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Biomedical subjects

G Benedini

Publications and source records attributed to G Benedini.

At least 37 records · Page 2Linked to original sources
PubMed1985

Pre-operative sinus node function in adult patients with atrial septal defect (ostium secundum type).

The authors studied, pre-operatively, the sinus node function in adult patients with secundum atrial septal defect and large left-right shunts, using Holter ECG and electrophysiological tests. Sinus node electrophysiological tests were found abnormal in 17 out of 26 patients; on the contrary, Holter monitoring was always within normal limits. The authors believe that concealed sinus node dysfunction existing before surgical correction may be a cause of early, acute, and reversible, post-operative sick sinus syndrome.

Adolescent↗
PubMed1985

[Hypotension during ventricular pacing. A study of the vagal reflex component].

It has been suggested that hypotension during ventricular pacing (V) could be caused by a parasympathetic vasodilating reflex. In order to evaluate this hypothesis, we studied 10 patients who had wide fluctuations of arterial pressure during V. Intra-arterial pressure, right atrial pressure, EKG and cardiac index (thermodilution) were determined in the following conditions: basal rhythm (B), V, atrioventricular pacing (A-V) and ventricular-atrial pacing (V-A). The same investigations have been carried out in the same conditions (B,V,A-V,V-A) after atropine 0.03 mg/Kg intravenously. The arterial blood pressure during V decreased markedly simultaneously with the appearance of cannon waves in the right atrial pressure tracing. During A-V the arterial pressure remained stable at the highest level observed during V. The start of V-A pacing induced a marked drop of arterial pressure, which, however, gradually increased to a level slightly lower than during A-V pacing. After atropine the arterial blood pressure during V decreased again in all patients concomitantly to the appearance of cannon waves in the atrium as before atropine. The values of arterial blood pressure during B, A-V and V-A were not different from those measured before atropine. Therefore, an increase of parasympathetic activity during V is not responsible for the wide fluctuation of arterial blood pressure. A possible role of sympathetic failure must be considered.

Adult↗
PubMed1984

Value of purinic compounds in assessing sinus node dysfunction in man: a new diagnostic method.

The purpose of this paper is to investigate whether the inhibitory action of purinic compounds (striadyne: STR) on the sinus node is quantitatively different on a pathological sinus node in comparison to a normal one and thus whether it is possible, as suggested by other authors, to use STR as a pharmacological test in the diagnosis of sick sinus syndrome (SSS). With this aim we investigated 55 patients, divided into 3 groups according to ECG and sinus function evaluation tests: 1--normal; 2--SSS (2a: flagrant SSS; 2b: latent SSS); 3--excess vagotonia and/or abnormal response to vagal stimulation. In all patients after a prophylactic insertion of a temporary pacemaker, 30 mg of STR were rapidly injected i.v. and the surface and intracavitary ECG continuously recorded until the basal state was regained; the following parameters were evaluated: average baseline sinus cycle (SC), minimum and maximum SC after the drug. In all patients STR caused first a slowing, then an acceleration of the sinus rate. SC lengthening was moderate in groups 1 and 3 [max SC was respectively 740-1820 ms (1198 +/- 290.9 ms) and 720-1440 ms (1157.5 +/- 223.3 ms)], but it was severe in patients with SSS [max SC in group 2a 2500-11880 ms (5398.3 +/- 2687.4 ms) in group 2b 1620-11140 ms. (4470.7 +/- 3660.6 ms)]. The difference between the max post STR SC of SSS patients, and the control group was highly significant P less than 0.001). Assuming as upper limit of the normal a value of 2071 ms. (corresponding to the mean + 3 standard deviations of the response of the control group) we recorded abnormal responses in 100% in group 2a and in 85.7% in group 2b, whereas there were no abnormal responses in group 3. In addition, nodal atrioventricular block occurred frequently. The authors believe this test could be useful in the diagnosis of SSS, but it is essential to insert a ventricular pacing catheter prophylactically if this test is used.

Adenosine Triphosphate↗
PubMed1984

[Acute myocardial infarction in a 13-year-old boy with Duchenne's disease].

A 13-year-old boy with Duchenne's muscular dystrophy suffered an acute myocardial infarction as shown by typical electrocardiographic and enzyme changes, and by the results of radionuclide studies. this is the third reported case of the acute myocardial infarction in a patient with Duchenne's muscular dystrophy.

