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Biomedical subjects

G Derumeaux

Publications and source records attributed to G Derumeaux.

At least 19 recordsLinked to original sources
PubMed2003

[Percutaneous artificial heart valves: from animal experimentation to the first human implantation in a case of calcified aortic stenosis].

The development of artificial cardiac valves capable of being positioned by catheter has become an important subject for research, with the objective of treating valvular patients who are not operable or at very high surgical risk. We tested an artificial valve implantable by the percutaneous route, consisting of three leaflets of bovine pericardium sutured to the inside of a stainless steel stent, deployable by inflating a balloon. Following laboratory evaluation, this valve was implanted with success in animals, then for the first time in man, in a case of calcified aortic stenosis. The patient, a 57 year old male in cardiogenic shock, had associated multiple non-cardiac pathology and could not be operated on. Implantation was carried out by the trans-septal anterograde route, the only route available due to severe end stage arteritis. The artificial valve was deposited in the centre of the native aortic valve, without obstructing the coronaries nor reaching the mitral valve. The result was spectacular with instantaneous haemodynamic improvement and excellent valvular function confirmed by transoesophageal echocardiography every 15 days after implantation. Non-cardiac complications marred the progress, dominated by aggravation of pre-existing leg ischaemia, necessitating amputation for which the consequences were fatal at 4 months. This case demonstrates that implantation of a cardiac valve by the percutaneous route is possible in calcified aortic stenosis, and that it brings rapid clinical improvement. This technique could in future constitute an important alternative therapeutic approach for selected patients.

Angioplasty, Balloon↗
PubMed2003

[What indicators for tissue Doppler?].

The analysis and quantification of regional myocardial function are necessary in numerous pathologies, of which ischaemic cardiomyopathy figures above all. Several ultrasound techniques have been developed with the objective of quantifying regional function. Among these methods, myocardial tissular Doppler is well placed, analysing the radial and longitudinal components of the myocardial fibres with different indices: movement indices (myocardial velocity and displacement) deformation indices (speed of deformation which is just the myocardial velocity gradient multiplied by the relative myocardial distance and deformation). The measurement of speeds, particularly at the level of the mitral ring, is a now well validated tool for the analysis of left ventricular filling. However, other indices (deformation in particular) are still being evaluated.

Echocardiography, Doppler↗
PubMed2003

[Measurement of the mitral area with three-dimensional cardiac echography].

Two dimensional planimetry of mitral stenosis is sometimes difficult due to the complex morphology of the mitral valve. Three dimensional cardiac echography images the projected area of the mitral valve allowing precise planimetry of the orifice. Thirty patients with mitral stenosis were included in this study in order to obtain planimetry of the mitral orifice with two dimensional and three dimensional "freehand" mode transthoracic echocardiography. In 10 patients, the measurements were taken before and after percutaneous commissurotomy. The mitral area measured with three dimensional echography was 1.36+/-0.45 cm2 and 1.39+/-0.43 cm2 in two dimensional mode. The correlation between the 2 methods was good (y=1.01x - 0.08, r=0.92, p<0.001) but three dimensional echocardiography significantly underestimated the two dimensional planimetry by 0.05+/-0.27 cm2 (4+/-20%, p<0.05). The intra- and inter-observer reproducibility of the three dimensional measurements were 0.95 and 0.91 respectively. Three dimensional free-hand mode cardiac echography allows precise measurement of the mitral orifice area in patients with mitral stenosis.

Echocardiography, Three-Dimensional↗
PubMed2002

[Changes in left ventricular torsion during ischemia-reperfusion].

