PubMed Health⌕ Search

Biomedical subjects

A Dutoit

Publications and source records attributed to A Dutoit.

At least 19 recordsLinked to original sources

Contribution of a pacemaker bradycardia detection algorithm in the study of patients with carotid sinus syndrome.

While carotid sinus syndrome (CSS) is often suspected as a cause of syncope in the elderly, whether it represents an indication for cardiac pacing may remain uncertain. Bradycardia algorithms included in pacemakers are now able to establish a precise relationship between spontaneous asystole and occurrence of symptoms and strengthen the indication for permanent pacing. This study included seven men and three women (70.5 +/- 7.3 years of age) who, over an average period of 54.1 +/- 17 months, had suffered from syncope (12.6 episodes/patient) and presyncope (11.2 episodes/patient) attributed to pure cardioinhibition (2 patients) or mixed CSS (8 patients). Other sources of symptoms were excluded by thorough clinical evaluations, including Holter monitoring, echocardiography, and electrophysiological testing. All patients received a CHORUS 6234 pacemaker, the memory of which includes a dedicated bradycardia detection algorithm capable of storing atrial and ventricular chains, and date and time of the last ten pauses and/or bradycardic events. After a initial period of 14.7 +/- 8 months, during which symptoms were suppressed, the bradycardia algorithm was activated. From then on, a cumulative increase in the number of patients presenting with diurnal pauses was measured (1 month, n = 0; 3 months, n = 6; 9 months, n = 7; 2 years, n = 8). Fourteen episodes of diurnal asystole were recorded. The mean duration of the longest episodes of spontaneous ventricular standstill was 6,319 +/- 1,615 ms and was due to sinoatrial block (n = 7), atrioventricular block (n = 5), and a combination of both (n = 2). In conclusion, activation of the CHORUS bradycardia algorithm allowed confirmation of the appropriateness of permanent pacing in a majority of patients suffering from CSS.

Aged↗

[Intra-arterial thrombolysis of a basilar vascular accident during coronary angiography].

The authors report the case of a 67 year old man with a previous history of aortobifemoral arterial graft who had unstable angina after carotid endarterectomy. Coronary angiography by the right brachial artery was complicated by a cerebrovascular accident with a reactive coma, convulsions and respiratory problems. Selective angiography of the right vertebral artery showed an image of occlusive thrombosis of the basilar artery. In view of the clinical state and angiographic appearances, the authors decided on immediate intra-arterial thrombolysis with Urokinase which dissolved the clot and reestablished flow in the basilar artery, the cerebellar and posterior cerebral arteries. The outcome was favourable with immediate and good recovery of consciousness and hospital discharge on the sixth day without neurological or radiological sequellae. Cerebrovascular accident is a rare and potentially serious complication of left heart catheterisation which requires immediate cerebral angiography to determine the mechanism and propose an appropriate therapeutic approach.

Aged↗

Reliability of single-lead VDD atrial sensing and pacing during exercise.

