Comparison of Doppler Flow Tei-Indexes With Pulmonary Artery Thermodilution Measurement of Cardiac Output in an Experimental Porcine Model

The objective of our study was to compare Doppler echocardiography imaging with pulmonary artery thermodilution measurement during mechanical ventilation. Total 78 piglets (6 weeks old, average weight 24 kg, under general anesthesia) were divided into 4 groups under different cardiac loading conditions (at rest, with increased left ventricular afterload, with increased right ventricular preload, and with increased afterload of both heart ventricles). At 60 and 120 min the animals were examined by echocardiography and simultaneously pulmonary artery thermodilution was used to measure cardiac output. Tei-indexes data were compared with invasively monitored hemodynamic data and cardiac output values together with calculated vascular resistance indices. A total of 224 parallel measurements were obtained. Correlation was found between values of right Tei-index of myocardial performance and changes in right ventricular preload (p<0.05) and afterload (p<0.01). Significant correlation was also found between left index values and changes of left ventricular preload (p<0.001), afterload (p<0.001), stroke volume (p<0.01), and cardiac output (p<0.01). In conclusion, echocardiographic examination and determination of the global performance selectively for the right and left ventricle can be recommended as a suitable non-invasive supplement to the whole set of methods used for monitoring of circulation and cardiac performance.

Download Full-text

Norepinephrine and dobutamine improve cardiac index equally by supporting opposite sides of the heart in an experimental model of chronic pulmonary hypertension

10.21203/rs.3.rs-458360/v1 ◽

2021 ◽

Author(s):

Janus Adler Hyldebrandt ◽

Nikolaj Bøgh ◽

Camilla Omann Christensen ◽

Peter Agger

Keyword(s):

Pulmonary Hypertension ◽

Cardiac Index ◽

Pulmonary Artery ◽

Right Ventricular ◽

Left Ventricular ◽

Ventricular Contractility ◽

End Diastolic Volume ◽

Chronic Pulmonary Hypertension ◽

Blood Pressures ◽

The Right

Abstract Background: Pulmonary hypertension is a significant risk factor in patients undergoing surgery. The combined effects of general anaesthesia and positive pressure ventilation can aggravate this condition and cause increased pulmonary blood pressures, reduced systemic blood pressures and ventricular contractility. Although perioperative use of inotropic support or vasopressors is almost mandatory for these patients, preference is disputed. In this study, we investigated the effects of norepinephrine and dobutamine and their ability to improve the arterio-ventricular relationship and haemodynamics in pigs suffering from chronic pulmonary hypertension.Method: Pulmonary hypertension was induced in five pigs by banding the pulmonary artery at 2–3 weeks of age. Six pigs served as controls. After 16 weeks of pulmonary artery banding, the animals were re-examined under general anaesthesia using biventricular conductance catheters and a pulmonary artery catheter. After baseline measurements, the animals were exposed to both norepinephrine and dobutamine infusions in incremental doses, with a stabilizing period in between the infusions. The hypothesis of differences between norepinephrine and dobutamine with incremental doses was tested using repeated two-way ANOVA and Bonferroni multiple comparisons post-test. Results: At baseline, pulmonary artery banded animals had increased right ventricular pressure (+39%, p=0.04), lower cardiac index (-23% p=0.04), lower systolic blood pressure (-13%, p=0.02) and reduced left ventricular end-diastolic volume (-33%, p=0.02). When incremental doses of norepinephrine and dobutamine were administered, the right ventricular arterio-ventricular coupling was improved only by dobutamine (p<0.05). Norepinephrine increased both left ventricular end-diastolic volume and left ventricular contractility to a greater extent (p<0.05) in pulmonary artery banded animals. While the cardiac index was improved equally by norepinephrine and dobutamine treatments in pulmonary artery banded animals, norepinephrine had a significantly greater effect on mean arterial pressure (p<0.05) and diastolic arterial pressure (p<0.05).Conclusion: While norepinephrine and dobutamine improved cardiac index equally, it was obtained in different manners. Dobutamine significantly improved the right ventricular function and the arterio-ventricular coupling. Norepinephrine increased systemic resistance, thereby improving arterial pressures and left ventricular systolic function by maintaining left ventricular end-diastolic volume.

