210 research outputs found

    Samenspel op maat

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    Cough up your lungs

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    Isolated unilateral absence of a pulmonary artery: a case report and review of the literature

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    OBJECTIVE: The purpose of the present study was to determine the symptomatology, diagnostic procedures, and therapeutic strategies of patients with an isolated unilateral absence of a pulmonary artery (UAPA). BACKGROUND: Isolated UAPA is a rare anomaly. Some case reports exist, but the best diagnostic and therapeutic approaches to these patients remain unclear. METHODS: A retrospective analysis was made of 108 cases reported between 1978 and 2000. The database of the National Library of Medicine (MEDLINE) was used to identify cases that were published in any language from 1978 onward. RESULTS: Of the 108 patients identified, 14 were asymptomatic. The median age was 14 years (range, 0.1 to 58 years). Most patients had symptoms such as frequent pulmonary infections (37%), dyspnea or limited exercise tolerance (40%), or hemoptysis (20%). Pulmonary hypertension was present in 44% of the patients. Surgical procedures were performed in 17% of patients, and the overall mortality rate was 7%. CONCLUSION: Only a few patients with isolated UAPA remain asymptomatic during follow-up. The diagnosis can be made by chest radiograph, echocardiography, CT scan, and MRI. Hilar arteries can be shown by cardiac catheterization and pulmonary venous wedge angiography. This is important since revascularization may improve pulmonary hypertension. The avoidance of high altitudes and pregnancy may further improve outcomes

    The R" wave in V1 and the negative terminal QRS vector in aVF combine to a novel 12-lead ECG algorithm to identify slow conducting anatomical isthmus 3 in patients with tetralogy of Fallot

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    AimsPatients with repaired tetralogy of Fallot (rTOF) have an increased risk of ventricular tachycardia (VT), with slow conducting anatomical isthmus (SCAI) 3 as dominant VT substrate. In patients with right bundle branch block (RBBB), SCAI 3 leads to local activation delay with a shift of terminal RV activation towards the lateral RV outflow tract which may be detected by terminal QRS vector changes on sinus rhythm electrocardiogram (ECG).Methods and resultsConsecutive rTOF patients aged ≥16 years with RBBB who underwent electroanatomical mapping at our institution between 2017–2022 and 2010–2016 comprised the derivation and validation cohort, respectively. Forty-six patients were included in the derivation cohort (aged 40±15 years, QRS duration 165±23 ms). Among patients with SCAI 3 (n = 31, 67%), 17 (55%) had an R″ in V1, 18 (58%) had a negative terminal QRS portion (NTP) ≥80 ms in aVF, and 12 (39%) had both ECG characteristics, compared to only 1 (7%), 1 (7%), and 0 patient without SCAI, respectively.Combining R″ in V1 and/or NTP ≥80 ms in aVF into a diagnostic algorithm resulted in a sensitivity of 74% and specificity of 87% in detecting SCAI 3. The inter-observer agreement for the diagnostic algorithm was 0.875. In the validation cohort [n = 33, 18 (55%) with SCAI 3], the diagnostic algorithm had a sensitivity of 83% and specificity of 80% for identifying SCAI 3.ConclusionA sinus rhythm ECG-based algorithm including R″ in V1 and/or NTP ≥80 ms in aVF can identify rTOF patients with a SCAI 3 and may contribute to non-invasive risk stratification for VT.Cardiolog

    Enforcing Security and Safety with Proof-Carrying Code

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    AbstractIn an environment where more and more code cannot be trusted to behave safety it is becoming necessary to employ mechanisms for detecting and preventing unsafe program behavior. This paper first reviews various such mechanisms and then focuses on static mechanisms with an emphasis on Proof-Carrying Code and its expressiveness.Proof-Carrying Code is a technique that allows a code receiver to verify statically that the code has certain required properties, which are stated in the form of a safety policy. To make this possible the code is accompanied by a representation of an easily checkable formal proof of compliance with the safety policy. This paper discusses first the general properties of the Proof-Carrying Code technique and then explores a particular implementation of the idea using verification condition generators. As a surprising result we prove that by adopting such an implementation choice we limit ourselves to safety properties, which constitute but a subset (albeit a very important one) of all the interesting program properties. We further speculate on what it takes to extend Proof-Carrying Code to handle more that safety properties
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