Aims This study was undertaken to evaluate the epidemiological features and the prognostic implications of syncope in young athletes. Methods and results A cohort of 7568 young athletes (5132 males, ...2436 females, aged 16.2±2.4) underwent a pre-participation evaluation. A syncopal spell in the last 5 years was reported by 474 athletes (6.2%). Syncope was unrelated with exercise in 411 athletes (86.7%), post-exertional in 57 (12.0%) and exertional in 6 (1.3%). All episodes of non-exertional or post-exertional syncope had the typical features of neurally-mediated fainting. The 6 athletes with exertional syncope underwent further testing allowing the diagnosis of hypertrophic cardiomyopathy in one case, and of right ventricular outflow tract tachycardia in another. The remaining 4 athletes only showed a positive response to tilt-testing. All athletes were followed for 6.4±3.1 years, during 48 066.6 person-years of follow-up. The recurrence rate was 20.3 per 1000 subject-years in athletes with non-exertional, and 19.2 per 1000 subject-years in athletes with post-exertional syncope. The incidence of first report of syncope was 2.2 per 1000 subject-years for non-exertional and 0.26 per 1000 subjects-years for post-exertional spells. No other adverse event was noted during follow-up. Conclusions In young athletes, syncope occurring before the initial pre-participation screening has a neurally-mediated origin in most cases and shows a low recurrence rate. Exercise-related syncope is infrequent and is not associated with an adverse outcome in subjects without cardiovascular abnormalities. The incidence of new syncope during competitive activity is particularly low.
Recently, the remote transmission of data detected by implantable loop recorders (ILRs) has become available. The aim of this study was to evaluate effectiveness and acceptance of remote monitoring ...in the clinical management of syncope and palpitations in patients with ILR.
Consecutive patients implanted with ILR (Reveal DX/XT Medtronic, Inc.) and followed up by means of remote monitoring (CareLink(®)) were included. The patients were requested to transmit the data stored in the ILR every week, via the CareLink system, or more frequently during the first period. Patient acceptance of ILR was evaluated by means of a questionnaire concerning physical and mental components. Forty-seven patients (27 males, average age 64 ± 19 years) were enrolled and followed up for 20 ± 13 weeks. Thirty-two patients (68%) had at least one ECG recording of a true relevant event. The mean time from ILR implantation to the first true relevant ECG was 28 ± 49 days, which was 71 ± 17 days less than in the clinical practice of 3-monthly in-office follow-up examinations. Thirty-eight patients (81%) had at least one false arrhythmic event, mainly false asystole and false fast ventricular tachycardia. In the absence of Carelink transmission, at least one episode of memory saturation of ILR would have occurred in 21 patients (45%) that would have limited the diagnostic yield. Patient compliance was good even though one-fifth had some minor psychological concern regarding the ILR implant. CareLink was well accepted and judged easy to use.
Remote monitoring enhances the diagnostic effectiveness of Reveal, limiting the risk of memory saturation due to the high number of false detections and reducing the time to diagnosis. Both ILR and CareLink were well accepted and well tolerated by the patients, as they were considered useful.
The purpose of this research was to evaluate the impact of athletic training and, in particular, physical deconditioning, on frequent and/or complex ventricular tachyarrhythmias assessed by 24-h ...ambulatory (Holter) electrocardiogram (ECG).
Sudden deaths in athletes are usually mediated by ventricular tachyarrhythmias.
Twenty-four hour ambulatory ECGs were recorded at peak training and after a deconditioning period of 19 ± 6 weeks (range, 12 to 24 weeks) in a population of 70 trained athletes selected on the basis of frequent and/or complex ventricular tachyarrhythmias (i.e., ≥2,000 premature ventricular depolarization PVD and/or ≥1 burst of non-sustained ventricular tachycardia NSVT/24 h).
A significant decrease in the frequency and complexity of ventricular arrhythmias was evident after deconditioning: PVDs/24 h: 10,611 ± 10,078 to 2,165 ± 4,877 (80% reduction; p < 0.001) and NSVT/24 h: 6 ± 22 to 0.5 ± 2, (90% reduction; p = 0.04). In 50 of the 70 athletes (71%), ventricular arrhythmias decreased substantially after detraining (to <500 PVDs/24 h and no NSVT). Most of these athletes with reduced arrhythmias did not have structural cardiovascular abnormalities (37 of 50; 74%). Over the 8 ± 4-year follow-up period, each of the 70 athletes survived without cardiac symptoms.
