with banding compared with reduced speed (p < 0.05). No significant dif-ferences were found between the two conditions for platelet activation and platelet aggregation. In conclusion, we have evaluated the hemocompatibility of the HVAD when used for RVAD support in the clinically used modes of reduced speed and outflow graft banding under a pulmonary flow conditions that are commonly used in the biventricular failure population. We anticipate the benchmark values in the current study will facilitate future RVAD development.

Non-invasive imaging of global and regional cardiac function in pulmonary hypertension.

Pulmonary hypertension (PH) is a progressive illness characterized by elevated pulmonary artery pressure; however, the main cause of mortality in PH patients is right ventricular (RV) failure. Historically, improving the hemodynamics of pulmonary circulation was the focus of treatment; however, it is now evident that cardiac response to a given level of pulmonary hemodynamic overload is variable but plays an important role in the subsequent prognosis. Non-invasive tests of RV function to determine prognosis and response to treatment in patients with PH is essential. Although the right ventricle is the focus of attention, it is clear that cardiac interaction can cause left ventricular dysfunction, thus biventricular assessment is paramount. There is also focus on the atrial chambers in their contribution to cardiac function in PH. Furthermore, there is evidence of regional dysfunction of the two ventricles in PH, so it would be useful to understand both global and regional components of dysfunction. In order to understand global and regional cardiac function in PH, the most obvious non-invasive imaging techniques are echocardiography and cardiac magnetic resonance imaging (CMRI). Both techniques have their advantages and disadvantages. Echocardiography is widely available, relatively inexpensive, provides information regarding RV function, and can be used to estimate RV pressures. CMRI, although expensive and less accessible, is the gold standard of biventricular functional measurements. The advent of 3D echocardiography and techniques including strain analysis and stress echocardiography have improved the usefulness of echocardiography while new CMRI technology allows the measurement of strain and measuring cardiac function during stress including exercise. In this review, we have analyzed the advantages and disadvantages of the two techniques and discuss pre-existing and novel forms of analysis where echocardiography and CMRI can be used to examine atrial, ventricular, and interventricular function in patients with PH at rest and under stress.

Disorders of Vasoregulative Endothelial Function, Echocardiographic Assessment of Myocardial Dysfunction and Hemodynamics of Pulmonary Circulation in Cirrhosis of the Liver

to study relationship between parameters of intracardiac hemodynamics assessed by Doppler echocardiography and functional activity of endothelium, hepatic blood flow and severity of portal hypertension in patients with cirrhosis of the liver (CL) of different etiology. We found that changes of structural and functional parameters of the heart in LC depended on the stage of compensation of portal hypertension and were accompanied by rearrangement of parameters of intracardiac hemodynamics. Pulmonary arterial hypertension (PAH) was found in 11.1% of patients with LC. PAH was moderate and was more frequent in patients with end-stage disease (Child-Pugh class C) compared with those with initial stage of LC (21.4% and 6.3%, p<0.05, respectively). Disorders of vasoregulating endothelial function in patients with CL were related to parameters of cardiopulmonary hemodynamics and functional state of the right ventricle and were more pronounced in patients with PAH.

HEART RHYTHM DISORDERS IN NEW-BORNS AND INFANTS: CLINICAL COURSE AND PERINATAL RISK FACTORS OF ARRHYTHMIAS APPEARANCE

Clinical course, prognosis and mechanisms of separate forms of heart rhythm disorders in children differ from those in adults. Especially, it refers to new-borns and infants whose conduction system differs by functional and morphologic immaturity. In connection with it, the assessment of natural history of heart rhythm disorders, occurred in a perinatal period, and determination of risk factors of arrhythmia appearance in infants are of some interest. 88 newborns took part in the study. The patients were involved by continuous sampling technique. Risk factors, occurred in a perinatal period and potentially influenced on development of heart rhythm disorders, were assessed. In our study we took biological, gynecologic and obstetric history, data of gestation and delivery course, early and late neonatal period, early infancy, Echo, neurosonography, Holter monitoring with determination of heart rhythm variability, and determined thyroid hormonal status. Maximum specific gravity had extrasystoles – 32.4% – in the structure of idiopathic arrhythmias in infants. Heart rhythm disorders with natural history were kept at six months of life only in 5,4% of children. Persistence of arrhythmias was marked during one year only for WPW syndrome. Heart rhythm disorders are often marked significantly in children whose mothers had acute respiratory disease during the pregnancy, or if the children were born from the first pregnancy, had the signs of central nervous system damage syndromes in an early perinatal period (arrest, intracranial hypertension, convulsive disorder). Disorders of autonomic imbalance of cardiac function and peculiarities of hemodynamics of pulmonary circulation contribute significantly into appearance and persistence of all types of arrhythmias. On the whole, the prognosis of heart rhythm disorders, occurred in the perinatal period, without organic and structural changes of myocardium is favorable. The exclusion can be made for congenital atrioventricular block and some types of supraventricular tachycardia which are not responded to treatment.

