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Biomedical subjects

B Magnani

Publications and source records attributed to B Magnani.

At least 37 records · Page 2Linked to original sources
PubMed1999

Evaluation of atrial refractoriness and atrial fibrillation inducibility immediately after internal cardioversion in patients with chronic persistent atrial fibrillation.

OBJECTIVE: To prospectively evaluate right atrial refractoriness and sustained atrial fibrillation (AF) inducibility at programmed electrical stimulation in two groups of patient: a series of patients with chronic persistent AF, studied immediately after successful low energy internal atrial cardioversion, and a group of control patients without history of supraventricular arrhythmias. PATIENTS: Nineteen patients with chronic persistent AF (mean AF duration 11 +/- 10 months, range 2-61 months) submitted to successful internal low energy atrial cardioversion in fully conscious state and 11 control patients without history of supraventricular arrhythmias. METHODS: An electrophysiological evaluation was performed to measure atrial refractoriness and AF inducibility, by delivering single atrial extrastimuli in high right atrium, at decremental coupling, during spontaneous sinus rhythm and after 8 beats at 600, 500, 400 and 330 ms cycle length. If sustained AF was induced the protocol was terminated. RESULTS: During programmed atrial stimulation sustained AF was induced in 8 out of 19 (42%) of the AF patients but in none of the control group. Atrial effective refractory period was significantly shorter in AF patients compared to controls both at basic cycle length, at 600 ms, 500 ms and 400 ms cycle length, meanwhile no statistically significant differences were found at 330 ms cycle length. An altered relationship between atrial effective refractory period and cycle length was found in AF patients compared to controls: the slope of linear correlation slope was significantly lower in AF group than in controls (0.04 +/- 0.07 vs 0.17 +/- 0.10, p < 0.002). CONCLUSIONS: Marked abnormalities of atrial refractoriness and of its heart rate relationship are observed after internal cardioversion of chronic persistent AF in humans and these abnormalities are associated with an high vulnerability to AF. These observations may explain the high risk of AF recurrences in the early phases following successful cardioversion. In this scenario antiarrhythmic drug therapy seems to be mandatory for reducing arrhythmia relapses.

Adult↗
PubMed1999

In vitro fertilization. Do short-term changes in estrogen levels produce increased fibrinolysis?

High estrogen levels have been implicated as a cause of thrombosis. Patients undergoing in vitro fertilization (IVF) present an opportunity to study isolated estrogen effects on the coagulation system, since hormonal manipulation is used to achieve varying estrogen concentrations. We evaluated the effect of estrogen levels on the fibrinolytic and clotting systems of 32 patients undergoing IVF from whom venous samples were obtained during a period of several weeks at baseline and retrieval times. Flow cytometric studies were performed to assay platelet activation. Hemostasis markers measured thrombin-antithrombin complexes (TAT), fibrinogen, plasmin-alpha 2-antiplasmin complexes (PAP), plasminogen activator inhibitor (PAI-1), and D-dimer. A significant decrease in PAI-1 and an increase in PAP were observed at high estrogen levels, suggesting an increase in fibrinolytic potential. However, the products of fibrinolysis, as measured by D-dimer levels, decreased at high estrogen levels. No changes were seen in platelet activation indicators or TAT levels. The fact that a decrease in products of fibrinolysis was seen at high estrogen levels despite concurrent changes in PAI-1 and PAP that normally accompany increased fibrinolysis may be due to alterations in the overall balance of the fibrinolytic system or to a delay in onset of fibrinolysis.

Estradiol↗
PubMed1999

Low energy internal atrial cardioversion in atrial fibrillation lasting more than a year.

