Development of a circulatory mock loop for biventricular device testing with various heart conditions

2020 ◽  
Vol 43 (9) ◽  
pp. 600-605 ◽  
Author(s):  
Yuichiro Kado ◽  
Takuma Miyamoto ◽  
David J Horvath ◽  
Shengqiang Gao ◽  
Kiyotaka Fukamachi ◽  
...  
Keyword(s):  
Heart Failure ◽  
Pulmonary Artery ◽  
Pulmonary Artery Pressure ◽  
Left Atrial ◽  
Aortic Pressure ◽  
Atrial Pressure ◽  
Left Atrial Pressure ◽  
Right Atrial ◽  
Right Atrial Pressure ◽  
Artery Pressure

This study aimed to evaluate a newly designed circulatory mock loop intended to model cardiac and circulatory hemodynamics for mechanical circulatory support device testing. The mock loop was built with dedicated ports suitable for attaching assist devices in various configurations. This biventricular mock loop uses two pneumatic pumps (Abiomed AB5000™, Danvers, MA, USA) driven by a dual-output driver (Thoratec Model 2600, Pleasanton, CA, USA). The drive pressures can be individually modified to simulate a healthy heart and left and/or right heart failure conditions, and variable compliance and fluid volume allow for additional customization. The loop output for a healthy heart was tested at 4.2 L/min with left and right atrial pressures of 1 and 5 mm Hg, respectively; a mean aortic pressure of 93 mm Hg; and pulmonary artery pressure of 17 mm Hg. Under conditions of left heart failure, these values were reduced to 2.1 L/min output, left atrial pressure = 28 mm Hg, right atrial pressure = 3 mm Hg, aortic pressure = 58 mm Hg, and pulmonary artery pressure = 35 mm Hg. Right heart failure resulted in the reverse balance: left atrial pressure = 0 mm Hg, right atrial pressure = 30 mm Hg, aortic pressure = 100 mm Hg, and pulmonary artery pressure = 13 mm Hg with a flow of 3.9 L/min. For biventricular heart failure, flow was decreased to 1.6 L/min, left atrial pressure = 13 mm Hg, right atrial pressure = 13 mm Hg, aortic pressure = 52 mm Hg, and pulmonary artery pressure = 18 mm Hg. This mock loop could become a reliable bench tool to simulate a range of heart failure conditions.

scholarly journals Accuracy and Diagnostic Performance of Doppler Echocardiography to Estimate Mean Pulmonary Artery Pressure in Heart Failure

2021 ◽  
Author(s):  
Alva Bjorkman ◽  
Lars H. Lund ◽  
Ulrika Faxen ◽  
Per Lindqvist ◽  
Ashwin Venkateshvaran
Keyword(s):  
Heart Failure ◽  
Pulmonary Artery ◽  
Pulmonary Artery Pressure ◽  
Doppler Echocardiography ◽  
Diagnostic Performance ◽  
Atrial Pressure ◽  
Right Atrial ◽  
Right Atrial Pressure ◽  
Artery Pressure ◽  
Strong Ability

BACKGROUND. Multiple Doppler Echocardiography (DE) algorithms have been proposed to estimate mean pulmonary artery pressure (PAP) and assess pulmonary hypertension (PH) likelihood. We assessed the accuracy of 4 different DE approaches to estimate PAP in patients with heart failure (HF) undergoing near-simultaneous right heart catheterization (RHC), and compared their diagnostic performance to identify PH with recommendation-advised tricuspid regurgitation peak velocity (TRV). METHODS. PAP was retrospectively assessed in 112 HF patients employing 4 previously validated DE algorithms. Association and agreement with invasive PAP were assessed. Diagnostic performance of DE methods vs. TRV=2.8m/sec to identify invasive PAP ≥ 25mmHg were compared. RESULTS. All DE algorithms demonstrated reasonable association (r = 0.41 to 0.65; p<0.001) and good agreement with invasive PAP, with relatively lower mean bias and higher precision observed in algorithms that included TRV or velocity time integral. All methods demonstrated strong ability (AUC=0.70-0.80; p<0.001) to identify PH but did not outperform TRV (AUC=0.84; p<0.001). Echocardiographic estimates of right atrial pressure were considered in 3 of 4 DE algorithms and falsely elevated in as many as 30% of patients. CONCLUSIONS. Echocardiographic estimates of PAP demonstrate reasonable accuracy to represent invasive PAP and strong ability to identify PH in HF. However, even the best performing algorithm did not outperform recommendation-advised TRV. The additional value of echocardiographic estimates of right atrial pressure may need to be re-evaluated.

scholarly journals Per-operative Changes of Pulmonary Artery Pressure following Closed Mitral Commissurotomy

