Prosthetic Valve Function Research Articles

Development of a Multi-modality Compatible Flow Loop System for the Functional Assessment of Mitral Valve Prostheses

We sought to build a robust pulsatile flow model permitting comparison of 3D Color Doppler and phase contrast magnetic resonance (PCMR) flow and orifice area measurements of prosthetic valve function that would provide an in vitro gold standard for evaluation of the accuracy of new imaging techniques. A multi-modality compatible, pulsatile linear actuation system, control software, and mock circulation loop was designed and created using non-ferromagnetic components, NI Labview, and rapid prototyping. The developed system’s ability to create pulsatile, controlled flow was assessed by examining peak diastolic flow, diastolic period, and diastolic flow volume (DFV) of 12 consecutive cardiac cycles at 3 different DFVs. Reproducibility of flow was tested by examining the systems ability to generate the same target DFV after draining and re-configuring the flow loop components. Furthermore, the system was evaluated by CMR and echocardiography to examine image quality, DFV quantification, and an initial functional assessment of prosthetic mitral valve (MV) orifice area by four different imaging methods. The system was able to reproducibly create prescribed flow volumes across 31 mm bioprosthetic and mechanical MV’s under a range of flow conditions. In vitro image quality for the identification of MV sewing ring, struts and leaflets was similar to clinical imaging quality for both echocardiographic and MRI methods. For the quantification of DFV, the PCMR method demonstrated an error range of 1.4–9.2% and a mean difference of 4 ± 2 mL/beat compared to the flowmeter reference standard. Across the three flow conditions the bioprosthetic MV diastolic flow area was statistically similar by MRI planimetry, phase contrast MRI planimetry, and 3D color Doppler planimetry methods (mean area 3.2 ± 0.5 cm2, ANOVA, p = NS), but the effective orifice area by 2D spectral Doppler (continuity) method was smaller (mean area 2.0 ± 0.3 cm2, ANOVA, p < 0.001). We describe the development and initial functional testing of a novel MRI-compatible flow loop system for comparison of multimodality imaging techniques to assess prosthetic valve function.

Acute respiratory failure due to giant aortic aneurysm mimicking massive pulmonary embolism in a patient with Marfan’s syndrome

A 41-year-old male with Marfan’s syndrome was admitted to the emergency department with severe dyspnoea. On his medical history, an operation of tube graft interposition to ascending aorta and aortic valve replacement ten years ago was remarkable. On physical examination, respiratory sound was almost inaudible on the left side of the chest. Cardiac auscultation revealed a grade 2/6 systolic murmur on the left 4th to 6th intercostal spaces. His pulse rate was 108 bpm and blood pressures were measured as 112/73 and 124/82 mm Hg in the left and right arm, respectively. The patient’s neck veins were distended. From the analysis of arterial blood gas on 10 L/min oxygen inhalation, pH 7.45, PaCO2 67 mm Hg, PaO2 71 mm Hg, SaO2 80%, and HCO3 – 20.1 mmol/L were obtained. A chest X-ray revealed widening of the mediastinum and collapsed left lung (Fig. 1). Transthoracic echocardiography revealed mitral valve prolapses, moderate degree of mitral regurgitation, normal left ventricular systolic function (LVEF 60%) and normal functioning of prosthetic aortic valve and significant dilatation and dissection of the descending aorta (Fig. 2). Aortic angiography by computed tomography (CTA) displayed the dissection and dilatation of the descending aorta accompanied by a thrombosed false lumen (Fig. 3A). Dissection membrane was extending from the origin of the left subclavian artery to the right iliac artery and was causing the compression of the left lung and right pulmonary artery (Fig. 3B). The patient was intubated and transferred to the intensive care unit. Unfortunately he died because of acutely developed progressive renal failure, cardiac and pulmonary failure complicated by lung infections over the subsequent ten days. In patients with Marfan’s syndrome, the risk of aortic dissection is approximately 1%. Aortic dissection is a tear within the layers of the aortic wall and the separation of them. An aortic aneurysm may present with symptoms of compression due to mass effect to the adjacent organs. Although the thoracic aorta is a close neighbour to the bronchus, pulmonary atelectasis and obstruction of the pulmonary artery due to an aortic aneurysm is uncommon. In our case, a giant thoracic aortic aneurysm had reached a large enough size to cause left sided collapse of the lung. Collapsed pulmonary volume and decreased aeration was complicated by oxygen and carbon dioxide exchange and led to hypercapnia and inability to respiratory compensation of acidosis induced by acute renal failure due to aortic dissection. Also, compression of the contralateral right pulmonary artery reduced the perfusion and aggravated the scenario.