Frequent and/or complex ventricular tachyarrhythmias in trained athletes (with and without cardiovascular abnormalities) are sensitive to brief periods of deconditioning. In athletes with heart disease, the resolution of such arrhythmias with detraining may represent a mechanism by which risk for sudden death is reduced. Conversely, in athletes without cardiovascular abnormalities, reduction in frequency of ventricular tachyarrhythmias and the absence of cardiac events in the follow-up support the benign clinical nature of these rhythm disturbances as another expression of athlete's heart.
BARBARO, V., et al.: Do European GSM Mobile Cellular Phones Pose a Potential Risk to Pacemaker Patients? A series of in vivo trials were carried out in order to verify whether the electromagnetic ...field radiated by GSM (Groupe Systemes Mobiles) mobile cellular phones might affect implanted pacemakers. Two European GSM phones of 2‐watt power were tested and trials conducted on 101 pacemaker implanted outpatients attending day hospital for routine check‐up, who volunteered for trials. Forty‐three pacemaker models from 11 manufacturers were tested in all. When the sensing threshold of the pacemakers was set at a minimum and the antenna of the phone was in direct contact with the patient's chest, interference was detected for 26 implanted pacemakers. Specifically, pulse inhibition in 10 of 101 cases, ventricular triggering in 9 of 46 DDD‐VDD pacemakers, and asynchronous pacing in 4 of 52 devices. Pulse inhibition was also observed combined with asynchronous pacing in 1 of 52 cases and with ventricular triggering in 2 of 46 cases. Minimum effect duration was ca. 3 seconds but in 6 cases effects continued as long as the interfering GSM signal was on. No permanent malfunctioning or changes in the programmed parameters were detected. Whenever interference was detected, trials were repeated to determine the maximum sensing threshold at which interference persisted (with the antenna in contact with the skin over the pacemaker). Then maximum distance between antenna and pacemaker at which interference occurred was determined at pacemaker maximum and minimum sensing threshold. Under our experimental conditions electromagnetic interference effects were detected at a maximum distance of 10 cm with the pacemaker programmed at its minimum sensing threshold. When the phone antenna was in direct contact with patient's skin over the implant, electromagnetic interference effects occurred at maximum ventricular and atrial sensing thresholds of 4 mV and 2.5 mV, respectively.
Introduction: Approximately 1-2% of the adult population in developed countries is affected by heart failure. The costs of heart failure are enormous both in Europe and in the US and are expected to ...rise. New technologies and remote monitoring, are valid tools for the management and treatment of these patients.
Areas covered: This review aims to cover both implantable and non-implantable devices available for monitoring various hemodynamic parameters and clinical features of patients, as well as algorithms implemented in the new generation ICDs and CRTs capable of simultaneous acquisition and transmission of multiple parameters that indirectly evaluate clinical and/or hemodynamic status. Both internet and PubMed searches were used in order to acquire the most recent developments in the technology of the field.
Expert commentary: As new technology offers an enormous data flow, the key for success in the battle against heart failure and related hospitalizations is understanding the correct way of utilizing the data acquired and their importance for the treatment of each individual person.
Key Clinical Message
We report the first case of a patient in whom an implantable cardioverter‐defibrillator (ICD) endowed with HeartLogic, a novel algorithm for heart failure (HF) monitoring, was ...implanted in clinical practice. The good temporal association between HeartLogic index threshold crossings and HF hospitalizations confirms the high sensitivity in detecting gradual worsening of HF.
We report the first case of a patient in whom an implantable cardioverter‐defibrillator (ICD) endowed with HeartLogic, a novel algorithm for heart failure (HF) monitoring, was implanted in clinical practice. The good temporal association between HeartLogic index threshold crossings and HF hospitalizations confirms the high sensitivity in detecting gradual worsening of HF.
Atrial fibrillation (AF) is considered to be maintained by multiple reentrant circuits without or with a very short excitable gap. However, the possibility of local atrial capture has been shown ...recently in experimental AF or induced AF in humans.
