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In this letter, a compact, wideband bandpass filter with 31% 3-dB bandwidth, with very sharp roll-off characteristics, low insertion loss of 0.45 dB, high return loss greater than 25 dB, and improved out-of-band performance, suitable for 2.4 GHz WLAN applications is presented. The developed prototype filter is based on a quadruple-mode square ring resonator, connected to two λg/2 short-circuited stubs. In order to improve the out-of-band performance and achieve a wider stopband response, two Γ-shaped band-stop sections are connected on the feeding lines without disturbing the geometric symmetry along the diagonal. Measurements of the fabricated prototype provide experimental verification of the theoretical and simulated behaviour of the proposed filter. [ABSTRACT FROM AUTHOR]

Reversed pulsus paradoxus was first described in 1973 as a rise in peak systolic pressure on inspiration in patients with idiopathic hypertrophic subaortic stenosis or isorhythmic ventricular rhythm and in patients with left ventricular systolic dysfunction on positive pressure ventilation. Positive pressure ventilation, for example, may impel blood from the pulmonary capillaries and venules into the left atrium. This may increase left ventricular preload and accelerate ventricular emptying, which in turn may cause the systolic arterial pressure to rise during inspiration. We observed this phenomenon in a patient with a large pericardial effusion, right ventricular failure, and pulmonary arterial hypertension, and we noted the lack of echocardiographic features of tamponade in the presence of right ventricular hypertrophy and pulmonary hypertension. This case report discusses the subsequent occurrence of acute congestive heart failure after pericardiocentesis. [ABSTRACT FROM AUTHOR]

Chronic critical limb ischemia (CLI) occurs when arterial perfusion is reduced below a threshold level that results in rest pain and/or tissue breakdown in the lower extremities. Importantly, it is associated with high cardiovascular morbidity and mortality. Without prompt revascularization, CLI may result in loss of a limb (i.e. amputation) and/or life. The goal of endovascular therapy is the re-establishment of pulsatile, straight-line flow to the distal extremity. Percutaneous transluminal angioplasty (PTA) has been shown to be effective and safe in the setting of CLI, with limb salvage rates that compare favorably with surgical procedures. Stents are indicated for failed PTA, while adjunctive therapies such as lasers, thermal angioplasty and atherectomy devices lack data demonstrating improved efficacy compared with conventional lower extremity interventions. In addition to successful revascularization, the institution of lifestyle changes, atherosclerotic risk factor modification, and pharmacologic therapies are indicated to reduce cardiovascular morbidity and mortality. [ABSTRACT FROM AUTHOR]

Studies have shown an association between left ventricular (LV) geometry and complex ventricular ectopic activity. Increased transmural dispersion of repolarization (TDR), which correlates to the interval from the peak to the end of the T wave (Tpe) on the surface electrocardiogram, is linked to ventricular tachyarrhythmias. The relation between LV geometry and TDR is unknown. The mean Tpe interval, measured from leads V1 to V3 of the surface electrocardiogram, was assessed in 300 patients (50% men) who had normal LV systolic function and QRS duration and were categorized into 3 equal groups, which were matched by age and gender, according to echocardiographically determined LV geometry (normal structure, concentric remodeling, and LV hypertrophy). The Tpe interval was corrected for the QT interval using Tpe/QTc and was compared among the 3 groups. Compared with those who had normal LV structure, the Tpe interval was significantly prolonged in those who had LV hypertrophy and significantly shortened in those who had concentric remodeling (p = <0.0001 for the 2 comparisons). Correcting for the QT interval using Tpe/QTc yielded similar results. Thus, TDR was increased in patients who had LV hypertrophy but decreased in concentric remodeling compared with those who had normal cardiac structure. Although LV hypertrophy represents a maladaptive geometric process that results in an unfavorable electrical substrate, concentric remodeling may represent a structural adaptation that has a more favorable electrical milieu. [Copyright &y& Elsevier]

Background The left renal vein (LRV) entrapment syndrome is a rare condition. Here, we present a 22-year-old female presenting with recurrent nausea, vomiting, weight loss and evidence of the LRV compression by the superior mesenteric artery and the abdominal aorta. Hemodynamic assessment confirmed a pressure gradient of > 3 mmHg between the LRV and the inferior vena cava. A self-expandable stent was then deployed in the LRV. Subsequent clinical follow-ups ensure full resolution of the patient's symptoms. Methods Multilingual search was performed in PubMed, Google scholar, Scielo, Korea Med and EMBASE with the medical subheadings “nutcracker syndrome”, “nutcracker phenomenon” and “compression vein syndrome” from January 1983 to September 2013. Results Review of the literature exhibited a plethora of individual case reports (291 citations). Importantly, few retrospective case series [5] comprising a total of 157 patients included successful endovascular interventions. Conclusion Endovascular therapy for nutcracker syndrome represents a safe and suitable treatment option, but prospective studies are needed to confirm these data. [ABSTRACT FROM AUTHOR]

A low-profile electronically reconfigurable WLAN band-notched dual port multiple-input multipleoutput (MIMO) antenna design for ultra-wideband applications has been presented. Antenna elements exhibit good impedance match (S11 ≤ -10 dB) over entire ultrawideband (3.1 to 10.6 GHz) spectrum. The decoupling structure is used to improve isolation (S12/S21) above 20 dB over entire UWB band. Moreover, reconfigurable band-notching is achieved by inserting PIN diodes along the inverted L-shaped slots, in each radiator. Notch at WLAN (5.5 GHz) frequency band is achieved by switching the PIN diode to 'OFF' state. The antenna design is fabricated as well as measured, and the results suggests that the proposed design with switchable WLAN band-notch characteristics is suitable candidate for ultra-wideband applications. [ABSTRACT FROM AUTHOR]

