[The Italian Group for the Study of Streptokinase in Myocardial Infarct: Study of arrhythmias]. / G.I.S.S.I.: Studio delle aritmie.

The purpose of the trial "Arrhythmias" was to evaluate all the arrhythmic events in the control and treated patients by considering, in the latter, the chronological relation to the infusion of Streptokinase (SK). This was done in order to determine if the presence of arrhythmias was significantly greater in the treated patients, and if these arrhythmias could be considered as possible markers of reperfusion. 10 Centres participated by recording and evaluating all the hyperkinetic and hypokinetic arrhythmic events in the treated and control patients for an observation period of 2 hours including infusion of SK. The recording method used was computerised UCIC or Holter recording. The centre for data handling carried out storage and statistical elaboration of the data. The Lown and the Italian Modified Lown classifications were used. When appropriate, the statistical significance of observed differences was assessed with chi-square and t tests. 433 patients, 227 treated and 206 controls, were randomised. No statistically significant differences were observed between the two groups as regards the quantity and quality of the hyperkinetic or hypokinetic arrhythmias. On the contrary, on dividing the patients into two groups in accordance with the incidence of Hyperkinetic Ventricular Arrhythmias (HVA), more serious HVA were observed in the controls both in absolute value and in relation to those with better functional class, younger patients (less than 65 yrs.) and with multiple site infarct. The results of the search for arrhythmias which can be markers of reperfusion, show that the Slow Ventricular Tachycardia is the only arrhythmia which can be used as such.

[Electrophysiologic evaluation of athletes with Wolff-Parkinson-White syndrome: induction of supraventricular arrhythmia at rest and under exertion with transesophageal atrial electrostimulation]. / La valutazione elettrofisiologica degli atleti con Wolff-Parkinson-White: induzione di tachiaritmia sopraventricolare di base e sotto sforzo con elettrostimolazione atriale transesofagea.

The most suitable approach to the athletes with WPW is controversial. Therefore 66 symptom-free athletes with WPW and without heart disease (53 M, 13 F, mean age 21.98 yrs, min 12--max 44) underwent a study protocol whose end-point was the induction of supraventricular tachyarrhythmia, i.e. atrial fibrillation or, if not possible, atrial flutter or atrial tachycardia at rest and during ergometric stress test. The athletes with shortest R-R interval between preexcited beats less than or equal to 240 ms at rest and/or less than or equal to 210 ms during exercise were judged as being at risk i.e. no fit for sport activity. The end-point was reached in 64/66 athletes (in 62 atrial fibrillation). In 4 athletes with life threatening arrhythmia induced at rest the evaluation during exercise was not performed. According to the evaluation at rest we were able to identify only 18 athletes (28.1%) as being at risk, while according to the complete study protocol 26 athletes (40.6%) were judged as such. In 23/64 athletes (36%) this judgement was discordant with the usual non invasive evaluation (i.e. Holter monitoring, ergometric stress test, ajmaline test). During induced atrial fibrillation no significant difference, was found between the percentage of preexcited beats at rest and during exercise. On the average, 40 min. are required for performance of this study protocol (if the induced arrhythmia lasts less than 5 min.). According to our results we conclude: a) the non invasive assessment of the WPW athletes is unsatisfactory; b) the induction of atrial fibrillation during exercise gives a remarkable increase of the diagnostic power with respect to the assessment only at rest; c) since it is simple to perform and not expensive (in time, staff and cost) and because of its high diagnostic yield, we regard this protocol as fundamental for the electrophysiological evaluation of WPW athletes and also suitable for systematic study of WPW patients.

[Sustained ventricular tachycardia: low-energy transcatheter internal cardioversion. Efficacy, reliability and tolerance in comparison with ventricular burst]. / Tachicardia ventricolare sostenuta: cardioversione interna a bassa energia transcatetere. Efficacia, affidabilità e tolleranza anche in confronto con il burst ventricolare.

The aim of this study is to evaluate the efficacy, reliability and patient tolerance of low-energy transcatheter intracardiac cardioversion in the treatment of Sustained Ventricular Tachycardia (VT), and to compare this method to ventricular burst. For this purpose 11 patients (pts) (10 M, 1 F, mean age 50.1 yrs, range 24-72) with 18 different types of VT (17 induced during Endocavitary Electrophysiological Study (EES), 1 "clinical"), who all underwent EES all but 1 with organic heart disease, were first treated by transcatheter intracardiac cardioversion and then, if possible, with ventricular burst at 125%-150% of VT rate. The Medtronic Cardioverter 5350 and the Medtronic catheter 6880 were used. The following results were obtained: transcatheter intracardiac cardioversion terminated 9/18 types of VT (8 types at least 3 times) in 6 pts. Cardioversion threshold was on average 1.31 J (range: 0.14-5). Transcatheter intracardiac cardioversion failed to terminate 9/18 types of VT (in 5 pts); VT acceleration or ventricular fibrillation occurred in 6/9 types. The mean cycle length of successfully cardioverted VT (382 +/- 61 msec.) was significantly longer (p = 0.05) than that of not successfully cardioverted VT (284 +/- 83 msec.) and of the VT in whom an acceleration or a degeneration into ventricular fibrillation was observed (240 +/- 55 msec.). In 4 pts it was necessary to use external DC shock and in 4 supraventricular hyperkinetic arrhythmia was induced. All pts complained of considerable discomfort at shocks greater than or equal to 0.5 J. In all the 7 types of successfully cardioverted VT as well as in 3 out of the 4 types of not successfully cardioverted VT in which it was possible to test ventricular burst, this latter proved to be effective. These results indicate that: the efficacy of transcatheter intracardiac cardioversion is not great at least in our pts (50%); moreover, the transcatheter intracardiac cardioversion is affected by a high incidence of acceleration of VT and degeneration into ventricular fibrillation (33.3%) and by the induction of supraventricular hyperkinetic arrhythmia (22.2%). Patient discomfort appears to be a major limitation to transcatheter intracardiac cardioversion. The VT cycle length is determinant for the success of the transcatheter intracardiac cardioversion and for the induction either of an acceleration of VT or of a degeneration into ventricular fibrillation (which are observed only in VT with cycle length less than or equal to 300 msec.).(ABSTRACT TRUNCATED AT 400 WORDS)