UNLABELLED: The aim of this study was to evaluate the efficacy of low energy internal atrial cardioversion in restoring sinus rhythm (SR) in patients with chronic atrial fibrillation (AF) persisting > 1 year. Fifteen patients with chronic AF lasting > 1 year (from 13-48 months, mean 24 +/- 13 months) were studied. R wave synchronized 3/3 ms biphasic shocks were delivered between right atrial and coronary sinus (left pulmonary artery in five patients) electrodes. Sedatives or anesthetics were administered only at the patient's request. RESULTS: Stable SR was restored in 14 (93%) of 15 patients after shocks with a mean leading edge voltage of 377 +/- 77 V (range 260-500) and a mean delivered energy of 7.3 +/- 3.4 J (range 2.6-12.9). The procedure was performed without anesthesia in 6 (40%) patients. All successfully cardioverted patients were treated with flecainide, sotalol, or amiodarone. During a follow up of 7.7 +/- 7.9 months (range 1-24) AF recurred in five (36%) patients. Three of five AF recurrences occurred within 3 days after conversion to SR. CONCLUSION: Internal low energy atrial cardioversion is highly effective in restoring SR even in patients with AF lasting > 1 year. The long-term results from the standpoint of freedom from AF recurrences, are satisfactory, although additional antiarrhythmic treatment is required, particularly in the first days after conversion.

Anti-Arrhythmia Agents↗
PubMed1999

Electrophysiological effects of flecainide and propafenone on atrial fibrillation cycle and relation with arrhythmia termination.

OBJECTIVES: (1) To investigate the electrophysiological effects of flecainide and propafenone during atrial fibrillation, and their relation to arrhythmia termination; (2) to investigate the effects of isoprenaline on atrial fibrillation in basal conditions and during treatment with class 1C drugs to evaluate the role of adrenergic stimulation on proarrhythmic events occurring during this treatment. DESIGN: Prospective, single centre study. SETTING: University hospital. METHODS: 10 patients with lone paroxysmal atrial fibrillation underwent an electrophysiological study. The dynamic behaviour of MFF (the mean of 100 consecutive atrial fibrillation intervals) was evaluated at two atrial sites after induction of atrial fibrillation either at baseline or after class 1C drug administration (flecainide or propafenone 2 mg/kg). The effects of isoprenaline on MFF and RR interval were also investigated both under basal conditions and during class 1C drug treatment. RESULTS: After induction of atrial fibrillation, mean (SD) MFF shortened with time, and was further shortened by isoprenaline infusion (177 (22) v 162 (16) v 144 (11) ms, p < 0.05). The administration of class 1C drugs reversed this trend and significantly increased the MFF to an average of 295 (49) ms, leading to conversion to sinus rhythm within 10 minutes in all patients. Atrial fibrillation was then reinduced on class 1C drugs: isoprenaline shortened the MFF and RR interval with a trend to AV synchronisation (223 (43) v 269 (49) ms for the MFF, 347 (55) v 509 (92) ms for the RR, p < 0.05); 1:1 sustained AV conduction occurred in two patients, at 187 and 222 beats/min respectively. One of these patients underwent electrical cardioversion because of haemodynamic collapse. CONCLUSIONS: Class 1C drugs are effective at restoring sinus rhythm by increasing the MFF to a much greater extent than observed in self terminating atrial fibrillation episodes, and reversing the spontaneous atrial fibrillation behaviour (progressive shortening of MFF and self perpetuation of atrial fibrillation). MFF prolongation with 1:1 conduction at fast ventricular rates may lead to synchronisation during adrenergic stimulation, with a very short ventricular cycle; hence it is advisable to keep the patients at rest after acute class 1C drug loading or to consider pharmacological modulation of AV conduction for patients who are prone to a fast ventricular response.

Adrenergic beta-Agonists↗
PubMed1999

Codeine intoxication in the neonate.

Although opiates can provide patients with relief from pain and the discomfort of cough, the routine prescription of these drugs for infants demands caution and concern. Infants, particularly neonates, are not merely small adults requiring smaller dosages, but rather uniquely different patients. Neonates present with an immature physiology and biochemistry with respect to drug metabolism. We report a case of codeine intoxication in the neonate, in which the drug was prescribed for cough control during an emergency department visit.

Codeine↗
PubMed1999

Coronary stenting for unstable angina: predictors of 30-day and long-term clinical outcome.

