Is syncope a risk predictor in the general population?

Syncope in the general population is a frequent event often leading to hospitalization, but it is unclear whether syncope in the general population is an independent risk marker for adverse prognosis. In this review, we investigate the current literature and evaluate the prognosis and impact of syncope on adverse outcomes including death and recurrences across different populations with focus on the general population. In wide terms, a syncopal event is related to a higher risk of subsequent falls and injury and cardiac syncope is particularly associated with increased mortality as compared to non-cardiac syncope. The overall prognosis in the general population is by large determined by the underlying presence and severity of a given cardiac disease, but a given underlying cardiac disease can very well be unknown at the time of first syncope so that syncope is the presenting symptom resulting in an independent risk increase. Moreover, syncope is a significant risk predictor of a recurrence across populations. It is im­portant to recognize several risk factors associated with adverse outcome in order to safely navigate in a population where most patients with syncope are healthy and low-risk but where a small number of patients have life-threatening conditions. Further research in the general population should attempt to categorize which patients with syncope need immediate referral and diagnostic testing, and whether this affects the outcome

The learning curve associated with the introduction of the subcutaneous implantable defibrillator

Aims: The subcutaneous implantable cardioverter defibrillator (S-ICD) was introduced to overcome complications related to transvenous leads. Adoption of the S-ICD requires implanters to learn a new implantation technique. The aim of this study was to assess the learning curve for S-ICD implanters with respect to implant-related complications, procedure time, and inappropriate shocks (IASs). Methods and results: In a pooled cohort from two clinical S-ICD databases, the IDE Trial and the EFFORTLESS Registry, complications, IASs at 180 days follow-up and implant procedure duration were assessed. Patients were grouped in quartiles based on experience of the implanter and Kaplan-Meier estimates of complication and IAS rates were calculated. A total of 882 patients implanted in 61 centres by 107 implanters with a median of 4 implants (IQR 1,8) were analysed. There were a total of 59 patients with complications and 48 patients with IAS. The complication rate decreased significantly from 9.8% in Quartile 1 (least experience) to 5.4% in Quartile 4 (most experience) (P = 0.02) and non-significantly for IAS from 7.9 to 4.8% (P = 0.10). Multivariable analysis demonstrated a hazard ratio of 0.78 (P = 0.045) for complications and 1.01 (P = 0.958) for IAS. Dual-zone programming increased with experience of the individual implanter (P 13 implants). Conclusion: There is a short and significant learning curve associated with physicians adopting the S-ICD. Performance stab

Are Compression Stockings an Effective Treatment for Orthostatic Presyncope?

Syncope, or fainting, affects approximately 6.2% of the population, and is associated with significant comorbidity. Many syncopal events occur secondary to excessive venous pooling and capillary filtration in the lower limbs when upright. As such, a common approach to the management of syncope is the use of compression stockings. However, research confirming their efficacy is lacking. We aimed to investigate the effect of graded calf compression stockings on orthostatic tolerance

Subcutaneous or Transvenous Defibrillator Therapy.

BACKGROUND: The subcutaneous implantable cardioverter-defibrillator (ICD) was designed to avoid complications related to the transvenous ICD lead by using an entirely extrathoracic placement. Evidence comparing these systems has been based primarily on observational studies. METHODS: We conducted a noninferiority trial in which patients with an indication for an ICD but no indication for pacing were assigned to receive a subcutaneous ICD or transvenous ICD. The primary end point was the composite of device-related complications and inappropriate shocks; the noninferiority margin for the upper boundary of the 95% confidence interval for the hazard ratio (subcutaneous ICD vs. transvenous ICD) was 1.45. A superiority analysis was prespecified if noninferiority was established. Secondary end points included death and appropriate shocks. RESULTS: A total of 849 patients (426 in the subcutaneous ICD group and 423 in the transvenous ICD group) were included in the analyses. At a median follow-up of 49.1 months, a primary end-point event occurred in 68 patients in the subcutaneous ICD group and in 68 patients in the transvenous ICD group (48-month Kaplan-Meier estimated cumulative incidence, 15.1% and 15.7%, respectively; hazard ratio, 0.99; 95% confidence interval [CI], 0.71 to 1.39; P = 0.01 for noninferiority; P = 0.95 for superiority). Device-related complications occurred in 31 patients in the subcutaneous ICD group and in 44 in the transvenous ICD group (hazard ratio, 0.69; 95% CI, 0.44 to 1.09); inappropriate shocks occurred in 41 and 29 patients, respectively (hazard ratio, 1.43; 95% CI, 0.89 to 2.30). Death occurred in 83 patients in the subcutaneous ICD group and in 68 in the transvenous ICD group (hazard ratio, 1.23; 95% CI, 0.89 to 1.70); appropriate shocks occurred in 83 and 57 patients, respectively (hazard ratio, 1.52; 95% CI, 1.08 to 2.12). CONCLUSIONS: In patients with an indication for an ICD but no indication for pacing, the subcutaneous ICD was noninferior to the transvenous ICD with respect to device-related complications and inappropriate shocks. (Funded by Boston Scientific; PRAETORIAN ClinicalTrials.gov number, NCT01296022.)