ラットにおける高所滞在・平地トレーニングが肺循環動態および肺動脈の血管内皮型一酸化窒素合成酵素タンパク質発現に与える影響

The present study was to evaluate endothelial nitric oxide synthase (eNOS) protein expression and hemodynamics of pulmonary circulation in rats of "Living high and Training low" (LH+TL). The Sprague Dawley strain of male rats were used at the age of 9 weeks. They were divided according to four conditions of a living low (LL) group, living low and training low (LL+TL) group, living high (LH) group and LH+TL group, for 10 days. We assessed the effects of LH+TL on exercise-induced pulmonary arterial pressure and blood lactic acids under sea-level altitude in catheter-implanted conscious rats. Also, we measured the pulmonary artery under anesthesia and analyzed eNOS protein expression by western blot analysis. The blood lactate levels in the LH+TL rats decreased after maximal treadmill running compared to LL, LL+TL and LH rats (p<0.05). The increase in pulmonary arterial blood pressure with exercise was significantly lower in the LH+TL group than in the LL group (p<0.05). The eNOS protein expressions of pulmonary artery were higher in the LH+TL group than in the LL group (p<0.05). This study indicates that LH+TL reduced the increase of pulmonary arterial blood pressure with exercise at below sea-level altitude. In addition, eNOS protein expressions were enhanced in the pulmonary arteries of LH+TL rats. Thus, we conclude that the high altitude training of LH+TL was a useful method for improvement of endurance exercise ability and this improvement may be associated with pulmonary arterial response.

The effect of pulmonary circulation hemodynamics on right ventricular unloading via the bidirectional Glenn shunt: Implications for congenitally corrected transposition repair

The bidirectional Glenn shunt has been successfully applied as an adjunct to ventricular septal defect closure and pulmonary valvulotomy to treat congenitally corrected transposition of the great arteries (ccTGA). The purpose of this study was to examine the volume and pressure unloading effects of the bidirectional Glenn shunt on the hypertrophied pulmonary ventricle in a canine model of ccTGA. Five beagles underwent survival surgery to band the pulmonary artery. Three months later, a polytetrafluoroethylene graft was anastomosed to the superior vena cava and right pulmonary artery. The graft or superior vena cava was clamped to create the normal or bidirectional Glenn circulation, and hemodynamic data were recorded. The bidirectional Glenn shunt significantly reduced right ventricular volume loading and stroke work. Dogs with normal pre-bidirectional Glenn cardiac outputs had greatly reduced right ventricular volumes and pressures with the bidirectional Glenn shunt. Dogs with pre-bidirectional Glenn right ventricular dysfunction had moderate volume but no pressure decreases with the bidirectional Glenn shunt owing to improved left ventricular output. In these dogs it is likely that the decreased level of pressure and volume unloading is because of a concomitant improvement in left ventricular output post-bidirectional Glenn shunt placement. The bidirectional Glenn shunt is effective at unloading the right ventricle in a canine model of ccTGA.

Hemodynamics of pulmonary circulation in asbestosis: study of 16 cases.

Pulmonary circulation hemodynamics was studied by microcatheterization at rest and during exercise in 16 workers with asbestosis. There was pulmonary arterial hypertension owing to increased total pulmonary resistance even in the early stages of pneumoconiosis, sometimes without impairment of lung function. In two cases, a partial reduction in pulmonary hypertension and total pulmonary resistance was obtained with aminophylline. The pathogenesis of pulmonary circulation impairment has been attributed in previous work to periarteriolar fibrosis originating in the lymphatic vessels, until now insufficiently emphasized as the anatomical basis of these physiological alterations.