Biomedical subjects

M Delay

Publications and source records attributed to M Delay.

At least 19 recordsLinked to original sources

PubMed2006

[Cardiac asystole during acute anterior myocardial infarction: a consequence of endocardiac reflexes].

The authors report a case of paroxysmal, complete atrioventricular block during an anterior acute myocardial infarction, leading to asystolia. The different possible physiopathological mechanisms are discussed, suggesting a paroxysmal nodal conduction defect, secondary to transient parasympathetic stimulation, triggered by a Bezold-Jarish type of cardiac reflex. This reflex is frequently involved in various pathologic situations or diagnostic procedures, usual in cardiology. Although it is frequently observed in inferior myocardial infarction, it can occur during an anterior acute myocardial infarction.

Aged↗

PubMed2006

[Clinical evolution of patients following investigation of atrial vulnerability after a first cerebral ischaemic accident].

Atrial vulnerability reflects the ability of the atrium to fibrillate. ISAV (Ischemic stroke and atrial vulnerability) is a French epidemiological registry whose main goal is to assess the evolution modalities of patients in whom an electrophysiological study of the atrium has been performed. A group of 269 patients with a history of non elucidated ischemic stroke and an electrophysiological study of the atrium performed in a mean delay of 3 months after the stroke has been included. Their mean age at the time of the stroke was 55 +/- 15.8 years. The electrophysiological study has measured the effective refractory period of the atrium, the locoregional right intra-atrial conduction time, the index of latent atrial vulnerability and assessed the inductibility. The mean delay between the date of the stroke and the date of the last news was 4.4 +/- 2.8 years. We observed 12 deaths and 11 patients presented during the follow up a spontaneous atrial arrhythmia and 17 a recurrence of stroke. If we consider the occurrence of the 28 combined events (atrial arrhythmia and/or stroke), it is not correlated with the presence of an atrial septal defect nor with the existence of an atrial vulnerability. On the contrary this occurrence is correlated with tobacco consumption and/or arterial hypertension; 82% of patients have these risk factors versus 54% of patients without events (p = 0.004). This association is not significant in patients younger than 55 years.

Adult↗

PubMed2005

[Prescriptions following acute coronary syndrome].

Each year in France, 150,000 to 180,000 new patients are the subject of prescriptions following acute coronary syndrome with or without ST segment elevation. There are two targets of the treatment, atherosclerosis, a diffuse, evolving trouble which, in this situation, is coming out of an unstable phase, and the myocardium, which has often been revascularised and has suffered deterioration of its contractile and electrophysiological characteristics to a greater or lesser extent. Prescriptions, based on proven factors and always centred on hygiene and dietary advice and the use of a combination of statins and aspirin, are adapted to suit the atherosclerotic and myocardial risk assessed for the individual patient. The prescription starts off the secondary preventive phase. It marks the first stage of the follow up, which is inevitable though of variable duration, for a disease which may evolve. It is the first step in the accompaniment of an attentive, informed patient whose confidence has been restored and who must now avoid falling into the double trap of not taking the treatment sufficiently seriously or of obsessively over-reacting.

Angina, Unstable↗

PubMed2005

[Ablation of ventricular extra-systole in the left Valsalva sinus. A case report].

We report the case of a patient presenting with unrelenting isolated or repetitive monomorphic ventricular extra-systoles, with left block and right axis deviation, which appeared to arise from the right ventricular chamber, but for which ablation was finally performed in the left Valsalva sinus. The ECG and endocavity electro-physiological features which led us to suspect this atypical, although not exceptional, situation are reported, as well as the techniques for ablation available in this case.

Adult↗

PubMed2004

Electrical storm in Brugada syndrome successfully treated using isoprenaline.