Assessment of prosthetic valve function and para-valvular regurgitation after trans-catheter aortic valve replacement

To review the current literature on prosthetic valve function and para-valvular regurgitation (PVR) after trans-catheter aortic valve replacement (TAVR). TAVR is a new alternative for the treatment of severe aortic stenosis in patients at high risk for surgical aortic valve replacement and nonsurgical candidates. The innovations in three-dimensional trans-esophageal echocardiography have made it an integral part of the TAVR procedure. PVR is more frequent with TAVR than surgical aortic valve replacement and is associated with worse cardiovascular outcomes. Recent publications focus on echocardiographic techniques to better assess the structural components of aortic valve complex, and begin to define the mechanism and risks of PVR after TAVR. Imaging innovations before, during, and after TAVR may lead to improved patient selection, accelerated development of TAVR prostheses, and ultimately a fuller characterization of the performance and potential limitations of a new generation of prosthetic heart valves.

Massive aortic regurgitation in the background of a quadricuspid aortic valve

A 52-year-old woman, with a previous history of hypertension, was admitted to our institution presenting exertional dyspnea. A comprehensive study was performed including a cardiology examination and echocardiography. Transesophageal echocardiography detected a quadricuspid aortic valve with a central severe aortic valve insufficiency. Moreover, a discrete dilation of the aortic root was seen. Left ventricular ejection fraction was in normal range. A computed tomography scan was performed especially to recognize any displacement of the coronary ostia and evaluate the aortic valve (Fig. A). No abnormality of coronary artery origin was confirmed. Surgical treatment was proposed, and the patient underwent open-heart surgery. Quadricuspid valve was confirmed (Fig. B). An aortoplasty to reduce the ascending aorta and a mechanical aortic valve replacement were performed. The postoperative course was favorable, and the patient had an uneventful recovery. Postoperative echocardiography assessment confirmed normal prosthetic aortic valve function and left ventricular ejection fraction. Quadricuspid aortic valve is a rare congenital abnormality, with an estimated incidence of 0.04%. In approximately 80-90% of cases, it is related to an aortic valve dysfunction. Quadricuspid aortic valve is usually associated with additional malformations, mainly related to the origin of coronary arteries. Due to the presence of an additional leaflet, absence or displacement of coronary ostia has been found in 10% of cases. It is of utmost importance to prevent coronary ostia obstruction with valve prosthesis implantation, and to plan myocardial protection during cardiopulmonary bypass. In the presence of prior surgery for congenital aortic valve abnormalities and regardless of patient age, we highlight the necessity to perform a careful evaluation of the coronary anatomy. 780

Evaluation of Prosthetic Valve Function by Platelet Function Analysis and Von Willebrand Factor Indices

