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Biomedical subjects

N Sadoul

Publications and source records attributed to N Sadoul.

71 records · Page 4Linked to original sources
PubMed1991

Diagnostic value of ventricular stimulation in patients with idiopathic dilated cardiomyopathy.

To assess the response to programmed ventricular stimulation and the clinical outcome, we performed a prospective study in 103 patients with idiopathic dilated cardiomyopathy. The protocol used up to three extrastimuli delivered at two right ventricular sites during sinus rhythm and ventricular pacing at 100 and 150 beats/min and was repeated during infusion of 1 to 4 micrograms/min of isoproterenol. Sustained monomorphic ventricular tachycardia (VT) was induced in 8 of 11 patients with spontaneous sustained VT, in none of 35 patients without significant ventricular arrhythmias during Holter monitoring, and in 9 of 56 patients with salvos of ventricular premature beats. Isoproterenol infusion facilitated the induction of two episodes of sustained VT in patients with spontaneous sustained VT; however, in all but one of the remaining patients, induction of ventricular tachyarrhythmias was not impaired. During the follow-up period there were eight sudden deaths among patients who initially had syncope, inducible sustained VT, or both and three episodes of sustained VT in patients who initially had nonsustained VT but inducible sustained VT. Isoproterenol infusion can be used to safely facilitate induction of ventricular tachyarrhythmias in patients with dilated cardiomyopathy. The induction of sustained VT was associated with a poor prognosis.

Anti-Arrhythmia Agents↗
PubMed1991

Factors determining the occurrence of late potentials on the signal-averaged electrocardiogram after a first myocardial infarction: a multivariate analysis.

To determine the natural history of late potentials on the signal-averaged electrocardiogram (ECG), multivariate analysis was performed in 167 patients (138 men, 29 women) with a first anterior or inferior acute myocardial infarction. Seventy-four patients received thrombolytic therapy; the remaining 93 patients were treated conventionally. All patients underwent coronary angiography, left ventricular ejection fraction determination and signal-averaged ECG recording. Eight variables thought to be correlated with the presence of late potentials were studied; that is, age, infarct location, number of diseased coronary vessels, left ventricular ejection fraction, infarct-related coronary artery patency, treatment received, delay between admission and signal-averaged recording and delay between admission and coronary angiography. Statistical analysis showed that two independent factors (coronary artery occlusion and impaired left ventricular ejection fraction) were highly correlated with the incidence of late potentials. The occurrence of late potentials was multiplied by 5 in case of an occluded infarct-related vessel and by 1.75 each time the left ventricular ejection fraction value decreased by 0.10. This study suggests that coronary artery patency is the most important factor that decrease the rate of late potentials after a first acute myocardial infarction and it occurs independently of infarct location and left ventricular function.

Coronary Angiography↗
PubMed1991

[Effects of fibrinolysis on late potentials in myocardial infarction].

Late potentials are an index of gravity following myocardial infarction, but there has been little investigation of the effects of fibrinolysis on their incidence. Eighty-two consecutive patients (68 men, 14 women, group men age = 55 +/- 8 years) admitted presenting with a primary infarction and who had received fibrinolytic treatment within the first four hours. Each patient was screened for late potentials, and underwent a coronary artery angiograph and determination of the left ventricular ejaculation fraction (LCEF) following the infarction. The incidence of late potentials was 38% in the patients with an occluded coronary artery (9/24) vs 12% in patients with a permeable artery (7/58) (p less than 0.02). The change in LVEF was greater if reperfusion was not achieved (47 +/- 13% vs 54 +/- 12%, p less than 0.05). This study suggests that following fibrinolysis, the incidence of late potentials is correlated with both an absence of coronary reperfusion and deterioration of left ventricular function.

Adult↗
PubMed1991

[Factors influencing the occurrence of delayed potentials after myocardial infarction. A multivariate study].