Download Full-text

Cardiac adjustments to left-side inotropic stimulation of in situ pig hearts

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1987.252.6.h1164 ◽

1987 ◽

Vol 252 (6) ◽

pp. H1164-H1174

Author(s):

O. A. Vengen ◽

K. Lande ◽

O. Ellingsen ◽

A. Ilebekk

Keyword(s):

Right Ventricular ◽

Systemic Circulation ◽

Left Ventricular ◽

Segment Length ◽

Ventricular Afterload ◽

Computer Based ◽

The Right ◽

Isoproterenol Infusion ◽

Inotropic Stimulation ◽

Stimulation Of

Cardiac adjustments to inotropic stimulation of the left side of the heart by continuous infusions of isoproterenol (0.6-0.8 microgram/min) and calcium chloride (240 mumol/min) into the left coronary artery were examined in open-chest pigs (17-36 kg) anesthetized with pentobarbital sodium. Both agents caused a reduction in the left ventricular (LV) preload and preejection segment length (PESL). Stroke volume (SV) rose by only 1.2 ml from 15.9 ml (P less than 0.01) during isoproterenol infusion, but when the reduction in LV PESL of 3.2% (P less than 0.01) was restored by saline infusion, SV increased by 27%. The LV PESL reduction was less at hypervolemia than at normovolemia. A computer-based model of the circulation predicted most of these changes and suggested redistribution of blood from the pulmonary to the systemic circulation. During isoproterenol infusion, the pulmonary arterial pressure fell, and the right ventricular end-ejection segment length declined. Reduced right ventricular afterload thus appears to be an important mechanism by which right ventricular output is increased during a selective increase in LV inotropy.

Download Full-text

Icariin Attenuates Monocrotaline-Induced Pulmonary Arterial Hypertension via the Inhibition of TGF-β1/Smads Pathway in Rats

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2020/9238428 ◽

2020 ◽

Vol 2020 ◽

pp. 1-8

Author(s):

Yijia Xiang ◽

Changhong Cai ◽

Yonghui Wu ◽

Lebing Yang ◽

Shiyong Ye ◽

...

Keyword(s):

Pulmonary Arterial Hypertension ◽

Pulmonary Artery ◽

Arterial Hypertension ◽

Right Ventricular ◽

Left Ventricular ◽

Matrix Metalloproteinase 2 ◽

Western Blots ◽

Pulmonary Arterial ◽

The Right ◽

Tgf Β1

Background. Pulmonary artery remodeling is important in the development of pulmonary artery hypertension. The TGF-β1/Smads signaling pathway is activated in pulmonary arterial hypertension (PAH) in rats. Icariin (ICA) suppresses the TGF-β1/Smad2 pathway in myocardial fibrosis in rats. Therefore, we investigated the role of icariin in PAH by inhibiting the TGF-β1/Smads pathway. Methods. Rats were randomly divided into control, monocrotaline (MCT), MCT + ICA-low, and MCT + ICA-high groups. MCT (60 mg/kg) was subcutaneously injected to induce PAH, and icariin (50 or 100 mg/kg.d) was orally administered for 2 weeks. At the end of the fourth week, right ventricular systolic pressure (RVSP) was obtained and the right ventricular hypertrophy index (RI) was determined as the ratio of the right ventricular weight to the left ventricular plus septal weight (RV/LV + S). Western blots were used to determine the expression of TGF-β1, Smad2/3, P-Smad2/3, and matrix metalloproteinase-2 (MMP2) in lung tissues. Results. Compared to the control group, RVSP and RI were increased in the MCT group (ρ < 0.05). Additionally, TGF-β1, Smad2/3, P-Smad2/3, and MMP2 expressions were obviously increased (ρ < 0.01). Compared to the MCT group, RVSP and RI were decreased in the MCT + ICA group (ρ < 0.05). TGF-β1, Smad2/3, P-Smad2/3, and MMP2 expressions were also inhibited in the icariin treatment groups (ρ < 0.05). Conclusions. Icariin may suppress MCT-induced PAH via the inhibition of the TGFβ1-Smad2/3 pathway.