If atrial sensing ability of a single-lead VDD pacemaker is well accepted at rest, the detection quality by atrial floating electrodes remains less recognized during exercise. The aim of this study was to verify, during treadmill test and a continous telemetry, the atrial tracking performance using four different leads technologies. From November 1994 to July 1997, 21 patients (71.3 +/- 6.3 years old, 7 female, cardiopathy: 57%) were paced for isolated high degree (permanent: 13, paroxystic: 8) AV block. The implanted devices were the Vitatron Saphir/Brillant lead (13 patients), Intermedics Unity/425/04-13 lead (5 patients), Pacesetter Addvent (2 patients), and Biotronik Eikos (1 patient). The acute atrial signal amplitude was 1.66 +/- 0.75 mV. The treadmill test used the chronotropic assessment exercise protocol after pacemaker reprogramming to detect atrial undersensing (AV delay < or = 120 ms, no hysteresis, no flywheel, upper rate increase). The mean delay was 31.1 weeks (range 1-100). The testing duration was 6.1 +/- 2.3 minutes, the number of steps was 3.3 +/- 1.3 per patient, and the peak exercise rate was 135 +/- 19 beats/min. At rest, complete atrial tracking was complete in 90% of the patients, and during testing in only 23.8% of the patients, while AV synchronization > 95% was present in 57.1%, > 90% in 71.4%, and > 85% in 90.4% of patients (Vitatron 13/13, Intermedics 3/5, Biotronik 1/1, and Pacesetter 1/2). During the recovery period synchronization was always > 95%. The mean P wave amplitude at rest was 1.1 +/- 0.5 mV; during the first step, 1.04 +/- 0.61 mV; second step, 0.94 +/- 0.53 mV; third step, 0.82 +/- 0.58 mV; fourth step, 0.67 +/- 0.39 mV; and during recovery, 1.13 +/- 0.67 mV. The mean P wave decrease signal at peak of exercise is 0.21 mV (from -1.31 to +0.5). In fact, P wave variations have several patterns: a decrease was measured in 7 patients, an increase in 2 patients, and no significant change in 7 patients. Single-lead VDD P wave identification during exercise was almost accurate. However, often there was progressive lowering of atrial sensing with transient loss of AV synchrony.

Aged↗

Early increase of von Willebrand factor predicts adverse outcome in unstable coronary artery disease: beneficial effects of enoxaparin. French Investigators of the ESSENCE Trial.

BACKGROUND: The pathogenesis of unstable angina and non-Q-wave myocardial infarction is still poorly understood, and early evaluation of prognosis remains difficult. We therefore studied the predictive value of 5 biological indicators of inflammation, thrombogenesis, vasoconstriction, and myocardial necrosis, and we examined the effects of enoxaparin and unfractionated heparin on these markers after 48 hours of treatment. METHODS AND RESULTS: Sixty-eight patients with unstable angina or non-Q-wave myocardial infarction randomized in the international ESSENCE trial participated in this French substudy. C-reactive protein, fibrinogen, von Willebrand factor antigen, endothelin-1 and troponin I were measured on admission and 48 hours later. The composite end point of death, myocardial infarction, recurrent angina, or revascularization was significantly lower at 14 and 30 days of follow-up in patients allocated to enoxaparin compared with unfractionated heparin. All acute-phase reactant proteins were elevated on admission and increased further at 48 hours. Multivariate analysis demonstrated that the rise of von Willebrand factor over 48 hours was a significant and independent predictor of the composite end point at both 14 days and 30 days. Moreover the early increase of von Willebrand factor was more frequent and more severe with unfractionated heparin than with enoxaparin (mean change was +8.7+/-8.8% with enoxaparin versus +93.9+/-11.7% with unfractionated heparin, P<0.0001). The other clinical and biological variables did not predict outcome. CONCLUSIONS: In patients with unstable angina or non-Q-wave myocardial infarction, the acute-phase proteins increase over the first 2 days despite medical treatment. The early rise of von Willebrand factor is an independent predictor of adverse clinical outcome at 14 days and at 30 days. Enoxaparin provides protection as evidenced by the reduced release of von Willebrand factor, which represents a favorable prognostic finding.

Aged↗

Wavelength and atrial vulnerability: an endocavitary approach in humans.

