PubMed Health⌕ Search

Biomedical subjects

J L Pasquié

Publications and source records attributed to J L Pasquié.

At least 19 recordsLinked to original sources

[Surgery of ventricular tachycardia in post-infarction left ventricular aneurysm].

The treatment of post-infarction ventricular tachycardias with antiarrhythmic drug therapy, implantable automatic defibrillators, radiofrequency ablation, also includes different surgical procedures such as endocardial resection of the infarct scar, encircling endocardial ventriculotomy and endocardial cryoablation or thermoexclusion by laser. These procedures may be extensive or limited, guided or not by preoperative mapping. The aim of this review of the literature is to update our knowledge of these different surgical techniques and to define their indications.

Cryosurgery↗

[Characterization of premature ventricular contraction initiating ventricular fibrillation].

UNLABELLED: The aim of this study is to characterize the electrocardiographic features of premature ventricular contractions (PVC) from different anatomical region that trigger ventricular fibrillation (VF). METHODS AND RESULTS: 36 consecutives patients (20 males, 42+/-14 yrs) undergoing VF ablation from 7 centres were studied (22 with idiopathic VF, 4 associated with a long QT syndrome, 3 with Brugada syndrome, 4 with ischaemic cardiomyopathy and 3 associated with other substrate). Mapping of these PVC showed 2 different origins, which were then confirmed by ablation: right ventricular outflow tract (RVOT) (22%) and peripheral Purkinje network (81%). One patient had PVC from both origins (Brugada). RVOT PVC were frequent but had triggered only 5+/-5 episodes of VF for 26+/-33 months. Purkinje PVC were more likely to be present during electrical storm with 18+/-28 episodes of VF for 33+/-45 months. Right Purkinje PVC have a left bundle branch block with superior axis morphology whereas left Purkinje ones have a right bundle branch block. The axis of activation showed variation from inferior to superior depending on the area of origin from the Purkinje network and the exit site to the myocardium. However Purkinje PVC were characterized by short QRS duration (126+/-18 vs 145+/-13ms for RVOT PVC; p=0.05). In addition the coupling interval was significantly shorter compared to RVOT PVC (292+/-45 vs 358+/-37ms respectively; p=0.005). CONCLUSION: PVC initiating VF demonstrate specific electrocardiographic features that facilitate determination of their origin. Ablation of these typical PVC is feasible in order to reduce ICD shock.

Adult↗

[Ventricular tachycardia due to branch to branch re-entry].

Ventricular tachycardia due to branch to branch re-entry constitutes a rare clinical entity. This circuit is remarkable by the fact that it is made up of the branches or hemi-branches of the bundle of His bifurcation. They occur under specific conditions, with a combination of left ventricular dilatation and atrioventricular or intraventricular conduction defects. They are also very often found in Steinert's disease. A positive diagnosis can sometimes be difficult and relies on a variety of factors. Recording of the His potential shows His activity preceding each ventriculogram, and variations in spontaneous cycles between 2 ventriculograms preceded by variations between the 2 His potentials. Atrial capture without modification of the QRS is possible, but fusion excludes the diagnosis. Drug therapy is only slightly effective, and the best treatment is ablation of the right branch of the bundle of His, which stops the tachycardia definitively.

Bundle of His↗

Mapping and ablation of ventricular fibrillation.

Sudden cardiac death frequently results from ventricular fibrillation (VF). While VF is frequently the eventual mode of death in patients with abnormal ventricular substrates, it has also been described in patients with structurally normally hearts. Until recently, the management of patients who have survived sudden cardiac death has focused on treating the consequences by implantation of a defibrillator. However, such therapy remains restricted in many countries, is associated with a prohibitive cost to the community, and may be a cause of significant morbidity in patients with frequent episodes or storms of arrhythmia. Evidence emerging from the study of fibrillation both in the atria and the ventricle suggests an important role for triggers arising from the Purkinje network or the right ventricular outflow tract in the initiation of VF. Initial experience in patients with idiopathic VF and even those with VF associated with abnormal repolarization syndromes (LQT or Brugada syndrome) or myocardial infarction suggests that long term suppression of recurrent VF may be feasible by the elimination of these triggers. With the development of new mapping and ablation technologies, and greater physician experience, catheter ablation of VF, with the ultimate aim of curing such patients at risks of sudden cardiac death, may not be an unrealistic goal in the future.