Download Full-text

Post-COVID-19 syndrome: morpho-functional abnormalities of the heart and arrhythmias

Russian Journal of Cardiology ◽

10.15829/1560-4071-2021-4485 ◽

2021 ◽

Vol 26 (7) ◽

pp. 4485

Author(s):

M. V. Chistyakova ◽

D. N. Zaitsev ◽

A. V. Govorin ◽

N. A. Medvedeva ◽

A. A. Kurokhtina

Keyword(s):

Pulmonary Artery ◽

Right Ventricular ◽

Cardiac Arrhythmias ◽

Myocardial Strain ◽

Left Ventricular ◽

Upper Respiratory Tract ◽

Regional Strain ◽

Group 3 ◽

The Right ◽

Group 1

Aim. To study the myocardial morpho-functional abnormalities, the incidence and nature of cardiac arrhythmias in patients 3 months after the coronavirus disease 2019 (COVID-19).Material and methods. The study included 77 patients (mean age, 35,9 years) treated for coronavirus infection, which underwent echocardiography and 24-hour Holter monitoring 3 months after COVID-19. The patients were divided into 3 groups: group 1 — 31 patients with upper respiratory tract involvement; group 2 — 27 patients with bilateral pneumonia (CT grade 1, 2), 3 — 19 patients with severe pneumonia (CT grade 3, 4). Statistical processing was carried out using Statistica 10.0.Results. According to echocardiography, the peak tricuspid late diastolic velocity and isovolumetric contraction time in all groups increased (P<0,001). The tricuspid and mitral Em/Am ratio decreased depending on the disease severity. In group 3, the right ventricular and atrial size increased (P<0,001). The pulmonary artery systolic pressure, left atrial volume in patients of the 2nd and 3rd groups was higher than in the control one (P<0,001). In group 1 and 2 patients, the regional strain in basal and basal/middle segments decreased, respectively, while, in group 3, not only regional but also global left ventricular (LV) strain decreased (P<0,001). In all groups, cardiac arrhythmias and pericardial effusion were found. The relationship was established between coronavirus activity and the structural and functional myocardial parameters (P<0,001).Conclusion. Cardiovascular injury 3 months after COVID-19 was found in 71%, 93%, and 95% of patients with mild, moderate and severe course. In mild course patients, a decrease in regional myocardial strain in LV basal segments, signs of past pericarditis, and various cardiac arrhythmias were noted. In patients of moderate severity, these changes were more pronounced and were accompanied by an additional decrease in regional strain in LV middle segments, impaired right ventricular diastole and increased pulmonary artery pressure. In severe patients, in addition to the above changes, dilatation of the right heart and inferior vena cava was recorded, as well as LV diastolic and global systolic function decreased.

Download Full-text

EVALUATION OF THE RELATIONSHIP BETWEEN PULMONARY ARTERY STIFFNESS AND RIGHT VENTRICULAR FUNCTION IN PATIENTS WITH BEHÇET’S DISEASE USING TRANSTHORACIC ECHOCARDIOGRAPHY

10.22541/au.163615894.48445737/v1 ◽

2021 ◽

Author(s):

Salim Yaşar ◽

Murat Unlu ◽

suat gormel ◽

Emre Yalcinkaya ◽

Baris BUGAN ◽

...

