A population-based study of familial clustering of inflammatory bowel disease in Florence

In the frame of a population-based epidemiological study inthe metropolitan area of Florence in a 15 year period (1978–1992)all prevalent patients affected with ulcerative colitis (UC)or Crohn's disease (CD) (alive and resident in the area at theend of the study) were investigated in order to identify familialclustering. Only 45 patients (5.2%) reported at least 1 relativewith a diagnosis of inflammatory bowel disease (IBD). Amongthese, 25 patients reported a first-degree relative affectedwith IBD (2.9%). All the 28 families were contacted and detailedpersonal interviews were carried out in order to collect familytrees. The affected relatives living outside the study areawere also identified and their IBD diagnoses were verified.Fifteen families included only affected members with a diagnosisof UC; 5 had only CD, while 8 families had members affectedwith both forms. Two large families had 4 affected members and2 other families had 3. Overall 9 parent-child affected pairswere identified (1 out of every 3 families). The high concordancewithin families for the type of disease (p=0.015) suggests thatthe disease susceptibility is specific. The authors discussthese findings and a possible interpretation of the low proportionof familial cases in this area.     

Modulated Parasystole Complicating Permanent Ventricular Pacing: The Different Influence of Spontaneous and Paced Impulses Upon the Parasystolic Rhythm

A case of modulated ventricular parasystole observed in a patient with a VVIM pacemaker is reported. Analysis reveals that the electronic influence (modulation) effected upon the parasystolic focus by the sinus impulses is different from that exerted by the paced impulses. Furthermore, fusion beats reflect an intermediate modulating effect according to the prevalence of the sinus or the paced wavefront.     

Ventricular Parasystole: A Chronobiologic Study

Previous works have reported circadian rhythms for several cardiovascular parameters. A chronobiologic rhythm is characterized by: mesor (a rhythm-determined average), amplitude (half difference between the highest and lowest values), and acrophase (timing of high point in degrees and/or in hours) along with 95% confidence limits. We performed 24-hour ECG Holler monitoring in seven patients (mean age, 50.6 years) with ventricular parasystole (VP) in order to determine whether the chronotropic activity of parasystolic foci has a circadian rhythm similar to that of the sinus node. For each Holter recording parasystolic rates (PRs) and heart rates (HRs) were calculated every hour. Furthermore, a mean hourly PR and a mean hourly HR were calculated from the hourly PRs and HRs of the patients. The statistic chronobiologic analysis was done by single and mean cosinor methods. Correlation between mean hourly PR and HR was evaluated by Pearson's V coefficient. A statistically significant rhythm (P < 0.05) was found for the single and mean rhythms both of HR and PR. In our patients, HR had acrophase at 1.27 P.M., mesor at 73.28 beats/min, and amplitude at 9.53 beats/min, whereas PR had acrophase at 1.42 P.M., mesor al 38.31 beats/min, and amplitude at 3.64 beats/ min. Chronobiological data and the high direct correlation between mean hourly HRs and mean hourly PRs (r = 0.96, P < 0.001) indicate a similar circadian variability of the chronotropic activity of sinus nodes and parasystolic foci. Although several hypotheses can be made, responsiveness of parasystolic foci to circadian variations of the autonomic nervous system tone (sympathetic and/or vagal) and/or circulating substances (particularly catecholamines) seems the more probable one for explaining our findings.     

Induction of supraventricular tachyarrhythmia at rest and during exercise with transoesophageal atrial pacing in the electrophysiological evaluation of asymptomatic athletes with Wolff-Parkinson-White Syndrome

