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Biomedical subjects

M Santini

Publications and source records attributed to M Santini.

At least 181 records · Page 10Linked to original sources
PubMed1980

Possible risks of general anesthesia in patients with intraventricular conduction disturbances.

In order to assess the risk of complete AV block in patients with intraventricular conduction disturbances who undergo general anesthesia, 20 patients with various conduction defects (7 LBBB, 1 RBBB and 1st degree AV block, 1 incomplete RBBB, 9 RBBB + LAH and 2 RBBB + LPH) were studied by means of His bundle recording and corrected sinus node recovery time (CSNRT) before and after the subministration of thiopental (0.2 g I.V.), succinylcholine (1 mg/kg I.V.), Fluothane (1%) and Ethrane (1.6%). Nineteen patients displayed signs of dizziness or syncope; both the sinus rate and the CSNRT, did not undergo significant variations. A slight and not significant variation of intranodal conduction during sinus rhythm was observed after Fluothane administration (AH was prolonged by 8%). A less evident negative dromotropic action of thiopental and Ethrane was only revealed by atrial pacing. No significant variations were demonstrated in His-ventricular conduction after administration of the various drugs. The maximum average increase (1.5%) of the H-V interval was observed after administration of succinylcholine. Acute AV block distal to the His bundle appeared in three patients after succinylcholine administration.

Anesthesia, General↗
PubMed1980

Intermittent and arrhythmic "runaway" pacemaker.

An unusual case of intermittent and arrhythmic runaway pacemaker is described. The malfunction was detected during implantation, at which time it caused ventricular fibrillation in the patient in whom it was implanted. The authors wish to emphasize the necessity of accurate pacemaker testing in the factory and the operating room, and to stress the importance of manufacturing pacemakers unable to emit a high number of impulses, even in the presence of a faulty circuit component.

Arrhythmias, Cardiac↗
PubMed1980

Dynamic ECG in normal subjects.

A study by dynamic electrocardiography has been carried out for 24 hours on 100 healthy subjects (50 males and 50 females), of ages included between 20 and 70 years. Recording were carried out during an average working day. Average high, mean and low heart rates have been calculated in the 24 hours, at various times of the day, during mental work, physical effort, sexual activity (20 cases) and sleep. Sinus arrhythmias of various degrees (bradycardia, S-A blocks) have been observed overall in 16% of cases. Incidence was higher in younger subjects (12%) as compared with the older group (4%), and during sleep (75%) as compared to periods of wakefulness (25%). Supraventricular and ventricular arrhythmias hae occurred respectively in 20 and 21% of all subjects. Both types of arrhythmias (S.V. and V.) occurred more frequently in older subjects (34 and 32%) as compared to the younger group (10 and 5%). Supraventricular ectopic beats were more frequent during wakefulness (59.3%) rather than during sleep (40.7%); vice-versa, ventricular ectopic beats have been noticed to appear more frequently during sleep (74.5%), than during wakefulness (25.5%). Overall, arrhythmias have not been common (less than 500 ectopic beats/24 hours and less than 50 ectopic beats/hour), and only rarely they were repetitive. During our study we have observed ST changes or upward deviation, but in all cases a definite pathological significance was missing.

Adult↗
PubMed1980

[Permanent endocardiac atrial pacing and sensing. Preliminary experience with screwing catheters].

25 patients affected by sick syndrome (SSS) and normal AV conduction (15), SSS with AV conduction defects (6) and complete AV block (3) were treated respectively by means of atrial pacing. AV sequential pacing and atrial triggered-ventricular pacing. In the cases for atrial pacing and sensing, the Medtronic mod. 6957 screwing lead has been utilized. The technique resulted very simple and safe. The average atrial threshold was 1.4 +/- .05 V. (1.95 +/- 0.75 mA). The average total impendance was 740 +/- 240 ohm and the average atrial potential 2.7 +/- 1.43 mV. Two cases of early displacement of the lead were observed (due to the operator poor familiarity with the new lead). Temporary sensing defect was observed in two patients and promptly abolished by steroid therapy. No exit block was observed. The patients have been followed for an average period of six months. All the leads are sensing and pacing correctly.

Aged↗
PubMed1978

[Pacemakers: concerning check-ups (author's transl)].

