Indications for dual-chamber cardioverter defibrillators at implant and at 1 year follow-up: a retrospective analysis in the single-chamber defibrillator era.

AIM: This retrospective four-centre study assessed the current indications for dual-chamber implantable cardioverter defibrillators (ICDs) at implant and during a medium-term follow-up period in a group of patients treated by single-chamber ICD in the pre dual-chamber ICD era. METHODS AND RESULTS: The study population consisted of 153 consecutive patients (127 males, mean age 58 +/- 6 years) treated by single-chamber ICD for ventricular tachycardia and/or ventricular fibrillation. Definite indications for having a dual-chamber ICD included the presence of sinus node dysfunction and of second- or third-degree atrioventricular (AV) block, while possible indications were represented by paroxysmal atrial fibrillation or flutter and first-degree AV block. At implant, dual-chamber ICD would appear definitely indicated in 10.5% of cases, and possibly indicated in an additional 17.5% of cases. During 12 +/- 10 months follow-up, such percentages remained stable (11 and 19.5%, respectively). Inappropriate ICD intervention was documented in five of 13 patients (38%), with episodes of paroxysmal atrial fibrillation or flutter. CONCLUSION: In this non-selected study population, a dual-chamber ICD would have potentially benefited approximately 30% of the patients. During medium-term follow-up, there was no progression towards increasing dual-chamber ICD indications. The 15% cumulative incidence of paroxysmal atrial tachyarrhythmias justifies the activation of dedicated detection algorithms.

Steady-state balance model to calculate the indoor climate of livestock buildings, demonstrated for finishing pigs.

The indoor climate of livestock buildings is of importance for the well-being and health of animals and their production performance (daily weight gain, milk yield etc). By using a steady-state model for the sensible and latent heat fluxes and the CO2 and odour mass flows, the indoor climate of mechanically ventilated livestock buildings can be calculated. These equations depend on the livestock (number of animals and how they are kept), the insulation of the building and the characteristics of the ventilation system (ventilation rate). Since the model can only be applied to animal houses where the ventilation systems are mechanically controlled (this is the case for a majority of finishing pig units), the calculations were done for an example of a finishing pig unit with 1,000 animal places. The model presented used 30 min values of the outdoor parameters temperature and humidity, collected over a 2-year period, as input. The projected environment inside the livestock building was compared with recommended values. The duration of condensation on the inside surfaces was also calculated.

[A regional experience with permanent cardiac pacing: in Friuli-Venezia Giulia the highest density of pacemaker patients in Italy, to-day (author's transl)]. / Un'esperienza regionale di elettrostimolazione cardiaca: nel Friuli-Venezia Giulia la maggior densità di portatori di pacemaker in Italia, oggi.

In Friuli-Venezia Giulia, a region of 1,243,463 inhabitants, a total of 1,629 first implants have been carried out since the first patient was treated with permanent cardiac pacing (P.C.P.) early in 1692. This patient is still alive. In the last four years, the annual rate of implants was 185 per million inhabitants. The average age of patients is 72.9. The most frequent indication for pacing is the a-v block (64.5%), followed by the fascicular blocks (10.8%) and the sick sinus syndrome. No asinchronous fixed rate generators are implanted at present; lithium batteries are the power source of choice to-day. There have been 1,120 replacements in the Region, mainly due to battery depletion (89.9% of cases). A total of 442 patient deaths have occurred in 10 years due to neoplasms (17%), cerebrovascular accidents (15.6%), respiratory infections (15%), myocardial infarction (8%) and other causes. In 8.8% of cases the death was sudden. There are 1,179 patients in follow-up in the Region (948 per million inhabitants). A computer system, described elsewhere in these proceedings, allows a close follow-up of these patients along with the evaluation of long term pacing on a reliable statistical basis.

[The Italian experience in permanent pacing. A casuistry for more of 10 years: a policentric study (author's transl)]. / L'esperienza italiana con l'elettrostimolazione permanente a lungo termine. Casistica in trattamento da oltre 10 anni: studio policentrico.

According to a recent national survey, 387 patients were treated by permanent pacing in 10 Italian centers, between 1961 and 1966. Of these patients 205 have died; 131 (77 males and 54 females) are still alive and no informations could be obtained for the remaining 51 (13%). The overall survival of patients treated during this period of time is therefore not less than 34% which is comparable to that of general population of the same age group. The 131 patients still alive have totaled 1,486 years of pacing and have used up to 784 pacers. Comparing the incidence of the most common causes for replacement during the periods 1961-66 and 1973-77, electrode failures dropped from 21 to 0.9%; circuitry malfunctions occurred in 10.5 and 7.8%; battery depletion rose from 36.8 to 69% of the cases. According to their clinical conditions, the 131 patients on long-term follow-up can be grouped as follows: 62% are in class 1 or 2 of NYHA; 26.7% are in class 3, and 3.8% in class 4. Moreover, 53.4% of patients are living an active life, having some sort of occupation and 29% are holding a driving license.