2019 ◽  
Vol 11 (2) ◽  
pp. 147-151
Author(s):  
Muhammed Abdul Quaium Chowdhury ◽  
Mohammad Fazle Maruf ◽  
Minhazur Rahman ◽  
Subir Barua ◽  
Mamunur Rahman ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Pulmonary Artery ◽  
Pulmonary Artery Pressure ◽  
Mitral Stenosis ◽  
Left Atrial ◽  
Atrial Pressure ◽  
Left Atrial Pressure ◽  
Artery Pressure ◽  
Mitral Commissurotomy ◽  
Closed Mitral Commissurotomy

Background: Mitral stenosis is often present with pulmonary hypertension. Closed Mitral Commissurotomy (CMC) is a treatment of choice for severe mitral stenosis. In this study, we examined the per-operative changes of pulmonary artery pressure following opening of stenosed mitral valve. Methods: All these CMCs were performed routinely through the left antero-lateral thoracotomy (4th intercostal space) and dilatation was done by metallic Tubb’s Dilator. Peroperative left atrial and Pulminary Arterial pressures were measured before and after dilatation. Results: 15 patients had undergone CMC. Following CMC, per-operative mean Pulmonary artery pressure was reduced from 45.5±7.1 mm of Hg to 39.0±8.8 mm of Hg (p=0.043). Mean left atrial pressure reduced from 35.9±5.6 mm of Hg to 30.0±9.1 mm of Hg (p = 0.049). At three months follow up after closed mitral commissurotomy mitral valve area at echocardiography was found 2.29±0.18 cm2. There was no case of death after closed mitral commissurotomy. Mild mitral regurgitation occurred in 1 patient. Conclusion: We conclude that there is immediate significant reduction of pulmonary Artery pressure following closed mitral commissurotomy. This reduction is apparently comparable with a similar reduction of left atrial pressure. Cardiovasc. j. 2019; 11(2): 147-151

Effect of diaphragm contraction on canine heart and pericardium

1983 ◽  
Vol 54 (5) ◽  
pp. 1261-1268 ◽  
Author(s):  
T. C. Lloyd ◽  
J. A. Cooper
Keyword(s):  
Cardiac Output ◽  
Left Atrial ◽  
Servo Control ◽  
Atrial Pressure ◽  
Left Atrial Pressure ◽  
Right Atrial ◽  
Right Atrial Pressure ◽  
Abdominal Pressure ◽  
Canine Heart ◽  
Pressure Changes

Pericardiophrenic attachments transmit diaphragm contraction to the pericardium. We investigated this in two ways. 1) We replaced the hearts of externally perfused dogs with a balloon from which we measured pressure changes. Diaphragm contraction increased pressure from 4.6 to 5.5 Torr, equivalent to an isobaric volume decrease of 1.5%, and decreased volumetric compliance by 3%. 2) We selectively servo controlled right atrial pressure, left atrial pressure, or cardiac output in open-chest dogs and monitored the effect of diaphragm contraction on cardiovascular and abdominal pressures, cardiac output, and the volume of blood added to or withdrawn from the circulation to achieve servo control. Diaphragm contraction decreased left atrial pressure 0.4 Torr when right atrial pressure was controlled and right atrial pressure increased 0.2 Torr while controlling left atrial pressure, but there were no significant changes in cardiac output. Atrial pressure did not change significantly when output was controlled. Servo control required removal of approximately 50 ml of blood, presumably reflecting a decreased splanchnic vascular capacity at the higher abdominal pressure. We conclude that the diaphragm may slightly tense the pericardium, but this has no important primary effect on the heart.

Correlation of Limb Bioimpedance to Echocardiographic Indicators of Congestion in Patients with NYHA Class II/III Heart Failure (Preprint)

2018 ◽  
Author(s):  
Andrew Accardi ◽  
Thomas Heywood ◽  
Anne Daleiden-Burns
Keyword(s):  
Heart Failure ◽  
Pulmonary Artery ◽  
Fluid Overload ◽  
Nyha Class ◽  
Systolic Pressure ◽  
Class Ii ◽  
Atrial Pressure ◽  
Right Atrial ◽  
Right Atrial Pressure ◽  
Pulmonary Artery Systolic Pressure

BACKGROUND The treatment of heart failure (HF) in the United States is estimated to exceed $30 billion each year and is anticipated to increase to a staggering $70 billion by the year 2030. This makes the management of HF one of the leading challenges Medicare will face in the years to come. Traditional methods to detect impending congestion such as body weight and physical examination findings are often non-specific and lack sensitivity making them inadequate to recognize fluid overload and prevent decompensation. It has been suggested that bioimpedance spectroscopy (BIS) can be used as a surrogate marker for detecting fluid overload and therefore, serve as an adjunct to clinical exam findings. OBJECTIVE This study examines the relationship between a BIS device and echocardiographic parameters associated with volume overload with same day measurements in the first 8 patients with NYHA Class II/III HF on an IRB approved protocol. METHODS Each patient was followed 3 times a week for 4 weeks within the hospital outpatient setting. At each visit BIS measures were recorded for whole body as well as arms and legs. Additionally, signs and symptoms, weight and echocardiograph findings were all recorded. RESULTS Correlations of BIS measurements with echo parameters were performed. The leg impedance measurement correlated strongly with echo findings; inferior vena cava (IVC) size (p=0.001), right atrial pressure (RAP) (p<0.001), and pulmonary artery systolic pressure (PAS) measurements (p<0.001). CONCLUSIONS Preliminary findings demonstrated excellent correlations with BIS measurements and IVC size, right atrial pressure and pulmonary artery systolic pressure measurements which suggest a possible alternative method to detect fluid overload despite the small sample size. Trending a patient's impedance using the SOZO device at home or the practitioner's office may assist clinicians in providing more accurate, individualized HF care.  CLINICALTRIAL . IRB approval was obtained for this study (Scripps IRB #IRB-16-6852).

