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Biomedical subjects

P Messner-Pellenc

Publications and source records attributed to P Messner-Pellenc.

At least 19 recordsLinked to original sources
PubMed2000

Postoperative exercise tolerance after aortic valve replacement by small-size prosthesis: functional consequence of small-size aortic prosthesis.

OBJECTIVES: The objective of this study was to determine whether a small-size valve prosthesis contributes to exercise intolerance, as assessed by VO2 measurement during an exhaustive cycle ergometer exercise. BACKGROUND: The determinants of exercise capacity after mechanical aortic replacement are not well known. The selection of small valve sizes has, however, been described as an independent predictor of exercise intolerance as assessed by exercise duration. Maximal oxygen uptake (VO2max) is a good index of exercise tolerance. METHODS: Fourteen patients were eligible, with a mean age of 62 +/- 6 years. Before surgery, the mean left ventricular ejection fraction (LVEF) was 73 +/- 8%. Two valve types with small diameter (19 to 21 mm) were used: Medtronic Hall and St Jude Medical. A healthy sedentary control group (n = 14) paired for age, weight and size was constituted. After one year of follow-up, cardiorespiratory tests were performed. In addition, the gradients through the prostheses were determined by continuous pulse Doppler at rest and immediately after the cardiorespiratory test. RESULTS The exercise tolerance was not significantly different between the control group and patient group: VO2 peak (21.7 vs. 20.4 ml/kg/min; p = 0.42), workloads (115 vs. 93 W; p = 0.13) and ventilatory parameters were similar. The mean and peak gradients at rest and during exercise were not correlated with VO2max. CONCLUSIONS: Valve replacement by small aortic prosthesis does not seem to be a factor of exercise intolerance as assessed by VO2max in patients without LVEF dysfunction before surgery.

Aged↗
PubMed2000

Successful conservative surgery of acute ascending aortic dissection occurring during coronary angiography.

We reported the case of an acute aortic dissection complicating right guiding catheter manipulation during engagement in the right coronary ostium. Despite absence of hemodynamic deterioration, dissection progressed rapidly from the sinus of Valsalva to the ascending aorta along its entire length. At surgery, performed in emergency, the aorta was not dilated and the aortic wall did not appear pathologic. Therefore conservative surgery was performed, consisting of suture of the aortic tear and incollage of the false lumen, with good immediate and mid-term results.

Aged↗
PubMed1999

A "dysautonomic" head-up tilt test pattern in elderly patients with neurocardiogenic syncope.

The characteristics of neurocardiogenic syncope (NCS) in elderly patients remain unclear. We compared the hemodynamic profiles of young and older patients with consecutive and positive head-up tilt tests (HUT). Continuous, noninvasive, and reliable monitoring of arterial pressure (AP) and heart rate (HR) was done throughout 46 consecutive positive HUTs of symptomatic patients. The population (12-82 years old) was divided into two groups: younger patients, Y (n = 25, < or = 65 years), and older patients, O (n = 21). Changes in AP and HR after the first minute of tilting, during the stable orthostatic phase and during syncope were compared. Except for systolic pressure, baseline hemodynamic parameters were similar in Y and O. No difference appeared in the mean time elapsed before syncope (19+/-9 vs 22+/-2 min). Asymptomatic hypotension was observed, only in O, 1 minute after tilting, followed by a progressive fall in the mean AP before syncope (0+/-0.9 vs -1+/-0.7 mmHg/min) without HR increase (0.7+/-1 vs 0+/-0.6 beats/min). This pressure slope was strongly related to age (r = 0.54, P < 0.001). Hemodynamic recording during HUT identifies a dysautonomic pattern in elderly patients with NCS and the abnormal AP/HR responses to orthostasis may be a feature specific to this population. Although the central mechanism of NCS is common to all ages, the age-related characteristics of the trigger event may indicate the need for specific management at different ages.

Adolescent↗
PubMed1999

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↗
PubMed1998

Exercise tolerance in heart transplant patients with altered pulmonary diffusion capacity.