If atrial vulnerability parameters are well defined, wavelength (WL) measurement (conduction velocity x refractory period), has never been assessed through an endocavitary electrophysiological exam. We investigated 30 patients (14 female, mean age 63.4 +/- 13 y.o.), 10 with paroxysmal atrial fibrillation (PAF group), 10 with ischemic cerebral injury (ICI group) by comparison with 10 controls (C group). The upper to lower right atrium conduction time and velocity were measured in the right atrium with a decapolar electrode catheter applied along the free wall. Others parameters correlated to atrial excitability were also taken into account: effective (ERP) and functional refractory periods (FRP); spontaneous or paced atrial electrogram (A1) or extrastimulated atrial electrogram (A2) widths, ERP/A2 ratio, provocative atrial testing. Measurements were taken in sinus rhythm and in 600-460 ms paced cycle lengths. If ERP, FRP, A1 widths are the same in the 3 groups, PAF and ICI groups have a significant increased conduction time and lower conduction velocity, leading to a shorter A1 WL during 600 and 460 ms paced rhythms (p < 0.05) and A2 WL during 460 ms paced rhythm. The provocative testing was positive in 60% of PAF and ICI groups, and there is a significant correlation between arrhythmia induction and 600 ms A1 WL or 460 ms A2 WL. This electrophysiological study suggests the possibility of an approach in humans of wavelength concept and proves the presence of correlation between a short wavelength and atrial spontaneous or induced arrhythmias. A no-arrhythmia band (A1 WL > 17 cm during 600 ms paced rhythm, A1 WL > 16 cm or A2 WL > 12 cm during 460 ms paced rhythm) and a fibrillation-band (A1 WL < 12 cm during 600 and 460 ms pacing, A2 WL < 7 cm during 460 ms pacing) can be defined. Therefore, the ICI group has the same atrial pattern as the AF group.

Atrial Fibrillation↗

[Short and medium-term outcome after radiofrequency ablation of the atrioventricular junction].

The aim of this retrospective study was to assess short and long-term mortality and morbidity after radiofrequency ablation of the atrioventricular junction in patients with supraventricular arrhythmias resistant to treatment. This cooperative series included 91 patients (47 men, mean age 68 +/- 9 years). The arrhythmia was paroxysmal in 56% of cases. The mean duration of symptoms was 67 +/- 61 months and 45 patients (49.4%) were in the NYHA Classes III and IV. An escape rhythm was present in 58 patients with a mean frequency of 39 +/- 9/min. Early complications were observed in 5 patients (venous thromboses, pulmonary embolism, mild pericardial effusion and haemothorax). The hospital mortality was 4 patients (4.4%). Death was of cardiac origin in 1 case (cardiac failure). The mean follow-up of patients was 14.5 +/- 8.6 months. Eleven patients died during this period, 8 of cardiac causes: cardiac failure (3 cases), sudden death (3 cases), thrombosis of a valve prosthesis (1 patient) and major electrolyte disturbances causing loss of stimulation in 1 case. Six patients had recurrences. Long-term morbidity was either related to cardiac pacing (3 cases) or cardiac failure (3 cases). Thirteen patients were in NYHA Classes III or IV at the end of follow-up. The authors conclude that radiofrequency ablation at the atrioventricular junction is an effective method of treating resistant supraventricular arrhythmias. Complications are not frequent but mortality appears to be high, probably due to the presence of advanced cardiac disease in the majority of cases. Sudden death seems to be rare and unrelated to pacing defects.

Adult↗

[Multifactor prevention of endocarditis and cardiac pacemakers. A prospective study apropos of 207 patients].

Infections after cardiac pacemaker implantation are rare (0.13 to 12.6%) but potentially severe complications. Staphylococcus is the genus most frequently isolated (72 to 100% of cases). The use of systematic prophylactic antibiotics remains controversial. From November 1991 to October 1993, 207 consecutive patients were submitted to a series of measures designed to reduce the risk of infection: a) intravenous bolus injection of Cefamindole, 15 minutes before implantation, b) cutaneous disinfection with iodinated polyvindone, c) injection of an ampoule of rifampin before closure of the pacemaker in the pouch, d) absence of drainage system. Patients were predominantly female (60.9%), with a mean age of 77 +/- 10 years, frequently suffering from heart disease (53.8%). The indication for implantation was atrioventricular block (39.7%), carotid sinus syndrome (27.5%), atrial arrhythmia (27.5%), resection of the node-His tract (5.3%). This procedure corresponded to the first implantation in 88.4% or replacement of a previous pacemaker in 11.6% of cases and the pacing mode was single-chamber (38.4% or replacement of a previous pacemaker in 11.6% of cases and the pacing mode was single-chamber (38.7%), or double chamber (61.3%). The mean duration of the procedure was 51.5 min +/- 30 min. The mean follow-up was 12.7 +/- 5 months. The overall mortality was 14% (11 cases of cardiac failure, 6 sudden deaths, 4 cerebrovascular accidents, 4 cases of pneumonia, 4 neoplasms). Only one infectious problem (endocarditis, i.e. 0.48%) was observed.

