[Transvenous cardioversion in the treatment of sustained ventricular tachycardia. Preliminary results in 3 patients with implantable cardioverter]. / La cardioversione transvenosa nel trattamento della tachicardia ventricolare sostenuta. Risultati preliminari in tre pazienti con cardioverter impiantabile.

The efficacy of intracardiac cardioversion was verified in 11 pts suffering from coronary heart disease and recurrent sustained VT. All pts were receiving anti-arrhythmic drugs. Tachycardia cycle length was between 280 and 400 msec. 65 episodes of VT (21 spontaneous and 44 induced) were treated with synchronized shocks of low energy between 0.27 and 2 J using the external cardioverter. Cardioversion was successful in 83% of VT episodes. VT acceleration occurred in one case; transient atrial fibrillation was induced six times. All pts tolerated shocks from 0.27 to 1 J with moderate discomfort; shocks exceeding 1.0 J were less well tolerated. CK levels were not increased. In three pts (VT cycle length of 320, 380 and 400 msec) a permanent Cardioverter (Medtronic Model 7210) was implanted and programmed to operate in non-automatic mode. Every month the pts underwent a follow-up visit to verify the electrophysiological features of VT in non invasively induced VT episodes and the efficacy of transvenous cardioversion. In a mean follow-up period of 9 months, respectively 5, 4 and 3 spontaneous VT episodes occurred. In two pts cardioversion resulted constantly effective, whereas in the third one provoked VT acceleration requiring DC-shock in the last spontaneous episode of VT.

[A new dual-chamber pacemaker with an automatic antitachycardia system in the treatment of the bradycardia-tachycardia syndrome]. / Un nuovo pacemaker a doppia camera con sistema antitachicardico automatico nel trattamento della sindrome bradicardia-tachicardia.

A new dual-chamber pacemaker with automatic tachycardia terminating system was used in three patients with bradycardia-tachycardia syndrome. This pacemaker (Medtronic Symbios 7008) is a multiprogrammable, bipolar device with bidirectional telemetry and six permanent pacing modes (DDD-DVI-VVI-DOO-VOO-AOO). The antitachycardia system can be programmed in two different modes: underdrive dual demand and overdrive atrial burts (1 to 16 stimuli with selectable coupling interval from 135 to 360 msec). The pacing modes are automatically activated when five consecutive R-R cycles shorter than the tachycardia detection interval are sensed. The pacemaker may sense the ventricle (when set on VVI or DVI mode) or sense both the atrium and the ventricle (in DDD mode). The pacemaker was programmed on DVI mode in all three patients, and the overdrive atrial burst program was used for tachycardia termination, with promptly and costantly effective results. The underdrive dual demand program was tested after the implantation, but it did not show constant results because inefficacy or late termination of tachycardias.

[Effects of digitalis on the parameters of sinus function in sick sinus syndrome. Evaluation using a multiprogrammable permanent atrial pacemaker with temporary inhibition]. / Effetti della digitale sui parametri di funzione sinusale nella sindrome del seno malato. Valutazione mediante pacemaker atriale definitivo (AAI) multiprogrammabile ad inibizione temporanea.

A non invasive electrophysiological study was performed in eight patients with sick sinus syndrome using a multiprogrammable AAI pacemaker (Medtronic Spectrax Sxt) with temporary pacing inhibition. We measured the corrected sinus node recovery time and sino-atrial conduction time (Narula method) before and after digoxin administration (acutely iv and orally for 10 days). Digitalis lengthened both the corrected sinus node recovery time and the sino-atrial conduction time; in particular, after the long-term oral treatment sinus function worsened markedly. The prolongation of the sino-atrial conduction time seems to be related to an indirect effect of the drug, since its disappears after atropine administration. Our results suggest that patients with the sick sinus syndrome need permanent pacing when long-term treatment with digitalis is requested; the pacemaker we used permits a non-invasive long-term evaluation of sinus function in such patients.

[Ribostamycin in chronic and recurrent bronchopulmonary and urinary infections]. / La ribostamicina nelle infezioni broncopolmonari ed urinarie croniche e ricorrenti.

Results in the treatment of mostly Gram-negative infections of the respiratory apparatus (30 subjects) and the urinary apparatus (20 subjects) with ribostamycin are reported. These were regarded as good overall, as shown by the bacteriological findings. An extremely high sensitivity to the antibiotic was noted in isolated germs from both types of infection. This good response in vitro was matched by an equally encouraging bacteriological result in vivo.

Effects of indomethacin on postural hypotension in Parkinsonism.

A study was conducted to evaluate the effect of indomethacin on orthostatic hypotension in Parkinsonism. Twelve elderly patients participated and the drug was given in two-ways--as an intravenous infusion of 50 mg over 30 minutes and by mouth 50 mg thrice daily for six days. Results were assessed by measuring the degree of hypotension on standing, response to the cold pressor test, and forearm blood flow (by strain-gauge plethysmography). Indomethacin significantly reduced the fall in blood pressure on standing (P less than 0:001) and lessened or reversed orthostatic symptoms. Furthermore, there was an enhanced response to the cold pressor test and a reduction in forearm blood flow. These findings suggest that indomethacin has a positive effect on systemic vascular resistance.

[The antegrade GAPs (author's transl)]. / I GAPS anterogradi.

GAP in a-v conduction is defined as a zone within the cardiac cycle where premature atrial impulses fail to evoke ventricular responses whereas atrial beats of greater and lesser prematurity do. This phenomenon occurs when the effective refractory period (ERP) of a distal site is greater than the functional refractory period (FRP) of a proximal site of the conduction system. To date, Damato and Co. classify antegrade gaps into six types on the basis of blocks location and proximal delay that permits conduction recovery: type I: HPS and AVN; type II: HPS (distal) and HPS (proximal); type III: HPS and His-bundle; type IV: AVN (distal) and AVN (proximal); type V: AVN or HPS and atrium; type pseudo-V: AVN or HPS and antrial miocardium proximal to stimulation site; type VI: HPS and supernormality (no proximal delay). The Authors propose, on the basis of 37 cases of GAP phenomenon observed in 185 electrophysiological studies, a new classification of antegrade gaps, which complete and partially modifies Damato's one. Tyes I-II-II-IV and V are divided into A and B forms according to the type and the site of the distal block. GAP type VI is replaced by Damato's pseudo-V. Two new types are proposed: in the first (type VII) the distal block is in the atrium and the proximal delay is in atrial miocardium proximal to stimulation site; in the second (type VIII), in subjects with pre-excitation, the block is in the accessory pathway and the proximal delay is in atrium.