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Biomedical subjects

F Arrigo

Publications and source records attributed to F Arrigo.

At least 55 records · Page 3Linked to original sources
PubMed1984

[Modulated parasystole. An arrhythmia waiting for diagnostic criteria. Deductive analysis of a case].

We report a case of ventricular parasystole in which the long interectopic intervals are always less than a multiple of the short interectopic intervals. Assuming a regular ectopic discharge, the above said phenomenon could theoretically be due to relative prolongation of the short interectopic intervals caused by delayed ectopic-ventricular conduction of the second consecutive conducted impulse (a Wenckebach-like phenomenon). Nevertheless, this hypothesis may be ruled out in this case by the analysis of a long tracing. The unusual relationship between the interectopic intervals may be explained assuming the modulation of the parasystolic activity by sinus beats. Experimental work has shown that despite the protection (or entrance) block, the sinus or dominant rhythm may affect the automaticity of a parasystolic focus by means of electrotonic influence. It has been pointed out that sinus impulses falling in the first part of the ectopic cycle delay the next ectopic discharge, while relatively late sinus beats (falling in the last 30-40% of the ectopic cycle) are able to anticipate the delivery of the parasystolic impulse. The phenomenon of modulation is marked by a characteristic biphasic phase-response curve. In the reported case a phase-response curve has been obtained, which explains the parasystolic cycle variations according to the phase of the cycle in which the sinus beats fall. The obtained curve is quite similar to those observed experimentally, therefore the diagnosis of modulated parasystole appears to be very likely.(ABSTRACT TRUNCATED AT 250 WORDS)

Arrhythmias, Cardiac↗
PubMed1983

Suppression of demand pacemakers due to spurious signals generated by inactive endocardial electrodes.

We report a case of oversensing observed in a patient with a VVI pacemaker. This phenomenon was provoked by an inactive lead whose tip was in close apposition with the tip of the stimulating electrode. Potentials of large amplitude arose from the contact between these two catheters, causing pacer suppression. These false signals have been revealed both by intracavitary recordings and by standard ECG. In the latter they assumed a P-like shape. Withdrawal of the temporary lead restored normal pacing.

Aged↗
PubMed1983

[Occult ventricular bigeminy. Description of a case with extrasystole variable coupling separated by sinus beats in even or odd numbers].

We have analyzed an electrocardiogram showing many unifocal ventricular extrasystoles with wide variations of the coupling intervals. Ventricular bigeminy was frequent but in many instances more than one sinus beat occurred between two consecutive extrasystoles. In such a case the intervening sinus beats occurred indifferently both in odd and even numbers. Moreover, extrasystoles preceded by an even number of sinus beats had a relatively long coupling interval whereas extrasystoles that followed and odd number of sinus beats showed shorter coupling intervals. An opposite pattern of the coupling interval was observed with the extrasystoles that followed an interpolated premature ventricular depolarization. In such a case the coupling interval was long after an odd number of sinus beats and vice versa. This mechanism may be interpreted as due to concealed ventricular bigeminy caused by a ventricular ectopic focus which is surrounded by two different zones of block: a proximal zone of 2:1 block, and a distal one in which the block occurs irregularly. Unlike what appears in typical concealed bigeminy, characterized by only odd numbers of sinus beats between consecutive extrasystoles the intervening sinus complexes are indifferently in odd and even numbers. The constant relationship between the coupling interval and the number (odd or even) of sinus beats by which the extrasystole is preceded, allows us to recognize the presence of an atypical form of concealed bigeminy.

Aged↗
PubMed1983

[Erythrocyte filtration in acute myocardial infarction].

