The applications of Wearable Cardioverter Defibrillators in Heart Failure and beyond.

Abstract: Wearable cardioverter defibrillator has revealed a crucial device both in patients with a clear indication of ICD implantation but with temporary contraindications or in expectation of a diagnosis, considering that its use should be individualized.

The potential impact of acute coronary syndromes on automatic sensing system in Subcutaneous-ICDs.

BACKGROUND: The Subcutaneous-ICD (S-ICD) is emerging as a suitable option for most ICD candidates, however some open issues regarding the sensing algorithm still remain. OBJECTIVES: We aimed to examine the performance of the S-ICD sensing algorithm in patients hospitalized for ST elevation myocardial infarction (STEMI), non ST elevation acute coronary syndrome (NSTE-ACS) or chronic coronary syndrome (CCS), before and after revascularization. METHODS: We performed a S-ICD automated screening on 75 patients, 21 hospitalized for STEMI, 23 for NSTE-ACS and 31 for CCS, before and after percutaneous revascularization, regardless their eligibility to ICD implantation. RESULTS: Patients did not differ in clinical, electrocardiographic and echocardiographic parameters. Rates of screening pass were significantly lower in STEMI patients compared to NSTE-ACS and CCS (5% vs 56.7% vs 81% respectively, p < .0001). The viability of the primary vector was lower in STEMI patients compared to NSTE-ACS and CCS (33% vs 56% vs 71%, p .027 respectively). After revascularization, there were no more significant differences between groups. Pairing subjects at baseline and after revascularization, STEMI subjects percentages of screening success were respectively 5% and 81% (p < .001) and the rates of primary vector viability were 33% and 81% (p .002). STEMI was the only independent predictor of screening failure at multivariate logistic regression analysis (odds ratio 10.68 confidence interval 2.77-41.38, p = .001). CONCLUSION: The performance of the S-ICD and possible malfunction detections in the context of an acute ischemic event deserve further evaluation. Adequate patient selection and the development of dynamic device programming are warranted.

Endothelial dysfunction as assessed by flow-mediated dilation in patients with cardiac syndrome X: role of inflammation.

BACKGROUND: Endothelial dysfunction, reduced coronary flow reserve and increased markers of inflammation are detectable in cardiac syndrome X (CSX). In this study we investigated the relation between inflammation and systemic endothelial function in CSX patients. METHODS: We studied 42 CSX patients (55 +/- 6 years, 14 men) and 20 healthy subjects (52 +/- 7 years, 9 men). Systemic endothelial function was assessed by flow-mediated dilation (FMD) of the brachial artery after 5-minute of forearm cuff inflation. Serum C-reactive protein (CRP) was measured by a high-sensitivity method. RESULTS: FMD was significantly lower in CSX patients compared to controls (4.8 +/- 4.4 vs. 13.7 +/- 4%, p < 0.001), whereas CRP levels were higher in CSX patients than in controls (2.7 +/- 2.4 vs. 0.7 +/- 0.4 mg/L, p = 0.001). In CSX patients FMD showed a significant inverse correlation with CRP levels, even after adjustment for potentially confounding variables (r = -0.34, p = 0.006). CONCLUSION: An impaired FMD is detectable in CSX patients, suggesting a generalized abnormality in vascular function. Subclinical inflammation se is to play a significant role in the impairment of endothelium-dependent vasodilator function of these patients.