BACKGROUND: Unstable angina is usually caused by acute thrombosis superimposed on a fissured plaque. Coronary artery stenting has been shown to improve short- and long-term results of coronary angioplasty in mainly stable patients with one-vessel disease, but it is uncertain whether its use in an unstable clinical setting can be safe and useful. This study sought to evaluate the results of coronary stenting in unstable angina and to determine patient, lesion and procedure-related predictors of 30-day and long-term ischemic events. METHODS: We studied 266 consecutive patients (mean age 62 +/- 9 years) with unstable angina who underwent coronary artery stenting. The procedure was performed electively in 24%, in bailout situations in 11% and for a suboptimal result of conventional angioplasty in 65%. After stent implantation, patients were treated with anticoagulation (61) on combined antiplatelet therapy (200). Multivariate logistic regression analyses were performed to determine 30-day and long-term predictive factors of ischemic complications. RESULTS: Procedural success was obtained in 261 patients (98.1%). During the first 30 days after stenting, one patient died from cardiogenic shock (0.3%) and six (22%) suffered a non-fatal Q-wave myocardial infarction. Patients with combined antiplatelet therapy had a significantly lower stent thrombosis rate (1.5% versus 11.4%, P = 0.002) than those treated with anticoagulant regimen. At long-term follow-up (17.7 +/- 9.4 months) cardiac mortality myocardial infarction and target-vessel revascularization rates were 0.4%, 1.5% and 9.3%, respectively. In multivessel and diabetic patients, a worse long-term event-free survival was observed. Logistic multivariate analysis revealed bailout stenting, anticoagulant therapy, implantation of stents longer than 15 mm as predictors of 30-day ischemic events. In addition, multivessel coronary artery disease and stent application with balloon size of less than 3 mm were predictive of long-term ischemic events. CONCLUSIONS: This study demonstrates that, either electively or after failure of conventional angioplasty, coronary stenting represents an effective therapy for patients with unstable angina. In the same clinical setting, combined antiplatelet therapy is associated with a lower 30-day stent thrombosis rate than anticoagulant therapy. Bailout stenting, anticoagulant therapy, implantation of stents longer than 15 mm were shown to be predictors of 30-day ischemic events, whereas multivessel coronary artery disease and stent application with small balloon size were predictive of long-term ischemic events.

Adult↗
PubMed1999

Long-term follow-up of stent implantation versus stent-like angioplasty in unstable angina.

Stent-like plain old balloon angioplasty (POBA, < or = 30% residual diameter stenosis) in patients with stable angina resulted in a clinical and angiographic long-term outcome equivalent to stenting. In unstable angina POBA showed lower acute and long-term efficacy than in the stable setting. Data comparing stent-like POBA and coronary stenting in unstable angina are lacking in the literature. The aim of this retrospective single-center study was to compare the long-term effectiveness of stent-like POBA and coronary stenting in unstable angina. From January 1996 to December 1996 we retrospectively examined 187 consecutive patients with unstable angina who underwent coronary angioplasty on a native vessel: 135 had coronary stenting in addition to POBA and 50 achieved a stent-like result with POBA. Two patients, with major contraindication to coronary stenting, who did not reach a stent-like angiographic result, were also treated with only POBA but were excluded from the study. Stent implantation indications were: elective (54 stents, 30%), suboptimal angiographic result (104 stents, 58%), and bail-out situation (21 stents, 12%). Stent implantation showed high angiographic (98.5%) and clinical (95.5%) success. Stent thrombosis occurred only in 2 patients (1.5%). At quantitative coronary angiography the stent group showed a higher post-procedure minimal lumen diameter (2.74 +/- 1.25 vs 2.27 +/- 0.58 mm, p = 0.025), acute gain (1.95 +/- 1.28 vs 1.43 +/- 0.57 mm, p = 0.007) and lower residual stenosis diameter (13.89 +/- 7.43 vs 20.4 +/- 7.28%, p = 0.001) than the stent-like POBA group. At 1-year follow-up the stent group showed a higher event-free survival rate (77.9 vs 64.6%, p = 0.009) mainly due to lower recurrence of angina and repetition of percutaneous procedures. Stent-like POBA procedure and baseline lesion length > or = 10 mm proved to be the only independent predictors of long-term ischemic event occurrence. In conclusion, in unstable angina, stent implantation appears more effective than stent-like POBA to avoid long-term ischemic complications.