Aged↗

[Characteristics and influence of different clinical forms on the development and prognosis of carotid sinus syndrome. Apropos of 215 cases].

The carotid sinus syndrome is a well-known cause of syncope: the cardio-inhibitory forms are the easiest to diagnose and probably the easiest to treat. However, the vasodepressive forms are as common but their outcome is mainly unknown. Eight hundred and fifty-three patients underwent endocavitary electrophysiological studies with invasive blood pressure measurement for unexplained syncope between October 1984 and January 1990. A carotid sinus syndrome was diagnosed in 215 cases. Fifty-two patients (24.2%) had a cardio-inhibitory form (ventricular standstill > or = 3 s during carotid sinus massage), 40 (18.6%) had a pure vasodepressive form (isolated fall of systolic blood pressure > 50 mmHg during massage) and 123 patients (57.2%) had a mixed form. The average age was 74.1 +/- 9.7 years with no difference between the different forms. A number of parameters was different on the cardio-inhibitory and vasodepressive forms: the number of men (75.6 vas 24.4%; p < 0.05) and the number of syncopes (83.3 vs 60%; p < 0.02) were greater in the cardio-inhibitory form; the vasodepressive forms were more often associated with a history of transient ischaemic attacks (15 vs 0%), a poor cardiovascular status (hypertension: 47.5 vs 15.7%; p < 0.01), coronary artery disease (47.5 vs 25.5%; p < 0.05), cardiac failure (27.5 vs 11.7%; p < 0.05), induction of sustained supraventricular tachycardia (50 vs 23.5%; p < 0.05) and a greater pacemaker effect (53.6 vs 34.8 mmHg; p < 0.01); of the 191 patients (84.9% of the population) followed up for an average of 21.2 months, 168 received treatment: implantation of a cardiac pacemaker in 108 patients, reduction of antihypertensive and/or potentially bradycardia-inducing drugs in 30 patients, prescription of antiarrhythmic therapy, in 30 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

[Emery-Dreifuss muscular dystrophy with major conduction disorders and cardiac excitability].

The case of a 53-year-old patient with scapulo-humero-peroneal wasting, early flexion contractures of the elbows and ankles, abnormal cardiac conduction and probable X-related heredity is reported. Histology was suggestive of a primary and very slowly progressive muscular disorder. CT scan revealed fatty muscle degeneration which was more extensive than suggested by clinical findings. Electrophysiological studies revealed right atrial paralysis, left atrial tachycardia and supra and, above all, infra-His block. Sustained episodes of ventricular tachycardia, an anomaly described only rarely in pathology of this type, occurred some time after the fitting of a permanent pacemaker. The originality of this case of Emery-Dreifuss progressive muscular dystrophy lies in the usefulness of muscle CT scan and the existence of life-threatening arrhythmias.

Arrhythmias, Cardiac↗

[Symptomatic sinus dysfunction. A new use of electrophysiology].

The authors undertook a prospective electrophysiological study of 950 patients: 53 subjects considered to be "controls" since they were free of any history of syncope or faintness were identified, as well as 39 symptomatic subjects with a strong suspicion of sinus dysfunction, since no other detectable cause of fainting episodes was found by extracardiac investigation, 24 hour ECG nor electrophysiology. Following the creation of a computerised tool enabling not only the entry of indirect tests, processing, averaging of results, printing and memorization, but also assistance in interpretation, several electrophysiological parameters were used: heart rate and existence of sinus arrhythmia, Strauss tests with adjusted data or not, effective nodal refractory period, Guize, Narula and Mandel tests, and an atropine (0.03 mg/kg) test which was performed only in the symptomatic group. These tests were studied by single-variate and correlative analysis to define their normal ranges, their critical values and their dependence or independence. The performance of each test (i.e. its efficiency, and the specificity and sensitivity of each critical value) was measured. Tests found to be most useful (specificity and efficiency > 90%) were as follows: Mandel test = CSRT > or = 534 ms, Narula test = TECASA > or = 339 ms, heart rate < or = 55/min, type II, IIa and chaotic Strauss curve associated with a pathological Guize test. The combination of these tests in this algorithm resulted in an increase in sensitivity to 84%, at the price of a very moderate fall in specificity to 87%.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