Delayed or late potentials after myocardial infarction is a marker of the risk of severe ventricular arrhythmias. We looked for the factors favorising the appearance of these potentials in 208 consecutive patients (172 men, 36 women) admitted to hospital for primary myocardial infarction. Coronary angiography, evaluation of the left ventricular ejection fraction and signal averaged electrocardiography were performed in all patients who were then divided into two groups (Group I: patients with delayed potentials; Group II: patients without delayed potentials). A multivariate analysis of 7 different clinical and paraclinical parameters possibly related to delayed potentials was undertaken. The overall incidence of delayed potentials was 20%. The coronary artery responsible for the infarct was occluded in 79% of patients in Group I and 31% of patients in Group II (p less than 0.00009). The left ventricular ejection fraction was significantly lower in Group I (45.9% vs 54.5%, p less than 0.0002). The incidence of anterior infarcts was 58% in Group I and 37% in Group II (p = 0.008). These 3 factors were independent and correlated with the presence of delayed potentials. The multivariate analysis showed that the major factor was coronary occlusion with presence of delayed potentials multiplied by 6.3, whereas anterior infarction multiplied the risk of delayed potentials by 2.6 and each 10% decrease in LV ejection fraction increased the risk by 1.4.

Action Potentials↗
PubMed1990

Calcium antagonists in myocardial infarction.

Calcium antagonists are effective cardioprotective agents in experimental models of myocardial infarction. However, clinical trials in acute myocardial infarction and in postinfarction secondary prevention led to conflicting results related to the small size of the majority of the trials and possible differences among individual agents with distinct ancillary properties. Furthermore, one has to consider separately the trials in patients with Q-wave infarction and in others with non-Q-wave infarction. Q-wave patients do not seem to benefit from therapy with calcium antagonists. However, the efficacy of early administration of verapamil or diltiazem cannot be ruled out as the available data are not conclusive, mainly because of the small size of the trials and the delay in administering the drugs. We have shown encouraging results with diltiazem, which, compared to placebo, decreased the infarct size measured with serial thallium SPECT defect scores, and increased left ventricular ejection fraction in acute Q-wave infarctions. Non-Q-wave infarction is another area where evidence of positive beneficial effects of diltiazem is strong, as shown by a recent trial conducted by Gibson et al. Diltiazem reduced the early reinfarction rate and postinfarction angina and 1-year cardiac mortality and nonfatal reinfarction rate. Consistent with these findings are results from subgroup analysis of the multicenter diltiazem postinfarction trial. Prophylactic use of diltiazem may be useful and should be considered in patients with non-Q-wave infarction along with aspirin, as no other treatment is yet available for this condition, at least for the time being and until the thrombolysis TIMI phase III trial is terminated.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcium Channel Blockers↗
PubMed1989

[Effect of conventional medical treatment on the course of unstable angina].

In spite of the frequency of unstable angina, the number of clinical trials which permit to evaluate the value of conventional medical treatments, remains limited, especially because of the difficulties in finding a "specific tracer" of the efficacy of the standard drugs used. The common form of unstable angina is different from the spastic form, in that inducement tests permit, in Prinzmetal angina, better codified selection and monitoring of the patients. The literature is reviewed for each therapeutic family (calcium inhibitors, amiodarone, nitro-compounds, molsidomine, etc.). On a short term basis, the conventional treatment permits, most of the time to perform a coronary angiography under good conditions. On a long term basis, medical treatment and surgical procedure give similar results, except for patients with three-vessels disease in whom surgical revascularization provides a more comfortable life.

Angina Pectoris↗
PubMed1987

Conversion from intravenous to oral slow-release disopyramide in acute myocardial infarction.

Twelve patients with acute myocardial infarction were given 1.5 mg/kg/5 min bolus +0.4 mg/kg/hr 6 hr IV infusion of disopyramide followed by 250 mg twice daily of a slow-release oral formulation of this drug. Plasma concentrations of total disopyramide rapidly reached steady-state within the therapeutic margins. The plasma steady-state concentrations of the major metabolite mono-N-dealkyl-disopyramide (MND) showed large intra-individual variations. There was no correlation between plasma levels of either disopyramide or MND and the occurrence of anticholinergic side effects. The drug had no significant effect on mean blood pressure, heart rate, or ECG intervals. This therapeutic regimen, including conversion from the IV form to oral slow-release tablets, could be recommended in myocardial infarction.