Aged↗
PubMed1998

Cardioverter-defibrillator oversensing due to double counting of ventricular tachycardia electrograms.

We report a case of a patient with idiopathic dilated cardiomyopathy and recurrent ventricular tachycardias refractory to antiarrhythmic treatment with amiodarone. A cardioverter defibrillator implantation was performed by the transvenous technique, but ventricular tachycardia detection resulted to be inappropriate because of constant double sensing of ventricular tachycardia electrograms (QRS width=250 ms). Device programmability didn't allow a satisfactory solution to this problem, therefore a more appropriate sensing system was considered. Through an anterior thoracotomy two epicardial wires were positioned and sensing by these wires, placed closer to ventricular tachycardia origin, resulted appropriate. An electrophysiologic study and subsequent follow up confirmed appropriate ICD detection of ventricular tachycardias. This case emphasizes how in some cases sensing by epicardial wires may be a solution for QRS double counting occurring with endocardial leads during ventricular tachycardia.

Defibrillators, Implantable↗
PubMed1998

Platelet and neutrophil activation during cardiac surgical procedures: impact of cardiopulmonary bypass.

BACKGROUND: Platelet and neutrophil activation plays a crucial role in reperfusion injury. To determine whether platelet and neutrophil activation occurs in the coronary circulation after cold cardioplegic arrest and reperfusion, we studied 22 patients undergoing coronary artery bypass or valve procedures, or both procedures. METHODS: Blood was sampled from the coronary sinus and the radial artery (A) before bypass; (B) immediately after cross-clamp release; and (C) 5 minutes after cross-clamp release; and was analyzed for surface markers of platelet (CD62P) and neutrophil (CD11b) activation. RESULTS: During bypass, platelet activation increased significantly (p < 0.01) over prebypass values, but no difference was seen between arterial and coronary sinus samples. Neutrophil activation also increased significantly (p < 0.001) during bypass, but there was no difference between arterial and coronary sinus samples. CONCLUSIONS: Cellular activation occurs locally in the coronary circulation during bypass, but no more so after cold cardioplegic arrest and reperfusion.

Aged↗
PubMed1998

Short- and long-term effects of early fosinopril administration in patients with acute anterior myocardial infarction undergoing intravenous thrombolysis: results from the Fosinopril in Acute Myocardial Infarction Study. FAMIS Working Party.

BACKGROUND: Angiotensin-converting enzyme inhibitors are used in patients who have myocardial infarction with left ventricular (LV) dysfunction. Few data are available in patients whose LV function is within the normal range. METHODS AND RESULTS: The Fosinopril in Acute Myocardial Infarction Study was a 2-year, randomized, double-blind, placebo-controlled, multicenter study of 285 patients with anterior acute myocardial infarction and was designed to investigate the effects of the early (<9 hours) administration of fosinopril and thrombolysis on (1) changes in echocardiographically evaluated LV volumes at 3 months and (2) long-term occurrence of death and congestive heart failure. LV volumes were normal at baseline in more than 70% of patients and were comparable between groups both at baseline and after 3 months of treatment. Fosinopril-treated patients showed a 30% reduction in the 2-year combined prevalence of death or moderate-to-severe congestive heart failure (New York Heart Association class III-IV) despite having a worse clinical profile at baseline. The benefit of fosinopril was confirmed both in patients without congestive heart failure at admission and in those with ejection fraction >40% at baseline. Moreover, the incidence of significant ventricular arrhythmias was lower in the fosinopril group (0.8% vs 6.0%, p < 0.02). CONCLUSIONS: The results of the Fosinopril in Acute Myocardial Infarction Study suggest that early treatment with fosinopril can benefit patients with acute myocardial infarction in addition to a prevention of LV remodeling.

