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Biomedical subjects

X Jeanrenaud

Publications and source records attributed to X Jeanrenaud.

At least 19 recordsLinked to original sources
PubMed2006

[Echocardiographic analysis in cardiac amyloidosis].

Systemic amyloidosis with cardiac involvement may clinically be suspected in the presence of heart failure or arrhythmia of unknown origin. Herein two cases of cardiac amyloidosis are described with a clinical presentation of heart failure refractory to usual treatment. The key role of echocardiography in the diagnosis and prognosis evaluation of cardiac amyloidosis is discussed. A treatment targeted against the generation of amyloid fibril should ideally be initiated before apparition of heart failure.

Aged↗
PubMed2005

[Surgical options for terminal heart failure].

Terminal heart failure can be the cause or the result of major dysfunctions of the organisms. Although, the outcome of the natural history is the same in both situations, it is of prime importance to differentiate the two, as only heart failure as the primary cause allows for successful mechanical circulatory support as bridge to transplantation or towards recovery. Various objective parameters allow for the establishment of the diagnosis of terminal heart failure despite optimal medical treatment. A cardiac index <2.0 l/min, and a mixed venous oxygen saturation <60%, in combination with progressive renal failure, should trigger a diagnostic work-up in order to identify cardiac defects that can be corrected or to list the patient for transplantation with/without mechanical circulatory support.

Assisted Circulation↗
PubMed2005

Morphological, clinical and genetic aspects in a family with a novel LAMP-2 gene mutation (Danon disease).

A family with several cases of severe cardiomyopathy and moderate myopathy is described, affecting two brothers and their cousin as well as their mothers. One boy died of sudden cardiac arrest at 17 years of age. The two brothers were treated with an implantable defibrillator and their mother died suddenly at 40 years of age. Muscle biopsy in males showed vacuolar myopathy in two cases, and no abnormality on standard staining in the third case. Cardiac biopsies showed hypertrophic and vacuolated fibres. Complete absence of LAMP-2 was demonstrated by immunohistochemistry on the vacuolated skeletal and cardiac muscle, but also on the morphologically normal skeletal muscle. Sequencing of LAMP-2 gene showed a novel S157X mutation in exon 4. Danon disease is a rare and potentially lethal cause of hypertrophic cardiomyopathy. Diagnosis can be made by immunohistochemistry performed on cardiac or muscle biopsy, and confirmed by genetic analysis, which also allows for easy family screening and counselling.

Adolescent↗
PubMed2004

Localization and quantification of mitral valve prolapse using three-dimensional echocardiography.

AIMS: Mitral valve prolapse is a common source of severe mitral regurgitation in Western countries. Three-dimensional echocardiography can provide views of the entire valve, allowing a complete assessment of the valve leaflets and commissures. It has the potential to precisely locate and quantify mitral valve prolapse. METHODS AND RESULTS: Between January 1997 and December 2000, 91 patients with severe mitral regurgitation due to mitral valve prolapse underwent a transesophageal echocardiography with three-dimensional reconstruction of the mitral valve as part of their pre-operative work-up. The location and extent of the prolapse by echo was compared to the surgical status. The volume of prolapsing leaflet was calculated and compared to the volume of resected tissue whenever a repair was attempted. There was an excellent correspondence between the echographic localization of the prolapse and surgical inspection, and between the volume of prolapsing and surgically resected tissue (r=0.94, p<0.0001). CONCLUSIONS: In patients with severe mitral regurgitation due to mitral valve prolapse, 3D echo allowed a precise localization and an accurate quantification of the prolapsing portion of the leaflets. This technique can provide refinements in the surgical planning of mitral valve repair and in the selection of candidates for this intervention.

Adult↗
PubMed1999

Significant improvement of quality of life following atrioventricular synchronous pacing in patients with hypertrophic obstructive cardiomyopathy. Data from 1 year of follow-up. PIC study group. Pacing In Cardiomyopathy.

