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Biomedical subjects

A Cribier

Publications and source records attributed to A Cribier.

At least 55 records · Page 3Linked to original sources
PubMed1999

Entrainment of typical AV nodal reentrant tachycardia using para-Hisian pacing: evidence for a lower common pathway within the AV node.

INTRODUCTION: Despite the ability to cure atrioventricular nodal reentrant tachycardia (AVNRT) by radiofrequency catheter ablation with a high success rate, the exact localization of the tachycardia circuit is still not well established. The presence of AV nodal tissue between the typical AVNRT circuit and the His bundle, constituting a lower common pathway (LCP), remains controversial. METHODS AND RESULTS: Entrainment of AVNRT during para-Hisian stimulation allows accurate measurement of the His- to- atrial (HA) interval which is part of the same circuit as that of the tachycardia. With an LCP, during tachycardia, there is simultaneous conduction from the low turnaround of the circuit to the atrium (via the fast pathway) and to the His bundle (via the LCP). However, during entrainment by para-Hisian pacing, the impulse has to retrogradely depolarize sequentially the LCP and the fast pathway. Therefore, in the presence of an LCP, the HA interval duration during tachycardia (HAt) should be shorter than that of during entrainment by para-Hisian stimulation (HAe). We considered an LCP present when Hae - HAt was > or = 10 msec. Entrainment of typical AVNRT with para-Hisian stimulation was performed in 23 consecutive patients (21 females) with a mean age of 45+/-17 years. LCP was considered to be present in 18 of 23 patients (78%). In addition, transient His-bundle dissociation from the ongoing tachycardia occurred in seven patients (30%). CONCLUSION: These results support the presence of a LCP during typical AVNRT.

Adolescent↗
PubMed1999

[Distinguishing between physiologic hypertrophy in athletes and primary hypertrophic cardiomyopathies. Importance of tissue color Doppler].

In order to assess the value of Doppler tissue imaging (DTI) in the differentiation of physiological hypertrophy of athletes from primary hypertrophic cardiomyopathy (HCM), the authors compared a group of 20 normal, non-athletic subjects, a group of 43 competitive athletes and a group of 20 patients with mild HCM. In addition to the conventional echocardiographic criteria, the velocity of wall motion at the endocardium and epicardium of the interventricular septum and the posterior wall as well as their gradients, were measured throughout the cardiac cycle. No significant difference was observed between normal subjects and the athletes with respect to velocities and the gradients of velocity. Early diastolic velocities of the posterior wall and interventricular septum were significantly lower than those of normal subjects and athletes. The systolic and early diastolic gradients of velocity of the posterior wall were significantly lower in HCM compared with the normal subjects and athletes. The gradient of velocity between the endocardium and epicardium of the interventricular septum was significantly lower in HCM compared with normal subjects in early diastole and with athletes in systole and early diastole. The best Doppler tissue imaging parameter to differentiate pathological hypertrophy of HCM from physiological hypertrophy of athletes was analysis of the gradient of velocity in early diastole of the posterior wall. A value of 0.7 sec-1 differentiated HCM with a sensitivity of 89%, a specificity of 95% and a diagnostic accuracy of 94%. Doppler tissue imaging is a more sensitive and specific technique than conventional Doppler echocardiography for detecting moderate forms of HCM.

Adult↗
PubMed1999

Thallium-gated SPECT in patients with major myocardial infarction: effect of filtering and zooming in comparison with equilibrium radionuclide imaging and left ventriculography.