Aged↗
PubMed1998

Prevalence of episodes of ST-segment depression among mild-to-moderate hypertensive patients in northern Italy: the Cardioscreening Study.

OBJECTIVES: To assess the prevalence of episodes of ST-segment depression in a population of consecutive patients with mild-to-moderate essential hypertension who are free of clinical signs of coronary artery disease. METHODS: The study involved 28 Italian centers that enrolled 414 hypertensive patients (aged 50-70 years; diastolic blood pressure > or = 95-115 mmHg or systolic blood pressure > or = 150-220 mmHg, or both, 10 days after withdrawal of medications). Silent myocardial ischemia was assessed by means of exercise stress testing and 48 h Holter monitoring. An ischemic episode was defined as a horizontal or downward sloping ST-segment depression > or = 100 microV, occurring 80 ms after the J point, and lasting for at least 1 min. RESULTS: Of the 414 patients enrolled, 411 completed the exercise stress test. During the test significant ST-segment depression occurred for 25 patients (6.1%) and all episodes but one were asymptomatic and not associated with arrhythmias. Of the 396 patients for whom we analyzed a 48 h Holter recording, 43 (10.9%) had at least one episode of ST-segment depression and seven of these had also had one during the exercise stress test The median number of episodes per patient was five (range 1-19), median duration was 9 min (range 1-20 min), and the mean amplitude of the ST-segment depression was 190 +/- 180 microV. None of these episodes was associated with symptoms and all of them occurred under resting condition. Patients with (n = 61) and without (n = 335) ST-segment depression during Holter monitoring or exercise stress testing had similar ages (59 +/- 6 versus 58 +/- 6 years) and did not differ for tobacco smoking, plasma lipid levels, blood pressure values and prevalence of echocardiographic left ventricular hypertrophy (57% of patients had left ventricular mass indexes > or = 134 g/m2 for men and > or = 110 g/m2 for women in both groups). Women had a higher prevalence of ST-segment depression than did men during Holter monitoring [32 of 183 (17.5%) versus 11 of 213 (5.2%)], whereas the prevalences of ischemia during the exercise stress test were similar. Female sex was the only significant factor associated with the occurrence of silent myocardial ischemia [odds ratio 2.56 (95% confidence interval 1.40-4.71)]. CONCLUSIONS: Our results show that 15% of patients with mild-to-moderate hypertension, who are free of clinical signs of coronary artery disease, experience episodes of ST-segment depression during Holter monitoring or exercise stress testing. Most of these episodes are asymptomatic and are not associated with the severity of hypertension, the presence of left ventricular hypertrophy, and other risk factors for coronary artery disease. Episodes of ST-segment depression are more common for women than they are for men, particularly during Holter monitoring. The early detection of silent myocardial ischemia by Holter monitoring or by the exercise stress test might be useful for the identification of hypertensive patients who should be investigated further and administered a more specific treatment.

Age Factors↗
PubMed1998

Risk factors associated with alterations in carotid intima-media thickness in hypertension: baseline data from the European Lacidipine Study on Atherosclerosis.