Two-incision technique for implantation of the subcutaneous implantable cardioverter-defibrillator

Three incisions in the chest are necessary for implantation of the entirely subcutaneous implantable cardioverter-defibrillator (S-ICD). The superior parasternal incision is a possible risk for infection and a potential source of discomfort. A less invasive alternative technique of implanting the S-ICD electrode--the two-incision technique--avoids the superior parasternal incision. The purpose of this prospective cohort study was to evaluate the safety and efficacy of the two-incision technique for implantation of the S-ICD. Consecutive patients who received an S-ICD between October 2010 and December 2011 were implanted using the two-incision technique, which positions the parasternal part of the S-ICD electrode using a standard 11Fr peel-away sheath. All patients were routinely evaluated for at least 1 year for complications and device interrogation at the outpatient clinic. Thirty-nine patients (46% male, mean age 44 ± 15 years) were implanted with a S-ICD using the two-incision technique. During mean follow-up of 18 months (range 14-27 months) no dislocations were observed, and there was no need for repositioning of either the ICD or the electrode. No serious infections occurred during follow-up except for 2 superficial wound infections of the pocket incision site. Device function was normal in all patients, and no inappropriate sensing occurred related to the implantation technique. The two-incision technique is a safe and efficacious alternative for S-ICD implantations and may help to reduce complications. The two-incision technique offers physicians a less invasive and simplified implantation procedure of the S-IC

Genetic aspects of vasovagal syncope: a systematic review of current evidence

Knowledge on the aetiology of vasovagal syncope (VVS) is of great importance to optimize its diagnostic and therapeutic options. To unravel the largely unknown pathophysiology, studies on genetic aspects of VVS can be of use. This systematic review on all available literature aims to provide an overview of the current knowledge of VVS genetics. The MEDLINE and EMBASE database were systematically searched for all studies discussing genetic factors as a cause of VVS. Hereditary aspects of VVS were studied in 19 studies. Six studies determined a positive family history in, respectively, 19-90% of the VVS patients. These numbers, however, are not higher than the cumulative incidence of VVS in the general population (35-39%). Four studies examined potential genetic polymorphisms associated with VVS. Only a Gly389 allele was more frequently present in VVS patients with a positive HUT test, although the significance level was set much higher than usual in genetic studies, and this result has not been replicated so far. Knowledge on genetic aspects of VVS could be very useful in clinical practice and research, but the current evidence that it has a genetic basis is not very stron

Inappropriate subcutaneous implantable cardioverter-defibrillator shocks due to T-wave oversensing can be prevented: implications for management