UNLABELLED: The effect of filtering and zooming on 201TI-gated SPECT was evaluated in patients with major myocardial infarction. METHODS: Rest thallium (TI)-gated SPECT was performed with a 90 degrees dual-head camera, 4 h after injection of 185 MBq 201TI in 32 patients (mean age 61 +/- 11 y) with large myocardial infarction (33% +/- 17% defect on bull's eye). End diastolic volume (EDV), end systolic volume (ESV) and left ventricular ejection fraction (LVEF) were calculated using a commercially available semiautomatic validated software. First, images were reconstructed using a 2.5 zoom, a Butterworth filter (order = 5) and six Nyquist cutoff frequencies: 0.13 (B5.13), 0.15 (B5.15), 0.20 (B5.20), 0.25 (B5.25), 0.30 (B5.30) and 0.35 (B5.35). Second, images were reconstructed using a zoom of 1 and a Butterworth filter (order = 5) (cutoff frequency 0.20 [B5.20Z1]) (total = 32 x 7 = 224 reconstructions). LVEF was calculated in all patients using equilibrium radionuclide angiocardiography (ERNA). EDV, ESV and LVEF were measured with contrast left ventriculography (LVG). RESULTS: LVEF was 39% +/- 2% (mean +/- SEM) for ERNA and 40% +/- 13% for LVG (P = 0.51). Gated SPECT with B5.20Z2.5 simultaneously offered a mean LVEF value (39% +/- 2%) similar to ERNA (39% +/- 2%) and LVG (40% +/- 3%), optimal correlations with both ERNA (r = 0.83) and LVG (r = 0.70) and minimal differences with both ERNA (-0.9% +/- 7.5% [mean +/- SD]) and LVG (1.1% +/- 10.5%). As a function of filter and zoom choice, correlation coefficients between ERNA or LVG LVEF, and gated SPECT ranged from 0.26 to 0.88; and correlation coefficients between LVG and gated SPECT volumes ranged from 0.87 to 0.94. There was a significant effect of filtering and zooming on EDV, ESV and LVEF (P < 0.0001). Low cutoff frequency (B5.13) overestimated LVEF (P < 0.0001 versus ERNA and LVG). Gated SPECT with 2.5 zoom and high cutoff frequencies (B5.15, B5.20, B5.25, B5.30 and B5.35) overestimated EDV and ESV (P < 0.04) compared with LVG. This volume overestimation with TI-gated SPECT in patients with large myocardial infarction was correlated to the infarct size. A zoom of 1 underestimated EDV, ESV and LVEF compared with a 2.5 zoom (P < 0.02). CONCLUSION: Accurate LVEF measurement is possible with TI-gated SPECT in patients with major myocardial infarction. However, filtering and zooming greatly influence EDV, ESV and LVEF measurements, and TI-gated SPECT overestimates left ventricular volumes, particularly when the infarct size increases.

Female↗
PubMed1999

[Analysis and quantification of longitudinal contraction of the left ventricle in myocardial infarction. Value of Doppler myocardial tissue imaging].

The authors compared the results of conventional 2D echocardiography and those of Doppler tissue imaging in 30 patients in the intensive care unit for acute pulmonary myocardial infarction and 10 normal control subjects, to assess the longitudinal contraction of the left ventricle. Echocardiography was performed in the apical 2 and 4 chamber views to analyse the septal, lateral, posterior and anterior left ventricular walls. Each wall was divided into 3 segments: basal, median and apical. Each segment was scored: 1-normo or hyperkinetic, 2-hypokinetic, 3-akinetic and 4-dyskinetic. Doppler tissue imaging provided the maximum instantaneous velocities in systole and diastole in each segment. In control subjects, the myocardial velocities decreased significantly from the base to the apex, resulting in a systolic and diastolic pressure gradient with each wall between the base and the apex. In patients with myocardial infarction, the myocardial velocities were decreased compared with the control group. Moreover, the myocardial velocity gradient between the base and apex was significantly reduced in the hypo and akinetic walls, both in systole and diastole. These results show that, in myocardial infarction, the longitudinal left ventricular contraction is abnormal and may be analysed and quantified by new indices of myocardial systolic and diastolic function, provided by Doppler tissue imaging.

Echocardiography↗
PubMed1999

201Tl and 99mTc-MIBI gated SPECT in patients with large perfusion defects and left ventricular dysfunction: comparison with equilibrium radionuclide angiography.