Keyword(s):

Pulmonary Artery ◽

Right Ventricular ◽

Patient Group ◽

Behcet’S Disease ◽

Left Ventricular ◽

Significant Difference ◽

Artery Stiffness ◽

The Right ◽

The Relationship ◽

Ventricular Functions

Background: Behçet’s disease is a systemic vasculitis that can affect all sizes of arteries and veins. Arterial stiffness is a term used to describe the visco-elastic properties of vessel wall. In this study, we aimed to evaluate the relationship between pulmonary artery stiffness (PAS) and the right ventricular (RV) functions in asymptomatic Behçet’s patients with no cardiovascular risk factors. Methods: We studied 40 patients who were diagnosed by the international diagnostic criteria of Behçet’s disease and 40 healthy individuals who were matching demographic properties with the patients. Two groups were matched by age, gender, clinical history and other clinical features. Substantial medical history concerning the factors that can affect right ventricle diastolic function (such as medications, smoking status, other comorbities, etc.) was taken and general physical examination was carried out. The right and left ventricular functions as well as valvular functions were evaluated by using echocardiography. Also Two-dimensional, M-mode, pulsed wave (PW) Doppler echocardiographic parameters were measured for right ventricular functions. PW Doppler flow trace was obtained from the pulmonary valve with regards to pulmonary artery stiffness. Results: There was no significant difference in terms of clinical and demographic properties. No statistically significant difference was found upon comparison of the left ventricular end of systole and diastole diameters, the diastolic and systolic thicknesses of the interventricular septum (IVS) and left ventricular posterior wall (LVPW), left atrium (LA) diameter and left ventricular ejection fraction (LVEF) values (p>0.05) of the two groups. Right ventricular myocardial performance index (MPI) value was found higher in Behçet’s patients and a statistically significant difference was detected between the groups (p<0.01). Tricuspid annular plane systolic excursion (TAPSE) values were found to be statistically significantly lower in the patient group as compared to the control group (p<0.01). In PW Doppler measurements, early passive filling (E) wave flow velocity and E/A ratio were found to be statistically significantly lower, deceleration time (DT) was higher in the patient group (p<0.01). In Behçet’s patients without clinical pulmonary involvement, the pulmonary artery systolic pressure (PASP) was found to be statistically significantly higher in the patient group (p<0.01). The values of pulmonary artery stiffness (PAS) were found to be significantly higher in the patient group (p<0.01). The relationship between the right ventricular function markers and PAS were evaluated in the patient group. There was no statistically significant relationship between PAS and MPI and TAPSE. But there was a significant correlation between PAS and PASP and duration of illness (p<0.001 and r=0.682 ; p=0.047 and r=0,316). Conclusion: Behçet’s patients without cardiac symptoms and signs, reduction in right ventricular functions and increase in PAS was detected. Although there is no correlation between right ventricular functions and PAS, increased PAS may be an early marker of reduction of the right ventricular functions. Consequently, routine cardiological examination and detailed evaluation of biventricular functions by using echocardiography should be greatly beneficial in Behcet’s patients, even though there are no signs or symptoms.

Download Full-text

Echocardiographic assessment of right heart indices in dogs with elevated pulmonary artery pressure associated with chronic respiratory disorders, heartworm disease, and chronic degenerative mitral valvular disease

Veterinární Medicína ◽

10.17221/7180-vetmed ◽

2013 ◽

Vol 58 (No. 12) ◽

pp. 613-620 ◽

Cited By ~ 7

Author(s):

HP Tai TC Huang

Keyword(s):