Inappropriate shocks (IASs) complicate implantable cardioverter-defibrillator (ICD) therapy. The management of IASs in patients with a subcutaneous ICD (S-ICD) differs from that in patients with a conventional ICD because of different sensing algorithms and programming options. To describe the management of IASs in patients with an S-ICD. Patients were implanted with an S-ICD between February 2009 and July 2012. The prevalence data and clinical determinants of IASs were prospectively collected. In the case of T-wave oversensing (TWOS), an exercise test was performed, and all possible sensing vectors were screened for TWOS. The absence of TWOS defined a suitable vector. Eleven of 69 patients (54% men; mean age 39 ± 14 years; 73% primary prevention) received IASs after 8.9 ± 10 months of implantation (10.8% annual incidence rate). In 8 cases, TWOS caused IASs. Seven of these IASs occurred during exercise and 1 during atrial fibrillation with a high ventricular rate. To manage TWOS, in 7 of 8 patients the sensing vector was changed and in 5 of 8 patients the (un)conditional zone was changed. Hereafter, IASs recurred in 3 of 8 patients, in 2 because of programming errors. Hence, after reprogramming, we observed no IASs in 87.5% of the patients with TWOS during a follow-up of 14.1 ± 13 months. IASs due to TWOS in the S-ICD can be managed by reprogramming the sensing vector and/or the therapy zones of the device using a template acquired during exercise. Exercise-optimized programming can reduce future IASs, and standard exercise testing shortly after the implantation of an S-ICD may be considered in patients at an increased risk for TWO

Prevalence of subcutaneous implantable cardioverter-defibrillator candidacy based on template ECG screening in patients with hypertrophic cardiomyopathy

Subcutaneous implantable cardioverter-defibrillator (S-ICD) is a promising option for patients with hypertrophic cardiomyopathy (HCM). Patients with HCM can present markedly abnormal electrocardiograms (ECGs), and there are no data on what percentage of patients with HCM fail the prerequisite S-ICD vector screening. The purpose of this study was to determine the failure rate of the prerequisite vector screening using 1 or 2 acceptable vectors stratified for risk profile for sudden cardiac death and predictors of failure. ECG recordings from consecutive patients with HCM simulating the S-ICD sensing vectors were analyzed with the S-ICD screening tool. Eligibility was defined by 1 or 2 appropriate vectors. Medical history, ultrasound characteristics, and 12-lead ECG characteristics were analyzed and the individual arrhythmic risk at 5 year was determined to study potential predictors of failure. One hundred sixty-five (118 men; mean age 51 ± 16 years) patients were analyzed. Twenty-two patients (13%) had a high risk of sudden cardiac death, 33 (20%) had intermediate to high risk, and 110 (67%) had low risk. Twenty-six patients (16%) had no suitable vector, including 8 of 22 high-risk patients (36%). The primary cause of failure was high T-wave voltages in 25% of the vectors analyzed. T-wave inversions in >2 leads on the surface 12-lead ECG (odds ratio 15.6; 95% confidence interval 4.9-50.3; P < .001) and prior myectomy (odds ratio 8.4; 95% confidence interval 2.1-33.1; P = .002) were significantly associated with screening failure in a multivariable model. Currently available preimplant screening algorithms recommended by the manufacturer are associated with a significant failure rate in patients with HCM, particularly in the high-risk subgrou

Implantable cardioverter-defibrillator harm in young patients with inherited arrhythmia syndromes: A systematic review and meta-analysis of inappropriate shocks and complications

Implantable cardioverter-defibrillators (ICDs) are implanted with the intention to prolong life in selected patients with inherited arrhythmia syndromes, but ICD implantation is also associated with inappropriate shocks and complications. We aimed to quantify the rate of inappropriate shocks and other ICD-related complications to be able to weigh benefit and harm in these patients. We performed a systematic review and meta-analysis of inappropriate shock and/or other ICD-related complication rates, including ICD-related mortality, in patients with inherited arrhythmia syndromes, that is, arrhythmogenic right ventricular cardiomyopathy/dysplasia, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, hypertrophic cardiomyopathy, dilated cardiomyopathy due to a mutation in the lamin A/C gene, long QT syndrome, and short QT syndrome. We searched MEDLINE and EMBASE from inception to May 30, 2014. Of 2471 unique citations, 63 studies comprising 4916 patients with inherited arrhythmia syndromes (mean age of 39 ± 15 years) were included. Inappropriate shocks occurred in 20% of patients (crude annual rate of 4.7% per year), with a significantly higher rate in studies published before 2008 (6.1% per year vs 4.1% per year). Moreover, 22% experienced ICD-related complications (4.4% per year) and there was a 0.5% ICD-related mortality (0.08% per year). ICD implantation carries a significant risk of inappropriate shocks and inhospital and postdischarge complications in relatively young patients with inherited arrhythmia syndromes. These data can be used to better inform patients and physicians about the expected risk of adverse ICD events and thereby facilitate shared decision makin