Primary Prevention Implantation of Cardioverter Defibrillator without Defibrillation Threshold Testing: 2-Year Follow-up

Background: Even though the intraoperative threshold testing of the implantable cardioverter defibrillator ( ICD ) may cause hemodynamic impairment or be unfeasible, it is still considered required standard practice at the time of implantation. We compared the outcome of ICD recipients who underwent defibrillation threshold testing (DFT) with that of patients in whom no testing was performed.
Methods: A total of 291 subjects with ischemic dilated cardiomyopathy received transvenous ICDs between January 2000 and December 2004 in five Italian cardiology centers. In two centers, DFT was routinely performed in 137 patients (81% men; mean age 69 ± 9 years; mean ejection fraction 26 ± 4%) (DFT group), while three centers never performed DFT in 154 patients (90% men; mean age 69 ± 9 years; mean ejection fraction 27 ± 5%) (no-DFT group).
Results: We compared total mortality, total cardiovascular mortality, sudden cardiac death (SCD), and spontaneous episodes of ventricular arrhythmia (sustained ventricular tachycardia, VT, and ventricular fibrillation, VF) between these groups 2 years after implantation (median 23 months, 25th–75th percentile, 12–44 months). On comparing the DFT and no-DFT groups, we found an overall mortality rate of 20% versus 16%, cardiovascular mortality of 13% versus 10%, SCD of 3% versus 0.6%, VT incidence of 8% versus 10%, and VF incidence of 6% versus 4% (no significant difference in any comparison).
Conclusions: No significant differences in the incidence of clinical outcomes considered emerged between no-DFT and DFT groups. These results should be confirmed in larger prospective studies.     

Specificity of Atrial Mode Switching in Detecting Atrial Fibrillation Episodes:

The number of automatic mode switch (AMS) has been used to measure the efficacy of atrial pacing in limiting atrial fibrillation (AF). We investigated the impact of length and contiguity on the specificity of AMS in detecting AF episodes in 24 recipients of dual chamber pacemakers with sick sinus syndrome and paroxysmal AF. An AMS algorithm and intracardiac electrogram recordings (IEGM) were activated in all patients to distinguish true arrhythmic events from unnecessary AMS. The length of AMS and the contiguity, that is, the probability of occurrence of another AMS within 5 minutes before or after AMS were examined to increase the specificity of the AMS. During a mean follow-up of 5 ± 3 months, 250 AMS were collected. The IEGM analysis confirmed a true AF episode in 193 of 250 AMS (77.2%). Using the contiguity criterion, 47 of 57 (82.5%) inappropriate AMS episodes were isolated (there were no other AMS within 5 minutes), whereas 54 of 193 (27.9%) appropriate AMS episode were isolated. Adopting both length and contiguity criteria the specificity of AMS in detecting true AF episodes increased from 77.2% to 93.2% at the cost of 11.9% loss of original sensitivity. Combining the length and contiguity criteria, we were able to improve the specificity of the AMS in the detection of AF.     

Radiofrequency Modification of the Atrioventricular Node in Patients with Chronic Atrial Fibrillation:

RF Modification of AVN in AF. Introduction : We compared, in a prospective and randomized fashion with a cross-over design, the anterior and posterior approaches to radiofrequency (RF) modification of the AV node in patients with chronic atrial fibrillation.
Methods and Results : Thirty-three patients were randomized to receive first an anterior (group I) or posterior (group II) approach for RF modification of AV nodal conduction. Patients who did not fill the endpoint ventricular rate (< 90 beats/min) were crossed over to the alternative approach. After the anterior approach in group I patients, mean ventricular rate was significantly lower than in group II patients after the posterior approach (79.6 ± 18.8 beats/min vs 110.8 ± 16.2 beats/min, P < 0.001). In group I, 14 (82%) of 17 patients fulfilled the endpoint, 1 (6%) had complete AV block, and 2 (12%) were crossed over to the posterior approach fulfilling the endpoint. In group II, 4 (25%) of 16 patients fulfilled the endpoint. No transient or permanent high-degree AV block was observed. Among the 12 patients who were crossed over to the anterior approach, 8 fulfilled the endpoint, whereas 4 had permanent high-degree AV block. RF ablation carried out only in the anterior region was safer than a stepwise approach (6% vs 33% incidence of AV block), even though the difference did not reach statistical significance (P = 0.09).
Conclusion : Posterior AV nodal modification is less effective but safer than anterior AV nodal modification. However, to reduce the incidence of AV block, the anterior approach is preferable to a stepwise approach from the posterior to the anterior zone.     

