scholarly journals THE INTRINSIC PROPERTIES OF AN IN SITU PERFUSED CROCODILE HEART

1994 ◽  
Vol 186 (1) ◽  
pp. 269-288 ◽  
Author(s):  
C. Franklin ◽  
M. Axelsson
Keyword(s):  
Pulmonary Artery ◽  
Stroke Volume ◽  
Right Ventricular ◽  
Filling Pressure ◽  
Perfused Heart ◽  
Output Pressure ◽  
Heart Preparation ◽  
Left And Right ◽  
The Right

An in situ perfused crocodile (Crocodylus porosus) heart preparation was developed to investigate the effects of input and output pressure on cardiac dynamics and to determine the conditions that lead to a right-to-left cardiac shunt. The pericardium was kept intact, both the left and right atria were perfused and all three outflow tracts (right aortic, left aortic and pulmonary) were cannulated, enabling pressures and flows to be monitored. The perfused heart preparation had an intrinsic heart rate of 34 beats min-1 and generated a physiological power output. Both the left and right sides of the heart were sensitive to filling pressure. Increasing the filling pressure to both atria resulted in an increase in stroke volume and cardiac output (Frank­Starling effect). Increasing the filling pressure to the right atrium also had a positive chronotropic effect. Large right ventricular stroke volumes initiated a right-to-left shunt, despite the left aorta having a pressure 1.5 kPa higher than the pulmonary output pressure. The left ventricle was able to maintain its output and stroke volume up to an output pressure of approximately 8 kPa. However, the right ventricle was significantly weaker. Right ventricular output and stroke volume showed a marked decrease when the output pressure was increased above 5 kPa. A right-to-left shunt occurred when pulmonary output pressure was increased. Surprisingly, a shunt occurred into the left aorta before the pressure in the pulmonary artery became greater than that in the left aorta. Once the pressure in the pulmonary artery exceeded the left aortic pressure, pulmonary artery flow ceased and right ventricular output was solely via the left aorta. A right-to-left shunt could also be initiated by increasing the filling pressure to the left atrium.

scholarly journals The role of the pericardium and the effects of adrenaline and changes in oxygen tension on the performance of an in situ perfused crocodile heart

1995 ◽  
Vol 198 (12) ◽  
pp. 2509-2518 ◽  
Author(s):  
M Axelsson ◽  
C Franklin
Keyword(s):  
Heart Rate ◽  
Oxygen Tension ◽  
Adrenergic Stimulation ◽  
Perfused Heart ◽  
Output Pressure ◽  
Before And After ◽  
Heart Preparation ◽  
The Right ◽  
Power Curves

An in situ perfused crocodile (Crocodylus porosus) heart preparation was used to examine the mechanical responses of the heart to increases in adrenaline concentration, to a decrease in oxygen tension and to opening of the pericardium. Starling and power curves were constructed before and after these experimental manipulations. Increasing adrenaline concentration in the perfusate from 5 nmol l-1 to 0.5 µmol l-1 produced a significant increase in heart rate and a decrease in stroke volume, leaving cardiac output unchanged. With maximal adrenergic stimulation, the left ventricle was able to generate greater power outputs at high right aortic output pressures; however, the right ventricle showed a decrease in performance with increasing output pressure. Decreasing the PO2 of the perfusate to 10 kPa resulted in a significant bradycardia. Both the flow and pressure-generating capabilities of the perfused heart preparation were reduced, although the heart was able to maintain low work levels at this PO2. Opening the pericardium permitted greater movement/expansion of the cardiac chambers and resulted in an increase in heart rate. Higher flows were generated at low filling pressures during the input pressure challenge as a result of an increase in the sensitivity of the Starling response.

Dimensional analysis of right and left ventricles during positive-pressure ventilation in dogs

1982 ◽  
Vol 242 (4) ◽  
pp. H549-H556 ◽  
Author(s):  
S. S. Cassidy ◽  
J. H. Mitchell ◽  
R. L. Johnson
Keyword(s):  
Left Ventricle ◽  
Stroke Volume ◽  
Right Ventricular ◽  
Left Ventricular ◽  
Left Ventricular Volumes ◽  
Ventricular Volumes ◽  
End Diastolic Volume ◽  
Left And Right ◽  
The Right ◽  
Ventricular Dimensions