We aimed to characterise the alterations of left ventricular twist during ischaemia-reperfusion and to study their relationship to global left ventricular function. Systolic left ventricular twist was measured at the mid-papillary muscle level by colour tissue Doppler echocardiography in 7 anaesthetised open-chest dogs at baseline, 90 min-occlusion of the left anterior descending, and 180 min after reflow. Tissue Doppler was also performed in 34 patients after anterior infarct and in 20 controls. In controls, rotation occurred counterclockwise when viewed from the base. In a random subset of subjects, the assessment of ventricular twist by tissue Doppler was validated against magnetic resonance myocardial tagging. Myocardial ischaemia led to a decrease in ventricular twist in dogs and infarct patients (p < 0.01). This decrease was correlated with the extent of the asynergic area and global left ventricular function (p < 0.001). In dogs, cardiac twist was higher after reflow relative to ischaemia (p < 0.01). Thus, acute myocardial ischaemia is responsible for a decrease in left ventricular twist that is related to global ventricular function. Colour tissue Doppler echocardiography provides straightforward assessment of left ventricular twist in humans.

Aged↗
PubMed2001

Recurrent cerebrovascular events associated with patent foramen ovale, atrial septal aneurysm, or both.

BACKGROUND: Patent foramen ovale and atrial septal aneurysm have been identified as potential risk factors for stroke, but information about their effect on the risk of recurrent stroke is limited. We studied the risks of recurrent cerebrovascular events associated with these cardiac abnormalities. METHODS: A total of 581 patients (age, 18 to 55 years) who had had an ischemic stroke of unknown origin within the preceding three months were consecutively enrolled at 30 neurology departments. All patients received aspirin (300 mg per day) for secondary prevention. RESULTS: After four years, the risk of recurrent stroke was 2.3 percent (95 percent confidence interval, 0.3 to 4.3 percent) among the patients with patent foramen ovale alone, 15.2 percent (95 percent confidence interval, 1.8 to 28.6 percent) among the patients with both patent foramen ovale and atrial septal aneurysm, and 4.2 percent (95 percent confidence interval, 1.8 to 6.6 percent) among the patients with neither of these cardiac abnormalities. There were no recurrences among the patients with an atrial septal aneurysm alone. The presence of both cardiac abnormalities was a significant predictor of an increased risk of recurrent stroke (hazard ratio for the comparison with the absence of these abnormalities, 4.17; 95 percent confidence interval, 1.47 to 11.84), whereas isolated patent foramen ovale, whether small or large, was not. CONCLUSIONS: Patients with both patent foramen ovale and atrial septal aneurysm who have had a stroke constitute a subgroup at substantial risk for recurrent stroke, and preventive strategies other than aspirin should be considered.

Adolescent↗
PubMed2001

Chronic ACE inhibition enhances the endothelial control of arterial mechanics and flow-dependent vasodilatation in heart failure.

Reduced conduit arteries flow-dependent dilatation and altered compliance have been described during heart failure. However, the role of shear stress, the relation between endothelial dysfunction and mechanics, and the effect of chronic ACE inhibition on this relationship have not been investigated. The present study was designed to evaluate in heart failure patients the relationship between flow-dependent dilatation and radial artery mechanics at known shear stress levels and to assess the effect of chronic ACE inhibition. Sixteen stable congestive heart failure patients, who had never been treated with ACE inhibitors, participated in the study. Arterial pressure, cardiac output (bioimpedance), radial artery diameter (echo tracking) and flow (Doppler), total blood viscosity, and mean artery wall shear stress were assessed before and during a gradual increase in the forearm blood flow in response to gradual distal hand skin heating. Cross-sectional radial artery compliance and distensibility indexes were calculated at 34 degrees C, 40 degrees C, and 44 degrees C. The endothelium-independent vasodilatation was evaluated by use of glyceryl trinitrate. All parameters were assessed before and 24 hours after the last administration of perindopril (4 mg once daily) or placebo in a 2-month double-blind randomized study. Before treatment, there was no difference between the 2 groups for all parameters. After chronic ACE inhibition, systolic arterial pressure decreased at baseline from 126+/-11 to 118+/-10 mm Hg (P<0.05). During heating, the increase in diameter in response to shear stress was higher after ACE inhibition than after placebo (time/treatment interaction, P<0.05). Moreover, in contrast to placebo, at the same shear stress, there was a significant increase in compliance (3.23+/-0.79 x 10(-7) to 6.82+/-2.47 x 10(-7) m(2)/kPa, P<0.05) and distensibility (5.71+/-1.35 x 10(-3) to 8.87+/-1.88 x 10(-3)/kPa, P<0.05) during heating after ACE inhibition. The effect of glyceryl trinitrate did not change. The present study demonstrates that chronic administration of the ACE inhibitor perindopril increases the magnitude of the flow-dependent dilatation and restores the flow-dependent increase in compliance and distensibility of the radial artery evaluated at stable shear stress. In addition, the decrease in baseline systolic arterial pressure after ACE inhibitor suggests an associated increase in the distensibility of the proximal elastic conduit arteries.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2001