AbstractAbstract 1128 BackgroundDysfunctional or mismatched prosthetic heart valves can results in high shear stress related von Willebrand factor (VWF) impairment, and clinical bleeding. This mechanism is similar to that seen in aortic stenosis patients, where gastrointestinal bleeding related to VWF multimer loss is well described (Heyde syndrome). In this study, we compared the results of VWF testing of patients with normally functioning cardiac valve prostheses, dysfunctional prosthetic valves, severe native aortic stenosis, and normal controls. MethodsA total of 75 patients, 31 female and 44 male with a median age of 79.5 years were recruited to this study. Thirty patients had severe aortic stenosis (mean gradient > 40 mm Hg); 39 patients had normally functioning prosthetic valves, 21 aortic (AVR) and 18 mitral valves (MVR); and 6 patients had with dysfunctional valves (4 aortic and 2 mitral). Whole blood and plasma samples were drawn from patients and tested for platelet function analyzer-100 collagen ADP closure time (PFA-CADP), VWF antigen (VWF:Ag), VWF activity by latex immunoassay (VWF:Ltx), VWF multimer analysis and VWF multimer densitometry ratio of large vs medium to low molecular weight multimers (>15 mers/2–15 mers). ResultsThe 6 dysfunctional prosthetic valve patients included patient-prosthesis mismatch (2) and (one each), thrombosed mechanical aortic prosthesis, torn biological aortic prosthesis, severe tissue mitral prosthetic regurgitation, and post-mitral valve repair severe mitral regurgitation. Four of six patients had clinically significant bleeding. Most aortic stenosis and all 6 prosthetic dysfunction patients had abnormal VWF multimers which is rare in normally functioning prostheses and completely absent in normal donors. VWF:Ltx/Ag was lower in AS and MVR than normal. VWF:Ltx/Ag ratio, VWF:multimer ratio and PFA-CADP were all significantly abnormal in patients with dysfunctional prosthetic valve. VWF:multimer ratios in normally functioning prostheses tended to be intermediate between normals and than those of patients with severe AS or prosthetic valve dysfunction (Table).TableNormalsProsthetic DysfunctionAVRMVRSevere ASAbnormal VWF multimers0/216/62/211/1826/30Multimer ratio >15/2–15 mers0.24 ± 0.050.13 ± 0.01*,†0.17 ± 0.02*0.19 ± 0.04*0.13 ± 0.03*,†PFA-100 CADP89 ± 16141 ± 36*,†98 ± 2993 ± 31181 ± 69*,†Ltx/Ag0.96 ± 0.110.71 ± 0.06*,†0.93 ± 0.09‡0.87 ± 0.05*0.87 ± 0.16*,†*p<0.001 vs normals. † p<0.001 vs AVR+MVR. cm=NS vs normal, but p<0.02 vs mitral valve replacement. ConclusionsVWF testing including quantitative von Willebrand multimer analysis and PFA-CADP reliably separate dysfunctional from normally functioning cardiac prostheses, and should be considered in the evaluation of patients with cardiac prostheses, especially those who have clinically significant bleeding. Disclosures:No relevant conflicts of interest to declare.

Updated standardized endpoint definitions for transcatheter aortic valve implantation: the Valve Academic Research Consortium-2 consensus document#

The aim of the current Valvular Academic Research Consortium (VARC)-2 initiative was to revisit the selection and definitions of transcatheter aortic valve implantation (TAVI)- clinical endpoints to make them more suitable to the present and future needs of clinical trials. In addition, this document is intended to expand understanding of patient risk stratification and case selection. A recent study confirmed that VARC definitions have already been incorporated into clinical and research practice and represent a new standard for consistency in reporting clinical outcomes of patients with symptomatic severe aortic stenosis (AS) undergoing TAVI. However, as the clinical experience with this technology has matured and expanded, certain definitions have become unsuitable or ambiguous. Two in-person meetings (held in September 2011 in Washington, DC, USA, and in February 2012 in Rotterdam, The Netherlands) involving VARC study group members, independent experts (including surgeons, interventional and non-interventional cardiologists, imaging specialists, neurologists, geriatric specialists, and clinical trialists), the United States Food and Drug Administration (FDA), and industry representatives, provided much of the substantive discussion from which this VARC-2 consensus manuscript was derived. This document also provides an overview of risk assessment and patient stratification that needed to be considered for accurate patient inclusion in studies. Working groups were assigned to define the following clinical endpoints: mortality, stroke, myocardial infarction, bleeding, acute kidney injury, vascular complications, conduction disturbances & arrhythmias, and a miscellaneous category including relevant complications not previously categorized. Furthermore, comprehensive echocardiographic recommendations are provided for evaluation of prosthetic valve (dys)function. Definitions for quality of life assessments are also reported. These endpoints formed the basis for several recommended composite endpoints. This VARC-2 document has provided further standardization of endpoint definitions for studies evaluating the use of TAVI, which will lead to improved comparability and interpretability of study results, supplying an increasingly growing body of evidence with respect to transcatheter aortic valve implantation and/or surgical aortic valve replacement. This initiative and document can furthermore be used as a model during current endeavors of applying definitions to other transcatheter valve therapies (for example, mitral valve repair).