To test whether orthotopic heart transplant (OHT) patients with low pulmonary diffusion capacity have a greater limitation to exercise than OHT patients with normal pulmonary diffusion capacity, we investigated cardiorespiratory responses and blood gases in two groups of OHT patients, one with low (LdG) and the other with normal pulmonary diffusion capacity (NdG), during a graded exercise test. The results showed 1) significantly reduced peak power (P < 0.05), peak oxygen uptake (VO2, P < 0.001), peak oxygen pulse (VO2/heart rate, P < 0.01), peak minute ventilation (VE, P < 0.05), and delta PaO2 (peak PaO2 - rest PaO2, P < 0.05) in LdG versus NdG; 2) a nonsignificant decrease in peak heart rate in LdG (P < 0.13, P = 24%); and 3) significant increases in peak respiratory equivalent for oxygen (VE/VO2, P < 0.05) and delta P(A-a)O2 (peak P(A-a)O2 - resting P(A-a)O2, P < 0.05) in LdG versus NdG. No significant difference was found for PaO2 and PaCO2 at rest or at peak exercise between the groups. A strong correlation was found between pulmonary diffusion capacity (TLCO/VA) and peak VO2 (r = 0.81, P < 0.01); that is, TLCO/VA explains 66% of the variance in peak VO2. We conclude that OHT patients with decreased pulmonary diffusion capacity have a lower exercise tolerance than patients with normal pulmonary diffusion capacity. However, because of the lack of exercise-induced hypoxemia, diffusion abnormalities are not the main limiting factor for exercise tolerance in the low diffusion group.

Blood Gas Analysis↗
PubMed1998

[Low-dose dobutamine echocardiographic assessment of reversible contractile dysfunction (myocardial stunning) after myocardial infarction].

Low dose (5 to 10 micrograms/min) dobutamine echocardiography was used to predict the presence of reversible contractile dysfunction (myocardial stunning) after myocardial infarction successfully revascularised in the acute phase of primary angioplasty. The investigation was undertaken in 40 patients, 4 +/- 1 days after inaugural myocardial infarction. The left ventricle was divided into 16 segments. Viable myocardium was diagnosed when the initial regional wall motion score decreased by at least 2. Resting echocardiography was performed at 2 months to evaluate the effective recovery of regional wall motion (myocardial viability). The presence of contractile reserve was documented by dobutamine echocardiography in 18 patients (45%). The sensitivity, specificity and positive and negative predictive values of dobutamine echocardiography for the diagnosis of myocardial viability were 82, 83, 78 and 86% respectively. The negative predictive value was high in all dysnergic segments (86%). The positive predictive value of the investigation was however higher in hypokinetic than in akinetic segments (73 vs 21%; p < 0.05). The recovery of regional wall motion during follow-up was statistically related to higher initial left ventricular ejection fraction (p < 0.04), the presence of angiographically documented collateral circulation before revascularisation (p = 0.007), the contractile response to dobutamine (p = 0.0001) and was observed more frequently in hypokinetic than in akinetic segments (p < 0.05). These results show that low-dose dobutamine echocardiography is a sensitive and specific investigation for predicting irreversible myocardial damage after successful primary angioplasty in acute myocardial infarction. However, even in the absence of residual coronary stenosis, the presence of viable myocardium is only identified specifically in hypokinetic segments.

Aged↗
PubMed1998

[Role and significance of cytokines in the development of cardiac insufficiency].

The hypothesis of immune and inflammatory activation occurring during chronic cardiac failure, capable of maintaining the disease, is supported by many experimental and clinical trials. Plasma cytokines levels, particularly the tumour necrosis factor alpha (TNF alpha), are raised at advanced stages of the disease, especially in cachectic patients. The correlations with other, more traditional markers, especially neurohumoral, are not very close, probably suggesting different mechanisms. Cytokines are a group of very different molecules with multiple, non-specific, and even beneficial effects. However, the lack of regulation in severe cardiac failure may lead to deleterious effects on the heart. The experimental effects of TNF alpha (mini-pumps, transgenic animals) include features of myocarditis, chamber dilatation and contractile dysfunction. Large scale therapeutic trials of long acting TNF alpha antagonists could confirm the "inflammation hypothesis" of mutual interaction between cardiac failure and the production of cytokines.