Adolescent↗
PubMed1983

Iopamidol: a new contrast medium in coronary angiography. Comparison, on electrophysiological changes in man, with a commonly used contrast medium.

In 30 patients undergoing coronary angiography the effects of Iopamidol on sinus node activity, atrioventricular and intraventricular conduction were evaluated using His Bundle recordings, and compared to the effects produced by Diatrizoate. Diatrizoate resulted in an increase in sinus cycle length and prolonged AV nodal conduction, resulting in second degree AV block in two patients. Iopamidol had significantly less effect on sinus cycle (P less than 0.01) and AV nodal conduction (P less than 0.01). Neither contrast media affected intraventricular conduction. No difference was noted in the imaging power of the two contrast media. It is suggested that non-ionic, low osmotic contrast media such as Iopamidol will result in increased patient safety during coronary angiography without loss of imaging power.

Adult↗
PubMed1982

[Reproducibility of electrophysiological tests of sinus node function in patients with sick sinus syndrome. Reproducibility of tests of sinus node recuperation time, corrected sinus node recuperation time and sino-atrial conduction time].

In order to clarify whether SNRT, CSNRT and SACT are reproducible tests, 20 patients with sick sinus syndrome underwent two successive electrophysiological studies with an interval of 24 hours; mean sinus cycle, SACT, SNRT, CSRNT were evaluated. Although no significant differences were found between the mean values of the two studies, in isolated cases remarkable variations of one or more parameters were observed. We conclude that SNRT, CSNRT and SACT are reproducible tests only if mean values in a large number of patients are considered, while they are not as useful in quantifying sinus node dysfunction in single cases. In conclusion, while SNRT, CSNRT and SACT are reproducible and useful in comparing data from relatively large number of patients, great caution should be used before drawing conclusions of potentially serious diagnostic and prognostic consequence in the single patient.

Aged↗
PubMed1981

[The effects of digoxin administration on normal and pathological sinus node function. An electrophysiological study (author's transl)].

In 12 normal subjects (group I), in 12 subjects with asymptomatic sinus bradycardia (group II) and in 18 patients with symptomatic sick sinus syndrome (group III), sinus node cycle length (SNCL), sinus node recovery time (SNRT), corrected sinus node recovery time (CSNRT), sino-atrial conduction time (SACT), have been evaluated before and after an acute digoxin administration. Mean value of SNCL lengthened significantly in all groups. Mean value of SNRT increased moderately in the first group, remarkably in the third group, whereas it showed a mild but statistically insignificant increase in the second group. Mean value of CSNRT was significantly lengthened only in the third group. Mean value of SACT showed a mild but statistically insignificant lengthening in all groups. In order to investigate the importance of the parasympathetic action induced by digitalis, in 4 normal subjects, in 4 patients with asymptomatic sinus bradycardia, and in 10 patients with symptomatic sick sinus syndrome, SNCL, CSNRT and SACT has been evaluated after an intravenously, administration of atropine, following digoxin. In the paper the intricate mechanisms by which digitalis affects the parameters of sinus nodal function especially in patients with symptomatic sick sinus syndrome, are discussed. In disagreement with the mot papers reported in the literature we think that an acute digoxin administration is able to worsen the electrophysiological parameters of sinus nodal function especially in patients with symptomatic sick sinus syndrome.

Adult↗
PubMed1976

[Syncope during potassium depletion (author's transl)].

The onset of serious arrhythmias during potassium depletion occurs rather frequently in female subjects who have undergone hypotensive-diuretic treatment, independently from the duration and doses of drugs. These arrhythmias which produce a cardiac arrest, can also occur in subjects not affected with heart disease. They are not necessarily preceeded by clinical prodrumus or other types of minor arrhythmias not accompanied by other important electrocardiographic or serum-logical alterations of hypokaliemia. The most commonly observed type is the "torsades de pointe", though cases of ventricular tachycardia or ventricular fibrillation are also documented. The ethiopathogenesis is discussed with regard to the alterations of the basic electrocardiogram as well as to the kind of major arrhythmia. In most cases , lidocaine has given the most satisfactory thmias, results in the treatment of these arrhythmias, probably because of the modality of the action which is substantially different from the other antiarrhythmic drugs.

Adult↗