Even today there is controversy as regards the best approachto asymptomatic or slightly symptomatic athletes with the WPMsyndrome as regards fitness for sports activity, especiallyin some countries where the doctor is responsible for certifyingsports fitness. This study concerns 84 asymptomatic or slightlysymptomatic athletes (66 males, 18 females, mean age 21.7 years,range 12–44 years) who underwent a stimulation protocolthe end-point of which was the induction of atrial fibrillation(or, if not possible, atrial tachyarrhythmia) in the basal stateand during bicycle stress test with transesophageal atrial pacing.The 81 athletes in whom the end-point was reached were dividedinto two groups: Group I includes the 32 athletes with the shortestR–R interval between pre-excited beats 240 ms in thebasal state and /or 210 ms during bicycle ergometer test, GroupII includes the other 49 patients. The evaluation during exercisewas not carried out in four athletes because of serious haemodynamiccompromise due to the arrhythmia induced in the basal state.Only 21/32 athletes would have been included in Group I if onlyevaluated in the basal state. In 30/81 athletes (37%), there was discrepancy between the resultof stimulation and the result of the usual non-invasive evaluation(Holter monitoring, ergometric stress test, ajmaline test).On average, 40 min are required for the performance of the studyprotocol except when the induced arrhythmia lasts more than5 min. The follow-up of the Group I athletes ranged from 10 to 36 months(mean 20.5 months); three athletes became symptomatic and intwo of these the clinical arrhythmia was like the one induced. On the basis of our results, we conclude that the inductionof atrial fibrillation under stress is useful in screening athleteswith WPM syndrome; and, as it is simple to perform and economical(in time, equipment and staff), we regard this protocol as fundamentalfor the electrophysiological evaluation of athletes with Wolff–Parkinson–Whitesyndrome.     

Late Sensing Due to Extremely Delayed Right Ventricular Activation in Arrhythmogenic Right Ventricular Cardiomyopathy

A patient with arrhythmogenic right ventricular cardiomyopathy/dysplasia, implanted with a dual-chamber implantable cardioverter-defibrillator programmed in DDD mode, showed an unexpected ventricular sensing dysfunction: despite a very long (320 ms) programmed atrioventricular (AV) interval, ventricular stimuli were delivered in the ST segment after each spontaneous conducted QRS complex. This suggested the presence of ventricular undersensing. When, however, the system was programmed in VVI mode, spontaneous QRS complexes were normally sensed, although electrogram (ECM) analysis revealed that ventricular sensing occurred 160 ms after the beginning of QRS complex. A new ventricular lead was then implanted in the outflow tract of the right ventricle, resulting in normal ventricular sensing function. At the time of intervention, the amplitude of the spontaneous ventricular signal recorded from the old ventricular lead was 2.8 mV. In this patient, no true undersensing occurred although ventricular stimuli were delivered 140 ms after the beginning of spontaneous QRS complexes when the system was in DDD mode: the cause of the apparent pacemaker malfunction was the extremely prolonged ventricular depolarization. Due to fibrofatty muscle replacement, the depolarization wavefront reached the ventricular muscle surrounding the pacemaker lead with such a delay that at the end of the programmed sensed AV interval (320 ms) the ventricular EGM had not yet attained the sensing threshold. This apparent undersensing should, thus, be defined as "late sensing."     

Melanoacanthoma Simulating Pigmented Spitz Nevus: an Unusual Dermoscopy Pitfall

BACKGROUND: The starburst pattern is the dermoscopic hallmark of pigmented Spitz nevus, although it has been rarely observed in melanoma as well. OBJECTIVE: To describe a case of melanoacanthoma simulating pigmented Spitz nevus. MATERIAL AND METHODS: Clinical, dermoscopic, and histopathologic examinations were performed for the occurrence of a 4-mm pigmented skin lesion on the hip of a 38-year-old Caucasian woman. RESULTS: Dermoscopy examination of the lesion disclosed a stereotypical starburst pattern characterized by pigmented streaks symmetrically distributed at the periphery. A preoperative diagnosis of pigmented Spitz nevus was made, and the lesion was excised. However, subsequent histopathologic examination revealed a melanoacanthoma. CONCLUSION: The starburst pattern, although diagnostic for pigmented Spitz nevus, can be rarely observed in other benign or malignant pigmented skin lesions. Accordingly, all lesions in adults exhibiting a starburst pattern or other spitzoid features should be excised for histopathologic evaluation.