Cardiac Output, Low↗
PubMed1997

Myocardial viability assessed by dobutamine echocardiography in acute myocardial infarction after successful primary coronary angioplasty.

Dobutamine echocardiography (5 and 10 microg/kg/ min) was performed in 40 patients 4 +/- 1 days after acute myocardial infarction reperfused by primary coronary angioplasty. The left ventricle was divided into 11 segments. Reversible myocardial dysfunction was indicated by a decrease in at least 2 grades in the total segmental score. Follow-up echocardiography was performed 2 months later. Contractile reserve was documented in 18 patients with dobutamine echocardiography (45%). Sensitivity, specificity, positive, and negative predictive value of dobutamine echocardiography in predicting improvement in contractile function at follow-up were 82%, 83%, 78%, and 86%, respectively. Negative predictive value was high in all dyssynergic segments (86%). Positive predictive value was higher in hypokinetic than in akinetic segments (73% vs 21%; p <0.05). Recovery of wall motion at follow-up was statistically associated with higher left ventricular ejection fraction (p <0.04), collateral blood flow before reperfusion (p = 0.007), and dobutamine responsiveness (p = 0.0001), and was more frequently observed in hypokinetic than in akinetic segments (p <0.05). Thus, low-dose dobutamine echocardiography accurately predicts the extent of irreversibly damaged myocardium early after successful direct coronary angioplasty in acute myocardial infarction.

Aged↗
PubMed1997

[Cardiorespiratory adaptations to exercise].

For the organism, adaptation corresponds to a physiological response to a problem raised by a modification in the internal medium and/or the environment while preserving homeostasis. Adaptations to muscle exercise can involve changes in metabolic, respiratory, or nutritional, or nutritional functions or any other modifications whose endpoint is the production more ATP for further muscle exercise. Adaptations occur at all the levels of the oxygen transport chain. We will thus focus successively on the notions of VO2max, ventilatory adaptations, thresholds, respiratory exchange, cardiac and vascular adaptations and peripheral adaptations.

Adaptation, Physiological↗
PubMed1997

[Cardiopulmonary exercise test in cardiology].

In the cardiopneumologic exercise test, a concomitant analysis of respiratory gas exchange is conducted in addition to the usual cardiologic exercise test: After excluding patients with the habitual contraindications, the test must be conducted with a rigorous methodology, with particular care being given to standardizing the equipment settings before each test and in choosing an individualized protocol allowing a maximal test for a duration of no longer than 10 to 12 minutes. This cardiopneumologic exercise test allows a good assessment of the pneumological pathophysiological factors participating in limited exercise capacity of cardiac origin. It can also help the clinician distinguish cardiac from pulmonary dyspnea, particularly by measuring ventilatory reserves at maximum effort. Most importantly, in clinical practice the test provides an objective and reproducible assessment of the patient's exercise capacity. This allows a functional classification useful for therapeutic decision making, as for example when determining the best moment to propose heart transplantation or when prescribing adapted exercise retraining for a heart failure patient. Finally, the exercise test provides objective evidence of symptom improvement, for example after rehabilitation, an improvement which is one of the mainstay objectives of treatment in patients with cardiac-related exercise intolerance.

Contraindications↗
PubMed1996

Exercise tolerance in patients with mitral stenosis before and after acute percutaneous mitral valvuloplasty. Role of lung diffusing capacity limitation?