Electrocardiography↗

[The electrocardiogram of atrioventricular blocks].

Atrioventricular block (AVB) is defined as delay or absence of transmission of one or more atrial excitations to the ventricle. Physiological functional block protects the ventricle against very rapid atrial rhythms. Organic blocks may be transient, due to an acute regressive condition, or chronic, in which case they fall into two groups--permanent blocks or paroxysmal and generally rate-dependant blocks. The blocks are classified in three categories according to whether the atrial activation is delayed, conducted intermittently or not at all. The site of AVB may be determined by His bundle recordings but it may also be deduced from the surface ECG recording. Fundamental studies have questioned the reality of Rosenbaum's phase 3 and 4 blocks and suggest abnormalities of excitability in pathological zones.

Electrocardiography↗

[Diagnosis of narrow QRS complex tachycardias].

Tachycardias with normal QRS complexes (less than 0.12 seconds) may have multiple origins which may be classified in 4 groups: sinusal, atrioventricular nodal, atrioventricular junctional and finally, some ventricular tachycardias arising from near the conduction pathways. The electrocardiographic diagnosis requires analysis of the QRS complexes to detect an eventual irregularity which would suggest atrial fibrillation. When the tachycardia is regular, analysis of the P waves is fundamental (position in the ventricular cycle and morphology). The relationship of the P waves and the QRS complexes enables identification of those forms independent of the AV node and some rare types of tachycardia. Finally, the response to vagal stimulation is essential whether the tachycardia stops, slows down or persists unchanged.

Atrial Fibrillation↗

[Concealed phenomena in electrocardiography].

Concealed phenomena in electrocardiography are events which, having no direct effect on the electrocardiogramme, nevertheless change the following sequences giving rise to very unusual appearances. They are diagnosed by deduction. First of all, there is concealed anterograde or retrograde conduction in the AV node, the consequences of which are either a block or the suppression of an escape rhythm or even facilitation of the transmission of activation. Concealed conduction is also possible in the Bundle of His and its branches, explaining the frequency of dependent blocks and aberrant conduction. There is also concealed conduction in accessory pathways. The second form is concealed rhythms: hisian extrasystoles giving rise to pseudo A-V block, and concealed extrasystoles and parasystoles. With temporary pacing of tachycardia, it has finally been possible to describe "visible" concealed phenomena, not on the surface but on the endocavitary electrogramme.

Arrhythmias, Cardiac↗

[Atypical forms of atrioventricular nodal reentrant tachycardia].

The concept of functional dissociation of atrioventricular nodal conduction on an underlying structure with different nodal inputs is well established. In the common form of AVNRT, the circuit comprises the slow pathway for antegrade conduction and the fast pathway for retrograde conduction. However, the tachycardia circuit may be slightly or totally different as it is not based on discrete anatomical pathways but on functional pathways due to non-uniform anisotropy of the perinodal atrial tissue involved in the circuit. First, there are variations of the common form. The fast retrograde pathway may be posterior or left instead of being anteriorly-located. The so-called uncommon forms of AVNRT consist in slow-slow and fast-slow forms. The slow-slow form uses two different slow pathways as antegrade and retrograde limb of the circuit. These pathways may be posterior or left. The fast-slow form appears to be complex and heterogeneous. The retrograde slow pathway may be located posteriorly, anteriorly, in-between or sometimes left-sided. Whatever the circuit, targeting the antegrade or retrograde slow pathway remains the aim of ablation and the only therapeutic issue. However, a 1%-AV block rate has to be kept in mind.

Atrioventricular Node↗

[Parasystole].

