The variation of serum lipoprotein (a) during surgical operations.
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Adult↗
Biomedical subjects
B Magnani
Publications and source records attributed to B Magnani.
Effectiveness of loading oral flecainide for converting recent-onset atrial fibrillation to sinus rhythm in patients without organic heart disease or with only systemic hypertension.
Sixty-two patients with recent-onset (less than or equal to 1 week) atrial fibrillation (New York Heart Association functional class 1 and 2) were randomized in a single-blind study to 1 of the following treatment groups: (1) flecainide (300 mg) as a single oral loading dose; or (2) amiodarone (5 mg/kg) as an intravenous bolus, followed by 1.8 g/day; or (3) placebo for the first 8 hours. Twenty-four-hour Holter recording was performed, and conversion to sinus rhythm at 3, 8, 12 and 24 hours was considered as the criterion of efficacy. Conversion to sinus rhythm was achieved within 8 hours (placebo-controlled period) in 20 of 22 patients (91%) treated with flecainide, 7 of 19 (37%) treated with amiodarone (p less than 0.001 vs flecainide), and 10 of 21 (48%) treated with placebo (p less than 0.01 vs flecainide). Resumption of sinus rhythm within 24 hours occurred in 21 of 22 patients (95%) with flecainide and in 17 of 19 (89%) with amiodarone (p = not significant). Mean conversion times were shorter for flecainide (190 +/- 147 minutes) than for amiodarone (705 +/- 418; p less than 0.001). No major side effects occurred. At Holter monitoring, a pause of 9.3 seconds was observed in 1 asymptomatic patient treated with flecainide. Phases of atrial flutter with a ventricular rate less than or equal to 150 beats/min were detected before sinus conversion in 1 patient receiving placebo and in 2 receiving flecainide.(ABSTRACT TRUNCATED AT 250 WORDS)
Administration, Oral↗
Effects of two dosages of subcutaneous low molecular weight heparin (Parnaparin) and of unfractionated heparin on fibrin formation and lipolysis in acute myocardial infarction.
Although low molecular weight heparins (LMWH) have been extensively investigated for the prophylaxis and treatment of venous thromboembolism in surgical environments, few data in acute myocardial infarction are available in the literature. In this study two dosages of a new LMWH, Parnaparin, and unfractionated heparin (UF) were investigated in 50 pts with acute myocardial infarction. 20 pts received UF (15.000 units, three subcutaneous injections, Group 1), 20 pts received Parnaparin (6.400 units, single injection, Group 2) and 10 pts received a higher dose of Parnaparin (12.800 units, single injection, Group 3). Similar fibrinopeptide A (FpA) levels were observed in Group 1 and Group 2. In Group 3 the dosage of Parnaparin resulted in a significant prolongation of the APTT and in lower FpA levels. Fibrin formation was decreased by Parnaparin in a concentration-dependent way, according to both the anti-Xa activity and the APTT ratio. Parnaparin did not result in a significant increase in free fatty acid concentration, in comparison with UF. Thus, Parnaparin may offer the advantage of a single subcutaneous injection in patients with acute myocardial infarction.
Aged↗
Sick sinus syndrome and diffuse impairment of the conduction system in a child: successful pacing with a steroid eluting endocardial pacing lead.
A 9-year-old patient who had had a syncope was found to have atrial flutter in a resting electrocardiogram (ECG). Brief phases of sinus arrest had previously occurred after drug conversion to sinus rhythm. Structural heart disease was excluded by cardiac catheterization and angiography. Electrophysiologic study revealed a sick sinus syndrome, associated with diffuse impairment of the conduction system (supra-, infra-, and intrahisian block). Epimyocardial and an endocardial pacemaker implantation failed because of high stimulation threshold, after 3 years and 2 weeks, respectively. At the third implantation a steroid-eluting endocardial pacing lead was used and satisfactory pacing was still present 2 years later.
Atrial Flutter↗
Atrial premature beats coupling interval determines lone paroxysmal atrial fibrillation onset.