In 12 patients with acute myocardial infarction we have studied the behavior of the red blood cell filterability using polycarbonate membranes of 13 mm diameter with pores of 5 mu diameter according to the Reid's method. The samples were drawn soon afterwards the admission and successively every 48 h for a period of about 12 days. In the meantime, erythrocyte sedimentation rate (ESR), fibrinogen, leukocyte, platelet and alpha 2-macroglobulin changes have been determined. The average initial filterability values in patients with infarction were 0.84 +/- 0.20, while in control subjects were 0.58 +/- 0.15. During the observation period, a statistically significant increase of filterability after 48 h (1.06 +/- 0.24) and after 96 h (0.88 +/- 0.21) was observed. Using the statistical analysis we have noticed a strong correlation among filterability and leukocytes and ESR. The effect of leukocytes is due to the reduction of membrane pores through which red blood cells filter. The correlation with the ESR shows the presence of a plasma factor different from fibrinogen and capable of transforming the red blood cell aggregation by reducing their filterability.

Blood Sedimentation↗
PubMed1982

Parasystolic ventricular tachycardia with variable exit block.

This case is an example of ventricular parasystolic tachycardia associated with variable expressions of ectopic-ventricular (E-V) exit block. The exit block manifested with 2:1, 3:2, 4:3 and higher ratios of E-V conductions, interspaced with periods of 1:1 conduction. Concealed E-V conduction of the ectopic impulse could also be deduced.

Aged↗
PubMed1981

[Physiopathologic mechanism of ventricular fibrillation induced by atropine. Report of two cases (author's transl)].

The authors report on two cases of ventricular fibrillation induced by bolus of atropine injected for diagnostic purpose. The electrophysiologic effect of adrenergic stimulation following the parasympathetic blockade, is probably the responsible mechanism rather than myocardial ischemia in the first patient, affected by complete a-v block with narrow QRS. The second patient, affected by coronary heart disease and suspected sick sinus syndrome, had more probably a ventricular fibrillation because of a worsening of the underlying myocardial ischemia due to the increase of the cardiac rate. the reported observations, together with those of other Authors, suggest that atropine, at least when used for diagnostic purpose, should be employed cautiously and preferably having available all the equipment for emergency treatment of cardiorespiratory arrest.

Aged↗
PubMed1980

[Acute amiodarone poisoning. Description of a case].

A case of attempted suicide with 2600 mg amiodarone is reported. This overdose did not cause any clinical symptoms, change in heart rate, blood pressure or biochemical parameters. No ventricular arrhythmias were observed in ECG monitoring, but a considerable lengthening of the Q-T interval and T wave inversion in the precordial leads with transient disappearance of the R wave in leads V1 - V4, simulating an anteroseptal infarction, were recorded. This case underlines the possibility of giving larger loading doses of amiodarone than those generally used.

Acute Disease↗
PubMed1980

[Atrial dissociation simulated by respiratory artifacts. Case report].

A case of likewise atrial dissociation in a twelve years old patient affected by mucovisclosis with severe respiratory failure is described. The classic criteria of the atrial dissociation were met in the ECG, in which, beside the sinus P waves, low P-like waves, whose rate was 69/m', were present: they did not conduct to the ventricles and were independent from the sinus rhythm. Such waves always coincided with the beginning of the inspiration, and disappeared during the apnoea. So they were not believed as being the results of electrical forces of the heart, but artifacts produced by respiratory movements. The diagnostic criteria of the atrial dissociation are discussed on the basis of these observations. the exclusion of artifacts, especially the respiratory ones, and the demonstration, obtained through the intracavitary ECG, that the waves are really produced by the heart, are necessary to diagnoses the arrhythmia. By the application of these diagnostic criteria only one of the cases found in the Literature has been accepted as demonstrative of atrial dissociation due to complete intraatrial block in man.

Child↗
PubMed1977

[Study on the rapid effects of SAMe in primary and secondary triglyceridemias].

A single dose of 30 mg of S-adenosylmethionine was administered to 15 fasting subjects, scrupolously typified, eight of which were affected with primary hypertriglyceridemia, either of type II B or IV according to Fredrickson's classification, and seven with secondary hypertriglyceridemia. Triglyceride and phosphatide concentrations determined 1, 2, 3 and 4 hours after SAMe administration have shown a decrease in blood triglycerides and an increase in phosphatide levels, with significant values for the subjects with the primary form.

Adult↗