BACKGROUND: The possibility that calcium antagonists exert an anti-atherosclerotic action at least partly independently of the blood-pressure-lowering effect is supported by results of a large number of experimental studies and can now be investigated by quantitative B-mode ultrasound imagining of the carotid artery walls. DESIGN: The European Lacidipine Study on Atherosclerosis (ELSA) is a prospective, randomized, double-blind, multinational trial comparing effects of 4-year treatment based on the long-acting, highly lipophilic calcium antagonist lacidipine with those of treatment based on the beta-blocker atenolol on the development of carotid artery wall alterations in patients (aged 45-75 years) with mild-to-moderate hypertension (systolic blood pressure 150-210 mmHg and diastolic blood pressure 95-115 mmHg). While the intervention study is progressing, this article summarizes baseline data obtained from the whole cohort of 2259 patients randomly allocated to treatment. METHODS: Baseline ultrasound data were obtained from two replicate examinations performed shortly before random allocation to treatment by certified sonographers at 23 referral centres and read at the ultrasound coordinating centre at the Wake Forest University School of Medicine. Intima-media thickness was measured at up to 12 different sites in the carotid artery tree and expressed as the mean of the maxima at these sites (Mmax), the mean of the maxima at four sites in the distal common carotid artery and bifurcation (CBMmax) and the maximum intima-media thickness (Tmax). Baseline demographic and clinical measurements were performed by investigators in 410 peripheral clinical units and 24 h ambulatory blood pressure monitorings read and validated by members of a centralized unit at the University of Milan. The statistical analysis centre at the Technische Universität München received and analysed all baseline data, by calculating means +/- SD, medians and ranges and performing correlation (Spearman correlation coefficients) and multiple regression analyses. RESULTS: Prevalence of carotid artery wall alterations among the hypertensive patients randomly allocated to treatment in the ELSA was very high: 82% had Tmax > or = 1.3 mm ('plaques' according to protocol) and 17% had Tmax > or = 1.0 and < 1.3 mm ('thickening'), with a median of two plaques per patient. We found significant correlations between ultrasound measurements and the following demographic and clinical variables: age, sex, systolic blood pressure and pulse pressure (both clinic and ambulatory), concentrations of total, high-density lipoprotein and low-density lipoprotein cholesterol and triglycerides, smoking habit and duration of hypertension. We found no significant correlation to diastolic blood pressure and glucose concentration. A multiple regression analysis indicated significant variables in the following rank order: age, 24 h ambulatory pulse pressure, sex, low-density lipoprotein cholesterol concentration, triglyceride concentration, smoking and clinic systolic blood pressure. CONCLUSIONS: Analysis of baseline data from the ELSA has shown that there is an extremely marked prevalence of carotid artery wall alterations among mild-to-moderate, middle-aged hypertensive patients. In addition to age, systolic blood pressure and pulse pressure, particularly if they are accurately measured by ambulatory monitoring, play a major role, somewhat greater than those of sex, low-density lipoprotein cholesterol concentration and smoking, in influencing intima-media thickness.

Adrenergic beta-Antagonists↗
PubMed1998

The Verapamil in Hypertension and Atherosclerosis Study (VHAS): results of long-term randomized treatment with either verapamil or chlorthalidone on carotid intima-media thickness.

BACKGROUND: It is unclear whether the carotid intima-media thickness can be influenced by antihypertensive treatment and whether some antihypertensive agents, such as calcium antagonists, may have a greater effect on this parameter than others, such as diuretics. The present paper reports the principal results of the ultrasound substudy of the randomized, prospective, controlled, Verapamil in Hypertension and Atherosclerosis Study (VHAS). DESIGN AND METHODS: In 498 hypertensive patients in eight Italian centres, randomized to either verapamil (240 mg once a day) or chlorthalidone (25 mg once a day), a B-mode ultrasound scan was performed according to a standardized procedure at baseline and after 3, 12, 24, 36 and 48 months of treatment. The maximum intima-media thicknesses of the far walls of common, bifurcation and internal carotid arteries were measured bilaterally, and the following indices calculated: the mean thickness at the six measured sites, the mean thickness at the common and bifurcation sites and the single maximum thickness. The primary endpoint for treatment efficacy was the slope of the change over 4 years (rate of change, mm/year), corrected by using the initial mean over the six sites (baseline + 3 months) as a covariate (mm/year per mm). The patients were also classified into three strata according to their baseline single maximum thickness: those with normal carotid arteries (single maximum ( 1 mm), those with thickened carotid arteries (single maximum > 1 and < or = 1.5 mm and those with carotid plaques (single maximum > 1.5 mm). RESULTS: Among the 456 patients with satisfactory baseline ultrasound readings, 33% were classified with normal carotid arteries, 27% with thickened carotid arteries and 40% with plaques. In the intention-to-treat population (377 patients with ultrasound measurements taken on at least three different occasions over a period of at least 2 years), the rate of change in the mean thickness at the six sites measured was rather small (0.015 mm/year), but significantly (P < 0.05) smaller in patients with plaques (0.003 mm/year) than in patients with thickened or with normal carotids (0.023 and 0.025 mm/year, respectively). When related to initial values, the rate of change in the mean thickness at the six sites had a negative slope (-0.059 mm/year per mm, P < 0.01). Although rates of change in the carotid intima-media thickness in unstratified patients were not different in those treated with verapamil or with chlorthalidone, when changes in the mean thickness of six sites were related to the initial value, the slope of this relationship was significantly different in the two treatment groups (verapamil -0.082 versus chlorthalidone -0.037 mm/year per mm, P < 0.02). The blood pressure-lowering effect of the two randomized treatments was similar. Taking fatal and nonfatal, major and minor cardiovascular events together, there were 19 events in the verapamil group and 35 in the chlorthalidone group, with a significantly (P < 0.01) greater incidence in patients with plaques, and among patients with plaques in those who were randomized to chlorthalidone (P < 0.05). CONCLUSIONS: In accord with evidence from animal models of atherosclerosis, the calcium antagonist verapamil was more effective than the diuretic chlorthalidone in promoting regression of thicker carotid lesions. Changes in the carotid intima-media thickness were small in both groups, and the differences between the changes under the two treatments were consequently small, but the observation that these small differences in carotid wall changes were paralleled by differences in the incidence of cardiovascular events (better intima-media thickness regression with verapamil paralleled by a lower cardiovascular event rate) suggests that even small effects on carotid plaques may have clinical and prognostic relevance.