Updated Standardized Endpoint Definitions for Transcatheter Aortic Valve Implantation: The Valve Academic Research Consortium-2 Consensus Document

The aim of the current Valve Academic Research Consortium (VARC)-2 initiative was to revisit the selection and definitions of transcatheter aortic valve implantation (TAVI) clinical endpoints to make them more suitable to the present and future needs of clinical trials. In addition, this document is intended to expand the understanding of patient risk stratification and case selection.A recent study confirmed that VARC definitions have already been incorporated into clinical and research practice and represent a new standard for consistency in reporting clinical outcomes of patients with symptomatic severe aortic stenosis (AS) undergoing TAVI. However, as the clinical experience with this technology has matured and expanded, certain definitions have become unsuitable or ambiguous.Two in-person meetings (held in September 2011 in Washington, DC, USA, and in February 2012 in Rotterdam, the Netherlands) involving VARC study group members, independent experts (including surgeons, interventional and non-interventional cardiologists, imaging specialists, neurologists, geriatric specialists, and clinical trialists), the US Food and Drug Administration (FDA), and industry representatives, provided much of the substantive discussion from which this VARC-2 consensus manuscript was derived. This document provides an overview of risk assessment and patient stratification that need to be considered for accurate patient inclusion in studies. Working groups were assigned to define the following clinical endpoints: mortality, stroke, myocardial infarction, bleeding complications, acute kidney injury, vascular complications, conduction disturbances and arrhythmias, and a miscellaneous category including relevant complications not previously categorized. Furthermore, comprehensive echocardiography recommendations are provided for the evaluation of prosthetic valve (dys)function. Definitions for the quality of life assessments are also reported. These endpoints formed the basis for several recommended composite endpoints.This VARC-2 document has provided further standardization of endpoint definitions for studies evaluating the use of TAVI, which will lead to improved comparability and interpretability of the study results, supplying an increasingly growing body of evidence with respect to TAVI and/or surgical aortic valve replacement. This initiative and document can furthermore be used as a model during current endeavors of applying definitions to other transcatheter valve therapies (for example, mitral valve repair).

Updated standardized endpoint definitions for transcatheter aortic valve implantation: the Valve Academic Research Consortium-2 consensus document†

The aim of the current Valve Academic Research Consortium (VARC)-2 initiative was to revisit the selection and definitions of transcatheter aortic valve implantation (TAVI)clinical endpoints to make them more suitable to the present and future needs of clinical trials. In addition, this document is intended to expand the understanding of patient risk stratification and case selection. A recent study confirmed that VARC definitions have already been incorporated into clinical and research practice and represent a new standard for consistency in reporting clinical outcomes of patients with symptomatic severe aortic stenosis (AS) undergoing TAVI. However, as the clinical experience with this technology has matured and expanded, certain definitions have become unsuitable or ambiguous. Two in-person meetings (held in September 2011 in Washington, DC, USA, and in February 2012 in Rotterdam, the Netherlands) involving VARC study group members, independent experts (including surgeons, interventional and non-interventional cardiologists, imaging specialists, neurologists, geriatric specialists, and clinical trialists), the US Food and Drug Administration (FDA), and industry representatives, provided much of the substantive discussion from which this VARC-2 consensus manuscript was derived. This document provides an overview of risk assessment and patient stratification that need to be considered for accurate patient inclusion in studies. Working groups were assigned to define the following clinical endpoints: mortality, stroke, myocardial infarction, bleeding complications, acute kidney injury, vascular complications, conduction disturbances and arrhythmias, and a miscellaneous category including relevant complications not previously categorized. Furthermore, comprehensive echocardiographic recommendations are provided for the evaluation of prosthetic valve (dys)function. Definitions for the quality of life assessments are also reported. These endpoints formed the basis for several recommended composite endpoints. This VARC-2 document has provided further standardization of endpoint definitions for studies evaluating the use of TAVI, which will lead to improved comparability and interpretability of the study results, supplying an increasingly growing body of evidence with respect to TAVI and/or surgical aortic valve replacement. This initiative and document can furthermore be used as a model during current endeavours of applying definitions to other transcatheter valve therapies (for example, mitral valve repair).