UNLABELLED: Left ventricular ejection fraction (LVEF) is a major prognostic factor in coronary artery disease and may be computed by 99mTc-methoxyisobutyl isonitrile (MIBI) gated SPECT. However, 201Tl remains widely used for assessing myocardial perfusion and viability. Therefore, we evaluated the feasibility and accuracy of both 99mTc-MIBI and 201Tl gated SPECT in assessing LVEF in patients with myocardial infarction, large perfusion defects and left ventricular (LV) dysfunction. METHODS: Fifty consecutive patients (43 men, 7 women; mean age 61 +/- 17 y) with a history of myocardial infarction (anterior, 26; inferior, 18; lateral, 6) were studied. All patients underwent equilibnum radionuclide angiography (ERNA) and rest myocardial gated SPECT, either 1 h after the injection of 1110 MBq 99mTc-MIBI (n = 19, group 1) or 4 h after the injection of 185-203 MBq 201Tl (n = 31, group 2) using a 90 degrees dual-head camera. After filtered backprojection (Butterworth filter: order 5, cutoff 0.25 99mTc or 0.20 201Tl), LVEF was calculated from reconstructed gated SPECT with a previously validated semiautomatic commercially available software quantitative gated SPECT (QGS). Perfusion defects were expressed as a percentage of the whole myocardium planimetered by bull's-eye polar map of composite nongated SPECT. RESULTS: Gated SPECT image quality was considered suitable for LVEF measurement in all patients. Mean perfusion defects were 36% +/- 18% (group 1), 33% +/- 17% (group 2), 34% +/- 17% (group 1 + group 2). LVEF was underestimated using gated SPECT compared with ERNA (34% +/- 12% and 39% +/- 12%, respectively; P = 0.0001). Correlations were high (group 1, r= 0.88; group 2, r = 0.76; group 1 + group 2, r = 0.82), and Bland-Altman plots showed a fair agreement between gated SPECT and ERNA. The difference between the two methods did not vary as LVEF, perfusion defect size or seventy increased or when the mitral valve plane was involved in the defect. CONCLUSION: LVEF measurement is feasible using myocardial gated SPECT with the QGS method in patients with large perfusion defects and LV dysfunction. However, both 201Tl and 99mTc-MIBI gated SPECT similarly and significantly underestimated LVEF in patients with LV dysfunction and large perfusion defects.

Electrocardiography↗
PubMed1999

[Indications for electrophysiological investigation of tachycardia].

Cardiologists are often confronted by the situation of discussing the indications for invasive electrophysiological procedures. In this field, the recommendations of American scientific societies have been published but they are relatively dated and require updating. These procedures require the introduction of one or more catheters by a femoral venous or arterial approach, or by the endoesophageal route for positioning at different sites in the heart. The first stage of the procedure is usually to evaluate the electrophysiological properties of the cardiac chamber under investigation; followed by provocative manoeuvres such as electrical stimulation, injection of a drug, the delivery of a CEE electrical shock percutaneously or by an intracardiac radiofrequency stimulation, according to the type of procedure or the centre concerned. Schematically, the indications of these procedures may be determined in different contexts according to the benefits that may be expected in a given clinical situation. This article is devoted to the principal rhythmological situations which may be encountered but, however, the indications of radiofrequency ablation are not discussed.

Bundle of His↗
PubMed1998

Doppler tissue imaging quantitates regional wall motion during myocardial ischemia and reperfusion.

BACKGROUND: Quantification of regional myocardial function is a major unresolved issue in cardiology. We evaluated the accuracy of pulsed Doppler tissue imaging (DTI), a new echocardiographic technique, to quantify regional myocardial dysfunction induced by acute ischemia and reperfusion. METHODS AND RESULTS: In nine open-chest anesthetized pigs, various degrees of regional wall motion abnormalities were induced by graded reduction of left anterior descending coronary artery (LAD) blood flow. Pulsed Doppler tissue imaging was performed from an epicardial apical four-chamber view with the sample placed within the middle part of the septal wall. Peak septal velocities were calculated during systole, isovolumic relaxation, and early and late diastole. Regional myocardial blood flow and systolic and diastolic dysfunctions were assessed by radioactive microspheres and ultrasonic crystals, respectively. Ischemia resulted in a significant rapid reduction of systolic velocities and an early decrease in the ratio of early to late diastolic velocities. Both changes were detected by pulsed DTI within 5 seconds of coronary artery occlusion. The decrease in systolic velocity significantly correlated with both systolic shortening (r=.90, P<.0001) and regional myocardial blood flow (r=.96, P<.0001) during reduction of LAD blood flow. CONCLUSIONS: These results suggest that DTI may be a promising new tool for the quantification of ischemia-induced regional myocardial dysfunction.