Pulmonary Artery ◽

Right Ventricular ◽

Aortic Root ◽

Peak Velocity ◽

Root Diameter ◽

Left Ventricular ◽

Right Heart ◽

Respiratory Disorders ◽

Heartworm Disease ◽

The Right

The aim of this study was to evaluate right ventricular (RV) remodeling and right heart failure associated with different causes of elevated pulmonary arterial pressure (PAP) in dogs. In total, 169 client-owned dogs with tricuspid regurgitation (TR) and 40 client-owned clinically healthy dogs were included. Dogs with TR were further categorised as suffering from chronic respiratory disorders (CRD), heartworm disease (HWD), mild/moderate chronic degenerative mitral valvular disease (CDMD), and severe CDMD. Among the echocardiographic indices of the right heart, no significant difference in the tricuspid annular plane systolic excursion to aortic root diameter ratio was found among the clinical healthy controls and the four different TR categories. No significant differences in TR peak velocity and pulmonic regurgitation peak velocity were found among dogs in the four different TR categories. The ratio of the right to left ventricular basal diameter in the right ventricular-focused view was significantly higher in dogs with chronic respiratory disorders and dogs with heartworms. Left ventricular compression quantified using the eccentricity index and the ratio of the main pulmonary artery to aortic root diameter were significantly higher in dogs with HWD. Their right ventricular acceleration to ejection time (AT/ET) was significantly lower in dogs with HWD. Based on these findings, we conclude that right heart indices are affected by CRD, HWD, and moderate to severe CDMD. However, right heart indices derived from left heart measurements might be underestimated in dogs with CDMD.

Download Full-text

Mechanical support of the pressure overloaded right ventricle: an acute feasibility study comparing low and high flow support

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00246.2015 ◽

2015 ◽

Vol 309 (4) ◽

pp. H615-H624 ◽

Cited By ~ 9

Author(s):

Tom Verbelen ◽

Jelle Verhoeven ◽

Motohiko Goda ◽

Daniel Burkhoff ◽

Marion Delcroix ◽

...

Keyword(s):

Blood Pressure ◽

Cardiac Output ◽

Pulmonary Artery ◽

Right Ventricle ◽

Right Ventricular ◽

High Flow ◽

Low Flow ◽

Mechanical Support ◽

Arterial Blood ◽

The Right

The objectives of this study were to assess the feasibility of low flow right ventricular support and to describe the hemodynamic effects of low versus high flow support in an animal model of acute right ventricular pressure overload. A Synergy Pocket Micro-pump (HeartWare International, Framingham, MA) was implanted in seven sheep. Blood was withdrawn from the right atrium to the pulmonary artery. Hemodynamics and pressure-volume loops were recorded in baseline conditions, after banding the pulmonary artery, and after ligating the right coronary artery in these banded sheep. End-organ perfusion (reflected by total cardiac output and arterial blood pressure) improved in all conditions. Intrinsic right ventricular contractility was not significantly impacted by support. Diastolic unloading of the pressure overloaded right ventricle (reflected by decreases in central venous pressure, end-diastolic pressure and volume, and ventricular capacitance) was successful, but with a concomitant and flow-dependent increase of the systolic afterload. This unloading diminished with right ventricular ischemia. Right ventricular mechanical support improves arterial blood pressure and cardiac output. It provides diastolic unloading of the right ventricle, but with a concomitant and right ventricular assist device flow-dependent increase of systolic afterload. These effects are most distinct in the pressure overloaded right ventricle without profound ischemic damage. We advocate the low flow strategy, which is potentially beneficial for the afterload sensitive right ventricle and has the advantage of avoiding excessive increases in pulmonary artery pressure when pulmonary hypertension exists. This might protect against the development of pulmonary edema and hemorrhage.

Download Full-text

Do alterations in pulmonary vascular tone result in changes in central blood volumes? An experimental study

Intensive Care Medicine Experimental ◽

10.1186/s40635-021-00421-8 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Jaap Jan Vos ◽

J. K. Götz Wietasch ◽

Andreas Hoeft ◽

Thomas W. L. Scheeren

Keyword(s):