Adult↗
PubMed1987

[Effects of intravenous nicardipine on blood pressure, hemorheology platelet function in arterial hypertension. Dose-effect relations].

In arterial hypertension, hyperviscosity with hemorheological disturbances and platelet dysfunction may play a role in the prognosis and complications of the disease. We studied the effects of Nicardipine (NIC) on these blood disturbances in a group of 21 untreated patients with essential hypertension, aged 25 to 70 years (SBP/DBP = 185 +/- 28/105 +/- 17 mmHg). During one hour before and 4 hours after the IV injection of single doses of 5, 7.5 or 10 mg NIC over 5 min, blood pressure was recorded automatically (Dinamap). Hemorheological variables and platelet function were studied before and 30 min, 3 h and 24 hours after the injection. NIC lowered blood pressure and increased heart rate significantly (At 5 min, SBP = -24 mmHg; DBP = -18 mmHg; HR = +22 b/min). These effects were dose-dependent with rapid onset and short duration (less than 2 hrs). NIC decreased plasma viscosity from 1.36 +/- 0.08 to 1.30 +/- 0.07 Cst; p less than 0.01, whole blood viscosity from 22.4 +/- 2.8 to 20.7 +/- 1.5 mPas; p less than 0.05 for gamma = 0.512 s-1, and erythrocyte filterability with the Ca++ ionophore A 23187 from 16.3 +/- 3.8 to 13.5 +/- 3.1; p less than 0.01. Platelet aggregation with ADP was unchanged, but aggregation with A 23187 decreased from 46.9 +/- 21.2 to 31.3 +/- 25.6; p less than 0.05, as well as plasma levels of beta-thromboglobulin (71.2 +/- 29.8 to 55.4 +/- 24.3 ng/ml; p less than 0.02) and platelet generated malonaldehyde (7.2 +/- 1.8 to 6.7 +/- 1.4 nM/10(9) platelets; NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Air embolism during liver resection: an unusual mechanism of entry from a peristaltic pump.

A case of venous air embolism occurring during liver resection is reported. Diagnosis was made early from the continuous recording of pulmonary artery pressure. The aetiology was neither surgical nor an obvious disconnection of a venous line. It was caused by a blockage of the blood filter, resulting in subambient pressure between the filter and a peristaltic pump, leading to aspiration of numerous small air bubbles. The clinical course after replacement of the defective material was uneventful, except for transient postoperative pulmonary oedema.

Adult↗
PubMed1986

[Isotopic exercise tests and selection of cases of inferior infarction requiring coronarography].

Exercise tests involving isotopes were evaluated in 38 subjects presenting inferior myocardial necrosis. Cardiographic data were used to calculate sensitivity and specificity of the method in detection of subjects requiring surgical treatment. Sensitivity was 90% and specificity 62% when three criteria were employed: ECG of positive exertion, reversible diminished accumulation of thallium 201 outside the necrotic site or decrease in the fraction of ejection force. Examination of the fraction of ejection force improved the results of myocardial scanning using thallium and increased detection of subjects requiring surgery from 61% to 90%.

Adult↗
PubMed1985

Ventilatory response to fatiguing and nonfatiguing resistive loads in awake sheep.