Animals↗
PubMed1998

Primary stenting of de novo lesions in small coronary arteries: a prospective, pilot study.

Technical advancement and new anti-thrombotic regimens have recently shown so much improvement in the results of coronary stenting that the conventional contra-indication for stenting in small coronary arteries (<3 mm) needs to be revised. We undertook a prospective pilot study of elective Palmaz-Schatz stenting in de novo lesions located in coronary arteries of less than 3 mm diameter. Fifty consecutive patients (63 +/- 9 years) with stable (n = 38) and unstable angina (n = 12) were included. Philips-DCI quantitative coronary analysis was used to measure reference diameter, minimal lumen diameter and percent diameter stenosis before PTCA, after stenting and at 6-month angiographic follow-up study. All measurements were performed after intracoronary injection of nitroglycerin (300 microg). All patients received ticlopidine (250 mg/day) and aspirin (100 mg/day). The mean lesion length was 9 +/- 3 mm. The balloon size used for stent delivery was 2.75 mm in 30 patients and 2.5 mm in 20 patients and the mean balloon inflation pressure used for stent deployment was 12 +/- 2 atm. All stents were deployed successfully. In-hospital complications occurred in two patients, diagonal branch occlusion at day 2 requiring emergency PTCA in one and a hematoma at the femoral puncture site requiring surgery in the other. Major adverse cardiac event (MACE) rate remained 2% (nonfatal infarct in one). Follow-up angiography (n = 46, 92%) at 6 +/- 3 months showed a 30% restenosis rate. Target vessel revascularization (TVR) rate was 13%. We conclude that elective stenting in small coronary arteries is feasible and involves an acceptable risk of restenosis.

Angina Pectoris↗
PubMed1998

Balloon angioplasty for the treatment of coronary in-stent restenosis: immediate results and 6-month angiographic recurrent restenosis rate.

OBJECTIVES: The purpose of this prospective study was to evaluate the immediate results and the 6-month angiographic recurrent restenosis rate after balloon angioplasty for in-stent restenosis. BACKGROUND: Despite excellent immediate and mid-term results, 20% to 30% of patients with coronary stent implantation will present an angiographic restenosis and may require additional treatment. The optimal treatment for in-stent restenosis is still unclear. METHODS: Quantitative coronary angiography (QCA) analyses were performed before and after stent implantation, before and after balloon angioplasty for in-stent restenosis and on a 6-month systematic coronary angiogram to assess the recurrent angiographic restenosis rate. RESULTS: Balloon angioplasty was performed in 52 patients presenting in-stent restenosis. In-stent restenosis was either diffuse (> or =10 mm) inside the stent (71%) or focal (29%). Mean stent length was 16+/-7 mm. Balloon diameter of 2.98+/-0.37 mm and maximal inflation pressure of 10+/-3 atm were used for balloon angioplasty. Angiographic success rate was 100% without any complication. Acute gain was lower after balloon angioplasty for in-stent restenosis than after stent implantation: 1.19+/-0.60 mm vs. 1.75+/-0.68 mm (p=0.0002). At 6-month follow-up, 60% of patients were asymptomatic and no patient died. Eighteen patients (35%) had repeat target vessel revascularization. Angiographic restenosis rate was 54%. Recurrent restenosis rate was higher when in-stent restenosis was diffuse: 63% vs. 31% when focal, p=0.046. CONCLUSIONS: Although balloon angioplasty for in-stent restenosis can be safely and successfully performed, it leads to less immediate stenosis improvement than at time of stent implantation and carries a high recurrent angiographic restenosis rate at 6 months, in particular in diffuse in-stent restenosis lesions.

Angioplasty, Balloon, Coronary↗
PubMed1998

Catheter ablation of atrioatrial conduction as a cure for atrial arrhythmia after orthotopic heart transplantation.

