Hypertension secondary to progressive vascular neurofibromatosis

A 4 year old girl with neurofibromatosis type 1 (NF1) was referred for hypertension. An aortogram showed narrowing of the left main renal artery. An angiogram three and a half years later showed coarctation of the abdominal aorta. She underwent aortoplasty but the stenosis recurred. Vascular involvement in NF1 may be progressive and requires long term follow up.     

Paradoxical embolization via a patent foramen ovale following acute pulmonary embolism

The foramen ovale is usually obliterated following establishment of the adult circulation but remains patent in 25% of individuals. This potential communication between the venous and arterial circulations can allow thromboembolic material to bypass the lungs and enter the systemic circulation. We report two cases of paradoxical embolization through a patent foramen ovale following acute large pulmonary embolism (PE) and discuss the factors that predispose to paradoxical embolization following PE.     

Rank‐based principal stratum sensitivity analyses

We describe rank‐based approaches to assess principal stratification treatment effects in studies where the outcome of interest is only well‐defined in a subgroup selected after randomization. Our methods are sensitivity analyses, in that estimands are identified by fixing a parameter and then we investigate the sensitivity of results by varying this parameter over a range of plausible values. We present three rank‐based test statistics and compare their performance through simulations, and provide recommendations. We also study three different bootstrap approaches for determining levels of significance. Finally, we apply our methods to two studies: an HIV vaccine trial and a prostate cancer prevention trial. Copyright © 2013 John Wiley & Sons, Ltd.     

Effect of treatment on systolic time intervals in systemic arterial hypertension

Twenty-six hypertensive patients and 25 control subjects were studied, and their systolic time intervals (STI) were measured. It was found that an alteration in STI, signifying left ventricular dysfunction, sets in most of the hypertensives earlier than any evidence of left ventricular hypertrophy (LVH) by clinical, radiological or electrocardiographic criteria. The parameters affected are the PEP interval which shows prolongation and PEP/LVET ratio which is increased. After treatment, the left ventricular performance was found to improve in those who did not reveal evidence of LVH. Thus, STI may be a sensitive indicator of early left ventricular dysfunction in hypertensives and a useful guide to assess improvement after treatment at a stage when other non-invasive methods are not so useful.