Echocardiography predicts embolic events in infective endocarditis.

OBJECTIVES: The aim of our study was to assess the value of transesophageal echocardiography (TEE) in predicting embolic events (EEs) in a large group of patients with definite endocarditis according to the Duke criteria, including silent embolism. BACKGROUND: The value of echocardiography in predicting embolism in patients with endocarditis remains controversial. Some studies reported an increased risk of embolism in patients with large and mobile vegetations, whereas other studies failed to demonstrate such a relationship. METHODS: Multiplane transesophageal echocardiograms of 178 consecutive patients with definite infective endocarditis (IE) were analyzed. The incidence of embolism was compared with the echocardiographic characteristics (localization, size and mobility) of the vegetations. To detect silent embolism, cerebral and thoraco-abdominal scans were performed in 95% of patients. RESULTS: Among 178 patients, 66 (37%) had one or more EEs. There was no difference between patients with and without embolism in terms of age, gender and left valve involved. On univariate analysis, Staphylococcus infection, right-side valve endocarditis and vegetation length and mobility were significantly related to EEs. A significant higher incidence of embolism was present in patients with vegetation length >10 mm (60%, p < 0.001) and in patients with mobile vegetations (62%, p < 0.001). Embolism was particularly frequent among 30 patients with both severely mobile and large vegetations (> 15 mm) (83%, p < 0.001). On multivariate analysis, the only predictors of embolism were vegetation length (p = 0.03) and mobility (p = 0.01). CONCLUSIONS: Our study shows that the presence of vegetations on TEE is predictive of embolism and that the morphologic characteristics of vegetations are helpful in predicting EEs in both mitral and aortic valve IE. It also suggests that early operation may be recommended in patients with vegetations > 15 mm and high mobility, irrespective of the degree of valve destruction, heart failure and response to antibiotic therapy.

Aortic Valve↗
PubMed2001

Tissue Doppler imaging differentiates transmural from nontransmural acute myocardial infarction after reperfusion therapy.

BACKGROUND: The evaluation of transmural extent of necrosis after acute myocardial infarction remains a major problem in clinical practice. We sought to determine whether color M-mode tissue Doppler imaging (TDI) could differentiate transmural from nontransmural myocardial infarction. METHODS AND RESULTS: Twenty-one anesthetized open-chest dogs underwent 90 or 120 minutes of left anterior descending coronary artery occlusion followed by 180 minutes of reperfusion. The transmural extension of infarct was measured by triphenyltetrazolium chloride (TTC) staining. Segment shortening in the endocardium and epicardium of the anterior and posterior walls was assessed by sonomicrometry. Regional myocardial blood flow was measured by radioactive microspheres. TDI was obtained from an epicardial short-axis view. We calculated systolic and diastolic velocities within the endocardium and epicardium of myocardial walls and the subsequent myocardial velocity gradient (MVG). TTC staining could identify 2 groups according to the transmural extent of necrosis: 15 dogs had a nontransmural (NT) necrosis (42+/-3% of wall thickness), and 6 dogs developed a transmural (T) infarct (81+/-4% of wall thickness). In both groups, ischemia resulted in a significant and similar reduction in endocardial and epicardial velocities, with a resulting low systolic MVG in the anterior wall (0.10+/-0.07 in NT and 0.10+/-0.08 s(-1) in T). At 60 minutes of reperfusion, systolic MVG failed to change significantly in the transmural group (-0.20+/-0.09 s(-1)). In contrast, it increased significantly after reflow in the NT group compared with ischemic values (-0.99+/-0.20 versus 0.10+/-0.07 s(-1), P:<0.05). CONCLUSIONS: TDI can differentiate transmural from nontransmural myocardial infarction early after reperfusion.