A case of an electrical storm occurring in a patient implanted with a cardioverter-defibrillator for Brugada syndrome is reported. Recurrent ventricular fibrillation was initiated by short-coupled isolated monomorphic ventricular premature beats probably originating from the right ventricular outflow tract, associated with a manifest electrocardiographic pattern of Brugada syndrome. Infusion of atropine accelerated the heart rate but did not prevent ventricular fibrillation, however, low doses of isoprenaline quickly obviated any recurrence of ventricular fibrillation. This was associated with the disappearance of the short-coupled premature beats together with a normalization of the electrocardiographic pattern. Possible mechanisms are discussed according to the accepted pathophysiological hypothesis.

Adrenergic beta-Agonists↗

PubMed2004

[Slow ventricular tachycardia presenting in the antenatal period].

The authors report two cases of slow ventricular tachycardia presenting in the antenatal period. One foetus had anasarca at 38 weeks' gestation. After birth, improved myocardial function contributed to the rapid resorption of the effusions. The other case was well tolerated in the foetal and neonatal periods. In both cases, Holter ECG recorded an intermittent ventricular arrhythmia with salvos of sustained ventricular tachycardia with a maximum rate of 185/min, only 10% higher than the underlying sinus rhythm, disappearing on acceleration of the sinus rhythm. The aetiological investigation was negative. Therapeutic abstention was supported by the spontaneously favourable outcome after 3 and 5 months. Slow ventricular tachycardia or accelerated idioventricular rhythms are usually considered to be benign but the case with foetal anasarca suggests that they should be carefully followed up in the neonatal period. In the absence of a consensus on management, therapeutic abstention implies regular cardiological examination until the arrhythmia has disappeared.

Female↗

PubMed2003

[Diagnosis of adrenergic ventricular tachycardia in two homozygotic twins].

The authors report the first case of adrenergic ventricular tachycardia observed in two 11 year old homozygotic twins. Syncope on exercise led to the investigation of the first twin with confirmation of the diagnosis by exercise stress testing. The same investigations led to the demonstration of the condition in the second asymptomatic twin. The two patients were treated with nadolol and there has been no recurrence of syncope with a 2 year follow-up. Adrenergic ventricular tachycardia is a rare arrhythmia with a risk of sudden death which may be prevented by betablocker therapy. An exhaustive familial inquiry is essential, but is only positive in one out of three cases. Mutations in the ryanodine receptor gene (hRyRZ) and also in the calsequestrin gene (CASQ2) have recently been reported. Progress in the understanding of the genetics of this condition should improve primary preventive measures.

Adrenergic beta-Antagonists↗

PubMed2001

[Prophylactic value of automatic implantable defibrillators: a case report of a patient with asymptomatic Brugada syndrome].

The authors report the case of an asymptomatic 32 year old man with no family history of sudden death but with ECG changes suggesting Brugada's syndrome. He underwent implantation of an automatic defibrillator after inducible syncope ventricular fibrillation had been demonstrated during electrophysiological investigation. The later occurrence of three episodes of ventricular fibrillation treated by the defibrillator confirmed a posteriori the logic of this therapeutic approach.

Adult↗

PubMed2001

[Atrial flutter: a possible early sign of acute rejection in heart transplantation. A case report].

The authors report the case of a cardiac transplant patient with a recurrence of atrial flutter two months after electrical cardioversion and despite long-term preventive treatment with amiodarone. Early investigation for signs of rejection with 4 endomyocardial biopsies was negative. Aggravation of the haemodynamic status due to flutter with a rapid ventricular response led to an attempted radio-frequency ablation. Endocavitary mapping confirmed persistence of sinus activity in the native atrium and the presence of a circuit of type I isthmic flutter (anticlockwise circuit) in the donor atrium. Ablation by radio-frequency in the same procedure was successful. A fifth myocardial biopsy the same day finally confirmed stage 3A acute rejection. No signs of recurrent rejection or arrhythmia have been observed after 24 months' follow-up in this patient. This preliminary experience confirms the need to look for graft rejection by repeated myocardial biopsies in cardiac transplant, patients with atrial flutter and the efficacy of radio-frequency ablation in cases of resistance to conventional therapy.

Atrial Flutter↗

PubMed2001

[Role of HDL cholesterol in the prediction of exercise stress test abnormalities in asymptomatic high-risk patients].