Updated standardized endpoint definitions for transcatheter aortic valve implantation: the Valve Academic Research Consortium-2 consensus document (VARC-2)

The aim of the current Valve Academic Research Consortium (VARC)-2 initiative was to revisit the selection and definitions of transcatheter aortic valve implantation (TAVI) clinical endpoints to make them more suitable to the present and future needs of clinical trials. In addition, this document is intended to expand the understanding of patient risk stratification and case selection. A recent study confirmed that VARC definitions have already been incorporated into clinical and research practice and represent a new standard for consistency in reporting clinical outcomes of patients with symptomatic severe aortic stenosis (AS) undergoing TAVI. However, as the clinical experience with this technology has matured and expanded, certain definitions have become unsuitable or ambiguous. Two in-person meetings (held in September 2011 in Washington, DC, USA, and in February 2012 in Rotterdam, Netherlands) involving VARC study group members, independent experts (including surgeons, interventional and non-interventional cardiologists, imaging specialists, neurologists, geriatric specialists, and clinical trialists), the US Food and Drug Administration (FDA), and industry representatives, provided much of the substantive discussion from which this VARC-2 consensus manuscript was derived. This document provides an overview of risk assessment and patient stratification that need to be considered for accurate patient inclusion in studies. Working groups were assigned to define the following clinical endpoints: mortality, stroke, myocardial infarction, bleeding complications, acute kidney injury, vascular complications, conduction disturbances and arrhythmias, and a miscellaneous category including relevant complications not previously categorized. Furthermore, comprehensive echocardiographic recommendations are provided for the evaluation of prosthetic valve (dys)function. Definitions for the quality of life assessments are also reported. These endpoints formed the basis for several recommended composite endpoints. This VARC-2 document has provided further standardization of endpoint definitions for studies evaluating the use of TAVI, which will lead to improved comparability and interpretability of the study results, supplying an increasingly growing body of evidence with respect to TAVI and/or surgical aortic valve replacement. This initiative and document can furthermore be used as a model during current endeavours of applying definitions to other transcatheter valve therapies (for example, mitral valve repair).

Tricuspid Valve Repair: Devega’s Tricuspid Annuloplasty in Moderate Secondary Tricuspid Regurgitation

Moderate secondary tricuspid incompetence has variable natural history if left unattended during mitral valve surgery. Recent data suggest progression of the secondary tricuspid incompetence over time.Secondary moderate tricuspid regurgitation in rheumatic mitral valve disease may regress after mitral valve surgery without direct intervention. The present study was done to assess early result of DeVega tricuspid valve annuloplasty amongst those with moderate tricuspid regurgitation due to rheumatic mitral valve disease. Group I(mitral value replacement with tricuspid repair) and group II (mitral value replacement only).The two groups were followed up at three months post-operatively and evaluated for their functional class and echocardiography variables. There were 43 patients who underwent mitral valve replacement with moderate tricuspid regurgitation. 23 underwent mitral valve replacement with tricuspid repair group (Group 1). Most of the patients were women (28/43). The mean age was 31.4 + 14.8 and 25.13 + 9.4 years. Group I had 21(91.3%) and Group II had 17 (85%) in NYHA class III and IV. The pre-operative echocardiographic cardiac left ventricular and left atrial dimensions, Left ventricular function and valve lesions were statistically similar for both groups, except PASP was higher amongst tricuspid repair (Group 1: 38.60 + 12.75 mHg, Group 2: 61.52 + 19.76 mmHg; p equals or less than 0.05). At three month review after surgery, four patients were in NYHA II amongst those without tricuspid repair (Group II), whilst the rest were in NYHA I. Left ventricular dimensions, Left Ventricular function and valve prosthetic valve function were similar between groups. Eleven (47.8%) patients in Group I and only five (25%) of Group II had trace or less TR at the follow-up. This was found to be statistically significant on chi square test (p less than 0.05). There were 7 (16.2%) patients who had persistent moderate TR. Higher PASP and larger LV dimensions at three months were predictive of persistent moderate TR. Mitral valve replacement does decrease the severity of tricuspid regurgitation amongst those with secondary moderate tricuspid regurgitation by at least one grade, but DeVega's annuloplasty confers a better repair result.