Parasystole is usually an extrasystolic rhythm which can occur at every level, but particularly in the ventricle. It is admitted that the parasystolic focus is protected from the environing myocardium by an entry block but can manifest itself. Actually, a pure unidirectional block does not exist and the environing myocardium affects the parasystolic rhythm by an electrotonic current which modulates the output. A non-parasystolic complex which occurs prematurely in the parasystolic cycle delays it. Conversely it accelerates the cycle when it occurs late. By this fact, a parasystole pacing is possible and can lead to a fixed coupling. This arrhythmia is frequently unknown and can be experimentally, reproduced by a sucrose gap preparation.

Animals↗

[Bouveret's tachycardia].

In 1889, in an age preceding the invention of the electrocardiogram, a physician working in the hospitals of Lyon published a remarkable paper on essential paroxysmal tachycardia, of which Bristowe in England and Huppert in Germany had already spoken. The study described 12 cases (including 3 personal cases) of essential paroxysmal tachycardia and 6 secondary tachycardias. They were not all benign, there being 4 deaths out of the 12 cases. From this period on, the term "Bouveret's tachycardia" has been used in France and, with the advances in rhythmology, some have assimilated it to paroxysmal nodal tachycardia. In fact, many forms of paroxysmal essential tachycardia have been recognised at atrial (nodal tachycardia, accessory pathway tachycardia, idiopathic atrial flutter and fibrillation) and ventricular levels (benign or ventricular Bouveret's tachycardia). This is an occasion to review the variety of clinical medicine in the accuracy of a rhythmological diagnosis without forgetting that the electrocardiogram is essential when the recordings are analysable. The term of Bouveret's tachycardia should be retained but, before electrocardiographic analysis, it englobes all paroxysmal tachycardia occurring in healthy hearts, and not only paroxysmal nodal tachycardia.

Diagnosis, Differential↗

Left ventricular adaptation to hypertension and plasma renin activity.

Chronic pressure and volume overload result in morphologically and functionally distinct forms of myocardial hypertrophy. In essential hypertension, the respective effect of these factors on the morphology of the left ventricle remains unknown. In the present study, we hypothesised that activity of the renin angiotensin system (assessed by plasma renin activity) may be associated to the variability of the left ventricular adaptation to essential hypertension. To assess this relation, we categorised by echocardiography 333 never-treated hypertensive patients, according to values of left ventricular mass and relative wall thickness. Higher systolic and pulse arterial pressure was strongly associated with concentric left ventricular hypertrophy (27% of hypertensives). When compared to the normal left ventricle group, patients with eccentric left ventricular hypertrophy (15% of hypertensives) had a high cardiac index (5 +/- 1 vs 4 +/- 0.8 L/min/m2; P = 0.0001), a lower basal plasma renin activity (0.81 +/- 0.63 vs 1.45 +/- 1.3 ng/ml/h; P = 0.02) and similar mean values of left ventricular performance and glomerular filtration rate. A tendency for depressed myocardial contractility assessed by the midwall shortening/end-systolic stress was associated with concentric left ventricular remodelling and hypertrophy when compared to hypertensive with a normal left ventricle. In conclusion, at the early phase of essential hypertension, in patients without renal dysfunction, each anatomic pattern of cardiac adaptation to hypertension was associated with a distinct profile of haemodynamics, myocardial function and activity of the renin-angiotensin system. Journal of Human Hypertension (2000) 14, 181-188.

Adaptation, Physiological↗

[Validation of the therapeutic role of amlodipine in 31,946 French hypertensive patients].

Amlodipine, a dihydropyridine calcium channel blocker (CCB), with a long duration of action, has been the subject of numerous controlled studies which showed its effectiveness and good tolerance in arterial hypertension in once-daily doses. We report the results of a large, multicentric, French, prospective phase IV study which evaluated the effectiveness and tolerance of amlodipine administered at a rate of 5 to 10 mg in only one daily dose. We also assess the evolution of the quality of life after 12 weeks of treatment among 31,946 hypertensive patients followed up to the ambulatory stage by general practitioners. The response rate--defined as the patients having had a reduction of 10 mmHg or more diastolic blood pressure--was 88%. The blood pressure standardization--defined by a diastolic blood pressure lower than 90 mmHg--was achieved for 70% of the patients. Amlodipine was administered in stand-alone therapy in 78% of the cases. The occurrence of an undesirable event was noted in the course of treatment in 12% of the patients and justified interruption of the treatment for 3.7% of the total population. The index average of quality of life was improved by the end of the 12-week treatment. This study carried out on a significant number of hypertensive patients (n = 31,946) under real prescription conditions confirms the efficacy and good tolerance of amlodipine, as has already been demonstrated in the preliminary developmental studies.