AIMS: Atrioventricular synchronous pacing exerts beneficial effects, including reduction of left ventricular outflow tract gradients, in patients with hypertrophic obstructive cardiomyopathy. The Pacing in Cardiomyopathy study was initiated to explore the effects of pacing in a double-blind randomized crossover fashion. The aims were to ascertain the beneficial effects of pacing in a controlled study and to rule out a placebo effect by pacing. This paper deals with the outcome of pacing on quality of life during 1 year of follow-up. METHODS: Quality of life was evaluated with the Karolinska questionnaire, validated for patients paced for bradyarrhythmias and ischaemic heart disease. Drug-refractory patients with hypertrophic obstructive cardiomyopathy were recruited for the study and after a temporary pacing procedure implanted with permanent pacemakers. Patients were randomized to two study arms defining the sequence of pacemaker programming. In one arm the pacemaker was inactive, in the other active. After 3 months the pacemaker was reprogrammed to the alternate mode and a further 3 months followed. After this period subsequent pacemaker programming corresponded to the mode preferred by the patient. A last assessment was made 1 year after baseline examinations. RESULTS: Eighty patients completed the first crossover period and 75 completed the full 1 year of follow-up. Active pacing induced significant quality of life improvements, in the order of 9-44%, regardless of programming sequence. Discontinuation of pacing after a first active period resulted in the return of symptoms. Fourteen patients requested early reprogramming after having been programmed to inactive pacing after a first period of active pacing. Seventy-six patients preferred active pacing after the crossover period. A further 6 months of pacing induced progressive improvement in symptoms already favourably influenced. CONCLUSION: Atrioventricular synchronous pacing has a profound beneficial effect on most domains of quality of life in patients with hypertrophic obstructive cardiomyopathy refractory to drug treatment.

Adult↗
PubMed1999

Clinical progress after randomized on/off pacemaker treatment for hypertrophic obstructive cardiomyopathy. Pacing in Cardiomyopathy (PIC) Study Group.

BACKGROUND: The therapeutic options for hypertrophic obstructive cardiomyopathy (HOCM) classically include medical treatment with beta-blockers and calcium antagonists or myectomy-myotomy as a surgical possibility for refractory cases. The observation that pacemaker activation of the heart in HOCM reduces the subaortic gradient is well known but less well investigated. METHODS: Eighty-three patients (33 female and 50 male) mean age 53 (18-82) years, with symptoms refractory to drug treatment and a resting gradient above 30 mmHg, who responded favourably to temporary pacing, were included in this prospective study and had a pacemaker (DDD) implanted. After an initial double-blind crossover phase of 6 months, patients were reinvestigated at 12 months and followed for a mean of 36 months. RESULTS: As observed during a screening investigation, the obstruction was significantly reduced from 72 +/- 35 mmHg to 29 +/- 24 mmHg (P < 0.01) when the pacemaker was on, while no major effect was seen during the sham phase. The effect was persistent at 1 year with a remaining resting gradient of 28 +/- 24 mmHg. In parallel, we documented an improvement in functional capacity, according to the NYHA classification and by quality of life analysis, and a significant improvement in dyspnoea and angina. Exercise on treadmill improved only in patients with reduced initial tolerance (< 8 min). During the mean follow-up of 36 months, 65 patients remained on pacing alone, with eight patients having additional AV-node ablation and five patients finally having surgery. CONCLUSION: This controlled multicentre study shows that pacemaker treatment is an option for HOCM patients; it is inoffensive and does not exclude alternative methods, but satisfies 79% of patients beyond 3 years.

Adolescent↗
PubMed1998

An echocardiographic and magnetic resonance imaging comparative study of right ventricular volume determination.

Assessment of right ventricular volume and function is important in many clinical settings involving heart or lung disease. However, the complexity of the right ventricular anatomy has prevented accurate volume determination by two-dimensional echocardiography. In the present study, 5 models incorporating standard echocardiographic views, were used to determine right ventricular volume in 10 human subjects. Two models were contingent on the true crescentic appearance of the right ventricle, whereas the remaining 3 calculated the right ventricular volume as a pyramid, an ellipsoid or other tapering geometrical figures, respectively. Subsequently, echocardiographic right ventricular volumes were compared to magnetic resonance imaging derived volumes. Correlation analysis and agreement measurement between the echocardiographic and magnetic resonance end-diastolic volume were performed in 10 out of 10 subjects and in 9 out of 10 subjects for the end-systolic volume. The 2 crescentic models resulted in the most reliable estimation of right ventricular volume. Those findings suggest that models based on right ventricular anatomical landmarks are feasible and should be preferred in echocardiographic studies.