The aim of this study was to specify in patients with tight mitral stenosis whether lung diffusing capacity could play a role in their exercise intolerance. A similar study was recently carried out in patients with moderate chronic heart failure. Ten patients with tight mitral stenosis were studied before and 6 months after successful percutaneous transvenous balloon valvuloplasty and compared to six control subjects. Measurements of diffusing capacity, evaluated by the lung transfer factor (TLCO) and by the transfer coefficient (TLCO/VA), obtained at rest and during early recovery after cardiopulmonary exercise testing were performed. Cardiac output was determined non-invasively, both at rest and during exercise, using the carbon dioxide exponential rebreathing technique. Prior to valvuloplasty, TLCO and TLCO/VA were not different at rest between the two groups. During exercise, patients differed from control subjects, with lower oxygen uptake (P < 0.001) and lower cardiac output at peak exercise (P < 0.001). These values at peak exercise were significantly correlated (P = 0.02; r = 0.75). Moreover, patients differed from control subjects at early recovery after peak exercise with an absence of increase in TLCO (P < 0.05). Six months after valvuloplasty, a decrease of both TLCO (P < 0.01) and TLCO/VA (P < 0.05) was observed at rest. During exercise, comparison of patients demonstrated a significant increase of both peak exercise oxygen uptake (SLVO2, P < 0.01) and cardiac output (P < 0.001). At early recovery after peak exercise there was a significant increase in TLCO (P < 0.05) and TLCO/VA (P < 0.01), such that a delta TLCO and a delta TLCO/VA appeared (P < 0.05) identical to that observed in control subjects. Moreover, delta SLVO2 was significantly correlated in patients with delta Q+ delta TLCO/VA (P = 0.02; r = 0.72). In conclusion, this study suggests a role, at least partial, of lung diffusing capacity in exercise intolerance in patients with tight mitral stenosis and in the improvement of their aerobic exercise capacity demonstrated after successful percutaneous balloon valvuloplasty.

Adult↗
PubMed1995

The use of technetium-99m hexamethylpropylene amine oxime labelled granulocytes with single-photon emission tomography imaging in the detection and follow-up of recurrence of infective endocarditis complicating transvenous endocardial pacemaker.

In this case report we present a patient with a recurrence of subacute bacterial infectious endocarditis (IE) complicating a transvenous endocardial pacemaker. Technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) labelled granulocytes were used for diagnosis and follow-up under medical treatment only, since surgical removal of the pacemaker lead was ruled out because of the general condition of the patient. Single-photon emission tomography (SPET) imaging displayed the active lesion previously suspected on echography. At the end of antibiotic therapy, SPET indicated a favourable disease outcome whereas echocardiographic abnormalities remained nearly unchanged. The medical treatment had eradicated the IE, and the patient did well for more than 1 year thereafter.

Aged↗
PubMed1995

Exercise intolerance in patients with chronic heart failure: role of pulmonary diffusing limitation.

In order to test the hypothesis of pulmonary diffusing capacity involvement in exercise limitation in subjects with chronic heart failure (CHF), lung transfer factor (TLCO), oxygen saturation (SaO2), cardiac output (CO) and gas exchange were studied over the course of an incremental exercise test in 10 patients and 10 controls. The TLCO and transfer coefficient for carbon monoxide (TLCO/VA) were measured at rest and during recovery by the single breath method. The SaO2 was followed non-invasively with a finger oximeter and CO was determined according to the carbon dioxide rebreathing method. Analysis of respiratory variables at maximal effort showed significantly lower values in patients with CHF as regards peak oxygen uptake (VO2), minute ventilation (VE), heart rate (HR), oxygen pulse (O2 pulse), and CO with higher ventilatory reserve (VR) than controls. At a comparable workload (30 W), patients with CHF demonstrated higher values for VE and lower values for CO than controls. The TLCO, expressed as percent of predicted values, was significantly lower in CHF patients than controls, respectively, at rest (90.5 +/- 3.75% vs 106.8 +/- 3.8%) and within 5 min after maximal exercise (87 +/- 4.4% vs 117.4 +/- 3.81%). The TLCO/VA showed comparable data between the two groups at rest (81.7 +/- 3.28 vs 90.3 +/- 2.86%). However, significantly lower values of TLCO/VA were obtained for CHF after maximal exercise in comparison to control subjects (77.5 +/- 3.85% vs 96.3 +/- 3.95%). These results confirm the alteration of the main variables in relation to cardiopulmonary exercise limitation in-tHF, and indicate a significant decrease in TLCO and TLCO/VA after maximal exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Exercise↗
PubMed1995

[Clinico-pathological polymorphism of hypertrophic cardiomyopathy in echocardiography].