[Sustained ventricular tachycardia in postinfarct ischemic heart disease: spontaneous polymorphism. Clinical, therapeutic and prognostic aspects]. / La tachicardia ventricolare sostenuta della cardiopatia ischemica postinfartuale: il polimorfismo spontaneo. Aspetti clinici, terapeutici e prognostici.

UNLABELLED: Spontaneous Polymorphism (SP) is present when at least two episodes of Sustained Ventricular Tachycardia (SVT) occur spontaneously in the same patient (pt) with different bundle branch block pattern or with shifting of QRS axis by greater than or equal to 90 in the various episodes. We undertook this study in order to investigate the clinical significance of SP in SVT as well as therapeutic and prognostic implications. MATERIAL AND METHODS. From our global pts populations we chose those with SVT in chronic ischemic heart disease (CIHD) with previous myocardial infarction (PMI), they had to be already studied by electrophysiologic technique (EES). The pts were divided into two groups (Gr.): Gr. I: 13 SP pts (12 M, 1 F, mean age 57.5 +/- 13; mean follow-up 19.2 +/- 11 months); Gr. II: 15 no SP pts (14 M, 1 F, mean age 60 +/- 10; mean follow-up 9.9 +/- 13 months). RESULTS: The two Gr. are comparable in terms of symptoms, exercise tolerance, infarct site, intraventricular conduction disturbances (61.5% and 66.6% respectively), ventricular wells kinetics (38.4% and 26.6% respectively) and time interval between acute myocardial infarction the first episode of SVT (7.58 +/- 6.02 and 8.27 +/- 6.57 years respectively). 8 of the 10 alive Gr. I pts have been treated with Amiodarone (A) (2800-4200 mg/wk). All 9 alive Gr. II pts are on A (1400-4200 mg/wk). A serum level in 7 Gr. I pts was 1.7 +/- 0.65 mcg/ml and 1.61 +/- 0.67 in 5 Gr. II pts. 3/13 Gr. I pts died: 2 for sudden death (15.3%), 6/15 Gr. II pts died: 4 suffered sudden death (26.6%).(ABSTRACT TRUNCATED AT 250 WORDS)

[Sustained ventricular tachycardia: induced polymorphism. Clinical and electrophysiological aspects; therapeutic implications]. / Tachicardia ventricolare sostenuta: polimorfismo indotto. Aspetti clinici ed elettrofisiologici, implicazioni terapeutiche.

By induced polymorphism (I.P.) we mean the electrical induction during endocavitary electrophysiologic study (E.E.S.) either of two or more morphologically distinct types of Sustained Ventricular Tachycardia (S.V.T.) (i.e. different bundle branch block patterns or with shifting of QRS by greater than or equal to 90 degrees) or of one type of sustained ventricular tachycardia other than the spontaneous one. Twenty-two patients with clinical sustained ventricular tachycardia, in whom at least one episode of sustained ventricular tachycardia was induced during endocavitary electrophysiologic study, were divided into 2 groups depending on the presence or not of induced polymorphism: Group I consisted of 13 patients with induced polymorphism; Group II consisted of 9 patients without induced polymorphism. All the patients of the Group I had chronic ischemic heart disease (C.I.H.D.); 12/13 previously had myocardial infarction. Only 1 patient of the Group II had chronic ischemic heart disease. Intraventricular conduction defect was present in 9 patients of the Group I and in 2 of the Group II. An overall of 26 sustained ventricular tachycardia episodes were induced in patients of the Group I: 9 with RBBB, 10 with LBBB and 7 with "bizarre" QRS morphology. Sustained ventricular tachycardia reinduction was attempted in 10 patients of the Group I after acute drug testing (Ajmaline, Propafenone, Amiodarone): sustained ventricular tachycardia was no longer inducible in 6, but in 3 of those 4 in whom it was, a marked increase in polymorphism was observed as compared to pre-test pattern. Of the 11 alive patients of Group I, 10 are on Amiodarone alone or in combination with other antiarrhythmic drugs. We conclude as follows: different morphological types of sustained ventricular tachycardia can be quite commonly induced during endocavitary electrophysiologic study; according to our cases induced polymorphism is observed only in patients with chronic ischemic heart disease; patients with induced polymorphism often have intraventricular conduction defect; induced polymorphism furtherly accounts for reentry as the mechanism of sustained ventricular tachycardia in patients with chronic ischemic heart disease; a prevalent morphology of the endocavitary electrophysiologic study induced sustained ventricular tachycardia in patients with chronic ischemic heart disease was not observed at least in our patients; Amiodarone is the drug of choice for the treatment of induced polymorphic sustained ventricular tachycardia patients.