Adult↗
PubMed1997

[Diastolic dysfunction of the left ventricle: from physiopathology to treatment].

Our understanding of cardiac failure has greatly changed over the last 15 years. Left ventricular diastolic dysfunction, which is now recognised as one of the primary causes of certain types of cardiac failure (1). Abnormal left ventricular diastolic function is the common determinant and indeed the earliest sign of all chronic left ventricular failures whether systolic left ventricular dysfunction is associated with it or not (2). In this paper, we review the basis of diastolic dysfunction and its impact on diagnosis and treatment of cardiac failure.

Aged↗
PubMed1997

Systematic surgical closure of patent foramen ovale in selected patients with cerebrovascular events due to paradoxical embolism. Early results of a preliminary study.

OBJECTIVE: To define therapeutic strategy for management of patients with ischemic stroke due to a high probability of paradoxical embolism through a Patent Foramen Ovale (PFO). METHODS: Since 1988 all consecutive patients with cerebrovascular events and PFO from the Stroke Registry of our population-based primary-care center are prospectively studied and followed. Since 1992, among 118 patients with cryptogenic embolic brain infarct or transient ischemic attack (TIA) and PFO, 32 consecutive patients younger than 60 years who presented at least two of the following criteria were admitted for surgery: history of Valsalva strain before stroke (11); multiple clinical events (13); multiple infarcts on brain Magnetic Resonance Imaging (MRI) (15); atrial septal aneurysm (ASA) (16); large right-to-left shunt (> 50 microbubbles) (12). RESULTS: Operative time 135' +/- 33'. CPB time 34' +/- 14'. Aortic crossclamping time 16' +/- 6'. Post-operative bleeding 485 +/- 170 ml. No homologous blood transfusion required. No neurological, cardiac or renal complications. All patients were followed-up corresponding to a cumulative time of 601 patient-months. This revealed no recurrent vascular events nor silent new brain lesions on brain MRI. Systematic simultaneous contrast Trans Esophageal Echocardiography (TEE)-Trans Cranial Doppler showed a small residual interatrial shunt in two patients. CONCLUSION: Surgical closure of a patent foramen ovale can be accomplished with very low morbidity and reduce efficiently the risk of stroke recurrence. It seems to be the option of choice in selected patients with a higher (> 1.5%/year) risk of stroke recurrence.

Adult↗
PubMed1997

Pacing in hypertrophic obstructive cardiomyopathy. A randomized crossover study. PIC Study Group.

BACKGROUND: Uncontrolled studies have shown that short atrioventricular delay dual chamber pacing reduces outflow tract obstruction in hypertrophic obstructive cardiomyopathy. Although the exact mechanism of this beneficial effect is unclear, this seems a promising potential new treatment for hypertrophic obstructive cardiomyopathy. METHOD: In order to evaluate the impact of pacing therapy, were performed a randomized multicentre double-blind cross-over (pacemaker activated vs non activated) study to investigate modification of echocardiography, exercise tolerance, angina, dyspnoea and quality of life in 83 patients with a mean age of 53 (range 22-87) years with symptoms refractory or intolerant to classical drug treatment. RESULTS: After 12 weeks of activated or inactivated pacing, independent of which phase was first, the pressure gradient fell from 59 +/- 36 mmHg to 30 +/- 25 mmHg (P < 0.001) with active pacing. Exercise tolerance improved by 21% in those patients who at baseline tolerated less than 10 min of Bruce protocol; symptoms of dyspnoea and angina also improved significantly from NYHA class 2.4 to 1.4 and 1.0 to 0.4, respectively (P < 0.007). Quality of life assessment with a validated questionnaire objectivated the subjective improvement. CONCLUSION: Pacemaker therapy is of clinical and haemodynamic benefit for patients with hypertrophic obstructive cardiomyopathy, left ventricular outflow gradient at rest over 30 mmHg who are symptomatic despite drug treatment.

