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1.
Ultrasound Med Biol ; 49(2): 473-488, 2023 02.
Article in English | MEDLINE | ID: mdl-36335055

ABSTRACT

Arterial pulse waves contain clinically useful information about cardiac performance, arterial stiffness and vessel tone. Here we describe a novel method for non-invasively assessing wave properties, based on measuring changes in blood flow velocity and arterial wall diameter during the cardiac cycle. Velocity and diameter were determined by tracking speckles in successive B-mode images acquired with an ultrafast scanner and plane-wave transmission. Blood speckle was separated from tissue by singular value decomposition and processed to correct biases in ultrasound imaging velocimetry. Results obtained in the rabbit aorta were compared with a conventional analysis based on blood velocity and pressure, employing measurements obtained with a clinical intra-arterial catheter system. This system had a poorer frequency response and greater lags but the pattern of net forward-traveling and backward-traveling waves was consistent between the two methods. Errors in wave speed were also similar in magnitude, and comparable reductions in wave intensity and delays in wave arrival were detected during ventricular dysfunction. The non-invasive method was applied to the carotid artery of a healthy human participant and gave a wave speed and patterns of wave intensity consistent with earlier measurements. The new system may have clinical utility in screening for heart failure.


Subject(s)
Carotid Arteries , Ventricular Dysfunction , Animals , Humans , Rabbits , Ultrasonography/methods , Blood Flow Velocity , Carotid Arteries/diagnostic imaging , Carotid Artery, Common , Blood Pressure , Pulse Wave Analysis
2.
Ann Cardiothorac Surg ; 10(3): 329-338, 2021 May.
Article in English | MEDLINE | ID: mdl-34159114

ABSTRACT

The success of ventricular assist devices (VADs) in the treatment of end-stage heart failure in the adult population has led to industrial innovation in VAD design, focusing on miniaturization and the reduction of complications. A byproduct of these innovations was that newer generation devices could have clinical applications in the pediatric population. Over the last decade, VAD usage in the pediatric population has increased dramatically, and the newer generation continuous flow (CF) devices have begun to supplant the older, pulsatile flow (PF) devices, formerly the sole option for ventricular assist in the pediatric population. However, despite the increase in VAD implants in the pediatric population, patient numbers remain low, and the need to share data between pediatric VAD centers has become that much more important for the continued growth of VAD programs worldwide. The creation of pediatric VAD registries, such as the Pediatric Registry for Mechanical Circulatory Support (PediMACS), the European Registry for Patients with Mechanical Circulatory Support (EUROMACS) and the Advanced Cardiac Therapies Improving Outcomes Network (ACTION) has enabled the collection of aggregate data from VAD centers worldwide, and provides a valuable resource for clinicians and programs, as more and more pediatric heart failure patients are considered candidates for VAD therapy.

3.
Oxf Med Case Reports ; 2021(2): omaa140, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33614050

ABSTRACT

Aorto-oesophageal fistula (AEF) is rare and fatal without intervention. Having consumed a date pit 2 weeks prior, the patient in this case presented with the 'Chiari' triad of chest pain, sentinel arterial upper gastro-intestinal haemorrhage and exsanguination after an asymptomatic interval. Following resuscitation, the patient was managed with a Blakemore tube with both oesophageal and gastric balloons inflated to systemic pressures. An aortic stent graft was planned but the patient died on the operating table. AEFs can be treated surgically with either open or endovascular repair. Open repair is highly risky and involves combined replacement/bypass of the thoracic aorta along with resection/repair of the involved oesophagus. Endovascular repair can prevent fatal exsanguination and increase the likelihood of survival but is associated with a significant rate of secondary infection, recurrence of fistula, mediastinitis and sepsis. Further studies are required to inform on management.

4.
J Thorac Cardiovasc Surg ; 147(5): 1524-8, 2014 May.
Article in English | MEDLINE | ID: mdl-23856199

ABSTRACT

OBJECTIVE: This study was performed to assess the Society of Thoracic Surgeons (STS) score as a measure of successful adoption of transapical transcatheter aortic valve implantation (TAVI). METHODS: The STS score for estimated surgical mortality was calculated and used to select the first 140 consecutive patients undergoing transapical TAVI. The STS score also was used to estimate postoperative morbidity. The comparisons were made between the observed and estimated mortality and morbidity in the entire group, as well as in the first 35, second 35, and last 70 consecutive patients. RESULTS: The differences in outcomes between the first 35, second 35, and last 70 patients were statistically significant for surgical mortality (20.0% vs 14.3% vs 2.9%; P = .045), composite morbidity/mortality (34.3% vs 40.1% vs 15.7%; P = .020), and long length of stay (34.3% vs 45.7% vs 18.6%; P = .027). There were trends of marked decreases in prolonged ventilation (11.4% vs 20.0% vs 4.3%; P = .061), and acute renal failure (14.3% vs 20.0% vs 4.3%; P = .059). In the first 70 patients there were no significant differences between observed and STS estimated incidences in mortality and composite mortality/major morbidity. In the latter 70 patients the observed incidences were lower than STS predicted values in mortality (2.9% vs 9.6%; P = .056), composite major morbidity/mortality (15.7% vs 33.8%; P = .001), and prolonged ventilation (4.3% vs 25.1%; P < .0001). CONCLUSIONS: Only after a protracted learning curve did the anticipated benefits of transapical TAVI materialize for patients at high risk for surgery as predicted by the STS risk algorithms.


Subject(s)
Algorithms , Aortic Valve Stenosis/therapy , Cardiac Catheterization/adverse effects , Heart Valve Prosthesis Implantation/adverse effects , Quality Indicators, Health Care , Acute Kidney Injury/etiology , Acute Kidney Injury/therapy , Aged , Aged, 80 and over , Aortic Valve Stenosis/diagnosis , Aortic Valve Stenosis/mortality , Aortic Valve Stenosis/physiopathology , Cardiac Catheterization/instrumentation , Clinical Competence , Decision Support Techniques , Female , Heart Valve Prosthesis Implantation/methods , Heart Valve Prosthesis Implantation/mortality , Humans , Learning Curve , Length of Stay , Male , Patient Selection , Respiration, Artificial , Risk Assessment , Risk Factors , Time Factors , Treatment Outcome
5.
J Card Surg ; 28(3): 298-300, 2013 May.
Article in English | MEDLINE | ID: mdl-23445403

ABSTRACT

A repeat Bentall procedure or a Bentall procedure in an immobile aortic root such as a prior homograft that has calcified can be problematic. Separating the valve from the conduit and with a modified elephant trunk concept we have simplified the proximal graft anastomosis using a running suture technique. This is followed by coronary ostia implantation and then by lowering the aortic valve onto the aortic annulus using a running suture technique.


Subject(s)
Anastomosis, Surgical/methods , Aorta/surgery , Aortic Aneurysm, Thoracic/surgery , Aortic Valve/surgery , Blood Vessel Prosthesis Implantation/methods , Coronary Vessels/surgery , Heart Valve Prosthesis Implantation/methods , Polyethylene Terephthalates , Sinus of Valsalva/surgery , Suture Techniques
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