Background: The Subcutaneous ICD (S-ICD) is safe and effective for sudden cardiac death prevention. However, patients in previous S-ICD studies had fewer comorbidities, less left ventricular dysfunction and received more inappropriate shocks (IAS) than in typical transvenous (TV)-ICD trials. The UNTOUCHED trial was designed to evaluate the IAS rate in a more typical, contemporary ICD patient population implanted with the S-ICD using standardized programming and enhanced discrimination algorithms. Methods: Primary prevention patients with left ventricular ejection fraction (LVEF) ≤ 35% and no pacing indications were included. Generation 2 or 3 S-ICD devices were implanted and programmed with rate-based therapy delivery for rates ≥ 250 beats per minute (bpm) and morphology discrimination for rates ≥200 and < 250 bpm. Patients were followed for 18 months. The primary endpoint was the IAS free rate compared to a 91.6% performance goal, derived from the results for the ICD-only patients in the MADIT-RIT study. Kaplan-Meier analyses were performed to evaluate event-free rates for IAS, all cause shock, and complications. Multivariable proportional hazard analysis was performed to determine predictors of endpoints. Results: S-ICD implant was attempted in 1116 patients and 1111 patients were included in post-implant follow-up analysis. The cohort had a mean age of 55.8±12.4 years, 25.6% women, 23.4% black race, 53.5% with ischemic heart disease, 87.7% with symptomatic heart failure and a mean LVEF of 26.4±5.8%. Eighteen-month freedom from IAS was 95.9% (Lower confidence limit LCL 94.8%). Predictors of reduced incidence of IAS were implanting the most recent generation of device, using the three-incision technique, no history of atrial fibrillation, and ischemic etiology. The 18-month all cause shock free rate was 90.6% (LCL 89.0%), meeting the prespecified performance goal of 85.8%. Conversion success rate for appropriate, discrete episodes was 98.4%. Complication free rate at 18 months was 92.7%. Conclusions: This study demonstrates high efficacy and safety with contemporary S-ICD devices and programming despite the relatively high incidence of co-morbidities in comparison to earlier S-ICD trials. The inappropriate shock rate (3.1% at one year) is the lowest reported for the S-ICD and lower than many TV ICD studies using contemporary programming to reduce IAS. Clinical Trial Registration: URL https://clinicaltrials.gov Unique Identifier NCT02433379
A new SCN5A-related cardiac syndrome, MEPPC, was identified. The SCN5A mutation leads to a gain of function of the sodium channel responsible for hyperexcitability of the fascicular-Purkinje system. The MEPPC syndrome is responsive to hydroquinidine.
Backgroung: Brugada Syndrome (BrS) is an arrhythmogenic disease associated with sudden
Objective: To assess the mechanisms through which an enlarged aortic root may facilitate right to left shunting through a patent foramen ovale. Patients: 19 patients with the platypnoea-orthodeoxia syndrome (POS) were compared with 30 control patients without platypnoea. Interventions: Multiplane transoesophageal echocardiography. Main outcome measures: The aortic root diameter, atrial septal dimension behind the aortic root, and amplitude of the phasic oscillation of the septum were measured. Four groups of patients were compared: 12 platypnoeic patients with a dilated aortic root (POS-D), 7 platypnoeic patients with a normal aortic root (POS-N), 15 control patients with a dilated aortic root (CONT-D), and 15 control patients with a normal aortic root (CONT-N). Results: In POS-D and CONT-D patients, the apparent atrial septal dimension was 16.3 (2.7) mm and 17.4 (5.9) mm respectively, compared with 24.4 (5.2) mm in POS-N patients and 25 (4) mm in CONT-N (p , 0.005). Furthermore, the amplitude of septal oscillation was 14.7 (2.5) mm in the POS-D group versus 5.8 (2.4) mm in CONT-N (p , 0.001) compared with 23.3 (3) mm in seven patients with an atrial septal aneurysm (p ,0.001). Conclusion: Patients with an enlarged aorta have an apparently smaller dimension and increased mobility of the atrial septum. These findings appear to result from compression by the aortic root and decreased septal tautness. Consequently, a ''spinnaker effect'' with the inferior vena caval flow may take place, opening the foramen ovale and leading to sustained right to left shunting.A patent foramen ovale (PFO) is a defect in the atrial septum that results from incomplete fusion of the septum primum to the septum secundum. The persistence of a PFO into adulthood may lead to several complications, including paradoxical embolism of thrombus, air or tumoural material, and refractory hypoxaemia.Normally, even if a potential channel between the atria remains, the higher left atrial pressure keeps the flap-like valve of the foramen ovale opposed to the septum secundum. Most cases of sustained right to left shunting through a PFO are seen in situations where right atrial pressure exceeds that of the left, forcing open the potentially patent foramen ovale.However, right to left shunting can be less often observed in the absence of any demonstrable pressure gradient between right and left atria. Right to left shunting despite normal right atrial pressure has been reported after right pneumonectomy 1 2 or in association with venous embryonic remnants. 3 4 In these situations, an altered relation between the caval veins and the atrial septum presumably accounts for flow related rather than pressure related shunting.A few cases of aneurysm of the ascending aorta associated with right to left shunting across a PFO have been reported, 5-10 but evidence for a non-fortuitous association is still lacking. Therefore, we conducted a study to further analyse factors facilitating right to left shunting in patients with PFO, with particular attention paid to t...
AimsThe purpose of the present study was too explore the role of interatrial dyssynchrony in heart failure with preserved ejection fraction (HFPEF). Methods and resultsFor the case study we selected seven patients with severe HFPEF, with interatrial block on electrocardiogram (ECG), and a delayed and interrupted A wave on mitral Doppler. Echocardiographic left atrial (LA) volumes/functions, mitral E/A and E/e' ratios, mitral A wave duration/deceleration time, and interatrial mechanical delays (IAMDs) at tissue Doppler, were studied. We performed right heart catheterization, and an electrophysiological study (EPS) for the measurement of interatrial conduction delay (IACD) and left atrioventricular interval (LAVI). Mean IAMD was 106 ms. All the patients exhibited a restrictive mitral Doppler pattern, high E/A and E/e' ratios, and short A wave duration/deceleration time. Left atrial volume was increased, with severely depressed functions. Right heart catheterization showed severe post-capillary pulmonary hypertension. The EPS showed an IACD of 170 + 20 ms, with a short LAVI. Left atrial pacing through the coronary sinus reduced the IACD to 25 + 15 ms. In the pilot study, 29 patients with HFPEF were compared with 27 age-matched control patients. HFPEF patients had longer P waves, shorter A waves, and a longer IAMD than the controls. Prevalence of severe IAMD .60 ms was 59% in HFPEF and 0% in controls. In the HFPEF group, patients with an IAMD .60 ms had significantly shorter A waves and higher E/e' ratio. ConclusionSome HFPEF patients present with IACD, delayed LA systole, shortened LA emptying, decreased LA compliance, and increased filling pressures. Whether the condition of these patients could be improved by atrial resynchronization deserves further investigation.--
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