Impact of the implantable cardioverter-defibrillator on rehospitalizations

Patients who survive out-of-hospital ventricular tachycardia or ventricular fibrillation are at risk of sudden cardiac death and often return to hospital after initial discharge. The frequency and duration of readmittance to hospital are not well known. Thus, the purpose of this study was to evaluate the impact of the implantable cardioverter defibrillator on frequency and duration of hospitalizations. Methods Between 1989 and 1993, 38 consecutive patients who had drug-refractory ventricular tachyarrhythmias were selected for the study. A total of 38 patients were implanted with the implantable cardioverter-defibrillator in accordance with the guidelines of the European Society of Cardiology. This analysis includes 35 of the 38 patients (92%). All hospitalizations which occurred one year before and one year after were studied. Clinical information for all patients was obtained by consulting medical records and by interviewing personal general practitioners. Results The annual number of hospitalizations before and after implantation of the implantable cardioverter defibrillator was, respectively, 3·28 ± 2 hospitalizations/patient/year and 0·88 ± 1·23 hospitalizations/patient/year (P<0·05). Before implantation of the implantable cardioverter-defibrillator, patients were hospitalized a mean of 32·94 plusmn; 24·18 days/patient/year and after, 9·31 ± 32·14 days/patient/year (P<0·05). The number of hospitalizations for cardiac reasons decreased by 90%. Before implantation, the most frequent cause was ventricular tachyarrhythmia (47 hospitalizations for ventricular tachycardia and eight for ventricular fibrillation), while after implantation, it was as a result of the shock from the implantable cardioverter defibrillator (II hospitalizations). The number of hospitalizations for non-cardiac reasons were similar in the two time periods. Of the 35 patients, 26 (74%) had at least one appropriate successful ventricular tachycardia interrupted by the implantable cardioverter-defibrillator, while 17 patients (49%) had their ventricular fibrillation terminated. There is a significant difference in the rate of hospitalizations to intensive care units (ICU) between the two periods. Before implantation, 30% of hospital days were spent in the ICU, with 3% after. Conclusions This study documents that the implantable cardioverter-defibrillator not only reduces the frequency and duration of hospital stays, but reduces admissions to the more expensive units in hospital. Taking into account the reduction in hospitalizations, the payback period for the implantation of an implantable cardioverter-defibrillator is 19 months. (Eur Heart J 1996; 17: 1565-1571

Impact of the implantable cardioverter-defibrillator on rehospitalizations

Patients who survive out-of-hospital ventricular tachycardia or ventricular fibrillation are at risk of sudden cardiac death and often return to hospital after initial discharge. The frequency and duration of readmittance to hospital are not well known. Thus, the purpose of this study was to evaluate the impact of the implantable cardioverter defibrillator on frequency and duration of hospitalizations. METHODS: Between 1989 and 1993, 38 consecutive patients who had drug-refractory ventricular tachyarrhythmias were selected for the study. A total of 38 patients were implanted with the implantable cardioverter-defibrillator in accordance with the guidelines of the European Society of Cardiology. This analysis includes 35 of the 38 patients (92%). All hospitalizations which occurred one year before and one year after were studied. Clinical information for all patients was obtained by consulting medical records and by interviewing personal general practitioners. RESULTS: The annual number of hospitalizations before and after implantation of the implantable cardioverter-defibrillator was, respectively, 3.28 +/- 2.38 hospitalizations/ patient/year and 0.88 +/- 1.23 hospitalizations/patient/year (P &lt; 0.05). Before implantation of the implantable cardioverter-defibrillator, patients were hospitalized a mean of 32.94 +/- 24.18 days/patient/year and after, 9.31 +/- 32.14 days/patient/year (P &lt; 0.05). The number of hospitalizations for cardiac reasons decreased by 90%. Before implantation, the most frequent cause was ventricular tachyarrhythmia (47 hospitalizations for ventricular tachycardia and eight for ventricular fibrillation), while after implantation, it was as a result of the shock from the implantable cardioverter-defibrillator (11 hospitalizations). The number of hospitalizations for non-cardiac reasons were similar in the two time periods. Of the 35 patients, 26 (74%) had at least one appropriate successful ventricular tachycardia interrupted by the implantable cardioverter-defibrillator, while 17 patients (49%) had their ventricular fibrillation terminated. There is a significant difference in the rate of hospitalizations to intensive care units (ICU) between the two periods. Before implantation, 30% of hospital days were spent in the ICU, with 3% after. CONCLUSIONS: This study documents that the implantable cardioverter-defibrillator not only reduces the frequency and duration of hospital stays, but reduces admissions to the more expensive units in hospital. Taking into account the reduction in hospitalizations, the payback period for the implantation of an implantable cardioverter-defibrillator is 19 months