Our purpose was to determine the effects of controlled ventilation with positive end-expired pressure (PEEP) on ventricular dimensions and to relate changes in shape to changes in stroke volume and left ventricular volumes. Left and right ventricular dimensions were measured using biplane cinefluorography of dogs with radiopaque markers implanted in their hearts, and left ventricular volumes were derived from left ventricular dimensions by assuming that the left ventricle conformed to the shape of a nonprolate ellipsoid. As PEEP increased from 0 to 5, 10, and 15 cmH2O, stroke volume fell 36%, and all three left ventricular end-diastolic dimensions fell, with apex-base falling 5%, anterior-posterior falling 7%, and septal-lateral falling nearly twice as much, 12%. This resulted in a 11.3 cm3 fall in left ventricular end-diastolic volume. The right ventricular end-diastolic dimensions changed in opposite directions with respect to each other as the level and PEEP was raised to 15 cmH2O; one axis fell 3.2 mm, and the midpoint of the right ventricular free wall moved outward by 1.7 mm. Thus the fall in cardiac output (and stroke volume) during PEEP was associated with a fall in left ventricular end-diastolic volume and a change both left and right ventricular configurations. It is not known whether the left ventricular septal-lateral narrowing is the consequence of lateral wall compression by the lungs or encroachment on the left ventricle by the septum.

scholarly journals EXPRESS: Chronic thromboembolic pulmonary hypertension following pulmonary embolism with a right ventricular thrombus: A report of two cases

2021 ◽  
pp. 204589402110136
Author(s):  
Tailong Zhang ◽  
Weitao Liang ◽  
Longrong Bian ◽  
Zhong Wu
Keyword(s):  
Pulmonary Hypertension ◽  
Right Ventricular ◽  
Chronic Thromboembolic Pulmonary Hypertension ◽  
Imaging Features ◽  
Pulmonary Endarterectomy ◽  
Right Heart ◽  
Thromboembolic Pulmonary Hypertension ◽  
The Right ◽  
Cardiac Masses

Right heart thrombus (RHT) accompanied by chronic thromboembolic pulmonary hypertension (CTEPH) is a rare entity. RHT may develop in the peripheral veins or in situ within the right heart chambers. The diagnosis of RHT is challenging, since its symptoms are typically non-specific and its imaging features resemble those of cardiac masses. Here, we report two cases of RHT with CTEPH that presented as right ventricular masses initially. Both patients underwent simultaneous pulmonary endarterectomy (PEA) and resection of the ventricular thrombi. Thus, when mass-like features are confirmed by imaging, RHT should be suspected in patients with CTEPH, and simultaneous RHT resection is required along with PEA.

Abstract 3143: Reverse Hemodynamic Remodelling May Be Possible Over Time

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Lynne W Stevenson ◽  
Yong K Cho ◽  
J. T Heywood ◽  
Robert C Bourge ◽  
William T Abraham ◽  
...  
Keyword(s):  
Heart Failure ◽  
Chronic Heart Failure ◽  
Pulmonary Artery ◽  
Right Ventricular ◽  
Nyha Class ◽  
Systolic Pressure ◽  
Filling Pressure ◽  
Class Iii ◽  
One Year ◽  
Over Time

Introduction : Elevated filling pressures are a hallmark of chronic heart failure. They can be reduced acutely during HF hospitalization but the hemodynamic impact of ongoing therapy to maintain optivolemia has not been established. Methods and Results : After recent HF hospitalization, 274 NYHA Class III or IV HF patients were enrolled in the COMPASS-HF study at 28 experienced HF centers and received intense HF management (average 24.7 staff contacts/ 6 months) ± access to filling pressure information to adjust diuretics to maintain optivolemia, usually defined as estimated pulmonary artery diastolic (PAD) pressure of 12±4 mmHg. Filling pressure information was available for half the patients during the first 6 months (the Chronicle group, <Access), and for all patients during the next 6 months. Diuretics were adjusted 12.7 times per patient in the Chronicle group and 8.2 times per patient in the Control (-Access) group during the first 6 months (p = 0.0001). Compared to baseline, decreases in RV systolic pressure (RVSP) and ePAD were significant for the +Access patients by one year (p=0.0012 and p =.04, respectively). The Control patients exhibited a similar trend 6 months after crossing to +Access (figure ). Conclusions: Targeted therapeutic adjustments, based on continuous filling pressures along with intensification of HF management contacts, are associated with a reduction in chronic left-sided filling pressures and right ventricular load.

scholarly journals Metastatic adenocarcinoma involving the right ventricle and pulmonary artery leading to right heart failure: case report