Adult↗
PubMed1997

Regional wall motion during pacing for hypertrophic obstructive cardiomyopathy.

In order to assess the influence of right ventricular stimulation on LV contraction sequence in hypertrophic obstructive cardiomyopathy (HOCM), we performed a regional wall-motion analysis of the left ventricle by comparing normal His-Purkinje activation to pacing from the right ventricular apex. In 9 patients (5 males and 4 females, mean age 61 +/- 9 years) assessed after a mean pacing period of 12 weeks (range 7-24 weeks), AV sequential pacing induced a 52% reduction in maximal pressure gradient from 76 +/- 36 to 40 +/- 28 mmHg (P < 0.01) as determined by Doppler examination. Regional wall-motion analysis of the left ventricle was computed from digitized two-dimensional echocardiographic images by means of the area shrinking method. Pacing induced a significant reduction of total septal area shrinking from 25% +/- 17% to 12% +/- 17% (P < 0.005). A tendency toward paradoxical septal motion was observed in one patient only. The apex showed no significant variation. A 6% increase in area shrinking was observed at the posterior wall and lateral free wall, from 38% +/- 13% to 43% +/- 10% (P < 0.05). Pacing did not significantly alter the global ejection fraction. A direct correlation between the magnitude of subaortic pressure gradient reduction and that of septal motion changes was found in a majority of patients. In conclusion, dual chamber pacing reduces septal wall motion in patients with HOCM obstructive cardiomyopathy. This might be one of the mechanisms involved in the reduction of LV outflow tract obstruction.

Cardiac Pacing, Artificial↗
PubMed1997

Acute hemodynamic effects of atrioventricular pacing at differing sites in the right ventricle individually and simultaneously.

We hypothesized that pacing, which provided a rapid uniform contraction of the ventricles with a narrower QRS, would produce a better stroke volume and cardiac output (CO). We sought to study whether pacing simultaneously at two sites in the right ventricle (right ventricular apex and outflow tract) would provide a narrower QRS and improved CO in 11 patients undergoing elective electrophysiology studies. Patients were studied by transthoracic echocardiography measurement of CO using the Doppler flow velocity method in normal sinus rhythm, AOO pacing (rate 80), DOO pacing in the right ventricular apex (AV delay 100 ms), DOO pacing in the right ventricular outflow tract, and DOO pacing at both right ventricular sites simultaneously in random order. The COs were 5.42 +/- 1.83, 5.61 +/- 1.97, 5.67 +/- 1.6, 5.84 +/- 1.68, and 5.86 +/- 1.52 L/min, respectively (no significant difference by repeated measures analysis of variance [ANOVA]). The QRS durations were 0.09 +/- 0.02, 0.09 +/- 0.02, 0.13 +/- 0.027, 0.13 +/- 0.03, and 0.11 +/- 0.03 secs respectively. Repeated measures ANOVA showed that the QRS duration significantly increased with right ventricular apex or right ventricular outflow tract pacing compared to sinus rhythm and AOO pacing (P < 0.001) but then diminished with pacing at both sites (P < 0.01). QRS duration was not correlated with CO, however the change in QRS duration correlated significantly with the change in CO when pacing was performed at the two right ventricular sites simultaneously. In conclusion, during DOO pacing, there was a trend for pacing in the right ventricular outflow tract or both sites to improve the CO compared to the right ventricular apex. With simultaneous pacing at both ventricular sites, the QRS narrowed. Further studies will be required to see if this approach has value in patients with poor left ventricular function or congestive heart failure.

Adult↗
PubMed1997

Dual chamber pacing in hypertrophic obstructive cardiomyopathy: beneficial effect of atrioventricular junction ablation for optimal left ventricular capture and filling.