The diagnosis of coronary artery disease in asymptomatic patients is useful in order to target therapeutic intervention in the patients at highest risk. Systematic testing of all asymptomatic adults with coronary risk factors is not feasible. The aim of this study, carried out in 950 healthy subjects, was to assess the predictive value of classical risk factors for positive exercise stress tests (EE). All subjects underwent stress testing using the Bruce protocol. Statistical analysis was performed by multiple logistic regression on half the samples, then by CART (Classification and Regression Trees) analysis on all subjects. Age, HDL-cholesterol and interaction between lipid lowering treatment and LDL-cholesterol were significantly correlated (p < 0.05) to a positive exercise stress test. In both groups, treated or untreated by lipid lowering drugs. CART identified HDL-cholesterol (< 0.40 g/l) as a predictive factor for positive stress testing. Subgroups of elderly patients (> or = 60 years) with probabilities of 20 to 28% for a positive stress test were identified. The authors conclude that the diagnosis of coronary artery disease by systematic exercise stress testing is potentially valuable in elderly patients with low HDL-cholesterol values.

Adult↗

PubMed2000

Prevalence of late potentials in a sample of 487 healthy, middle-aged men from southwestern France.

Late potentials (LPS) have been shown to be predictive of ventricular tachycardia in coronary artery disease subjects, but the prevalence of LP in the general population is not as well-known. The study included 487 men without a history of cardiovascular disease (aged 50-59) living in Southwestern France. Standard-averaged high resolution electrocardiogram was performed using Butterworth filtering at 40-250 Hz. LPS were defined as two or more of the following criteria: QRS > 114 ms, duration of the low amplitude signals in the terminal portion of QRS > 38 ms, root mean square (RMS) voltage of the last 40 ms < 20 microV. The mean QRS duration was 97 +/- 12 ms (mean +/- SD), duration of the low amplitude signals in the terminal portion of QRS was 32 +/- 10 ms, and RMS voltage in the last 40 ms was 39 +/- 27 microV. Eight percent of subjects (95% confidence interval [CI]: 6%-11%) had a QRS duration > 114 ms; 22% (95% CI: 18%-26%) had a duration of low amplitude signals > 38 ms, and 25% (95% CI: 22%-29%) had RMS voltage in the last 40 ms < 20 microV. Finally, the prevalence of LP was 21% (95% CI: 18%-25%). In conclusion, according to commonly used criteria, the prevalence of LP in this healthy population of middle-aged men is 21%, close to the values found in the literature for myocardial infarction patients. Those findings indicate the need for reconsidering the definition of LPS.

Coronary Disease↗

PubMed2000

[Anomalties of the interatrial septum and latent atrial vulnerability in unexplained ischemic stroke in young adults].

Seventy-four consecutive patients (18 to 55 years) underwent programmed atrial stimulation in the investigation of unexplained ischaemic stroke after a full work-up including transoesophageal echocardiography to exclude abnormalities of the interatrial septum (patent foramen ovale and/or atrial septal aneurysm). The parameters recorded during atrial electrophysiological investigation were: the effective atrial refractory period, loco-regional intra-atrial conduction, the index of latent atrial vulnerability and the inducibility by the extrastimulus technique. Seventy five per cent of patients with a patent foramen ovale and/or an atrial septal aneurysm were inducible compared with only 38% of patients with normal interatrial septa on transoesophageal echocardiography (p = 0.001). Fifty two per cent of patients with an anomaly of the atrial septum had latent atrial vulnerability compared with 26% of those with normal transoesophageal echocardiography (p = 0.02). These results confirm the relationship between atrial septal anomalies and latent atrial vulnerability in unexplained ischaemic stroke of young adults.

Adolescent↗

PubMed2000

[Utilization of heart rate at the ventilatory threshold for the prescription of intensity of exercise training in cardiac failure].