A novel dynamically reconfigurable bandpass filter (BPF) employing stepped-impedance resonators (SIRs) that can operate as either a single-band or a dual-band filter is demonstrated. The reconfigurable BPF uses four positive-intrinsic-negative (p-i-n) diodes as switching elements. With the four p-i-n diodes in the “OFF” state, the filter behaves as a low-loss (0.85 dB) single-band BPF with a passband around 2.45 GHz. The reconfigurable SIR filter can operate as a dual-band BPF with two center frequencies at 1.6 and 2.45 GHz. The diodes are dynamically set to the “ON” state in the presence of a 1.6-GHz RF signal that is received by an RF triggered power management unit (PMU), integrated on the back side of the microstrip filter in a dual-layer architecture. The RF triggered PMU consists of a planar inverted-F antenna, a high-efficiency voltage doubler rectifier (47% at −13 dBm) and an active dc-to-dc power booster. The rectified output voltage is used as the enabling voltage for the dc-to-dc power booster. This, in turn, provides the required dc power for the diodes biasing. The filter switches from single-band to dual-band when a wireless input RF signal (> −13 dBm) is received by the RF triggered PMU antenna. [ABSTRACT FROM AUTHOR]

Background: Out-of-hospital cardiac arrest (OHCA) is associated with high mortality. Current methods for predicting mortality post-arrest require data unavailable at the time of initial medical contact. We created and validated a risk prediction model for patients experiencing OHCA who achieved return of spontaneous circulation (ROSC) which relies only on objective information routinely obtained at first medical contact.Methods: We performed a retrospective evaluation of 14,892 OHCA patients in a large metropolitan cardiac arrest registry, of which 3952 patients had usable data. This population was divided into a derivation cohort (n = 2,635) and a verification cohort (n = 1,317) in a 2:1 ratio. Backward stepwise logistic regression was used to identify baseline factors independently associated with death after sustained ROSC in the derivation cohort. The cardiac arrest survival score (CASS) was created from the model and its association with in-hospital mortality was examined in both the derivation and verification cohorts.Results: Baseline characteristics of the derivation and verification cohorts were not different. The final CASS model included age >75 years (odds ratio [OR] = 1.61, confidence interval [CI][1.30-1.99], p < 0.001), unwitnessed arrest (OR = 1.95, CI[1.58-2.40], p < 0.001), home arrest (OR = 1.28, CI[1.07-1.53], p = 0.008), absence of bystander CPR (OR = 1.35, CI[1.12-1.64], p = 0.003), and non-shockable initial rhythm (OR = 3.81, CI[3.19-4.56], p < 0.001). The area under the curve for the model derivation and model verification cohorts were 0.7172 and 0.7081, respectively.Conclusion: CASS accurately predicts mortality in OHCA patients. The model uses only binary, objective clinical data routinely obtained at first medical contact. Early risk stratification may allow identification of more patients in whom timely and aggressive invasive management may improve outcomes. [ABSTRACT FROM AUTHOR]

Background: Acute influenza infection can trigger acute myocardial infarction, however, outcome of patients with acute myocardial infarction during influenza infection is largely unknown.Methods: Patients ≥18 years old with ST-elevation and non-ST-elevation myocardial infarction during January 2013-December 2014 were identified using the National Inpatient Sample. The clinical outcomes were compared among patients who had no respiratory infection to the ones with influenza and other viral respiratory infections using propensity score-matched analysis.Results: Of 1,884,985 admissions for acute myocardial infarction, acute influenza and other viral infections were diagnosed in 9,885 and 11,485 patients, respectively, accounting for 1.1% of patients. Acute myocardial infarction patients with concomitant influenza infection had a worse outcome than those with acute myocardial infarction alone, in terms of in-hospital case fatality rate, development of shock, acute respiratory failure, acute kidney injury, and higher rate of blood transfusion after propensity scores. The length of stay is also significantly longer in influenza patients with acute myocardial infarction, compared with patients with acute myocardial infarction alone. However, patients who developed acute myocardial infarction during other viral respiratory infection have a higher rate of acute respiratory failure but overall lower mortality rate, and are less likely to develop shock or require blood transfusion after propensity match. Despite presenting with acute myocardial infarction, less than one-fourth of patients with concomitant influenza infection underwent coronary angiography, but more than half (51.4%) required revascularization.Conclusion: Influenza infection is associated with worse outcomes in acute myocardial infarction patients, and patients were less likely to receive further evaluation with invasive coronary angiography. [ABSTRACT FROM AUTHOR]

The article presents the case study of a 60-year-old man with end-stage renal disease who developed hypotension during dialysis. The patient's medical history is explored who had hypertension, heart failure with preserved ejection fraction, atrial fibrillation, and recurrent methicillin-sensitive Staphylococcus aureus mitral endocarditis with embolic stroke. The patient was diagnosed with ruptured aortic pseudoaneurysm and underwent pseudoaneurysm resection and aortic reconstruction.

The use of the Impella 2.5 liter (L) device for hemodynamic support has been well described. The typical access site for the Impella 2.5 L device is the femoral artery. The use of the axillary and subclavian artery has been described via surgical cut down for the Impella 5 L device when femoral artery access is not possible. In patients with severe aortoiliac disease and difficult anatomy the femoral artery access for the Impella 2.5 L device is not feasible. We describe the successful percutaneous use of the Impella 2.5 L device for hemodynamic support via the left axillary artery in 2 patients undergoing high-risk PCI with concomitant severe aortoiliac disease. (J Interven Cardiol 2012;25:210-213) [ABSTRACT FROM AUTHOR]