Low radiation dose non-contrast cardiac CT: is it of value in the evaluation of mechanical aortic valve

Prosthetic bileaflet mechanical valve function has been traditionally evaluated using echocardiography and fluoroscopy. Multidetector computed tomography (MDCT) is a novel technique for cardiac evaluation. To evaluate bileaflet mechanical aortic valves using a low-milliampere (mA), non-contrast MDCT protocol with a limited scan range. Forty patients with a bileaflet mechanical aortic valve were evaluated using a non-contrast, low-mA, ECG-gated 64 MDCT protocol with a limited scan range. MDCT findings of opening and closing valve angles were correlated to fluoroscopy and echocardiography. Also, the valve visibility was evaluated on MDCT and fluoroscopy according to a 3-point grading scale. The visualization score with the MDCT was significantly superior to the fluoroscopy (3 vs. 2.7). A strong correlation was noted between the opening (r = 0.82) and closing (r = 0.96) valve angles with MDCT and fluoroscopy without a statistically significant difference (P = 0.31 and 0.16, respectively). The mean effective radiation dose of the suggested protocol was 4 ± 0.5 mSv. Five valves were evaluated using transesophageal echocardiography because the valves were difficult to evaluate with transthoracic echocardiography, and all of these valves were evaluated optimally with MDCT. A high-pressure gradient was noted in nine valves, and the MDCT showed that seven of these valves inadequately opened, and two valves opened well, which resulted in patient valve mismatch. Incomplete valve closure was noted in five valves, and the echocardiography showed significant transvalvular regurgitation in all five valves. MDCT can provide a precise measurement of valve function and can potentially evaluate high-pressure gradients and transvalvular regurgitation.

Comprehensive Haemodynamic Description of Prosthetic Valve Function by Transthoracic Echocardiography in 171 Normal Mitral Valve Prostheses

Comprehensive Haemodynamic Description of Prosthetic Valve Function by Transthoracic Echocardiography in 171 Normal Mitral Valve Prostheses

Real Time Triplane Echocardiography in the Assessment of the Functional Area of Prosthetic Aortic Valves: Reliability and Feasibility

Our study is aimed at evaluating the feasibility and reliability of a simple method for the measurement of the functional area of prosthetic aortic valves (EOA). Three-dimensional echocardiography has proven accurate for left ventricular volume, stroke volume, and aortic valve area measurement. We studied the feasibility and reliability of real time simultaneous triplane echocardiography (RT3P) for assessing the EOA with a fast formula based on the principle of continuity equation, in which we replaced Doppler-derived stroke volume (SV) with SV directly measured with RT3P. EOA of prosthetic aortic valves were measured in 23 consecutive patients requiring periodical follow up. EOA was calculated using Doppler continuity equation (DCE) and the RT3P method by replacing Doppler-derived SV with SV measured with real time triplane echocardiography. We compared functional areas obtained with the two methods with the prosthetic area indicated in the manufacturer's specifications and with the mean transprosthetic gradient. Both methods had a good correlation with the area indicated by the manufacturer. RT3P revealed an inverse correlation between functional area and mean gradient that was better than DCE (P = 0.0359). Inter- and intraobserver variability was not different between the two methods. Execution time was significantly shorter for RT3P. RT3P is a simple method that can be performed quite rapidly, and can complement the overall assessment of prosthetic valve function. Further studies can confirm our technique.