Adult↗
PubMed1998

Oral loading with propafenone: a placebo-controlled study in elderly and nonelderly patients with recent onset atrial fibrillation.

UNLABELLED: The efficacy and safety of propafenone as an oral loading dose (600-mg single oral dose) in converting recent-onset atrial fibrillation (< or = 7 days duration) to sinus rhythm were evaluated in a single-blind, placebo-controlled study according to patients' age. Overall, 240 hospitalized patients, NYHA Class < or = 2 without signs or symptoms of heart failure were enrolled: among patients aged < or = 60 years, 55 were allocated to propafenone treatment and 59 to placebo, respectively, and among patients aged > 60 years, 64 were allocated to propafenone treatment and 62 to placebo, respectively. RESULTS: In each age group, the likelihood of conversion to sinus rhythm was significantly greater after propafenone compared with placebo at 3 and 8 hours. For patients aged < or = 60 years, corresponding odd ratios were 3.78 (95% CI = 1.80-7.92, P = 0.04) at 3 hours and 4.74 (95% CI = 2.12-10.54, P = 0.02) at 8 hours; for patients aged > 60 years odd ratios were 5.03 (95% CI = 2.08-12.12, P = 0.02) at 3 hours and 6.75 (95% CI = 3.28-73.86, P = 0.01) at 8 hours, respectively. Logistic regression analysis showed that conversion to sinus rhythm within 3 hours was predicted by age < or = 60 years (P = 0.0064) and by propafenone treatment (P < 0.0001), and conversion to sinus rhythm within 8 hours was predicted by age < or = 60 years (P = 0.0467) and by propafenone treatment (P < 0.0001). The occurrence of adverse effects was observed in 14%-16% of propafenone treated patients and in 8% of placebo treated patients without significant differences according to age. In conclusion, in patients with recent-onset atrial fibrillation without signs of heart failure, propafenone as a single oral loading dose is effective. It is also effective in selected elderly subjects with a favorable safety profile. Moreover, spontaneous conversion to sinus rhythm appears to occur less frequently in elderly patients.

Administration, Oral↗
PubMed1998

Conversion of recent-onset atrial fibrillation to sinus rhythm: effects of different drug protocols.