OBJECTIVES: We present three patients in whom atrial arrhythmia was treated by ablation of electrical conduction across a surgical suture line. BACKGROUND: Conduction across the suture line separating the donor and native right atria has recently been described after orthotopic heart transplantation. METHODS: Mapping and pacing of both grafted and recipient right atrium was performed to assess the relation between both atria and its relevance to clinical arrhythmia, prior to successful radiofrequency at the site of electrical communication. RESULTS: In cases 1 and 3, atrioatrial conduction was bidirectional. In both, two types of P waves were observed during sinus rhythm. In case 2, conduction from the recipient to the grafted atrium yielded a very particular surface ECG pattern of atrial extrasystole. The block being unidirectional, the recipient atrial sinus rhythm was not perturbed and behaved like an atrial parasystole. Ablation was performed during sinus rhythm in case 1, recipient right atrial pacing in case 2 and grafted right atrial pacing in case 3 at the site with the shortest conduction time to the other tissue. At the successful ablation site multiple component potentials were recorded. Respectively, 1, 4 and 2 radiofrequency pulses were followed by total atrioatrial conduction interruption. No tachycardia could be induced at the end of the procedure and late follow-up was event free. CONCLUSIONS: The existence of arrhythmogenic atrioatrial conduction should be taken into account when evaluating atrial arrhythmias in the transplanted heart because it is potentially curable by radiofrequency catheter ablation.

Adolescent↗
PubMed1998

Assessment of the progression of cardiac allograft vasculopathy by dobutamine stress echocardiography.

BACKGROUND: After heart transplantation, accelerated coronary vasculopathy is a major factor that limits long-term survival and is usually detected by serial coronary angiography. The aim of this study was to determine whether dobutamine stress echocardiography could accurately identify the progression of cardiac allograft vasculopathy. METHODS: Two sequential controls by dobutamine stress echocardiography were performed at an 18-month interval in 37 heart transplant recipients at the time of their routine coronary angiography. The first control (control 1) occurred 37+/-20 months after transplantation, and the second control (control 2) occurred after 56+/-21 months. Standard echocardiographic views were acquired at baseline and at incremental dobutamine infusion levels. Regional wall motion score was calculated in a 16-segment model, and each segment was graded from 1 (normal) to 4 (dyskinesia). Visual and quantitative coronary angiographic analysis were used to assess the severity of the coronary vasculopathy. RESULTS: The incidence of coronary vasculopathy increased from 46% (17/37 patients, four of whom had stenoses > 50%) at control 1 fo 70% (26/37 patients, six of whom had stenoses > 50%) at control 2. Progression of coronary vasculopathy was diagnosed by coronary angiography in 25 patients (new abnormalities in 19 and worsening of previous abnormalities in 6). Dobutamine stress echocardiography correctly identified the progression of vasculopathy in 21 of these 25 patients (84%) with new abnormalities in 17 and worsening in four. In the four remaining patients with evidence of progression of vasculopathy on coronary angiography, the result of dobutamine stress echocardiography was abnormal in three patients and normal in only one. Therefore dobutamine stress echocardiography results were abnormal in 12 patients at control 1 (sensitivity: 65%, specificity: 95%) and in 27 at control 2 (92% sensitivity, 73% specificity). CONCLUSION: Dobutamine stress echocardiography is a sensitive, noninvasive method to diagnose the progression of allograft vasculopathy, and a negative test result is a strong predictor of absence of allograft coronary vasculopathy. Therefore serial routine coronary angiography may be deferred when dobutamine stress echocardiography results are normal.

Cardiotonic Agents↗
PubMed1998

[Blood flow in the isovolumetric relaxation phase in heart transplant patients. Its use in the noninvasive diagnosis of acute rejection].