To study the changes in ventilation induced by inspiratory flow-resistive (IFR) loads, we applied moderate and severe IFR loads in chronically instrumented and awake sheep. We measured inspired minute ventilation (VI), ventilatory pattern [inspiratory time (TI), expiratory time (TE), respiratory cycle time (TT), tidal volume (VT), mean inspiratory flow (VT/TI), and respiratory duty cycle (TI/TT)], transdiaphragmatic pressure (Pdi), functional residual capacity (FRC), blood gas tensions, and recorded diaphragmatic electromyogram. With both moderate and severe loads, Pdi, TI, and TI/TT increased, TE, TT, VT, VT/TI, and VI decreased, and hypercapnia ensued. FRC did not change significantly with moderate loads but decreased by 30-40% with severe loads. With severe loads, arterial PCO2 (PaCO2) stabilized at approximately 60 Torr within 10-15 min and rose further to levels exceeding 80 Torr when Pdi dropped. This was associated with a lengthening in TE and a decrease in breathing frequency, VI, and TI/TT. We conclude that 1) timing and volume responses to IFR loads are not sufficient to prevent alveolar hypoventilation, 2) with severe loads the considerable increase in Pdi, TI/TT, and PaCO2 may reduce respiratory muscle endurance, and 3) the changes in ventilation associated with neuromuscular fatigue occur after the drop in Pdi. We believe that these ventilatory changes are dictated by the mechanical capability of the respiratory muscles or induced by a decrease in central neural output to these muscles or both.

Airway Resistance↗
PubMed1985

[The scimitar sign: a pulmonary vein or systemic artery? Apropos of a case of pure vascular sequestration].

The scimitar sign, characterised by a vertical opacity crossing the medial part of the right diaphragm, is generally attributed to abnormal pulmonary venous return draining into the inferior vena cava. This is not the only situation in which the scimitar sign is observed, which can also be seen in association with systemic anomalies, in particular sequestration. The authors report the case of a young adult in whom the chest x-ray presented the scimitar sign from childhood. This image was related to a pure pulmonary vessel sequestration by a right sub-phrenic artery. The authors stress the possibility of a purely arterial origin for the scimitar sign in the absence of any abnormality of pulmonary venous return.

Adolescent↗
PubMedDate not supplied

Cavotricuspid isthmus mapping to assess bidirectional block during common atrial flutter radiofrequency ablation.

BACKGROUND: We sought to compare published methods to an alternative approach ascertaining cavotricuspid isthmus (CTI) block during atrial flutter ablation. METHODS AND RESULTS: In 39 consecutive patients who underwent an atrial flutter ablation procedure, a 24-pole mapping catheter was positioned so that 2 adjacent dipoles were bracketing the targeted CTI line of block (LOB), with proximal dipoles lateral to the LOB and distal dipoles in the coronary sinus. Two pacing sites were lateral (positions A and B) and 2 were septal (positions C and D) to the LOB, with locations A and D closest to the LOB. A resulting CTI block was accepted when 3 criteria were fulfilled: (1) complete reversal of the right atrial depolarization on the 24-pole catheter when pacing in the coronary sinus, (2) conduction delays from A to D greater than from B to D, and (3) conduction delays from D to A greater than from C to A. A successful CTI block was obtained in all patients. Before CTI block was obtained, a progressive CTI conduction delay was observed in 11 patients (28.2%). During the procedure, the 3 criteria defined above were either all present or all absent. CONCLUSIONS: This study establishes that reversal of the atrial depolarization sequence up to the LOB is a definitive and mandatory criteria of successful atrial flutter ablation.

Aged↗
PubMedDate not supplied

[Which assessment of coagulation, for which operation?].

Patient's bleeding history is an important part of preoperative evaluation but must be associated with hemostatic tests. The choice in between these different hemostatic tests will be made according to the knowledge of the bleeding history and; the type of surgery planned. In case of hemostatic abnormality, additional tests can be performed in order to determine a more precise state of the patient's hemostatic dysfunction. However, complete preoperative hemostatic evaluation (including patient's bleeding history and blood tests) may not entirely avoid per and post-operative hemostatic complications. Indeed, there is no absolute correlation between hemostatic screening and bleeding or thrombosis risks. Some other factors, completely independent from hemostatic function, such as shock, surgical bleeding, anoxia... may intervene.

Blood Coagulation Tests↗