2017 ◽  
Vol 136 (3) ◽  
pp. 262-265 ◽  
Author(s):  
Turgut Karabag ◽  
Caner Arslan ◽  
Turab Yakisan ◽  
Aziz Vatan ◽  
Duygu Sak
Keyword(s):  
Heart Failure ◽  
Case Report ◽  
Pulmonary Artery ◽  
Right Ventricle ◽  
Right Ventricular ◽  
Right Ventricular Outflow Tract ◽  
Right Heart Failure ◽  
Ventricular Outflow Tract ◽  
Right Heart ◽  
The Right

ABSTRACT CONTEXT: Obstruction of the right ventricular outflow tract due to metastatic disease is rare. Clinical recognition of cardiac metastatic tumors is rare and continues to present a diagnostic and therapeutic challenge. CASE REPORT: We present the case of a patient who had severe respiratory insufficiency and whose clinical examinations revealed a giant tumor mass extending from the right ventricle to the pulmonary artery. We discuss the diagnostic and therapeutic options. CONCLUSION: In patients presenting with acute right heart failure, right ventricular masses should be kept in mind. Transthoracic echocardiography appears to be the most easily available, noninvasive, cost-effective and useful technique in making the differential diagnosis.

scholarly journals The Association Between Notching of the Right Ventricular Outflow Tract Flow Velocity Doppler Envelope and Impaired Right Ventricular Function After Acute High-Altitude Exposure

2021 ◽  
Vol 12 ◽  
Author(s):  
Fangzhengyuan Yuan ◽  
Chuan Liu ◽  
Shiyong Yu ◽  
Shizhu Bian ◽  
Jie Yang ◽  
...  
Keyword(s):  
Pulmonary Artery ◽  
Right Ventricular ◽  
Flow Velocity ◽  
Healthy Subjects ◽  
Right Ventricular Outflow Tract ◽  
Ventricular Outflow Tract ◽  
Tricuspid Annulus ◽  
Doppler Flow ◽  
The Right ◽  
Rv Function

IntroductionPulmonary artery pressure (PAP) is increased and right ventricular (RV) function is well preserved in healthy subjects upon exposure to high altitude (HA). An increase in PAP may trigger notching of the right ventricular outflow tract Doppler flow velocity envelope (RVOT notch), which is associated with impaired RV function in patients with pulmonary hypertension. However, whether HA exposure can induce RVOT notch formation and the subsequent impact on cardiac function in healthy subjects remains unclear.MethodsA total of 99 subjects (69 males and 30 females) with a median age of 25 years were enrolled in this study; they traveled from 500 to 4100 m by bus over a 2-day period. All subjects underwent a comprehensive physiological and echocardiographic examination 1 day before ascension at low altitude and 15 ± 3 h after arrival at HA. The RVOT notch was determined by the presence of a notched shape in the RVOT Doppler flow velocity envelope. The systolic PAP (SPAP) was calculated as Bernoulli equation SPAP = 4 × (maximum tricuspid regurgitation velocity)2+5 and mean PAP (mPAP) = 0.61 × SPAP+2. Cardiac output was calculated as stroke volume × heart rate. Pulmonary capillary wedge pressure (PCWP) was calculated as 1.9+1.24 × mitral E/e’. Pulmonary vascular resistance (PVR) was calculated as (mPAP-PCWP)/CO.ResultsAfter HA exposure, 20 (20.2%) subjects had an RVOT notch [notch (+)], and 79 (79.8%) subjects did not have an RVOT notch [notch (−)]. In the multivariate logistic regression analysis, the SPAP, right ventricular global longitude strain (RV GLS), and tricuspid E/A were independently associated with the RVOT notch. The SPAP, mPAP, PVR, standard deviations of the times to peak systolic strain in the four mid-basal RV segments (RVSD4), peak velocity of the isovolumic contraction period (ICV), and the peak systolic velocity (s’) at the mitral/tricuspid annulus were increased in all subjects. Conversely, the pulse oxygen saturation (SpO2), RV GLS, and tricuspid annulus plane systolic excursion (TAPSE)/SPAP were decreased. However, the increases of SPAP, mPAP, PVR, and RVSD4 and the decreases of SpO2, RV GLS, and TAPSE/SPAP were more pronounced in the notch (+) group than in the notch (−) group. Additionally, increased tricuspid ICV and mitral/tricuspid s’ were found only in the notch (−) group.ConclusionHA exposure-induced RVOT notch formation is associated with impaired RV function, including no increase in the tricuspid ICV or s’, reduction of RV deformation, deterioration in RV-pulmonary artery coupling, and RV intraventricular synchrony.

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