[Measurement of pacemaker effect: incidences on the choice of pacing mode? A prospective and statistical study of 396 patients].

Single ventricular stimulation induces haemodynamic disturbances, the best known of which is the pacemaker syndrome. In order to assess the prevalence and severity of these abnormalities, invasive blood pressure monitoring was performed in 396 consecutive patients undergoing endocavitary electrophysiological investigations: a decrease in systolic blood pressure at a rate near to that of the spontaneous rhythm defines the pacemaker syndrome. It is maximal after 3 to 5 beats of equivalent intensity with or without retrograde conduction. The pacemaker syndrome is greater in hypertensive and coronary patients than in subjects with healthy hearts (-44.2 mmHg and -37.2 mmHg versus -33 mmHg, p < 0.001 and p < 0.04). It is less pronounced in cases of cardiac failure (-31.8 mmHg). The pacemaker syndrome increases in intensity with age (-44.3 mmHg after 80 years of age versus -23.1 mmHg in subjects under 50 years of age; p < 0.001). Two electrophysiological abnormalities are associated with an increased pacemaker syndrome even in apparently normal hearts: sustained induced supraventricular tachycardia (-34.2 mmHg versus -26 mmHg, p < 0.002), mixed carotid sinus syndromes (-38 mmHg) and pure vasodepressive syndromes (-48.5 mmHg, p < 0.001). The study of the pacemaker syndrome is useful for three reasons: the detection of another cardiac abnormality in cases of sustained induced supraventricular tachycardia, even in an apparently healthy heart; to assess the presence of a second haemodynamic abnormality independent of the vagal effect in cases of carotid sinus syndrome with vasodepression; finally, to identify the patients at high risk of a pacemaker syndrome.

Adult↗

[Value of intravenous flecainide in electro-induced supraventricular arrhythmia. Apropos of 37 cases].

Thirty-seven patients presenting with electro-induced supraventricular arrhythmia sustained for more than 10 min or symptomatic received an intravenous injection of flecainide acetate (1.5 mg/kg; 10 mg/min). There were 24 cases of atrial fibrillation, 13 of atrial tachysystole with more than 180 beats per minute. Electrophysiological exploration was carried out for syncope (13 cases), lipothymia with palpitations (11 cases) or without palpitations (8 cases), or for a stroke of unknown origin. The induced arrhythmia was the only electrophysiological abnormality in 57% of cases. A return of sinus rhythm was obtained in 70% of cases during the injection (12 cases) or shortly after the end of the injection (14 patients). Safety was good, with the exception of the onset of two junctional rhythms and one case of non-syncopal monomorphic ventricular tachycardia. After an initial reduction, the PR, QRS, PA and HV intervals were significantly longer than baseline, whereas the AH space and the systolic blood pressure remained virtually unchanged. Thus the provision of IV flecainide acetate can only be beneficial in carrying out study protocols of abnormalities of the atrial substrate.

Adult↗

[The single coronary artery].

Single coronary artery is a fairly rare entity which may nevertheless be found in 0.4 per cent of coronary arteriograms. The authors report 3 cases seen in 2 departments of cardiology. In each patient, despite the existence of definite cardiovascular risk factors, this distribution was a factor worsening coronary ischemia, leading to complete thrombosis in one case. Although most often a chance discovery, a review of the literature justifies the attribution to this anomaly of the onset of angina, infarction or even sudden death.

