Extravascular lung water (EVLW) is a key variable in heart failure management and prognosis, but its objective assessment remains elusive. Lung imaging has been traditionally considered off-limits for ultrasound techniques due to the acoustic barrier of high-impedance air wall. In pulmonary congestion however, the presence of both air and water creates a peculiar echo fingerprint. Lung ultrasound shows B-lines, comet-like signals arising from a hyper-echoic pleural line with a to-and-fro movement synchronized with respiration. Increasing EVLW accumulation changes the normal, no-echo signal (black lung, no EVLW) into a black-and-white pattern (interstitial sub-pleural oedema with multiple B-lines) or a white lung pattern (alveolar pulmonary oedema) with coalescing B-lines. The number and spatial extent of B-lines on the antero-lateral chest allows a semi-quantitative estimation of EVLW (from absent, ≤5, to severe pulmonary oedema, >30 B-lines). Wet B-lines are made by water and decreased by diuretics, which cannot modify dry B-lines made by connective tissue. B-lines can be evaluated anywhere (including extreme environmental conditions with pocket size instruments to detect high-altitude pulmonary oedema), anytime (during dialysis to titrate intervention), by anyone (even a novice sonographer after 1 h training), and on anybody (since the chest acoustic window usually remains patent when echocardiography is not feasible). Cardiologists can achieve much diagnostic gain with little investment of technology, training, and time. B-lines represent ‘the shape of lung water’. They allow non-invasive detection, in real time, of even sub-clinical forms of pulmonary oedema with a low cost, radiation-free approach.

Exposure to medical radiation Use of radiation for medical examinations and tests is the largest manmade source of radiation exposure. The biological effect of radiation dose received is expressed in milliSievert (mSv). According to the latest estimation of the United Nations, an average of 2.4 mSv/year comes from natural sources.1 The medical sources of radiation were about one fifth of the natural radiation in 1987,2 close to half in 1993,3 and almost 100% of natural radiation in 1997 in most affluent countries (fig 1).4 In 1997, the German Federal Office for Radiation Protection reported 136 million x ray examinations and 4 million nuclear medicine diagnostic tests, resulting in a mean effective dose of 2.15 mSv per person per year.4 View larger version: In this window In a new window Fig 1 Medical and natural sources of radiation 3 Dimensional reconstruction of child's head from computed tomography data Credit: PHILLIPPE PLAILLY/SPL The use of procedures with a high load of radiation continues to grow steadily.5 The medical sources of radiation in industrialised countries may therefore soon be greater than natural sources. Ivan Illich wrote in 1976 (at the beginning of the imaging era): “Act so that the effect of your action is compatible with the permanence of genuine human life. Very concretely applied this could mean: Do not raise radiation levels unless you know that this action will not be visited upon your grandchild.”6 The contemporary practice of imaging seems to ignore this sound advice.

Embolism of cardiac origin accounts for around 15-30% of ischaemic strokes. Strokes due to cardioembolism are generally severe and early and long-term recurrence and mortality are high. The diagnosis of a cardioembolic source of stroke is frequently uncertain and relies on the identification of a potential cardiac source of embolism in the absence of significant autochthone cerebrovascular occlusive disease. In this respect, echocardiography (both transthoracic and/or transoesophageal) serves as a cornerstone in the evaluation, diagnosis, and management of these patients. A clear understanding of the various types of cardiac conditions associated with cardioembolic stroke and their intrinsic risk is therefore very important. This article reviews potential cardiac sources of embolism and discusses the role of echocardiography in clinical practice. Recommendations for the use of echocardiography in the diagnosis of cardiac sources of embolism are given including major and minor conditions associated with the risk of embolism.

The most commonly prescribed oral anticoagulants worldwide are the vitamin K antagonists (VKAs) such as warfarin. Factors affecting the pharmacokinetics of VKAs are important because deviations from their narrow therapeutic window can result in bleedings due to over-anticoagulation or thrombosis because of under-anticoagulation. In addition to pharmacodynamic interactions (e.g., augmented bleeding risk for concomitant use of NSAIDs), interactions with drugs, foods, herbs, and over-the-counter medications may affect the risk/benefit ratio of VKAs. Direct oral anticoagulants (DOACs) including Factor Xa inhibitors (rivaroxaban, apixaban and edoxaban) and thrombin inhibitor (dabigatran) are poised to replace warfarin. Phase-3 studies and real-world evaluations have established that the safety profile of DOACs is superior to those of VKAs. However, some pharmacokinetic and pharmacodynamic interactions are expected. Herein we present a critical review of VKAs and DOACs with focus on their potential for interactions with drugs, foods, herbs and over-the-counter medications.