In 20 patients with recurrent episodes of lone paroxysmal atrial fibrillation we assessed the onset pattern of each episode of either atrial fibrillation or of atrial flutter during a 24-h Holter monitoring. We evaluated 24 twenty-four-hour Holter tape recordings and our data are related to 168 episodes of paroxysmal atrial fibrillation and 27 episodes of paroxysmal atrial flutter. Eighty-five percent of atrial fibrillations and 67% of atrial flutters were of short duration (less than 5 min). The majority of patients (80%) had either nocturnal or daily episodes of arrhythmia and PP intervals immediately before onset of arrhythmia did not show significant variations in 77% of cases. The coupling interval of the supraventricular premature beats eliciting atrial fibrillation was significantly shorter than the coupling intervals of the spontaneous isolated supraventricular premature beats (p less than 0.0001); again, in 6 patients with either atrial fibrillation or flutter, the coupling interval at onset of fibrillation was significantly shorter in comparison to flutter (p less than 0.0001). In conclusion, vagal or sympathetic prevalence does not seem to influence significantly the beginning of the arrhythmia, while the coupling interval of the atrial premature beats plays a critical role in the inducibility of atrial flutter or fibrillation.
Adult↗
Use of multiple-action agents on the heart: pathophysiological and therapeutic considerations.
The introduction of beta-adrenoreceptor antagonists into clinical practice has resulted in major progress in the treatment of hypertension, angina pectoris, and congestive heart failure. However, the first and second (beta 1 selective) generations of beta-blockers induce a series of unwanted functional and metabolic effects, suggesting the search for a third generation of beta-antagonists. The new multiple-action beta-blockers, which have important peripheral vasodilator properties, appear to be promising with regard to clinical efficacy and side effects. In hypertensive patients, the vasodilation could add a more pathophysiological mechanism and therefore could induce a better preservation of systolic function. The global cardioprotection may be further improved by the absence of long-term metabolic effects. By virtue of their peripheral and coronary vasodilating properties, multiple-action beta-blockers could exert more favorable anti-ischemic effects in patients with angina pectoris than the traditional beta-blockers. In congestive heart failure, afterload reduction, and possibly myocardial beta 2-activation induced by multiple-action beta-blockers can minimize the negative inotropic effects, leading to better toleration at the beginning of treatment. The potential benefits of multiple-action beta-blockers have been assessed by preliminary studies and should be confirmed by trials in progress.
Adrenergic beta-Antagonists↗
Evaluation by cardiopulmonary exercise test of DDDR versus DDD pacing.
UNLABELLED: In eight patients (age 62 +/- 6 years) a DDDR pacemaker was implanted for sick sinus syndrome (three cases) or second- and third-degree AV block (five cases). In five subjects chronotropic incompetence (maximal heart rate on effort < 110 beats/min) was present before implantation. One month after implantation the patients were randomized to DDDR or DDD pacing for 3 weeks each, with subsequent crossover, and at the end of each period a symptom limited cardiopulmonary exercise test (25 watts/2 min) was performed and the patients were requested to fill a symptoms questionnaire. RESULTS: DDDR pacing, compared to DDD, was associated with higher maximal heart rates (127 +/- 20 vs 110 +/- 27 beats/min, P < 0.02), higher [VO2 max (25.4 +/- 6.1 vs 21.5 +/- 7.8 mL/kg/per min, P < 0.03) and higher VO2 at the anaerobic threshold (20.3 +/- 5.0 vs 15.8 +/- 4.9 mL/kg per min, P < 0.03), without significant differences in mean exercise time (526 +/- 193 vs 472 +/- 216 sec, NS). The increase in VO2 max obtained in DDDR versus DDD was significantly related to the increase in maximal heart rate (r = 0.72, P < 0.05) and the increase in VO2 at the anaerobic threshold obtained in DDDR versus DDD was related to the increase in heart rate at the anaerobic threshold (r = 0.81, P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)
Anaerobic Threshold↗
Preliminary clinical experience with calcium antagonists in atherosclerosis. Verapamil in Hypertension Atherosclerosis Study Investigators.