Physical exercise is a treatment for cardiac failure but a large range of intensities of exercise is proposed. The aims of this study were to determine the range of intensities of effort used and to individualize the intensities used. Thirty patients with stable cardiac failure (NYHA Classes II-III, age: 53 +/- 2.1 years, ejection fraction: 31 +/- 1.4%) underwent a cardiorespiratory exercise stress test before and after individualized training at the ventilatory threshold. However, before and after the training period, standard methods of calculation of the intensities at the ventilatory threshold showed individual differences greater than +/- 2 standard deviations, indicating different metabolic stimulations. After the individualized training programme, peak oxygen consumption on exercise (1679 +/- 100 vs 1487 +/- 89 ml.min-1, p = 0.0001) and at ventilatory threshold increased (1365 +/- 85 vs 1133 +/- 65 ml.min-1, p = 0.0001), the ventilatory threshold/peak exercise ratio increased (81.2 +/- 1.3 vs 76.7 +/- 1.4%, p = 0.0008), and there was a decrease in heart and ventilatory rates at submaximal metabolic levels (p = 0.0001). The authors conclude that protocols using intensity of effort at the ventilatory threshold give similar results with respect to improvement of aerobic capacity as other methods of indirect calculation, based on maximal heart rate of oxygen consumption. The value of this particular method lies in the adequation between aerobic capacity of the patient and the intensity of training. The results obtained attain the physiopathological aims of rehabilitation.

Calibration↗

PubMed1999

[Evaluation of arrhythmic risk in coronary insufficiency].

Half of all deaths occurring in patients with heart failure are sudden deaths probably related to a malignant ventricular arrhythmia. The pathophysiological mechanisms of these arrhythmias are unclear, but left ventricular function, hypokalaemia accentuated by diuretics and treatments altering inotropism play a definite role. Because of the diversity of aetiologies generating heart failure, the multiplicity of fatal arrhythmias and the multifactorial origin of these arrhythmias, there is no formal marker for the risk of sudden death in patients with heart failure, at the present time. In addition to the NYHA classification and detection of episodes of syncope, assessment of these patients must be as complete as possible, at least including repeated evaluation of the ejection fraction, Holter ECG monitoring and detection of delayed ventricular potentials.

Arrhythmias, Cardiac↗

PubMed1997

[Repolarisation anomalies simulating anterior myocardial infarction during ischemic cerebrovascular accident].

The authors report the case of a woman admitted to hospital for minor trauma of the left hip and who presented major ST segment elevation on the second day suggesting an acute anterior wall myocardial infarction at the same time as a cerebrovascular accident. Complementary investigations and follow-up excluded the diagnosis of myocardial infarction with normalisation of the ECG on the 5th day. ECG changes during cerebrovascular accidents may be very variable ranging from extrasystoles to ST elevation mimicking myocardial infarction. They carry a poor prognosis with an increased risk of sudden death necessitating continuous ECG monitoring until the ECG reverts to normal. The cardiac involvement is not ischaemic but due to disease of the insular cortex of the brain which induces myocytolysis (centered around the intra-cardiac nerve endings) due to the sudden liberation of catecholamines. These lesions may be treated by propranolol or phentolamine.

Adrenergic alpha-Antagonists↗

PubMed1996

Evaluation of a new sensor-based algorithm to protect against atrial arrhythmias.

UNLABELLED: The SmarTracking (ST) algorithm (Marathon 294-09, Intermedics Inc.) uses the sensor-calculated rate (SCR) to define a "variation band" for the intrinsic sinus rate. If the sinus rate exceeds the upper limit of the band, the ventricular pacing rate is limited by the ST rate (STR) and Wenckebach behavior is observed. The present study was aimed at evaluating the behavior of the ST mechanism in patients with healthy sinus node, during exercise and at rest. METHODS: Twenty-one patients (15 men; mean age 67.8 +/- 9.7 years) with normal sinus function were studied. Heart rate was recorded via the rate profile of the implanted pacemaker (Relay 294-03, Intermedics Inc.), and STR and SCR were obtained via a previously calibrated strap-on pacemaker. A 15-minute protocol was used during which subjects alternated periods of walking with periods of rest. RESULTS: The relative difference between the average STR and the average sinus rate (DST) was calculated for each phase of the protocol as well as the maximum number of patients showing inappropriate Wenckebach behavior (#W). At nominal settings, DST was always positive and did not fall below 20%. #W was maximum at rest (5) and during heavy exercise (3). By increasing the STR at rest to 95 ppm and the maximum pacing rate to 150 ppm, the #W was reduced to zero for all types of activity except during very fast walk where #W was 1. CONCLUSION: In general, there was no competition observed between the STR and the intrinsic rhythm. In some cases, the STR at rest and the maximum pacing rate had to be reprogrammed for optimal performance.