UNLABELLED: In a population of 417 hospitalized patients, the efficacy and safety of different drug regimens administered to convert atrial fibrillation (AF) of recent onset (< or = 7 days duration) to sinus rhythm were evaluated. All patients were in NYHA Class < or = 2, and free of heart failure. They were randomly allocated to treatment with placebo in 121 patients; i.v. amiodarone, 5 mg/kg bolus, followed by 1.8 g/24 hours in 51 patients; i.v. propafenone, 2 mg/kg bolus, followed by 0.0078 mg/kg/min in 57 patients; p.o. propafenone, 600 mg p.o. in a single dose in 119 patients; and p.o. flecainide, 300 mg p.o. in a single dose in 69 patients. All patients were continuously monitored by Holter ECG, and the number of conversions to sinus rhythm was measured at 1, 3, and 8 hours. RESULTS: (1) I.v. propafenone resulted in a higher conversion rate within 1 hour compared with the oral loading regimens of propafenone or flecainide, but the conversion rates at 3 and 8 hours were comparable, approximately 75% at 8 hours; 2) i.v. amiodarone was not different from placebo until 8 hours when it was associated with 57% of conversions; (3) conversion to sinus rhythm at 8 hours was observed in 37% of the placebo treated patients. Serious adverse effects occurred in few patients: two patients treated with flecainide and one treated with i.v. propafenone experienced left ventricular decompensation; one patient treated with placebo and two treated with flecainide had atrial flutter with rapid ventricular response. In conclusion, single-dose, oral loading with propafenone or flecainide are acceptable alternatives to conventional drug regimens in selected hospitalized patients. In addition, the measure of a placebo effect is mandatory in studies of recent-onset AF.

Amiodarone↗
PubMed1998

N-acetylcysteine reduces methemoglobin in an in-vitro model of glucose-6-phosphate dehydrogenase deficiency.

OBJECTIVE: To determine whether N-acetylcysteine (NAC) reduces methemoglobin (MHB) in an in-vitro model of glucose-6-phosphate dehydrogenase (G6PD) deficiency, given that methylene blue is an ineffective MHB antidote in G6PD deficiency. METHODS: Five volunteers donated blood, which was divided equally into 2 test tubes, centrifuged, and washed with Tris-Mopps buffer (pH 7.4, 15 mmol/L glucose). Both tubes were incubated with epiandrosterone (EA) (400 micromol), a specific inhibitor of G6PD. After 75 microL of 0.18 mol hydroxylamine (HA) was added to induce MHB formation, 150 microL of NAC (20 mg/mL) was added to tube 1 and 150 microL of phosphate-buffered saline (PBS) was added to tube 2 as a volume control. Serial MHB levels are reported as a percentage of total hemoglobin (Hb). G6PD activity was measured at baseline, 15 minutes after EA, and at 5 hours. RESULTS: Mean G6PD activity at baseline was 9.2+/-2.9 U/g Hb (normal >4.6 U/g Hb); 15 minutes after EA was 3.0+/-1.0 U/g Hb; and at experiment's end was 2.3+/-0.7 U/g Hb. The mean (+/-SD) areas under the concentration-time curves (AUCs) of NAC-EA-HA and PBS-EA-HA samples were compared using an unpaired t-test and were significantly different: PBS-EA-HA, 20,400+/-1,100 % min, vs NAC-EA-HA, 10,400+/-1,000 % min, respectively (p < 0.05). CONCLUSION: In this in-vitro model of G6PD deficiency, NAC efficiently reduced MHB.

Acetylcysteine↗
PubMed1998

Primary pulmonary hypertension: insights into pathogenesis from epidemiology.

Primary pulmonary hypertension (PPH) is a rare disease that affects young people predominantly of female gender. Early epidemiologic studies have shown that the diagnosis is usually made 1 to 2 years after symptoms onset, and the mean survival is reduced to 2 to 3 years thereafter. New insights into the pathogenesis of PPH by epidemiologic studies may be obtained through the utilization of informatic technologies coupled to a clear definition of the disease. Early stages of precapillary pulmonary hypertension could be identified through screening tests like echocardiography in populations with higher incidence, such as familial PPH and the conditions associated with pulmonary hypertension. These latter conditions are hemodynamically and pathologically similar to the primary form, and they can give insight into several possible aspects of the pathogenesis of PPH. Prospective registries are very useful in coordinating the collection of epidemiologic data, and new technologies, such as informatics, may improve the management and the continuous updating of the databases.

Adult↗