Flow Acceleration Time and Ratio of Acceleration Time to Ejection Time for Prosthetic Aortic Valve Function

We sought to evaluate whether ejection dynamics, particularly acceleration time (AT) and the ratio of AT to ejection time (ET), can differentiate prosthetic aortic valve (PAV) stenosis from controls and prosthesis-patient mismatch (PPM). Diagnosing PAV stenosis, especially in mechanical valves, may be challenging and has significant clinical implications. Doppler echocardiography was quantitated in 88 patients with PAV (44 mechanical and 44 bioprosthetic; age 63 ± 16 years; valve size range 18 to 25 mm) of whom 22 patients had documented PAV stenosis, 22 had PPM, and 44 served as controls. Quantitative Doppler parameters included ejection dynamics (AT, ET, and AT/ET) and conventional PAV parameters. Patients with PAV stenosis had significantly lower effective orifice area (EOA) values and higher gradients compared with controls and PPM. Flow ejection parameters (AT and AT/ET) were significantly longer in the stenotic valves compared with PPM and controls (respective values for AT: 120 ± 24 ms, 89 ± 16 ms, and 71 ± 15 ms; for AT/ET: 0.4, 0.32, and 0.3, p ≤ 0.001). Patients with PPM had gradients and ejection dynamics that were intermediate between normal and stenotic valves. Receiver-operator characteristic (ROC) curve analysis showed that AT and AT/ET discriminated PAV stenosis from PPM and controls (area under ROC curve = 0.92 and 0.88, respectively). Combining AT with the conventional Doppler velocity index gave the highest area under the curve of 0.98 but was not statistically different from that of AT alone (p = 0.12). A cutoff of AT = 100 ms had a sensitivity and specificity of 86% for identifying PAV stenosis; for an AT/ET = 0.37, the sensitivity and specificity were 96% and 82%, respectively. Analysis by valve type (mechanical and biological) revealed similar results; however, biological valves had slightly higher areas under the curve for all systolic time intervals. Ejection dynamics through PAV, particularly AT and AT/ET, are reliable angle-independent parameters that can help evaluate valve function and identify PAV stenosis.

Bioprosthetic tricuspid valve dysfunction evaluated by real-time three-dimensional transesophageal echocardiography.

A 27-year-old man was referred to our hospital for rightsided heart failure. At the age of 19 years, he had undergone tricuspid valve replacement (TVR) with a bioprosthesis, a Carpentier–Edwards pericardial (CEP) valve, because of infective endocarditis of the tricuspid valve (TV). On examination, he was afebrile, with a blood pressure of 110/66 mmHg and a heart rate of 84 bpm. Auscultation of the heart was notable for a grade 3/6 holosystolic regurgitant murmur and diastolic murmur at the 4th left sternal border. Jugular venous distention and peripheral edema were observed. Dilatation of the right atrium was observed in transthoracic echocardiography and a tricuspid regurgitation (TR) jet was seen on a color Doppler image. Continuouswave Doppler showed a mean pressure gradient of about 12 mmHg across the bioprosthetic TV. Real-time threedimensional transesophageal echocardiography (RT3DTEE) (iE33; Philips, Bothell, WA, USA) was performed in order to evaluate the prosthetic valve function. The RT3DTEE demonstrated tricuspid stenosis with restricted leaflet motion, incomplete closing bioprosthetic TV, and obvious TR (Figs. 1 and 2). The leaflets are thickened and fibrocalcific, with decreased mobility. A redo TVR was performed for valve dysfunction of the CEP. The causes of bioprosthetic valve dysfunction in this case were concluded to be fibrotic and sclerotic degeneration with calcification based on the pathological findings of the extracted bioprosthesis. The RT3D-TEE findings were consistent with these pathological findings.

