[The pocket infection-erosion of permanent pacemakers: the results of a conservative approach without substitution of the components]. / Infecção-erosão da loca de pacemakers permanentes: resultados de uma abordagem conservadora sem substituição dos componentes.

OBJECTIVE: To assess the value of a morphologic classification of pocket lesions in eroded-infected permanent pulse generators and its influence in the efficacy or surgical management without removal and with system reutilization. DESIGN: Retrospective evaluation of patients, presenting with eroded-infected pacemaker, submitted to surgery. SETTING: Pacing Center and Cardiology Department of Faro District Hospital. PATIENTS: 43 consecutive patients treated by the same surgeon between 1985 and 1994. INTERVENTIONS: We considered three groups, based on morphologic characterization of the pocket lesions: G1-partial extrusion from the pulse generator with focal, adherent, discoloured and eroded skin; G2-identical to the previous group but with inclusion of lead segments or only lead extrusion; G3-tender pacing sites with fluctuation and, usually, fistula formation without the skin lesions of the other groups. In every patients a new ipsilateral generator pocket has been created just aside from the previous one with reimplantation of the same pacemaker. Failure was defined as the need for explantation of the system, with a new pacemaker implantation on the contralateral site, after the first attempt in G3 and a second in the other two groups. MEASUREMENTS AND RESULTS: The erosion-infection rate was 6.9%. Recurrences appeared in, 8.3%, 36.3% and 75% for, respectively, G1, G2 and G3. The initial and final success rates of G1 were significantly different from G3 success rates (p, respectively, < 0.07 and < 0.001). At the end of our study, reutilization surgery was successful in 91.4% of G1 and G2 assembled patients compared with 25% of the G3 patients (p < 0.003). Mean hospital stay for G3 patients was 7.4 +/- 1.0 days while G1 and G2 were managed as outpatients. The mean follow-up of patients without recurrences of pocket erosion-infection was 32.8 months. CONCLUSIONS: Our data suggest that a morphologic classification of lesions is very useful for treatment choice. It is possible, then, to select patients that may successfully managed by ipsilateral reimplantation without removal of pacing systems or hospital stay. The differences in the appearance of lesions and management results must reflect different etiopathogenic mechanisms.

[Echocardiography-guided temporary implantation of electrode catheters: an alternative with reliable results even during prolonged use]. / Implantação de electrocateteres temporários sob controlo ecocardiográfico: alternativa de resultados fiáveis mesmo durante a utilização prolongada.

OBJECTIVE: Two-dimensional echocardiography (2D-ECO) evaluation as an alternative guidance technique during temporary pacing wire placement. DESIGN: Prospective evaluation of implantation and pacing parameters. SETTING: Admission from the Emergency Room and patients studied in the Cardiology Department of the Hospital Distrital in Faro. PATIENTS: Twenty patients with indication for temporary cardiac pacing during, at least, twelve hours (H). Fluoroscopy equipment shouldn't be readily available for implantation. INTERVENTIONS: The mean ages of the 20 pts. (14 men and 6 women) were 71.90 +/- 2.12 years. All pts. had a temporary pacing lead implantation under 2D-ECO guidance. Indications for cardiac pacing were: second or complete atrioventricular block (17 pts.), new onset bifascicular bundle branch block during anterior acute myocardial infarction (1 patient) and sick sinus syndrome (2 pts.). The transvenous route of approach has been the right internal jugular in all the cases and venipuncture time accounts for the calculation of total implantation time. MEASUREMENTS AND RESULTS: Ventricular capture was achieved in all pts., with stable stimulation thresholds. The mean implantation time was +/- 9.21 minutes and the mean acute stimulation threshold 0.33 +/- 0.20 V and 0.65 +/- 0.35 mA. The mean voltage of the intracavitary QRS was 11.15 +/- 2.95 mV and the mean lead resistance was 851.33 +/- 194.04 Ohms. The mean utilization time of the pacing leads was 95.15 +/- 87.49 H and the mean stimulation threshold during lead explanation was 0.85 +/- 0.47 mA. The only complication appearing during our study has been one lead dislodgment (5%), 72 h after implantation, placed again with the guidance of 2D-ECO and used during 216 H without further complications. Subcostal 2D-ECO window alone was used in 85% of the pts. but in the remaining (15%), it was insufficient and an apical window was needed too. CONCLUSIONS: The 2D-ECO was an efficient alternative technique of guidance during temporary lead placement, ensuring satisfactory longterm pacing and sensing. Our results indicate that 2D-ECO may be the best alternative control for urgent lead implantation whenever fluoroscopic facilities are remote or logistically not convenient.

[Diagnosis of silent ischemia in patients with previous myocardial infarct, under 45 years of age]. / Diagnóstico de isquémia silenciosa em doentes com enfarte do miocárdio prévio, com menos de 45 anos de idade.

STUDY OBJECTIVE: Diagnostic methods validation and incidence estimation of silent myocardial ischemia in patients with previous myocardial infarction under 45 years. DESIGN: Prospective in comparison with a healthy group. SETTING: Cardiac outpatients follow-up at Faro's District Hospital. PATIENTS AND PARTICIPANTS: A random group of 23 outpatients (GI) under 45 years, with previous myocardial infarction. A second group of healthy volunteers (GII) similar in age and sex. INTERVENTIONS: After discontinuing therapy, a maximal treadmill exercise test (E.T.) was performed in both groups, using the Bruce protocol. A ST segment depression greater than or equal to 1 mm, measured 80 ms after J point was the positive criteria. Simultaneously a 24 h Holter recording was obtained using a two channel real time recorder. ST segment depression greater than or equal to 1 mm, measured 80 ms after J point and lasting over 60 s., was the positive criteria. Patients with left bundle branch block or left ventricular hypertrophy criteria were excluded. Concerning ventricular arrhythmias only repetitive forms were considered. MEASUREMENTS AND RESULTS: Ten E.T. (43.5%) resulted positive in GI. Simultaneous Holter recording was positive in nine patients (one false negative). From the 13 patients with negative E.T., 12 had negative Holter recordings (one false positive). Every E.T. and simultaneous Holter resulted negative in GII. Silent ischemia was detected in eight GI patients (34.8%) all of them belonging to the subgroup with positive E.T. In four patients the silent ischemia was detected by asymptomatic E.T., and simultaneous Holter. The remaining four patients had silent ischemia diagnosed on the subsequent Holter. Silent ischemia episodes were not detected in the subgroup of 13 patients with negative E.T. Between those two subgroups it is highly significant (p less than 0.001) the difference in the incidence of silent ischemia. The patients with silent ischemia recorded an average of 6.5 episodes/patient/day mainly in day time (p less than 0.001). Episodes of silent ischemia were more frequent in the subgroup of patients with asymptomatic positive E.T. than in the subgroup of positive E.T. with pain (p less than 0.004). It was not confirmed any significant difference in the incidence of ventricular arrhythmias among patients with or without silent ischemia. CONCLUSIONS: We have verified an high incidence of silent ischemia in a group of patients with previous myocardial infarction. Holter's electrocardiographic monitoring has a high concordance with E.T. results, when performed simultaneously. In fact, it does not provide any significant additional information since every patient with silent ischemia had positive E.T., but can be complementary in the evaluation of the total ischemic burden. It has been checked that episodes of silent ischemia have a major incidence at day time, appearing more often in patients with asymptomatic positive E.T.