Implant and long-term evaluation of atrial signal amplification in a single-lead ICD.

BACKGROUND: In patients without clinical indications for pacing the use of a single-lead implantable cardioverter defibrillator (ICD) implementing atrial sensing capability with proper signal amplification management may represent a useful therapeutic option, combining the positive features of both single and dual-chamber devices. The aim of the study was to evaluate the atrial signal amplification and its long-term stability in a single-lead ICD system adding atrial sensing to a standard single-chamber ICD. METHODS: P-wave amplitudes were collected and compared at implant both with a conventional external device ("unfiltered" P wave) and telemetrically with the implanted ICD ("filtered" P wave). Filtered/unfiltered P-wave ratio (amplification factor, AmF) was evaluated at implant and during follow-up. RESULTS: In 43 enrolled patients (38 men, age 64 ± 16 years), the mean filtered P wave at implant was significantly higher than the unfiltered P wave (3.85 ± 0.81 mV vs 2.0 ± 1.49 mV; P < 10(-11) ), with a mean AmF value of 2.77 ± 1.62. In seven patients with atrial fibrillation at implant, the AmF was higher (4.62 ± 1.94) than in patients in sinus rhythm (2.41 ± 1.30; P < 0.001). A significant linear correlation was found between the inverse of P wave and the AmF (R = 0.82, P < 0.00001). In 25 patients followed for 384 ± 244 days, atrial undersensing was never documented and AmF did not change from implant (3.19 ± 1.82; P = 0.24), also in different body position and breathing conditions. CONCLUSIONS: The single-lead ICD system evaluated reliably amplified P-wave amplitudes by a factor of about three, maintaining this performance during the observed follow-up.

Bleomycin-induced scleroderma: report of a case with a chronic course rather than the typical acute/subacute self-limiting form.

We report a case of bleomycin-induced scleroderma in a 35-year-old woman treated with chemotherapy for Hodgkin's disease. Approximately 6 months after the first chemotherapy cycle, the patient developed skin sclerosis in both arms. The lesion showed no signs of spontaneous clinical amelioration and treatment with steroids was unsuccessful. A partial remission of the skin sclerosis was instead obtained by the administration of D-penicillamine. A family history revealed other cases of autoimmune diseases and HLA typing showed the presence of antigens associated with scleroderma. The association between bleomycin therapy and scleroderma is discussed.

Takayasu's arteritis overlapping with systemic sclerosis.

We describe an unusual case of overlap between Takayasu's arteritis (TA) and systemic sclerosis (SSc). TA has been found in association with several diseases, but not with SSc. To our knowledge this is the first case report of TA associated with SSc in the literature. It is possible that the expression of the two diseases in our patient was influenced by the presence of genetic factors predisposing to both TA and SSc.

Effect of electrode configuration and capacitor size on internal atrial defibrillation threshold using leads currently used for ventricular defibrillation.

BACKGROUND: Previous studies have shown that endocardial atrial defibrillation, using lead configurations specifically designed for ventricular defibrillation, is feasible but the substantial patient discomfort might prevent the widespread use of the technique unless significant improvements in shock tolerability are achieved. It has been suggested that the peak voltage or the peak current but not the total energy delivered determines the patient pain perception and therefore, lower defibrillating voltage and current achieved with modifications in lead and waveforms may increase shock tolerability. This study was undertaken to evaluate the effect, on the atrial defibrillation threshold (ADFT), of the addition of a patch electrode (mimicking the can electrode) to the right ventricle (RV)-superior vena cava (SVC) lead configuration. The influence of capacitor size on ADFT using the RV-SVC+skin patch configuration was also assessed. METHODS: In 10 patients (pts) (Group 1) cardioversion thresholds were evaluated using biphasic shocks in two different configurations: 1) right ventricle (RV) to superior vena cava (SVC); 2) RV to SVC+skin patch. In a second group of twelve patients (Group 2) atrial defibrillation thresholds of biphasic waveforms that differed with the total capacitance (90 or 170 microF) were assessed using the RV to SVC+skin patch configuration. RESULTS: In Group 1 AF was terminated in 10/10 pts (100 %) with both configurations. There was no significant difference in delivered energy at the defibrillation threshold between the two configurations (7.1 +/- 5.1 J vs 7.1 +/- 2.6 J; p < 0.05). In group 2 AF was terminated in 12/12 pts (100%) with both waveforms. The 170 microF waveform provided a significantly lower defibrillating voltage (323.7 +/- 74.6 V vs 380 +/- 70.2 V; p < 0.03) and current (8.1 +/- 2.7 A vs 10.0 +/- 2.3 A; p < 0.04) than the 90 microF waveform. All pts, in both groups, perceived the shock of the lowest energy tested (180 V) as painful or uncomfortable. CONCLUSIONS: The addition of a patch electrode to the RV-SVC lead configuration does not reduce the ADFT. Shocks from larger capacitors defibrillate with lower voltage and current but pts still perceive low energy subthreshold shocks as painful or uncomfortable.