Acceleration↗

PubMed1996

[Value of the study of latent atrial vulnerability in unexplained ischemic cerebrovascular accident of young subjects].

This study searched for abnormalities of the atrial electrophysiological substrate in young subjects with unexplained ischaemic cerebrovascular accidents. Thirty-seven patients (18 to 45 years) underwent programmed atrial stimulation at 2 sites in the right atrium after an unexplained ischaemic cerebrovascular accident. Seventeen of them underwent repeat study at 6 months. The following parameters were analysed: indices of atrioventricular conduction and sinus node automaticity; indices related to atrial hyperexcitability: effective refractory period; adaptation of the refractory periods to heart rate, intraatrial conduction and the index of latent vulnerability; the inducibility test by the extrastimulus technique. The following results were obtained: 54% of patients had an inducible atrial arrhythmia; the effective refractory periods and index of latent vulnerability were lower (204 +/- 21 ms and 2.25 +/- 0.7) in the inducible patients than in the non-inducible patients (232 +/- 28 ms and 3.4 +/- 1.1) (p < 0.001 and p < 0.002 respectively); 76% of patients had latent atrial vulnerability indicating and underlying arrhythmogenic substrate; this substrate was still present 6 months later in 80% of these cases; in patients with an abnormality of the interatrial septum, there was an abnormality of the electrophysiological investigation in 85% of cases compared with 65% in those with normal transoesophageal echocardiography. These results confirm the presence of an arrhythmogenic substrate similar to that of patients with paroxysmal atrial fibrillation in over two thirds of cases. Programmed atrial stimulation is a reproducible technique. The relationship between latent atrial vulnerability and abnormalities of the interatrial septum requires confirmation in a series with a larger numbers of patients.

Adolescent↗

PubMed1995

Carotid sinus syndrome: acute hemodynamic evaluation of a dual chamber pacing mode.

Cardiac pacing is the treatment of choice in patients with carotid sinus syndrome (CSS). Three different pacing modes were tested in 20 patients (16 males, 4 females; mean age 75 +/- 9 years) with documented symptomatic CSS. Three carotid sinus massages (CSM) were performed in each supine patient successively paced in random order in: DDI--the reference pacing mode; DDD--automatic mode conversion (DDD/AMC) allowing automatic switching from AAI to DDD when AV block occurs; DDD/AMC plus atrial acceleration (DDD/AMC+acc); and OOO (CSM without pacing) to determine whether the vasodepressive effect was still present 10 minutes after the preceding CSM. Intraarterial blood pressure was continuously monitored. Results were expressed as the value of the mean systolic BP at T0 + 3 s + 6 s ... T0 + 30 s divided by the value of the mean systolic blood pressure prior to onset of CSM. The drop in arterial blood pressure was more severe in the DDI mode than in DDD/AMC (P < 0.001) and DDD/AMC+acc (P < 0.0001) in 20 patients. In the OOO mode, the drop in arterial blood pressure was most marked and greater than in the DDI mode (P < 0.0001). The average time between start of the CSM and onset of the drop in blood pressure was the same in the three dual chamber modes. We conclude that the DDD/AMC mode significantly improves the vasodepressor response to CSM compared to the DDI mode. There is a current trend favoring DDD/AMC+acc over DDD/AMC.

Aged↗