Animals↗
PubMed2001

Anticoagulant (fluindione)-aspirin combination in patients with high-risk atrial fibrillation. A randomized trial (Fluindione, Fibrillation Auriculaire, Aspirin et Contraste Spontané; FFAACS).

BACKGROUND: A combination of low-dose aspirin with anticoagulants may provide better protection against thromboembolic events compared to anticoagulants alone in high-risk patients with atrial fibrillation. OBJECTIVE: Evaluation of the preventive efficacy against nonfatal thromboembolic events and vascular deaths of the combination of the oral anticoagulant fluindione and aspirin (100 mg) in patients with high-risk atrial fibrillation. METHODS: A multicenter, placebo-controlled, double-blind, randomized trial was conducted at 49 investigating centers in France. Atrial fibrillation patients with a previous thromboembolic event or older than 65 years and with either a history of hypertension, a recent episode of heart failure or decreased left ventricular function were included in the study. Patients were treated with fluindione plus placebo (i.e. anticoagulant alone) or fluindione plus aspirin (i.e. combination therapy), with an international normalized ratio target of between 2 and 2.6. The combined primary endpoint was stroke (ischemic or hemorrhagic), myocardial infarction, systemic arterial emboli or vascular death. The secondary endpoint was the incidence of hemorrhagic complications. RESULTS: The 157 participants (average age 74 years; 52% women; 42% with paroxysmal atrial fibrillation) were followed for an average of 0.84 years. Three nonfatal thromboembolic events were observed (1 in the anticoagulation group, 2 in the combination group) and 6 patients died (3 in the anticoagulation group, 3 in the combination group), none of them from a thromboembolic complication. However, 3 deaths were secondary to severe hemorrhagic complications (1 in the anticoagulation group, 2 in the combination group). Nonfatal hemorrhagic complications occurred more often in the combination group (n = 10, 13.1%) compared to the anticoagulation group (n = 1, 1.2%) (p = 0.003). CONCLUSION: The combination of aspirin with anticoagulant is associated with increased bleeding in elderly atrial fibrillation patients. The effect on thromboembolism and the overall balance of benefit to risk could not be accurately assessed in this study due to the limited number of ischemic events.

Administration, Oral↗
PubMed2001

[Acute changes in load: effects of myocardial velocities measured by doppler tissue imaging].

The value of measuring the velocities of myocardial motion in the analysis of regional contractility has been demonstrated. The effects of changes in load on myocardial velocities has not been extensively studied. The aim of this study was to increase the change in myocardial velocities during haemodialysis. The velocities of longitudinal myocardial motion of the posterior wall and mitral annulus were measured by Doppler tissue imaging in 33 chronic haemodialysis patients (16 men: ages 64 +/- 14 years). Using the apical 2 chamber view: systolic (S), diastolic (D) and late (A) velocities were measured before and immediately after haemodialysis. The weight loss and decrease in mean blood pressure was 2.6 +/- 1.2 Kg and 10 +/- 17% respectively. Before dialysis, the systolic and diastolic velocities were maximal at the mitral annulus and decreased from the base to the apical region of the posterior wall. After dialysis, the velocities of the basal, median and apical segments of the posterior wall increased in systole but decreased in early diastole. Conversely, diastolic velocities of the mitral annulus did not change after dialysis. The authors conclude that the systolic and diastolic velocities of myocardial motion are affected by acute changes in left ventricular load induced by haemodialysis whereas those of the mitral annulus are little affected.