Aged↗

Left ventricular lead insertion using a modified transseptal catheterization technique: A totally endocardial approach for permanent biventricular pacing in end-stage heart failure.

This article describes a new technique of LV lead insertion, using transseptal catheterization performed through the right internal jugular vein, to obtain a totally endocardial biventricular chronic pacing in end-stage heart failure. Three patients with QRS widening (> 180 ms) linked to complete left bundle branch block (n = 2) or right ventricular pacing (n = 1) were included in this preliminary study. Catheterization was performed under fluoroscopy and transesophageal echocardiography guidance. Transseptal catheterization was achieved by puncture of the right internal jugular vein at the base of the neck and by using a Brockenbrough needle, the tip curve of which was more curved than the standard model. A flexible long sheath was advanced in the left atrium through the interatrial septum and then a unipolar electrode was placed easily in the LV. The proximal tip of the LV lead was tunneled from the neck to the subclavian area and connected to the ventricular channel of a dual (n = 1) or simple (n = 2) chamber pacemaker. Efficient acute sensing (V wave amplitude = 13 +/- 3 m V) and pacing (acute pacing threshold = 0. 7 +/- 0.4 V) were obtained in the three patients. Early loss of capture occurred in two patients requiring lead replacement. Functional status dramatically improved in all three patients. At 6-month follow-up, biventricular pacing was maintained in all patients (mean threshold 1.4 V) who were free of clinical embolic event with oral anticoagulation therapy. This modified technique of jugular transseptal catheterization appears promising for the development of left heart pacing.

Aged↗

Combined assessment of reflow and collateral blood flow by myocardial contrast echocardiography after acute reperfused myocardial infarction.

OBJECTIVE: To evaluate the combined assessment of reflow and collateral blood flow by myocardial contrast echocardiography after myocardial infarction. DESIGN: Myocardial contrast echocardiography was performed in patients with acute myocardial infarction shortly after successful coronary reperfusion (TIMI 3 patency) by direct angioplasty. Collateral flow was assessed before coronary angioplasty, and contrast reflow was evaluated 15 minutes after reperfusion. The presence of contractile reserve was assessed by low dose dobutamine echocardiography (5 to 15 micrograms/kg/min) at (mean (SD)) 3 (2) days after myocardial infarction. Recovery of segmental function (myocardial viability) was evaluated by resting echocardiography at a two month follow up. The study was prospective. PATIENTS: 35 consecutive patients referred for acute transmural myocardial infarction. RESULTS: Contrast reflow was observed in 20 patients (57%) and collateral flow in 14 (40%). Contrast reflow and collateral contrast flow were both correlated with reversible dysfunction on initial dobutamine echocardiography and at follow up (p < 0.05). The presence of reflow or collateral flow on myocardial contrast echocardiography was a highly sensitive (100%) but weakly specific (60%) indicator of segmental dysfunction recovery. Simultaneous presence of contrast reflow and collateral flow was more specific of reversible dysfunction than reflow alone (90% v 60%). CONCLUSIONS: Combined assessment of reflow and collateral blood flow enhanced the sensitivity of myocardial contrast echocardiography in predicting myocardial viability after acute, reperfused myocardial infarction. The simultaneous presence of reflow and collateral blood flow was highly specific of recovery of segmental dysfunction.

Adult↗

Chronic bradykinin infusion and receptor blockade in angiotensin II hypertension in rats.