Adult↗

[Effects on the bone metabolism of long-term treatment with antivitamins K1].

Oral anticoagulants (OC) prevent the activation by carboxylation of coagulation proteins. However this action also affects osteocalcin, or bone Gla-protein, a parameter of bone remodelling. Phosphorus and calcium metabolism, osteocalcin levels and bone mineral content were studied in twelve men aged under 60, and who had been taking OC for more than a year, in comparison with a paired group of nine controls with the same cardiovascular pathology but not taking anticoagulants. Osteocalcin levels were lower in the OC group (3.44 ng/ml) than in the control group (5.88 ng/ml) (p = 0.01). There was no significant difference in other phosphorus/calcium balance parameters nor in bone density between the two groups. No evidence was found of any osteopathy in the OC group, but the decrease in serum osteocalcin could result either from inhibition of its secretion or of its carboxylation, or from an action on the osteoblast.

Anticoagulants↗

[Myocardial infarction in patients aged 70 years and over].

109 subjects aged 70 years (58 women, 51 men; average age 77 years) were hospitalized in the CICU (Cardiology Intensive Care Unit) over the period stretching from 1984 to 1986. The average length of stay in the CICU was 1 week, completed by an average stay of 5 days in the cardiology department. 100 per cent of the patients were followed up. Of the clinical parameters made evident by this study, the authors note that hypertension was the predominant risk factor (52.2 per cent); a history of coronary disease was noted in 60.5 per cent; 26.6 per cent of the patients were hospitalized before the 6th hour, chest pain being typical in 78 per cent versus painless in 11 per cent of patients; topographically, the infarction was anterior in 55 per cent, posterior in 40.4 per cent, and around the circumference in 4.6 per cent of cases; 80.8 per cent of the infarctions were transmural versus 19.2 per cent of infarctions without the Q wave--the latter accounted for a higher hospital mortality rate (38 per cent versus 27.3 per cent). The main complications were disturbances in rhythm (60.6 per cent) and LVI (56.9 per cent). Complications on the form of infections were noted in 15.6 per cent. Apart from the usual indicators of severity (cardiogenic shock, VF, LVI), infarction of the RV and AF had a serious effect on the prognosis. latrogenic disease accounted for 18.9 per cent. From the point of view of prognosis, hospital mortality was 30 per cent; mortality after one year was 44 per cent and 47.7 per cent after 2 years (in a group of 76 subjects).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

[Carotid sinus syndrome. Contribution of arterial pressure monitoring to intracavitary electrophysiological exploration].

A prospective study based on intracavitary electrophysiological exploration coupled with invasive arterial pressure monitoring was conducted in 245 patients aged 70.2 +/- 13 years who had experienced syncopes and/or lipothymias of uncertain origin. The study showed that 63 patients (25.7 p. 100) had carotid sinus syndrome (CSS). The syndrome was of the vagal type (cardiac inhibition) in 27 p. 100 of the cases, of the depressor type (vasodepression) in 22 p. 100 of the cases and mixed in 51 p. 100 of the cases with the two types of pathological response: electrophysiological and haemodynamic. Compared with the remaining 182 patients, these 63 patients were more frequently male (63.5 p. 100, p less than 0.01), of the same age (71.7 years, NS) and more symptomatic, meaning that syncopes occurred in 80 p. 100 of the cases and that their number per patient was higher (2.92, p less than 0.01). A predisposing factor (usually a vagal predominance) was found in 26.9 p. 100 of the cases. In 30 p. 100 of the patients CSS was associated with a sinus node disease or with disorders of atrioventricular conduction. Another haemodynamic abnormality often associated with CSS was a more pronounced (-38.7 mmHg, p less than 0.01) and more frequent (68 p. 100, p less than 0.01) pacemaker effect. 62 p. 100 of patients with mixed CSS had an increase in systolic arterial pressure during vagogenic manoeuvres with DDD mode stimulation as compared with the VVI mode stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