Aged↗
PubMed2000

Selective endothelin-A versus combined endothelin-A/endothelin-B receptor blockade in rat chronic heart failure.

BACKGROUND: The relative efficacy of endothelin-A (ET(A)) receptor blockade versus combined ET(A)-ET(B) receptor blockade in chronic heart failure (CHF) is still largely unknown. METHODS AND RESULTS: We compared, in a rat model of CHF (coronary ligation), the hemodynamic and structural effects of 1 month of treatment with the ET(A) antagonist ABT-627 (5 mg x kg(-1) x d(-1)), the ET(B) antagonist A-192621 (30 mg x kg(-1) x d(-1)) or a combination of the 2 drugs. Doses were chosen for their capacity to block the pressor response to ET-1 (for ET(A) blockade) or the depressor responses to sarafotoxin S6c or ET-1 (for ET(B) blockade). ET(A) and combined ET(A)-ET(B) blockade reduced systolic blood pressure to the same extent, whereas ET(B) blockade had no effect. In contrast, only combined ET(A)-ET(B) blockade significantly reduced heart rate. Both ET(A) and combined ET(A)-ET(B) blockade, but not ET(B) blockade alone, increased left ventricular (LV) fractional shortening and wall thickening and reduced LV end-diastolic pressure, as well as LV end-diastolic and end-systolic volumes. However, all treatments (including ET(B) blockade) decreased LV collagen accumulation. CONCLUSIONS: The chronic blockade of both ET(A) and ET(B) receptors improved systemic hemodynamics, as well as LV function and remodeling, to the same extent as ET(A) receptor blockade alone. However, only combined ET(A)-ET(B) receptor blockade decreased heart rate. Whether this differential effect on heart rate affects the long-term outcome after treatment with ET(A) or mixed ET(A)-ET(B) antagonists in CHF remains to be determined.

Animals↗
PubMed2000

Assessment of nonuniformity of transmural myocardial velocities by color-coded tissue Doppler imaging: characterization of normal, ischemic, and stunned myocardium.

BACKGROUND: Transmural myocardial contractile performance is nonuniform across the different layers of the left ventricular wall. We evaluated the accuracy of color M-mode tissue Doppler imaging (TDI) to assess the transmural distribution of myocardial velocities and to quantify the severity of dysfunction induced by acute ischemia and reperfusion in the inner and outer myocardial layers. METHODS AND RESULTS: Thirteen open-chest dogs underwent 15 minutes of left anterior descending coronary artery occlusion followed by 120 minutes of reperfusion. M-mode TDI was obtained from an epicardial short-axis view. Systolic velocities were calculated within endocardium and epicardium of the anterior and posterior walls. Regional myocardial blood flow was assessed by radioactive microspheres. Segment shortening was measured by sonomicrometry in endocardium and epicardium of both the anterior and posterior walls. At baseline, endocardial velocities were higher than epicardial velocities, resulting in an inner/outer myocardial velocity gradient. Ischemia caused a significant and comparable reduction in endocardial and epicardial systolic velocities in the anterior wall with the disappearance of the velocity gradient. Systolic velocities significantly correlated with segment shortening in both endocardium and epicardium during ischemia and reperfusion. In the first minutes after reflow, endocardial velocities showed a greater improvement than epicardial velocities, and the velocity gradient resumed although to a limited extent, indicative of stunning. CONCLUSIONS: TDI is an accurate method to assess the nonuniformity of transmural velocities and may be a promising new tool for quantifying ischemia-induced regional myocardial dysfunction.

Animals↗
PubMed2000

[Percutaneous mitral commissurotomy by metallic dilator. Multicenter experience with 500 patients].