Animal experiments have shown that the administration of calcium antagonists can prevent or slow the progression of atherosclerosis by inhibiting calcium overload and interfering with lipid metabolism and deposition. These encouraging results have prompted clinical trials to evaluate the effects of calcium antagonists (dihydropyridines and diphenylalkylamines) on atherosclerotic plaque formation. In patients with coronary heart disease, several studies have already shown that calcium antagonists can have a positive effect on plaque evolution, while in hypertensive patients no such study has been published to date. The Verapamil in Hypertension Atherosclerosis Study is an ongoing multicentre randomised double-blind parallel group trial comparing the antihypertensive efficacy of verapamil SR 240 mg/day with that of chlorthalidone 25 mg/day in 1464 patients with essential hypertension aged 40 to 65 years. In a randomised subgroup of patients (n = 550), who will be followed up for 3 years, B-mode ultrasonography is being employed to evaluate the effects of the 2 drugs on carotid wall thickness and carotid plaque development. Ultrasonographic evaluations are performed at baseline, after 3 months, and 1, 2 and 3 years after a standardised protocol to determine intimal-medial thickness in 4 segments of the extracranial carotid tree. The most interesting result to date is the high incidence of carotid alterations, with plaques present in 35% and arterial wall thickening in 31.8% of the 311 asymptomatic hypertensive patients processed so far. A preliminary evaluation of the antihypertensive efficacy of the trial medications after 6 months of double-blind treatment indicates a 63.5% response rate to monotherapy and a 7.8% drop-out rate because of drug inefficacy or intolerance.
Adult↗
Effects of nisoldipine in coronary artery disease: a radioisotopic approach.
The clinical, electrocardiographic, and scintigraphic effects of oral administration of nisoldipine were investigated using two separate study protocols. In the first, the acute effects of nisoldipine were evaluated by means of nuclear ventricolography and demonstrated no deleterious effects on global contractility and an amelioration of several hypokinetic segments. In the second protocol, myocardial perfusion effects were evaluated by means of tomoscintigraphy. An improvement of segmental uptake of thallium was caused by nisoldipine. The addition of atenolol markedly reduced the rate-pressure product and further improved myocardial perfusion.
Administration, Oral↗
Atherosclerosis and calcium antagonists: the VHAS. The Verapamil-Hypertension Atherosclerosis Study (VHAS) Investigators.
Whether or not some classes of antihypertensive drugs have an anti-atherogenic action independent of the antihypertensive one has been investigated through a large series of experimental studies, primarily involving calcium antagonists. Most experimental investigations have shown a significant anti-atherogenic action of calcium antagonists, but only when the drug is administered simultaneously with the atherogenic stimulus (mainly cholesterol feeding). When the drug is administered weeks or months after the beginning of the atherosclerotic process (as in the Watanabe heritable hyperlipidemic rabbit), with a single exception, no antiatherogenic effect has been shown. The few clinical studies completed so far have been on symptomatic coronary patients. Little is known of the effects of calcium antagonists on asymptomatic lesions in the carotid arteries of hypertensive patients, in whom carotid plaques can be identified and followed-up by non-invasive ultrasound techniques. However, two such trials are underway. The Verapamil in Hypertension Atherosclerosis Study (VHAS) is an ongoing randomized trial, comparing the antihypertensive efficacy of verapamil 240 mg SR with chlorthalidone 25 mg in 1,464 essential hypertensives aged 40-65 years. In a random subgroup of patients (500), who will be followed for three years, B-mode ultrasonography is being carried out blindly to evaluate the effect of the two drugs on carotid wall thickness and on carotid plaques, when present. Preliminary baseline data are available in 440 of the hypertensive patients in whom ultrasound investigation was performed. The mean (+/- SD) age of these patients was 53.7 +/- 6.9 years; 32.5% had echocardiographically normal carotid walls; 30.9% showed intima-media thickening; and 36.6% had one or more plaques.(ABSTRACT TRUNCATED AT 250 WORDS)
Arteriosclerosis↗
[The effect of peripheral reflections on the left ventricle].