The influence of endogenous bradykinin(BK) on the control of arterial pressure and the development of cardiac hypertrophy was assessed in chronically angiotensin II(Ang II)-infused rats (200 ng. kg-1. min-1) through the effects of concomitant infusion of 3 doses of BK (15 ng. kg-1. d-1, 100 ng. kg-1. d-1 and 100 ng. kg-1. min-1 ie, 144 000 ng. kg-1. d-1) or BK-blockade by Hoe140 (300 microg. kg-1. d-1) for 10 days. In Ang II-infused rats, tail-cuff pressure increased from 124+/-3 to 174+/-6 mm Hg (P<0.001). The pressor effect of Ang II was not affected by simultaneous infusion of BK or Hoe140. At the end of the experiments, cardiac mass was higher in rats infused with Ang II alone (3.56+/-0.10 versus 2.89+/-0.05 mg/g in untreated controls, P<0.01) and the development of cardiac hypertrophy was not modified by administration of the 3 doses of BK or Hoe140. In addition, the fall in cardiac output associated with Ang II was prevented only by the moderate and high doses of BK, mainly through an increase in stroke volume and a decrease in total peripheral resistance. In the same way, the renal vasoconstrictor effect of Ang II was abolished by the medium and high dose of BK. Hoe140 did not affect cardiac output or renal blood flow in this model. No influence of BK or Hoe140 on the increase in albuminuria induced by Ang II was detected. In conclusion, exogenous BK may oppose the effect of Ang II on vascular tone, but it cannot prevent hypertension and target-organ damage associated with this experimental model of hypertension, even at a very high dose.

Albuminuria↗

[Determinant of left ventricular hypertrophy in the hypertensive woman. Influence of hormone replacement therapy for menopause].

BACKGROUND: This study investigated the influence of hormone replacement therapy on the variability of the cardiac hypertrophic response to hypertension in postmenopausal women. METHODS: 25 menopausal essential hypertensive women (mean age 54 +/- 0.8 years, range 45 to 70) treated with estrogen (without progestin) for at least 1 year were studied and compared with 25 menopausal age-matched women (55 +/- 1 years old, range 46 to 70) not taking such therapy. No women had ever received antihypertensive therapy. Left ventricular mass corrected by height2.7 and relative wall thickness were assessed by M mode echocardiography. RESULTS: Age, blood pressure, body mass index, 24 h urinary sodium excretion and plasma renin activity were in the 2 groups with and without hormone replacement therapy. Left ventricular mass corrected by height2.7 was significantly higher in the group with without estrogen replacement therapy when compared to menopausal women with estrogen replacement (55 +/- 3 vs 45 +/- 4 g/m2.7 p < 0.02). In addition the slope of the regression line between LV mass and systolic BP was significantly higher (p < 0.01) in the group of women without hormonal therapy r = 0.50 p < 0.001. CONCLUSION: These results suggest that estrogen therapy of menopause attenuate the cardiac hypertrophic response to hypertension.

Aged↗

Large encircling cryoablation without mapping for ventricular tachycardia after anterior myocardial infarction: long-term outcome.

OBJECTIVE: Map-guided procedures have been the accepted standard for ventricular tachycardia surgery. However, promising results of visually guided resections without mapping have been reported. The goal of this study was to evaluate the efficacy of large encircling cryoablation without mapping for ventricular tachycardia after anterior myocardial infarction. METHODS: Between 1985 and 1996, this procedure, along with aneurysmectomy, was performed on 38 patients for malignant ventricular tachycardia. The mean interval between the operation and myocardial infarction was 59.2 months; 7 patients (18.4%) were operated on within 1 month of myocardial infarction. The mean patient age was 62.1 +/-7.3 years and the mean left ventricular ejection fraction was 29.0% +/-7.2%. RESULTS: Hospital mortality was 2.6% (1 patient). The electrical success rate based on postoperative electrophysiologic studies was 94.5%. Overall electrical success rate was 89.1%. Freedom from ventricular tachycardia was 77% (95% CI 61%-94%) at both 5 and 7 years. Freedom from sudden cardiac death was 91% (95% CI 80%-100%) at both 5 and 7 years, with overall actuarial survivals at 5 and 7 years of 63% (95% CI 47%-80%) and 42% (95% CI 22%-63%), respectively. The main cause of late death was congestive heart failure in 62.6% of these patients. CONCLUSIONS: One can achieve good results without intraoperative mapping in the treatment of patients with ventricular tachycardia after anterior myocardial infarction by using large encircling cryoablation.

Actuarial Analysis↗