A clinical investigation has been conducted since January 1996 with a new valve dilator for percutaneous treatment of mitral stenosis: metallic commissurotome. This new technique is based on the principle of surgical commissurotome but, in its mechanism of action, differs from the usual techniques with balloon catheters. It also offers the unique possibility for multiple utilizations of the same device after resterilization. This article reports a multicenter international investigation involving 500 patients, mean age of 34 +/- 13 years, with a isolated mitral stenosis and an echography score of 7.7 +/- 1.9. Our technique has been feasible in 489 cases (98%) with a success rate (mitral area > 1.5 cm2 without MR > grade 2) of 93%. The transmitral gradient has diminished from 20 +/- 8 mmHg to 4 +/- 3 mm Hg and the mitral area (assessed by planimetry at 24 hrs) has increased from 0.91 +/- 0.20 to 2.12 +/- 0.34 cm2. Complications were uncommon (13 patients: 2.6%) and consisted in 6 tamponades, 5 mitral insufficiencies (one patient required an emergency valve replacement) and 2 neurological transient accidents. The outcomes of this clinical investigation appear most encouraging and at least comparable to those being reported with the commonly used techniques. The most serious complications appear to be closely related to the level of experience with this technique. Considering the possibility to reutilize the metal segments of the apparatus, this technique notably reduces the cost of the procedure per patient and it represents a significant benefit in countries with limited resources.

Adult↗
PubMed2000

[Alterations of left ventricular mechanics after anterior myocardial infarction. Quantitative analysis by tissue doppler echocardiography].

Myocardial ischemia is usually responsible for alterations of regional left ventricular function which are not quantified by routine echocardiography. We used tissue Doppler echocardiography to quantitate the three main components (radial, longitudinal and angular) of left ventricular function, and their alterations after acute anterior myocardial infarction. Radial function was assessed by the myocardial velocity gradient derived from M-mode color tissue Doppler echocardiography, and longitudinal function by the pulsed wave tissue Doppler echocardiography, in 26 patients who experienced a first acute anterior myocardial infarction and in 11 matched healthy subjects. We describe a new tissue Doppler method for the measurement of septal angular deformation during cardiac contraction. In healthy subjects, our results showed heterogeneous regional myocardial contraction. Septal angular deformation occurred in the same direction and was of the same order as predicted by previous MRI studies. After anterior infarction, systolic and diastolic myocardial velocity gradients were dramatically decreased in the anterior wall when compared with controls (p < 0.01), whereas the systolic velocity gradient was significantly higher in the opposite wall (p < 0.05). Pulsed wave tissue Doppler echocardiography revealed significant alterations of longitudinal left ventricular function. Septal angular deformation was decreased after anterior infarct, and a good correlation was found between the angle of rotation and the left ventricular ejection fraction by cineangiography. These results indicate that tissue Doppler echocardiography has the potential for measuring the three main components of regional left ventricular function, and for quantitatively assessing their functional alterations induced by acute myocardial ischemia.

Diastole↗
PubMed1999

Percutaneous mechanical mitral commissurotomy with a newly designed metallic valvulotome: immediate results of the initial experience in 153 patients.