In order to evaluate the effect of modifications in reflections timing on the ventricular performance, 10 isolated rabbit hearts were connected to rubber tubes of different lengths (0.5, 0.8, 1.0, 2.5 m) with terminal stopper and 2 cylindric small tubes as constant hydraulic resistance. The terminal connection produced wide reflections which returned to the ventricle in early, mid, late systole and in the diastolic phase (2.5 m). Ventricular and aortic pressure, and aortic flow were continuously recorded, sampled and stored on a personal computer. Instantaneous and total systolic ventricular work and stroke volume were calculated using an automatic procedure. Mean coronary perfusion pressure was calculated as difference between aortic and ventricular pressure in diastolic phase. The results demonstrate an important modification of the ventricular performance related to the anticipation of the reflected pulse. The anticipation produces a decrease in the stroke volume (-14.5%), a decrease in the external work of the ventricle (-21%) and a decrease in mean coronary perfusion pressure (-28%). The first two parameters describe the performance of the pump with respect to the load, and the third evaluates the perfusion of the pump itself. Reported to the clinical situation, these results demonstrate that an increased stiffness of the aorta has a double negative effect, a decrease in cardiac output and in external ventricular work, and moreover a decrease in coronary pressure, which produces a reduction of coronary flow.
Animals↗
[Critical mitral stenosis in pregnancy: description of a case treated with percutaneous valvuloplasty].
We report the case of a 26-year-old woman who underwent mitral valvuloplasty during the 23rd week of gestation, following an episode of pulmonary edema. Dilation, performed without complications, increased mitral valve area from 0.9 to 1.8 cm2, cardiac output from 4.8 to 5.9 l/min, and decreased mean transvalvular gradient from 13.2 to 5 mmHg. The patient delivered spontaneously a full-term normal baby. Echocardiographic evaluation at 6 months confirmed the persistency of procedure's good outcome. According to some Authors and to our results it can be inferred that mitral valvuloplasty is a feasible and effective treatment for critical mitral stenosis during pregnancy.
Adult↗
[Post-infarction aneurysm of the left ventricle. Physiopathology].
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Angiography↗
[A case of oxalosis with heart and lung involvement].
We report the case of a 37-year-old woman with oxalosis, and cardiopulmonary involvement. Two-dimensional and Doppler echocardiography disclosed intracardiac calcifications compatible with deposition of calcium oxalate, and severe chronic pulmonary hypertension. Endomyocardial biopsy showed interstitial deposition of calcium oxalate. The absence of severe cardiac disease strengthened a deposition of calcium oxalate even in the arteries of the lungs, with secondary chronic pulmonary hypertension.
Adult↗
Early treatment of acute myocardial infarction with angiotensin-converting enzyme inhibition: safety considerations. SMILE pilot study working party.
The use of angiotensin-converting enzyme (ACE) inhibitors in acute myocardial infarction (AMI) is based on their capacity to limit ventricular enlargement and dysfunction. To date, the safety profile of administration of ACE inhibitors early in the course of AMI has not been established. In-hospital and long-term consequences of treatment with the ACE inhibitor zofenopril initiated within 24 hours of the onset of symptoms were compared with those of standard treatment in an open-label trial involving 204 patients with AMI who were not undergoing thrombolytic treatment. Zofenopril promptly blocked ACE activation. Blockade was almost complete (91 +/- 6%) after 72 hours and paralleled decreases in systolic blood pressure. Systemic blood pressure was acutely reduced by zofenopril, and severe but reversible hypotension occurred in 15% of hospitalized patients and in 3% of those treated over the long term. No adverse clinical or biochemical events were reported during the course of zofenopril therapy. Overall cardiovascular mortality was not significantly reduced by early zofenopril compared with placebo therapy (7.8% vs 10.7% [difference not significant]). The inhospital incidence of acute left ventricular failure and ventricular arrhythmias decreased by 63% and 39%, respectively, among zofenopril-treated patients, who also reported fewer anginal episodes both acutely (68% reduction) and over the long term (56% reduction) and did not require as much drug treatment (i.e., diuretics, digoxin, and/or anti-ischemic agents) during the follow-up phase. Left ventricular size decreased and ejection fraction (EF) increased in patients who received zofenopril, and the improvement was greater among patients with poorer ventricular function (EF less than 40%). Early administration of ACE inhibitors may therefore constitute a safe form of therapy for patients with AMI, particularly when the event is complicated by clinical signs or evidence of ventricular dysfunction.