An echocardiographic Study of 322 adults (age: 40 +/- 16 years), belonging to 20 families with hypertrophic cardiomyopathy (HCM), was undertaken. Affected subjects had a LV diastolic wall thickness > 13 mm. The patients were classified according to the distribution of left ventricular hypertrophy (LVH) and by Maron's classification: 189 subjects were normal, 127 were affected and 6 could not been classified. By Maron's classification: 3% were type I, 33% were type II, 58% were type III and 6% were type IV. LVH was asymmetrical in 95% of cases (septum/posterior wall ratio > 1.3). The familial distribution of LVH of the 4 families in which HCM was genetically related to different loci (chromosome 11, 14 exon 13, 14 exon 8, fifth locus); the LVH was analysed from two short axis LV parasternal views and each plane was divided into 5 segments. The distribution of LVH was said to be identical between two first degree relations when all the same segments were affected, similar when they differed by only 1 or 2 segments and different when they differed by 3 or more segments. In the 26 pairs studied, LVH was identical in 2/26 (8%), similar in 11/26 (42%) and different in 13/26 (50%). Familial HCM usually gives rise to asymmetrical LVH affecting the septum and free wall. An identical distribution in 50% of affected first degree relatives.

Adolescent↗
PubMed1995

[Ventricular fibrillation and defibrillation; electrophysiological bases and clinical applications].

During sinus rhythm, the successive responses to the application of electrical stimuli of increasing intensity during the vulnerable period are cardiac stimulations followed by repetitive ventricular responses and then ventricular fibrillation. An impulse of even greater intensity is not followed by ventricular fibrillation (shock at the upper limit of vulnerability) suggesting that defibrillatory shock is effective only when it does not reinduce fibrillation. Two other hypotheses are also proposed in fibrillation, that of critical mass and that of extension of the refractory periods, in particular after biphasic shocks. Clinically, the measurement of the threshold of defibrillation is difficult as it is a random process which does not obey the all or nothing principle. Ideally, a graph of efficacy versus energy should be constructed but this is only possible under experimental conditions. The effects of different antiarrhythmic drugs have been studied in this manner; in general, the sodium channel blockers improve the energies of defibrillation.

Animals↗
PubMed1995

[Transesophageal echocardiography in cardiac and paracardiac tumors. A multicenter study].

A multicentre study was undertaken to determine the diagnostic value of transoesophageal echocardiography (TOE) in tumours of the heart and pericardium. Forty-five cases were recensed: 24 myxomas, 1 fibroma, 1 hydatid cyst, 2 lymphomas, 3 sarcomas, 1 pleuropericardial cyst, 1 branchogenic cyst and 12 cardiac metastases. The diagnosis was made in all 45 cases by TOE but only in 35 cases by conventional transthoracic echocardiography which failed to recognise 2 myxomas, 1 hydatid cyst, 1 sarcoma, 2 paracardiac cysts and 4 cardiac metastases. The site of the tumour was identified 45 times by TOE compared with only 12 times by transthoracic echocardiography. However, the anatomical investigation of mediastinal tumours requires complementary computerised tomography. Moreover, TOE, like all other imaging techniques, is unable to predict the benign or malignant nature of the tumour, 1 leiomyosarcoma having been confused with a myxoma.

Adult↗
PubMed1995

[Transient entrainment of tachycardia].

Transient entrainment of tachycardia by pacing at a faster rate corresponds to its acceleration with return to sinus rhythm either when the pacing is interrupted or when the pacing rate is slowed. It conforms to strict criteria detectable either on the surface electrocardiogramme (constant fusion, progressive fusion, change of morphology before termination of a tachycardia) or on selective endocavitary recording when entrainment is hidden. The phenomenon described by Waldo in 1977 in atrial flutter is found in all reentrant tachycardias. It is currently being studied in ventricular tachycardia. The electrophysiological concept is useful because it facilitates the understanding of the mode of termination of tachycardia by stimulation and the localisation of zones for destruction during ablation.

Cardiac Pacing, Artificial↗