BACKGROUND: Percutaneous balloon valvotomy has become a common treatment of mitral stenosis, but the cost of the procedure remains a limitation in countries with restricted financial resources, leading to a frequent reuse of the disposable catheters. To overcome this limitation, a reusable metallic valvotomy device has been developed with the goals of both improving the mitral valvotomy results and decreasing the cost of the procedure. METHODS AND RESULTS: The device consists of a detachable metallic cylinder with 2 articulated bars screwed onto the distal end of a disposable catheter whose proximal end is connected to an activating pliers. By the transseptal route, the device is advanced across the valve over a traction guidewire. Squeezing the pliers opens the bars up to a maximum extent of 40 mm. The clinical experience consisted of 153 patients with a broad spectrum of mitral valve deformities. The procedure was successful in 92% of cases and resulted in a significant increase in mitral valve area, from 0.95+/-0.2 to 2. 16+/-0.4 cm2. No increase in mitral regurgitation was noted in 80% of cases. Bilateral splitting of the commissures was observed in 87%. Complications were 2 cases of severe mitral regurgitation (1 requiring surgery), 1 pericardial tamponade, and 1 transient cerebrovascular embolic event. In this series, the maximum number of consecutive patients treated with the same device was 35. CONCLUSIONS: The results obtained with this new device are encouraging and at least comparable to those of current balloon techniques. Multiple uses after sterilization should markedly decrease the procedural cost, a major advantage in countries with limited resources and high incidence of mitral stenosis.

Adolescent↗
PubMed1999

Value and limitations of the Duke criteria for the diagnosis of infective endocarditis.

OBJECTIVES: The purpose of this study was to assess the value and limitations of Duke criteria for the diagnosis of infective endocarditis (IE). BACKGROUND: Duke criteria have been shown to be more sensitive in diagnosing IE than the von Reyn criteria, but the diagnosis of IE remains difficult in some patients. METHODS: Both classifications were applied in 93 consecutive patients with pathologically proven IE. Blood cultures, and transthoracic and transesophageal echocardiography were performed in all patients. RESULTS: Sensitivities for the diagnosis of IE were 56% and 76% for von Reyn and Duke criteria, respectively. Fifty-two patients were correctly classified as "probable IE" by von Reyn and "definite IE" by Duke criteria (group 1). However, discrepancies were observed in 41 patients. Eleven patients (group 2) were misclassified as "rejected" by von Reyn, but were "definite IE" by Duke criteria; this difference could be explained by negative blood cultures and positive echocardiogram in all patients. In eight patients (group 3), the diagnosis of IE was "possible" by von Reyn but "definite" by Duke criteria. This difference was essentially explained by the failure of the von Reyn classification to consider echocardiographic abnormalities as major criteria. Twenty-two patients (group 4) were misclassified as possible IE using Duke criteria, being false negative of this classification. Echocardiographic major criteria were present in 19 patients, but blood cultures were negative in 21 patients. The cause of negative blood cultures was prior antibiotic therapy in 11 patients and Q-fever endocarditis diagnosed by positive serology in three cases. CONCLUSIONS: Twenty-four percent of patients with proved IE remain misclassified as "possible IE" despite the use of Duke criteria, especially in cases of culture-negative and Q-fever IE. Increasing the diagnostic value of echographic criteria in patients with prior antibiotic therapy and typical echocardiographic findings and considering the serologic diagnosis of Q fever as a major criterion would further improve the clinical diagnosis of IE.

Bacteria↗
PubMed1999

Can power motion imaging mode combined with contrast agent assess myocardial contraction and perfusion? In vitro and in vivo studies.

Power motion imaging (PMI) is a new Doppler imaging technology that can enhance contrast agent visualization. We hypothesized that PMI combined with Albunex injection (CPMI) could provide new insights into myocardial contractility and perfusion. In a first step, PMI signal was studied with an in vitro phantom. In a second step, PMI signal was studied in 10 rabbits at different workloads. In a third step, 10 rabbits were studied before and after ischemia produced by coronary ligation and finally during reperfusion. During the latter protocol, epicardial echocardiography analyzed by PMI and fundamental mode was performed before and after Albunex injection. PMI signal was well correlated with phantom velocity. PMI signal and myocardial wall thickening were well correlated, particularly in the septal area. On the coronary occlusion model, ischemia was associated with a significant decrease in PMI and CPMI signals, whereas reperfusion was associated with a significant decrease in PMI signals only, indicating stunning. We conclude that PMI combined with CPMI is a powerful tool to assess myocardial contractility and perfusion.

Albumins↗