Administration, Oral↗
Flecainide: evidence of non-linear kinetics.
The pharmacokinetics of flecainide has been studied in 12 patients with ventricular arrhythmias, both after single administration and during chronic treatment. Both the half-life and the AUC were significantly increased during chronic treatment. This suggests that the kinetics of flecainide might be non-linear also in patients with normal kidney and liver function. The increase in plasma flecainide levels during chronic treatment could not be predicted, so close monitoring of its plasma levels is advisable.
Adult↗
Myocardial metabolic and hemodynamic effects of a sustained intravenous infusion of nifedipine with and without metoprolol in patients with unstable angina.
We tested the usefulness of a sustained intravenous infusion of nifedipine and a combination of nifedipine and metoprolol in the early management of 14 patients with unstable angina pectoris. After a 24-hour run-in period, nifedipine was titrated in a stepwise fashion (mean dose 27 +/- 7 micrograms/min). After nifedipine treatment coronary blood flow increased from 150 +/- 66 to 183 +/- 74 ml/min (p less than 0.05), whereas double product, myocardial oxygen consumption, and both arterial and coronary sinus (nor)epinephrine levels were unchanged. Myocardial lactate uptake increased from 3.4 +/- 26.1 to 31.3 +/- 26.6 mumol/min (p less than 0.005) and free fatty acid uptake from 7.2 +/- 22.1 to 34.5 +/- 33.7 mumol/min (p less than 0.05). A small nonsignificant improvement in amino acid metabolism was observed. Metoprolol was added in seven patients and led to a decrease in double product (-2.2 +/- 1.6 x 10(3); p less than 0.01) and myocardial oxygen consumption (-3.2 +/- 3.8 ml/min; p less than 0.05). The lactate uptake/oxygen uptake ratio increased by 18% after metoprolol (p = NS). The number of episodes of chest pain decreased from 2.4 +/- 1.1/24 hours to 0.1 +/- 0.2 in the nifedipine group and from 2.9 +/- 1.1/24 hours to 0.3 +/- 0.5 in the nifedipine plus metoprolol group (both p less than 0.01). We conclude that in the acute phase of unstable angina, intravenous nifedipine can be carefully titrated to improve coronary blood flow and oxidative metabolism. The addition of metoprolol is also associated with a reduction in myocardial oxygen demand. This treatment results in significant hemodynamic stability.
Adult↗
Percutaneous transluminal coronary angioplasty of the very proximal left anterior descending artery lesions: immediate results and follow-up.
In order to assess the results of percutaneous transluminal coronary angioplasty of the proximal (before the first septal branch) left anterior descending artery lesions, we analyzed the results in 206 consecutive patients, aged 56 +/- 12 years. The distance of the lesion from the origin of the left anterior descending artery was measured in the right oblique angiogram. The location of the lesions proved to be very proximal (less than 0.5 cm from the origin) in 22 patients, intermediate (0.5-1 cm from the origin) in 26 patients and distal (greater than 1 cm from the origin) in 158 patients. The initial angiographic success rate was similar among the 3 groups of patients: 95.8% in those with very proximal and intermediate lesions and 98.1% in those with distal lesions. Occlusive dissection of the left anterior descending artery without involvement of the mainstem occurred in 3.8% of the patients with intermediate lesions and in 1.9% of those with distal lesions. No complications occurred in any patient with very proximal lesions. The clinical follow-up was 25.2 +/- 12 months; angina recurred in 15.5% (31 out of 206 patients). Coronary angiography was performed in 103 patients. Restenosis occurred in 42.3% of the patients with very proximal and intermediate lesions (11 out of 26) and 31.2% of those with distal lesions (24 out of 77). In conclusion, in most patients with very proximal and intermediate lesions of left anterior descending artery, coronary angioplasty can be performed with low risk. The location of the lesion in the proximal portion of left anterior descending artery does not affect the overall success rate.(ABSTRACT TRUNCATED AT 250 WORDS)
Angioplasty, Balloon, Coronary↗