The Authors have re-examined their case histories of 1503 patients who have had 2459 pacemakers implanted and who have undergone check-ups as outpatients. All the complications which have arisen from 1967 to the present have been taken into consideration. The total number of complications has been found in 355 patients with 14% of the total number of pacemakers and they have been subdivided into 3 groups: 1st group: complications arising during the stay in hospital (110); 2nd group: complications arising after discharge from hospital and discovered by the patient (239); 3rd group: complications found casually during outpatients' check-ups (6). Of the complications found after discharge, 97% belong to the second group and only 3% to the third group. 657 substituted pacemakers have also been taken into consideration with the purpose of finding out the parameters which showed up as the battery was running down. Out of 145 pacemakers substituted because of flat batteries, 130 (90%) have shown brusque variations in the frequency of stimulation, while only 15 (10%) have shown variations in other parameters (width, length of impulse, etc). The Authors therefore retain that a periodic outpatients' check-up of the pacemakers is of little use as regards the patients' safety and the complete utilization of the device, while they advise that the patient be educated so as to be able to carry out his own daily control of the pacemaker.

Bioelectric Energy Sources↗
PubMed1978

[Analysis of the Luciani-Wenckebach phenomenon in the A-V node. II. Relationship between conduction and recovery times].

We have studied 20 cases Wenckebach A-V block by atrial pacing. The relationships between conduction time and recovery time of N. AV Wenckebach point, basal A-H time and A-H time of first cycle beat were analysed. No correlation was found between W point, basal A-H and A-H of the first beat by analysing the A-H = f (H-A) we found different curves which occur when the first A-H is longer or shorter than 110. These data were discussed on the basis of modern hypotheses of electrophysiological mechanism of Wenckebach periodism.

Electrocardiography↗
PubMed1978

[Old and new methods for control of pacemakers (author's transl)].

First there is a description of present methods available for controlling the functioning of pacemakers, most of which are already being used in traditional clinic-electronic control. There follows a presentation of telephone monitoring (ECG + Pacing Rate) and its limits so far as photoanalysis is concerned. Mention is made of the new italian system of telephone monitoring which also includes measurement of amplitude and width of the pulse. Personal experience of the diagnostic value of photoanalysis is given. This concords with others as to its necessity to detect any failure from circuitry defects or from breakage or insulation of electrode. In conclusion the hope is expressed of actuating a completely trustworthy control system which includes a high degree of foreseeing failure (telephone monitoring) and diagnostic value (Rx + photoanalysis). At last the advantages of an automatic follow-up system in a pacemaker patient clinic are discussed.

Computers↗
PubMed1978

[The experience in cardiac pacing at the Cardiology Department of St. Camillo Hospital (Rome) (author's transl)].

The experience of the Cardiac Electrostimulation Center of S. Camillo Hospital in Rome on 1503 patients treated with permanent pacemakers for an 11 year period is referred. The Authors analyze the increase of the activity of the Center during these years and some events that caused it. 94.5% of the patients were more than 50 years old; the dominant pathology has been ischemic and idiopathic cardiopathy, which together include 94.7% of the totality. The indication to the implant has been A-V block in 70% of the patients; intraventricular block in 20%; sick sinus syndrome in 10%. In the last years the prophylactic indication has increased (from 0.4% to 4.4%). 2459 pacemakers have been used, of which 79.5% was QRS-inhibit. The mercury prosthesis have been progressively substituted with the lithium ones. 1642 catheters (implant and reimplant) have been used; principally endocardic (95%) and monopolar (85%). The substitution of the catheter has been necessary in 9% of the totality; in 2.6% of the endocardic and in 15.9% of the epimyocardic. Among 50 electrodes, after a period of observation of about 7.7 years, 36 are still in function. The percentage of the complications has been 17.1%; the most important complications have been: dislocation (6%), microdislocation (1.5%), late high threshold (2.1%), failure of catheter (1.2%), generator malfunction (2.3%). The total mortality has been 15.4%; 0.2% caused by deficit of the implant; 2% sudden deaths and 13.2% not depending from the implant; 243 patients (16%) are not to be found. The frequency of out-patients controls has decreased in the last 2 years (from 3.8 controls per years to 1.8).

Aged↗