Bordetella pertussis Infection or Vaccination Substantially Protects Mice against B. bronchiseptica Infection

Although B. bronchiseptica efficiently infects a wide range of mammalian hosts and efficiently spreads among them, it is rarely observed in humans. In contrast to the many other hosts of B. bronchiseptica, humans are host to the apparently specialized pathogen B. pertussis, the great majority having immunity due to vaccination, infection or both. Here we explore whether immunity to B. pertussis protects against B. bronchiseptica infection. In a murine model, either infection or vaccination with B. pertussis induced antibodies that recognized antigens of B. bronchiseptica and protected the lower respiratory tract of mice against three phylogenetically disparate strains of B. bronchiseptica that efficiently infect naïve animals. Furthermore, vaccination with purified B. pertussis-derived pertactin, filamentous hemagglutinin or the human acellular vaccine, Adacel, conferred similar protection against B. bronchiseptica challenge. These data indicate that individual immunity to B. pertussis affects B. bronchiseptica infection, and suggest that the high levels of herd immunity against B. pertussis in humans could explain the lack of observed B. bronchiseptica transmission. This could also explain the apparent association of B. bronchiseptica infections with an immunocompromised state

Le diagnostic electrocardiographique d'hypertrophie ventriculaire gauche est-il possible en presence d'un hemibloc anterieur? [Is electrocardiographic diagnosis of left ventricular hypertrophy possible in the presence of an anterior hemiblock?]

The electrocardiographic diagnosis of left ventricular hypertrophy is often difficult because it is based on a large number of criteria which, even if taken on their own or as "scoring systems", have a poor sensitivity ranging from 10 to 60%. Some authors have shown that the diagnosis is easier--though at first sight this seems paradoxical--in the presence of altered ventricular depolarization. To verify this statement in the case of left anterior fascicular block, we tested the value of six different indices for the detection of left ventricular hypertrophy. We analyzed 100 patients with left anterior fascicular block and compared the six electrocardiographic indices with the echocardiographic reference method, using the formula of the Penn convention, to establish the left ventricular mass. The best index of the six was that of Gertsch: [S3+ (R+S) maximal precordial] greater than or equal to 30 mm. Its sensitivity was 74%, its specificity 69%, its positive predictive value 79% and its negative predictive value 63%. The other tested indices had a sensitivity of less than 45% with a specificity of more than 80%. Furthermore, Gertsch's index was of equal value in confirming the increased left ventricular mass due either to concentric hypertrophy or to dilated cardiomyopathy. This study therefore confirms that electrocardiographic diagnosis of left ventricular hypertrophy is even easier in the presence of left anterior fascicular block than in absence of altered ventricular depolarization. This result is of practical interest, the incidence of left anterior fascicular block being 1 to 5% in the general population and as high as 30% after the age of 80

Experience lausannoise de l'ablation percutanee par radiofrequence de la voie lente de la tachycardie nodale. [Lausanne experience in radiofrequency percutaneous ablation of the slow pathway in nodal tachycardia]