The aim of this study was to assess a Doppler-echocardiographic parameter which has not been previously reported for the diagnosis of acute cardiac rejection. The parameter was left ventricular isovolumic relaxation blood flow. Eighty patients who had undergone orthoptic cardiac transplantation were followed up regularly with echocardiography for a period of 2 years. In all, 495 echocardiographic studies were performed and the results compared with those of endomyocardial biopsy performed on the same day (11.4 echocardiographic studies per patient). In the absence of cardiac rejection, isovolumic relaxation Doppler signal was recorded in all patients (364/387 echo studies). This was a positive signal directed towards the apex detected by continuous mode Doppler in the apical position, arising along the interventricular septum in the mid part of the left ventricle (82% of cases) or from the basal region of the septum (18% of cases) and lasting throughout the phase of isovolumic relaxation. The maximal velocity was 0.53 +/- 0.08 m/s (range 0.32 to 0.73 m/s) : the velocity-time integral was 34 +/- 33 cm. This signal was associated with medioventricular endosystolic acceleration of blood flow in 75% of cases. The incidence of the isovolumic relaxation flow signal decreased in cardiac rejection with no significant changes in the other usual Doppler-echocardiographic parameters except for a significant decrease in the ejection fraction in the group with severe rejection. In the group with mild rejection (n = 89) an isovolumic relaxation flow signal was only observed in 52 cases (including 29 in whom immunosuppressive treatment was not increased). In patients with moderate rejection (n = 12) there were only 5 cases in which a isovolumic relaxation flow signal was recorded, and in the group with severe rejection (n = 7), the signal could only be recorded in 1 case. The authors conclude that the absence of an isovolumic relaxation blood flow signal in a cardiac transplant patient is a reliable sign of cardiac rejection with an excellent specificity (94%). The absence of this signal is a sensitive indicator of severe rejection (86%) but less so for moderate (58%) or mild rejection (42%).

Acceleration↗
PubMed1998

[Percutaneous coronary angioscopy in the diagnosis of cardiac graft coronary disease: comparison with the results of angiography].

Coronary disease in cardiac transplant patients is a major factor in the limitation of long term survival. The aim of this study was to compare the results of angioscopy with those of coronary angiography performed systematically every 18 months in our center. Twenty-nine patients (31 angioscopies) were assessed 38 +/- 21 months after transplantation. The appearance observed by angioscopy were: 1) normal, 2) yellow pigmentation of the arterial surface, 3) elevated plaque < 50%, 4) elevated plaque > or = 50% stenosis. Angiography was: 1) normal, 2) iregularities of the lumen or < 50% stenosis, 3) > or = 50% stenosis. The films were viewed by two independent investigators. Angioscopy was performed on the left anterior descending artery (N = 35), the left circumflex (N = 24) and the right coronary artery (N = 9). One to three arterial segments were examined per vessel (total of 117 segments: average 3.8 segments per patient). Angioscopy was uniterpretable in 13/117 (11%) of cases. Of the 81 (78%) segments considered normal at coronary angiography, only 55 seemed normal at angioscopy (68%). Of the 23 segments considered to be abnormal at coronary angiography, all were also considered to be abnormal at angioscopy. The authors conclude that coronary angioscopy seems to be more sensitive than coronary angiography for the detection of coronary disease due to chronic rejection. Prospective studies are required to determine whether the infra-angiographic angioscopic lesions correspond to earlier stages of coronary disease of the cardiac graft.

Aged↗
PubMed1998

[Gaps: practical implications].

The French translations of the word "gap" include "hole, breach, opening". In the Anglo-saxon literature, the conduction gap or the gap phenomenon is defined as the period of the cardiac cycle during which a premature beat is blocked whereas more delayed or more premature beats are conducted. This rare phenomenon, observed mainly during extrasystolic stimulation, was previously called supernormal conduction. The underlying mechanism is distal block in the conduction system occurring when more premature beats lead to delay in the proximal conduction which gives the distal site time to become excitable again. The excitability gap is one of the main characteristics of reentrant arrhythmias. Its presence in a reentrant circuit ensures the regularity and stability of the arrhythmia. It also allows penetration of the circuit by external stimuli. This different extrasystolic stimulation technique (resetting) or rapid fixed rate pacing (entrainment) may be used diagnostically and therapeutically. It enables the identification of the arrhythmia circuit and a critical zone (protected isthmus, zone of slow conduction) which may constitute a target for ablation. It also offers a possibility for terminating the arrhythmia by external stimulation. Finally, the duration of the excitable gap may guide the choice of antiarrhythmic agent during pharmacological cardioversion of a reentrant tachycardia.