Antibodies reactive with neutrophils following allogeneic haematopoietic stem cell transplantation.

Allogeneic haematopoietic stem cell transplants might induce immunological alterations leading to autoimmune-like syndromes. In particular neutrophil-associated antigens could represent the target for autoantibodies against neutrophils in patients receiving an allogeneic peripheral stem cell or bone marrow transplantation, giving rise to granulocytopenia. With this aim we studied prospectively 43 allotransplanted patients for the presence of antibodies reacting with neutrophils (ARN), looking for a correlation with a post-engraftment neutropenia. Our data showed that the direct test for ARN was positive in 30 patients. Interestingly, 7/7 patients who received a T-cell-depleted marrow transplant developed ARN. Antibodies with a specific neutrophil-antigen reactivity were detected in 4 patients, 1 with an anti-CD16/FcbetaRIIIb receptor reactivity and 3 with anti-NA 1 reacting patterns, respectively. From a clinical point of view, it was not possible to demonstrate a close and significant relationship between neutropenia and ARN, although patients showing ARN had slightly lower absolute levels of peripheral neutrophils until 6 months after BMT. In conclusion, ARN may be detected in the majority of patients following allogeneic stem cell transplantation; in addition, since ex vivo or in vivo T-cell-depletion leads to a higher percentage of patients positive for ARN, it could be hypothesized that "autoimmune-like" disorders in transplanted patients might be related to a T-cell derangement due to different numbers and subsets of T lymphocytes.

DDD pacing with rate drop response function versus DDI with rate hysteresis pacing for cardioinhibitory vasovagal syncope.

BACKGROUND: The effectiveness of cardiac pacing in preventing vasovagal syncope remains controversial. However, DDI pacing with rate hysteresis has been reported to prevent the recurrence of cardioinhibitory vasovagal syncope in up to 35% of affected subjects and to reduce the overall incidence of syncopal episodes in the others. Recently, DDD pacing with a new promising rate drop response function (Medtronic Thera-I model 7960) has become available in clinical practice. AIM OF THE STUDY: The aim of the present open trial was to test the effectiveness of this new pacing modality in patients with cardioinhibitory vasovagal syncope. STUDY POPULATION AND METHODS: The study population included 20 patients (12 males and 8 females; mean age 61.1 +/- 14 yrs) with recurrent syncope (mean number of prior episode = 6.8, range 5-11) and cardioinhibitory responses during two head-up tilt tests: the first diagnostic and the second during drug therapy with either beta-blockade or etilephrine. The study patients were randomized to receive either DDI pacing with rate hysteresis (8 patients) or DDD pacing with rate drop response function (11 patients). The head-up tilt test performed 1 month after pacemaker implantation was positive in 3 of 12 patients (25%) with DDD pacing with rate drop response function and in 5 of 8 patients (62.5%) with DDI pacing with rate hysteresis. The mean duration of follow-up was 17.7 +/- 7.4 months. During follow-up no patients with a DDD pacemaker with rate drop response function had syncope, while 3 of 8 patients with a DDI pacemaker with rate hysteresis had recurrence of syncope (P < 0.05). CONCLUSIONS: These data suggest that DDD pacing with rate drop response function is effective in cardioinhibitory vasovagal syncope and may be preferable to DDI pacing with rate hysteresis.

Serum CA 242 in pancreatic cancer. Comparison with CA 19-9 and CEA.

Serum CA 242, CA 19-9 and CEA concentrations were determined in 94 subjects divided into 5 groups: Group 1 consisted of 22 healthy subjects; Group 2 consisted of 40 patients with pancreatic adenocarcinoma; according to Cubilla and Fitzgerald's classification, 11 tumours were Stage I, 4 were Stage II, and 25 were Stage III. Group 3 consisted of 10 chronic pancreatitis patients, group 4 of 10 acute pancreatitis patients, group 5 of 12 patients with nonpancreatic digestive carcinomas. Ten of these 12 patients had distant metastases. The sensitivity of CA 19-9 in the diagnosis of pancreatic cancer was higher than that of CEA and CA 242 (p < 0.05 and p < 0.005, respectively). In Stage I cancer patients the sensitivity of the markers studied was less than 50% (45% for CA 19-9, 18% for CEA, and 9% for CA 242) whereas most of the 25 patients with metastatic tumours of the pancreas had elevated serum levels of all 3 markers. The various combinations of the three markers did not significantly improve the sensitivity in diagnosing pancreatic cancer. No relationship was found between the localization of the tumour and the serum levels of the 3 markers studied. Similarly, no differences were found between patients with cholestasis and those without. The specificity of the 3 markers, evaluated in patients with benign pancreatic diseases, was 100% for CA 242, 90% for CA 199 and 70% for CEA.(ABSTRACT TRUNCATED AT 250 WORDS)