Exercise Hemodynamics in Valvular Heart Disease

Exercise hemodynamics play an important role in the evaluation and management of patients with both severe stenotic or regurgitant valve lesions. Exercise testing in patients with valvular heart disease can help to unmask latent symptoms and define the timing of surgical intervention. Additionally, exercise-induced hemodynamics are an important tool to assess prosthetic valve function. This review summarizes both background literature and recent publications that assess the use of exercise hemodynamics in the evaluation and management of valvular heart disease.

Sutureless mitral valve replacement with bioprostheses and Nitinol attachment rings: Feasibility in acute pig experiments

There is a need for fast, minimally invasive sutureless replacement of mitral valves. Unchanged FDA-approved biological valve prostheses were sutured to Nitinol attachment rings (Endosmart, Stutensee, Germany) that were covered with textile (devices). The lower flange of the device was stretched in ice water and maintained in a stretched position with stretching sutures. In 9 acute pig experiments through a limited left thoracotomy, a single suture was placed around the mitral annulus, the device was positioned, the annular suture tied, the stretching sutures retracted, and the device activated by warm saline. Position of the device, heart and valve function, coronary arteries, left ventricular outflow tract, and surrounding structures were observed with transoesophageal echocardiography, left ventricular and coronary angiograms, and pathologic examination at autopsy. The devices could be easily navigated to the mitral valve annulus and actuated within seconds. Three devices were placed with warm blood in the operative field and were tilted or dislocated at autopsy. In the other 6 devices, transesophageal echocardiography and left ventricular and coronary angiography demonstrated normal prosthetic valve and heart function, without valvular or para-device leakage, and with normal aortic valve and coronary arteries. At autopsy in these 6 cases, the devices were strongly fixed at the anatomic mitral valve annulus, without abnormalities of the device, heart valve prosthesis, left ventricular outflow tract, or aortic valve ostium. Nitinol attachments rings combined with unchanged biological valve prostheses can make fast and strong sutureless replacement of the mitral valve feasible in acute pig experiments. Applicators that constrain and release the device mechanically need to be developed.

Misleading image of mechanical valve leaflet by transesophageal echocardiography.

Although bileaflet prosthetic valve function is commonly assessed by means of transesophageal echocardiography (TEE) during surgery, the author reports that the leaflet image is not a real image but an artifact. As the depth of the transducer is altered, the leaflet image is gradually skewed in relation to the plane of the prosthetic valve ring. The leaflet-like image consistently overlaps the line that is drawn from the transducer position to the atrial side edge of the leaflet, indicating that this image is caused by reverberations. Three-dimensional TEE shows that the leaflet image is not semilunar but is elongated towards the left ventricle and unusually tilted. As viewed from the ventricular side, the ring image is elongated and forms a cylinder-like image in the left ventricle, and the leaflets appear to be opening and closing at the bottom of this cylinder. Therefore, TEE assessment of leaflets in the open position can be misleading.

Anesthetic considerations of percutaneous transcatheter aortic valve implantation: first attempt in Korea -A report of 2 cases-

Conventional aortic valve replacement for severe aortic stenosis is associated with a high operative mortality in the elderly patients with significant comorbidities, including severe respiratory dysfunction, renal insufficiency, and compromised cardiac function. Human transcatheter aortic valve implantation was first reported in 2002 and has become a valid alternative in selected high-risk patients in Europe and North America. This article describes the first attempt of transfemoral transcatheter aortic valve implantation in Korea. The procedure was applied in two consecutive patients with severe aortic stenosis. Despite several intra-operative complications during procedure, the post-operative outcomes were good for both patients. At post-operative 30 days there was satisfactory prosthetic valve function and hemodynamic stability.

Transaortic chordae and pannus removal without redo mitral valve replacement in prosthetic mitral valve malfunction

Both anterior and posterior chordae of the mitral valve are occasionally spared during mitral valve surgery to preserve left ventricular function. In this report, a 43-year-old woman who had undergone mitral valve replacement surgery with anterior and posterior chordal preservation 9 years ago subsequently had mitral valve pannus and anterior chordae covering the prosthetic valve, which led to valve malfunction. Prosthetic mitral valve function was successfully recovered by performing transaortic pannus and chordae removal, avoiding redo mitral valve replacement.