Arrhythmias, Cardiac↗
PubMed1998

[Detection of myocardial viability by echocardiography with dobutamine infusion three weeks after myocardial infarction].

The aim of this study was to assess the value of low dose dobutamine (5 and 10 gammas/Kg/min) echocardiography for the detection of hibernating myocardium in an infarcted zone three weeks after the initial infarction. The authors studied 23 patients (18 men, 15 women) with an average age of 59 +/- 8 years before and 3 months after angioplasty of the culprit artery. Segmental wall motion was assessed semi-quantitatively by the criteria of the American Society of Echocardiography. All patients had regional contractile abnormalities under basal conditions and all underwent control coronary angiography at 3 months. Improvement of segmental wall motion with dobutamine predicted improvement after revascularisation with positive and negative predictive values of 95% and 85% respectively. The sensitivity and specificity of the test calculated in the usual manner were 83% and 96% respectively. In addition, assessment of diastolic function showed reduction of the isovolumic relaxation time with dobutamine only in patients with hibernating myocardium (120 +/- 30 ms decreasing to 114 +/- 29 ms with dobutamine, p < 0.02). Low dose dobutamine echocardiography therefore allows reliable non-invasive prediction of hibernating myocardium three weeks after infarction. The reduction of isovolumic relaxation time with dobutamine could be an additional argument in favour of the diagnosis.

Aged↗
PubMed1998

[Detection of acute rejection of heart transplantation by Doppler color imaging].

Doppler tissue imaging is a new technique of measuring the velocities of myocardial wall motion. In order to assess its value in the diagnosis of acute rejection, the velocities of the interventricular septum and left ventricular posterior wall were measured in systole and early diastole in 34 cardiac transplant patients at the time of their endomyocardial biopsy, using an M mode left parasternal short axis view. During 40 episodes of acute rejection (26 mild and/or moderate, 10 sub-severe and 4 severe), the wall velocities decreased significantly (p < 0.001) both in the interventricular septum and endocardium of the posterior wall. Myocardial velocities were significantly slower in sub-severe or severe rejection than in mild or moderate rejection. The most sensitive criterion was the measurement of posterior wall endocardial velocity in early diastole, a decrease of 10% having a sensitivity of 92% whereas the sensitivity of usual Doppler echocardiographic parameters is only 73%. Acute rejection, even mild cases, can be diagnosed with excellent sensitivity by measuring myocardial velocities by Doppler tissue imaging. This technique has the advantage of being non-invasive, reproducible and reliable in the follow-up of cardiac transplant patients.

Adult↗
PubMed1998

[Immediate and 6-month results of balloon angioplasty in the treatment of intra-stent restenosis in symptomatic patients].

The aim of this prospective study was to assess the clinical and angiographic immediate and 6 month results of balloon angioplasty in intra-stent restenosis. Quantitative angiographic analysis (Philips DCI) was performed before and after implantation of the stent, before and after angioplasty for restenosis and at the 6 month control procedure. The study included 59 patients with 65 stents with an intra-stent restenosis. Restenosis was diffuse (10 mm) in 70% of cases, and focal in 30% of cases. The length of the stent was 16 +/- 7 mm (Palmaz-Schatz: 58%). The diameter of the balloon used for angioplasty was 2.9 +/- 0.4 mm and the maximal inflation pressure was 10 +/- 3 bars. The success rate was 100% with no complications. Control coronary angiography was performed in 92% of patients after an average of 5.9 months. The angiographic restenosis rate was 54% and revascularisation was required in 21 patients (36%). The restenosis rate was higher in cases of diffuse intra-stent restenosis (64%) than in focal restenosis (29%), p = 0.02. The authors conclude that balloon angioplasty for intra-stent restenosis is safe and carries a high success rate. Nevertheless, the angiographic restenosis rate at 6 months seems to be higher, especially in cases of diffuse restenosis.

Angioplasty, Balloon, Coronary↗