This study was undertaken to evaluate the feasibility of atrial capture-suggestive of an excitable gap-in spontaneous chronic AF. Decremental pacing was performed in 47 right atrial sites in 14 patients with chronic AF, not taking antiarrhythmic drugs. A Franz catheter (for pacing and monophasic action potential recording) and a recording quadripolar catheter positioned about 10 mm apart were used. Local capture was achieved in 41 (87.2%) sites for a total of 100 captures. In 71 episodes the capture was lost within 15 seconds, while in the remaining 29, pacing was stopped after 15 seconds of stable capture. AF types immediately before capture were type 1 in 83 and type 2 in 17 episodes. Type 3 AF was never captured. Pacing cycle at capture was 175.7 +/- 20.9 ms. The baseline atrial interval (FF) was 185.4 +/- 24.5, significantly longer than the FF recorded during pacing immediately before capture (176.0 +/- 19.8 ms) (P < .02).
During spontaneous chronic AF in humans, (1) local capture by atrial pacing is possible up to at least 15 mm from the pacing site, (2) regional entrainment is possible during type 1 and type 2 AF but not type 3 AF, and (3) pacing before capture accelerates AF, probably by transient or local capture. These findings suggest that an excitable gap is present in chronic AF, therefore supporting the hypothesis that leading circle reentry is not the unique electrophysiological mechanism maintaining the arrhythmia.
Aims
Aim of this observational study is to evaluate the clinical performance of a Syncope Unit, in order to assess whether the implemented organization really improves syncope management.
Methods and ...results
The study enrolled patients with unexplained syncope who were consecutively referred to our Syncope Unit, either as outpatients or during hospitalization, in a 2-month period. The design of this observational study consists in three phases: a retrospective analysis of their clinical management in the 9 months prior to the first attendance at the Syncope Unit (phase one), their subsequent clinical management in the Syncope Unit (phase two) and a 9-month follow-up (phase three). The retrospective analysis of phase one showed that 25% of patients had already been hospitalized without diagnosis. After Syncope Unit evaluation, diagnosis was obtained in 82% of patients, with 15% of patients indicated to pacing. In the follow-up, 23% of patients experienced a syncopal recurrence. Our analysis indicated an 85% reduction of hospital costs in the follow-up period.
Conclusion
The clinical and economic analysis of the three phases of our study demonstrates that a Syncope Unit allows an improved management of patients with syncope.
External defibrillation is widely used for the termination of various atrial and ventricular tachyarrhythmias, including pacemaker patients. Our study was intended to evaluate the effects of DC ...shocks in 36 patients with unipolar pacemakers implanted in the right pectoral region (25 DDD, 10 VVI, 3 AAI). The shocks were delivered with paddles on the anterior surface of the thorax, as far as possible away from the pacemaker. The pacing output was programmed at 0.5 msec and 5 V (25 patients), 4 V (1 patient), and 2.5 V (10 patients). Transient loss of capture occurred in 18 patients (50%). These patients, compared with those without capture failure, received higher peak and cumulative shock energies, respectively, 216 ± 99 versus 123 ± 50 joules (P < 0.002) and 352 ± 62 versus 147 ± 98 joules (P < 0.004) and had a lower pacemaker pulse amplitude (4.0 ± 1.2 vs 4.6 ± 1.0 V, P = 0.11). Failure to capture lasted from 5 seconds to 30 minutes (mean 157 sec). In 15 patients the ventricular stimulation threshold was measured before and serially after cardioversion. A six‐fold threshold increase was observed 3 minutes after the shock (P < 0.004) with gradual recovery to nearly baseline values at 24 hours. Transient sensing failure occurred in 7 of the 17 patients in whom it could be evaluated (41%). Furthermore, three cases of shock induced pacemaker malfunctions were observed requiring replacement of the stimulator in two patients. In conclusion, the incidence of loss of capture in pacemaker patients subjected to electrical cardioversion/defibrillation is high. The phenomenon is due to an abrupt rise in stimulation threshold, caused by the electrical shock, and may represent a serious hazard in pacemaker dependent patients. The risk of pacing failure could be reduced by utilizing low shock energies when possible, and by programming the pacemaker at its maximal output before cardioversion.
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