Atrioventricular nodal reentrant tachycardia (AVNRT) is the most frequent paroxysmal supraventricular tachycardia and results from reentry in the atrioventricular nodal region via slow and fast pathways. The curative treatment of choice consists of selective radio-frequency catheter ablation of the slow pathway. In this retrospective study we report our experience of 73 consecutive patients suffering from AVNRT treated by selective slow pathway ablation and also review some features of AVNRT. AVNRT appeared for the first time at the age of 29 +/- 15 years and lasted for 17 +/- 13 years. In 37% of the patients AVNRT recurred at least weekly, 10% presented with syncope and 15% were admitted to hospital more than 5 times. On average, 2.5+/-1.6 drugs were prescribed to 66 of the 73 patients and 83% of them were drug-refractory. Selective slow pathway ablation was successfully performed in 65 patients (89%). The procedure, although effective, was complicated by atrioventricular block in 2 patients (2.7%) and failed in 6 patients. In 5 of them, fast pathway ablation was attempted and was successful in 2 cases, resulted in atrioventricular block in one case and failed in 2 cases. The complications, apart from atrioventricular block necessitating a pacemaker in all cases, were one pulmonary embolism and 2 pneumothorax. The mean follow-up for the 70 patients for whom ablation was effective (with or without atrioventricular block) is 12.7+/-7.3 months. AVNRT relapsed in 5 patients (7%); all of them underwent a second ablation with 4 successes (slow pathway) and one atrioventricular block (fast pathway after failed slow pathway ablation). 11 patients (16%) developed palpitations: in one case they were due to atrial fibrillation and in 10 cases they remained of unknown origin. The palpitations were of short duration and well tolerated, and these patients nevertheless felt an improvement after the ablation. Therefore, at medium term, 62 patients (85%) remained free from symptoms or only slightly symptomatic and without a pacemaker, and 51 of them (70%) remained completely asymptomatic and without a pacemaker. AVNRT can result in considerable morbidity and antiarrhythmic drugs are frequently ineffective. Slow pathway ablation is a safe and effective treatment for AVNRT. In our opinion, if AVNRT or medical treatment diminish the quality of life, ablation is indicated. When AVNRT presents with hemodynamic collapse, ablation is mandatory. Fast pathway ablation after failed slow pathway ablation is associated with a high incidence of atrioventricular block and is targeted only at very symptomatic patients who accept the possibility of definitive pacemaker implantation

La tachycardie jonctionnelle reciproque permanente: une entite clinique meconnue, curable par l'ablation par radiofrequence. [Permanent junctional reciprocating tachycardia: a little-known clinical entity curable with radiofrequency ablation]

We report our experience of 5 patients with the permanent form of junctional reciprocating tachycardia (PJRT), a rare form of supraventricular arrhythmia. PJRT was discovered at a mean age of 31 years (8-60 years) and the mean duration of tachycardia was 13 years (1-40 years). 4 patients had nearly incessant tachycardia and one had paroxysmal attacks. Heart rate varied between 100 and 190 beats/minute and the minimal heart rate was on average 114 beats/minute. Four patients had palpitations, 2 developed tachycardia-induced cardiomyopathy, reversible after control of the arrhythmia, and 4 had asymptomatic episodes of PJRT. ECG showed in all cases a narrow-complex tachycardia with inverted P waves in inferior leads and RP interval greater than PR. All patients presented a posteroseptal accessory pathway. 4 patients received different antiarrhythmic drugs with only partially effective results. Radiofrequency catheter ablation of the accessory pathway was performed in all patients and was successful in 4, who remained free of recurrence after a mean follow-up of 26.5 months (4-37 months). The procedure was partially successful in the 5th patient, who is now asymptomatic under sotalol. Radiofrequency catheter ablation is therefore the treatment of choice of PJRT, a rare arrhythmia which should nevertheless be known in order to treat the patient correctly and avoid progression to cardiac failure, which is not always completely reversible

Mortalite apres tachycardie ventriculaire soutenue traitee selon les resultats de la stimulation ventriculaire programmee. [Mortality following sustained ventricular tachycardia treated according to the results of programmed ventricular stimulation]

The purpose of this study was to evaluate longterm mortality in 44 patients undergoing electrophysiologically guided therapy for sustained monomorphic ventricular tachycardia. We applied the following modified response criteria: non-inducibility or slowing of induced ventricular tachycardia to &lt; or = 150 bpm. On this basis, 25/44 (57%) patients were classified as responders, and 19/44 (43%) as non-responders. Responders had palpitations significantly more often as the leading clinical sign (68% vs. 21%, p &lt; 0.05). Non-responders showed a lower mean ejection fraction (36 +/- 15% vs. 46 +/- 17%, p &lt; 0.05) and a trend to higher incidence of syncopal ventricular tachycardia (58% vs. 12%, p = 0.15). All responders and 3/19 non-responders continued on drug therapy. 11 non-responders received an implantable cardioverter-defibrillator (ICD), 3 underwent surgery and 2 catheter ablation. 14/44 patients (32%) died during a mean follow-up of 3.2 years. Sudden arrhythmic death occurred in 3/28 patients on drug therapy (1/25 responders, 2/3 non-responders), and in 2/16 non-responders with invasive therapy (one with an ICD and one after catheter ablation). The cumulative all-cause mortality at 3 years was similar in both groups (26% vs 22%, n.s.), but the mortality from sudden arrhythmic death showed a trend to be lower in the responder-group (0% vs 17%, p = 0.09).(ABSTRACT TRUNCATED AT 250 WORDS