scholarly journals Continuous cardiac output and left atrial pressure monitoring by long time interval analysis of the pulmonary artery pressure waveform: proof of concept in dogs

2009 ◽  
Vol 106 (2) ◽  
pp. 651-661 ◽  
Author(s):  
Da Xu ◽  
N. Bari Olivier ◽  
Ramakrishna Mukkamala
Keyword(s):  
Cardiac Output ◽  
Pulmonary Artery ◽  
Pulmonary Artery Pressure ◽  
Exponential Decay ◽  
Left Atrial ◽  
Atrial Pressure ◽  
Left Atrial Pressure ◽  
Inertial Effects ◽  
Wave Reflections ◽  
Equilibrium Pressure

We developed a technique to continuously (i.e., automatically) monitor cardiac output (CO) and left atrial pressure (LAP) by mathematical analysis of the pulmonary artery pressure (PAP) waveform. The technique is unique to the few previous related techniques in that it jointly estimates the two hemodynamic variables and analyzes the PAP waveform over time scales greater than a cardiac cycle wherein wave reflections and inertial effects cease to be major factors. First, a 6-min PAP waveform segment is analyzed so as to determine the pure exponential decay and equilibrium pressure that would eventually result if cardiac activity suddenly ceased (i.e., after the confounding wave reflections and inertial effects vanish). Then, the time constant of this exponential decay is computed and assumed to be proportional to the average pulmonary arterial resistance according to a Windkessel model, while the equilibrium pressure is regarded as average LAP. Finally, average proportional CO is determined similar to invoking Ohm's law and readily calibrated with one thermodilution measurement. To evaluate the technique, we performed experiments in five dogs in which the PAP waveform and accurate, but highly invasive, aortic flow probe CO and LAP catheter measurements were simultaneously recorded during common hemodynamic interventions. Our results showed overall calibrated CO and absolute LAP root-mean-squared errors of 15.2% and 1.7 mmHg, respectively. For comparison, the root-mean-squared error of classic end-diastolic PAP estimates of LAP was 4.7 mmHg. On future successful human testing, the technique may potentially be employed for continuous hemodynamic monitoring in critically ill patients with pulmonary artery catheters.

scholarly journals Acute and Long-Term Hemodynamic Effects of MitraClip Implantation on a Preexisting Secondary Right Heart Failure

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
M. Hünlich ◽  
E. Lubos ◽  
B. E. Beuthner ◽  
M. Puls ◽  
A. Bleckmann ◽  
...  
Keyword(s):  
Heart Failure ◽  
Pulmonary Hypertension ◽  
Pulmonary Artery ◽  
Pulmonary Artery Pressure ◽  
Tricuspid Regurgitation ◽  
Right Heart Failure ◽  
Right Atrial ◽  
Right Heart ◽  
Artery Pressure

Positive results of MitraClip in terms of improvement in clinical and left ventricular parameters have been described in detail. However, long-term effects on secondary pulmonary hypertension were not investigated in a larger patient cohort to date. 70 patients with severe mitral regurgitation, additional pulmonary hypertension, and right heart failure as a result of left heart disease were treated in the heart centers Hamburg and Göttingen. Immediately after successful MitraClip implantation, a reduction of the RVOT diameter from 3.52 cm to 3.44 cm was observed reaching a statistically significant value of 3.39 cm after 12 months. In contrast, there was a significant reduction in the velocity of the tricuspid regurgitation (TR) from 4.17 m/s to 3.11 m/s, the gradient of the TR from 48.5 mmHg to 39.3 mmHg, and the systolic pulmonary artery pressure (PAPsyst) from 58.6 mmHg to 50.0 mmHg. This decline continued in the following months (Vmax TR 3.09 m/s, peak TR 38.6 mmHg, and PAPsyst 47.4 mmHg). The tricuspid annular plane systolic excursion (TAPSE) increased from 16.5 mm to 18.9 mm after 12 months. MitraClip implantation improves pulmonary artery pressure, tricuspid regurgitation, and TAPSE after 12 months. At the same time, there is a decrease in the RVOT diameter without significant changes in other right ventricular and right atrial dimensions.

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