Cardiac Output ◽

Right Ventricular ◽

Blood Volume ◽

Vascular Tone ◽

Left Ventricular ◽

Cardiac Preload ◽

Circulating Blood Volume ◽

Ventricular Afterload ◽

Spontaneously Breathing ◽

Blood Volumes

Abstract Background The effects of selective pulmonary vascular tone alterations on cardiac preload have not been previously examined. Therefore, we evaluated whether changing pulmonary vascular tone either by hypoxia or the inhalation of aerosolized prostacyclin (PGI2) altered intrathoracic or pulmonary blood volume (ITBV, PBV, respectively), both as surrogate for left ventricular preload. Additionally, the mean systemic filling pressure analogue (Pmsa) and pressure for venous return (Pvr) were calculated as surrogate of right ventricular preload. Methods In a randomized controlled animal study in 6 spontaneously breathing dogs, pulmonary vascular tone was increased by controlled moderate hypoxia (FiO2 about 0.10) and decreased by aerosolized PGI2. Also, inhalation of PGI2 was instituted to induce pulmonary vasodilation during normoxia and hypoxia. PBV, ITBV and circulating blood volume (Vdcirc) were measured using transpulmonary thermo-dye dilution. Pmsa and Pvr were calculated post hoc. Either the Wilcoxon-signed rank test or Friedman ANOVA test was performed. Results During hypoxia, mean pulmonary artery pressure (PAP) increased from median [IQR] 12 [8–15] to 19 [17–25] mmHg (p < 0.05). ITBV, PBV and their ratio with Vdcirc remained unaltered, which was also true for Pmsa, Pvr and cardiac output. PGI2 co-inhalation during hypoxia normalized mean PAP to 13 (12–16) mmHg (p < 0.05), but left cardiac preload surrogates unaltered. PGI2 inhalation during normoxia further decreased mean PAP to 10 (9–13) mmHg (p < 0.05) without changing any of the other investigated hemodynamic variables. Conclusions In spontaneously breathing dogs, changes in pulmonary vascular tone altered PAP but had no effect on cardiac output, central blood volumes or their relation to circulating blood volume, nor on Pmsa and Pvr. These observations suggest that cardiac preload is preserved despite substantial alterations in right ventricular afterload.

Download Full-text

P885 Pulmonary artery stent implantation in an adult with chronic thromboembolic pulmonary stenosis

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jez319.525 ◽

2020 ◽

Vol 21 (Supplement_1) ◽

Author(s):

E A Khalifa ◽

S Helmy ◽

F Elallus ◽

S F Mohamed ◽

M Alkuwari

Keyword(s):

Pulmonary Hypertension ◽

Pulmonary Artery ◽

Right Ventricular ◽

Stent Implantation ◽

Pulmonary Valve ◽

Main Pulmonary Artery ◽

Left Ventricular ◽

Artery Stenosis ◽

Pulmonary Artery Stenosis ◽

The Right

Abstract Introduction Pulmonary artery stenosis presenting in adults is rare. Chronic thromboembolic pulmonary hypertension (CTEPH) is by far the most common cause of pulmonary artery stenosis. Stenosis in these patients are not caused by an abnormality of the arterial wall itself, but by intraluminal narrowing as a result of the only partially resolved and organized thromboembolism. In contrast to paediatric patients, in adults with pulmonary artery stenosis, pulmonary stenting is not routinely performed. Case report A 51-year male, smoker, diabetic, hypertensive, and with chronic kidney disease. He was diagnosed two years earlier with bilateral multiple pulmonary emboli and was maintained on oral anticoagulation therapy. Recently, he presented with gradually progressive shortness of breath and signs of right ventricular failure. Diagnostic imaging: 1-Transthoracic and transesophageal echocardiography showed normal global systolic left ventricular function with no regional wall motion abnormalities, dilated right ventricle (RV) with moderately impaired function, severe pulmonic valve incompetence, mild tricuspid incompetence and a severely elevated right ventricular systolic pressure (RVSP) of 82 mmHg. In addition, a small rounded mass (6 x 11 mm) was visualized attached to the posterior wall of the RV outflow tract (RVOT) about 15mm proximal to the pulmonary valve annulus, (figure A). 2- Computed tomography pulmonary angiography showed a right main pulmonary artery (RPA) with circumferential narrowing, which was highly suggestive of chronic thrombosis. There was an abrupt tapering noted in the segmental branches of the right lower lobar pulmonary artery, with non-opacification of the distal arteries. No contrast opacification was noted in the right upper lobe pulmonary arteries. The left main pulmonary artery showed thickening of its bifurcation, again suggestive of chronic thrombosis, with narrowing of its left upper lobar branch, (figures B&C). 3-Cardiac magnetic resonance (CMR) showed a non enhancing RVOT mass protruding through the incompetent pulmonary valve during systole with features suggestive of a thrombus. Management In view of the clinical history, CTEPH was considered to be the most likely aetiology of the pulmonary hypertension. The decision was to perform balloon angioplasty and stent implantation in the RPA. Immediately after the procedure, RVSP was reduced from 80 to 50 mmHg. The clinical course after this procedure was uncomplicated and the patient showed significant clinical improvement. Follow up CMR showed patent stent with improvement of RV function ( fig D) Abstract P885 Figure.