Clinical improvement with dual chamber pacing has largely been reported in patients suffering from hypertrophic obstructive cardiomyopathy and mainly attributed to the reduction of the subaortic pressure gradient. To be effective, pacing must induce a permanent and complete capture of the LV. In two patients of our collective, symptoms (angina and dyspnea NYHA Class III and/or syncopes) persisted or relapsed despite pacing. This was related to the inability to obtain full LV capture due to a too-short native PR interval. RF ablation of the AV junction was therefore performed in both patients, resulting in permanent AV block in one and prolonged PR interval up 310 ms in the second. Pacing was thereafter associated with an immediate and significant clinical improvement related to permanent LV capture, whatever the patient's activity. After RF ablation, the AV delay was set up to induce the best LV filling, as assessed by Doppler analysis of mitral flow. Our observations suggest that RF ablation or modification of the AV junction can be a successful procedure in some patients with residual or recurrent symptoms, when the latter result from a loss of capture or from the inability to program an AV delay that does not compromise the active component to LV filling. Doppler echocardiography is a simple and effective mean to assess the hemodynamic effect of AV interval modulation in this setting.

Angina Pectoris↗
PubMed1997

Complementarity of contrast transcranial Doppler and contrast transesophageal echocardiography for the detection of patent foramen ovale in stroke patients.

All studies concerning the detection of patent foramen ovale (PFO) have compared transthoracic or transesophageal echocardiography (c-TEE) to transcranial Doppler ultrasound after contrast injection (c-TCD), but combining both techniques in the search of PFO has received no consideration. Our study aims to substantiate this claim in 37 patients with cryptogenic stroke. It includes two protocols for the detection of PFO to assess the complementarity of c-TCD and c-TEE performed simultaneously or separately. Firstly, we used a standardized protocol, performing c-TCD alone. Secondly, we used a standardized and a simultaneous protocol which associated c-TCD with c-TEE. When c-TCD and/or c-TEE found right-to-left shunts, they were classified as minimal, intermediate and massive. c-TCD revealed all PFO detected by c-TEE in 24 patients out of 37 (65%). Furthermore, c-TCD was positive for a PFO in 5 other patients whereas c-TEE was negative. The degree of right-to-left interatrial shunting varied according to the protocol: c-TCD performed alone found 15 massive, 4 intermediate and 5 minimal shunts whereas 10, 9 and 5, respectively, were detected by c-TCD when it was combined with c-TEE. In contrast, c-TEE revealed 8 massive, 8 intermediate and 8 minimal shunts. c-TCD can identify minimal shunts missed by c-TEE and could be more relevant to detect massive shunts, particularly when not performed simultaneously with c-TEE because no sedation is required for c-TCD alone as opposed to c-TEE: thus patients are more cooperative and produce a better Valsalva strain. c-TEE confirms pulmonary shunts suspected by c-TCD and determines the morphologic characteristics of the interatrial septum. While previous studies opposed c-TEE against c-TCD for the detection of a PFO, we think that both techniques are complementary and that it is interesting to associate them, particularly when they are deferred, to increase the ability of detecting PFO and to specify the degree of right-to-left shunting.

Adult↗
PubMed1997

[Effect of stimulation on ventricular kinetics: contribution to the treatment of cardiomyopathies].

Cardiac pacing using the apex of the right ventricle as site of excitation induces asynchronous contraction between the right ventricle and the left ventricle as well as inversion of the normal left ventricular activation sequence. These two phenomena are responsible for alteration of septal kinetics and overall contractility. It has recently been demonstrated that these alterations can be used to advantage to reduce the degree of subaortic obstruction of patients suffering from hypertrophic and obstructive cardiomyopathy, and to improve their exercise tolerance. Using an opposite approach, consisting of reducing the degree of asynchronous contraction related to the presence of intraventricular conduction disorders, while optimizing atrioventricular synchronism, new pacing methods have recently been able to improve cardiac output and functional tolerance of some patients suffering from dilated cardiomyopathy. Although cardiac pacing can now be considered to be an alternative a surgery for the treatment of refractory forms of hypertrophic and obstructive cardiomyopathy, it still constitutes a research technique in the field of dilated cardiomyopathy.

Cardiac Pacing, Artificial↗