NEUROPEPTIDERGIC ACRAL DYSESTHESIA: A NEW ENTITY

During a 4 year period, we observed three patients, aged 74, 47, and 55, with an average 12-year history of chronic itching and prickling skin discomfort. The dorsal and paimar surface of the hands and feet were involved without observable cutaneous lesions. We followed the patients for 1.5 years in our department. None of the subjects was dermographic, had personal or family history of atopy, or took drugs. The symptoms were not related to the degree of skin dryness, serum IgE levels, exercise, neoplasias, or high environmental temperature and low humidity caused by central heating or seasonal variations. No neurologic alterations were observed in a complete neurologic examination. Emotional upset did not induce symptoms. Upon psychiatric evaluation, the patients showed no alterations in their personality profile. Water exposure did not modify the symptoms. The wheals and pruritus induced by the intradermal injection of 1:10,000 histamine phosphate did not differ from those in three controls¹ Immersion of one hand and foot for 5 days per week for 2 weeks in water at different temperatures (0–45°C) for varying lengths of time and the administration of one minimum erythemal dose of ultraviolet light (280–340 nm) to the controlateral part of the body three times per week for 3 weeks both failed to reduce the severity of the discomfort. Biopsy specimens were taken from the symptomatic skin of the three subjects and from three controls. The specimens were routinely stained with hematoxylineosin for mast cells, elastic fibers, and glycosaminoglycans. There were no significant differences between the two groups. Cutaneous fibrinolytic activity, which is due to the release of cutaneous plasminogen activators, was similar in both groups.² Direct immuno-fluorescence staining (dif ) for neuropeptides substance P (sp) (Fig. 1), vasointestinal polypeptide (vip ), and calcitonin gene related peptide (CGRP) showed an increased number of pep-tidergic fibers in affected skin. After 2 weeks of three times daily application of 0.25% capsaicin in cold cream (8-methyl-N- vanillyl-6-nonenamide, known to interfere with the storage and release of neuropeptides), the symptoms disappeared completely, and neuropetidergic fibers were no longer de-tectable in the skin, as shown by dif . The application of cold cream alone on the contralateral part of the body did not modify DIF or the clinical symptoms. After suspension of capsaicin treatment, a relative to absolute refractory period of 10 to 18 days was observed, and the symptoms reappeared. Previous treatments with systemic Hi (with and without H²) antihistamines, antide-pressants, hypnotics, and topical corticosteroid prepara-tions did not achieve significant results. The increased number of neuropeptidergic fibers in the affected acral skin, the dramatic action of capsaicin in reducing the storage of neuropeptides in the same cutaneous fibers, and the com-plete disappearance of the clinical symptoms suggest that the cases reported here represent a distinct clinical entity, which could be called or described as neuropeptidergic acral dysesthesia.     

Treatment of Diffuse Proliferative Lupus Nephritis by Intravenous High-dose Methylprednisolone

Twenty-five patients with diffuse proliferative lupus nephritiswere treated with three consecutive Intravenous injections of1 g methylprednisolone pulses followed by small doses of prednisone.These patients were followed for at least three months. Majorside-effects were observed only in one patient. After steroid administration, extrarenal symptoms rapidly disappearedin all patients. Except for four patients with diffuse glomerularsclerosis a significant improvement of serum creatinine wasobserved after one month and the improvement was more sustainedafter three months. No deterioration was observed in patientswith normal functioning kidneys. Proteinuria decreased significantlyover three months. When tested, anti-dsDNA binding capacityand serum complement components became normal within four weeks. Seventeen patients were then followed for 12–93 months.Ten patients received only small doses of oral prednisone andseven were also treated with cytotoxic agents. Eight ‘flare-ups’of disease occurred in these patients over a cumulative periodof 688 months. Additional steroid pulses were administered duringthe ‘flare-ups’, with subsequent improvement ofsymptoms and renal function in all but one patient, who haddiffuse glomerular sclerosis at biopsy. At present the meanvalues of serum creatinine are lower than baseline values. Onepatient has renal failure and another one has moderate renalinsufficiency. No patient has the nephrotic syndrome and sixpatients are free from proteinuria. We suggest that aggressive treatment based on short-term intravenousmethylprednisolone during relapse followed by a low-dose maintenanceregimen may be a safe and effective way to manage most patientswith diffuse lupus nephris.     

Antiarrhythmic Drug Therapy after Radiofrequency Catheter Ablation in Patients with Atrial Fibrillation

Objectives: The use of antiarrhythmic drugs after ablation is a controversial issue when evaluating the efficacy of atrial fibrillation (AF) ablation. This study compares in a prospective and randomized fashion the impact of an antiarrhythmic drug in preventing AF recurrence after AF ablation.
Methods: From February 2004 to May 2005, 107 consecutive patients (mean age 57 ± 10 years, 69 men), with paroxysmal (60%) or persistent (40%) drug refractory AF, were randomly assigned to ablation alone (Group A, 53 patients) or combined with the best antiarrhythmic therapy, preferably amiodarone (Group B, 54 patients). All patients underwent cavo-tricuspid and left inferior pulmonary vein (PV)-mitral isthmus ablation plus circumferential PV ablation, using a guided electro-anatomical approach. Standard electrocardiograms (ECG), and ambulatory and transtelephonic ECG monitoring were used to assess AF recurrences. Recurrences during the first month after ablation were excluded from this analysis.
Results: At 12 months of follow-up, no significant difference was observed in the rates of AF recurrences between Group A (18/53 patients, 34%) and Group B (16/54 patients, 30%). The percentage of patients with ≥1 asymptomatic AF episode was higher in Group B than in Group A (10/16 patients, 63%, vs 5/18 patients, 28%, P = 0.04).
Conclusions: Continuing antiarrhythmic drug therapy in patients who undergo catheter ablation for AF did not lower the rate of AF recurrences. Antiarrhythmic drugs increased the proportion of patients with asymptomatic AF episodes.