Download Full-text

Norepinephrine and dobutamine improve cardiac index equally by supporting opposite sides of the heart in an experimental model of chronic pulmonary hypertension

Intensive Care Medicine Experimental ◽

10.1186/s40635-021-00391-x ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Janus Adler Hyldebrandt ◽

Nikolaj Bøgh ◽

Camilla Omann ◽

Peter Agger

Keyword(s):

Pulmonary Hypertension ◽

Cardiac Index ◽

Pulmonary Artery ◽

Right Ventricular ◽

Left Ventricular ◽

Ventricular Contractility ◽

End Diastolic Volume ◽

Chronic Pulmonary Hypertension ◽

Blood Pressures ◽

The Right

Abstract Background Pulmonary hypertension is a significant risk factor in patients undergoing surgery. The combined effects of general anaesthesia and positive pressure ventilation can aggravate this condition and cause increased pulmonary blood pressures, reduced systemic blood pressures and ventricular contractility. Although perioperative use of inotropic support or vasopressors is almost mandatory for these patients, preference is disputed. In this study, we investigated the effects of norepinephrine and dobutamine and their ability to improve the arterio-ventricular relationship and haemodynamics in pigs suffering from chronic pulmonary hypertension. Method Pulmonary hypertension was induced in five pigs by banding the pulmonary artery at 2–3 weeks of age. Six pigs served as controls. After 16 weeks of pulmonary artery banding, the animals were re-examined under general anaesthesia using biventricular conductance catheters and a pulmonary artery catheter. After baseline measurements, the animals were exposed to both norepinephrine and dobutamine infusions in incremental doses, with a stabilising period in between the infusions. The hypothesis of differences between norepinephrine and dobutamine with incremental doses was tested using repeated two-way ANOVA and Bonferroni multiple comparisons post-test. Results At baseline, pulmonary artery-banded animals had increased right ventricular pressure (+ 39%, p = 0.04), lower cardiac index (− 23% p = 0.04), lower systolic blood pressure (− 13%, p = 0.02) and reduced left ventricular end-diastolic volume (− 33%, p = 0.02). When incremental doses of norepinephrine and dobutamine were administered, the right ventricular arterio-ventricular coupling was improved only by dobutamine (p < 0.05). Norepinephrine increased both left ventricular end-diastolic volume and left ventricular contractility to a greater extent (p < 0.05) in pulmonary artery-banded animals. While the cardiac index was improved equally by norepinephrine and dobutamine treatments in pulmonary artery-banded animals, norepinephrine had a significantly greater effect on mean arterial pressure (p < 0.05) and diastolic arterial pressure (p < 0.05). Conclusion While norepinephrine and dobutamine improved cardiac index equally, it was obtained in different manners. Dobutamine significantly improved the right ventricular function and the arterio-ventricular coupling. Norepinephrine increased systemic resistance, thereby improving arterial pressures and left ventricular systolic function by maintaining left ventricular end-diastolic volume.

Download Full-text