3D Echo in Routine Clinical Practice - State of the Art in 2019.

Three-dimensional (3D) echo has been around for almost five decades. Recent advances in ultrasound, electronic and computing technologies have moved 3D echo from the research environment to everyday clinical practice. Real time 3D echo and full volume acquisition are now possible with transthoracic as well as transoesophageal probes. The main advantages of 3D echo are the infinite cut planes possible, allowing direct, en face, and anatomical views of cardiac structures, avoiding foreshortening and circumventing the geometric assumptions of the cardiac chambers inherent in any 2D echo techniques. Three-dimensional echo is still dependent on image quality, subjected to ultrasound artifacts and faces the compromise between spatial and temporal resolution. In routine clinical practice in 2019, we recommend a focussed 3D examination after a full 2D echo study. The area where 3D echo has been consistently shown to have superior accuracy and reproducibility over 2D echo is in the assessment of left ventricular (LV) volumes and ejection fraction. We recommend obtaining a full volume 3D echo data set from the apical window, from which LV volumes and LV global longitudinal strain can be measured. Further 3D examination can be performed depending on the pathologies identified on 2D examination. Three-dimensional echo is superior to 2D echo in the assessment of mitral valve pathologies and atrial septal defects. Furthermore, real time 3D transoesophageal echo is a very useful technique in guiding structural cardiac intervention, both before, during and after the procedure. While 3D echo is not the holy grail of echocardiography, it does represent a useful technique in selected areas of cardiac imaging.

An Unexpected Cause of Heart Failure in a Young Woman With Treated Lymphoma.

Arteriovenous fistula is a rare complication of lumbar surgery that may cause high-output cardiac failure. We describe the case of a patient with treated lymphoma and recent spinal surgery who presented with heart failure. Logical deduction from clinical and imaging findings helped us arrive at this unusual diagnosis. (Level of Difficulty: Intermediate.).

Non-inferiority trials in cardiology: what clinicians need to know.

Clinical trials traditionally aim to show a new treatment is superior to placebo or standard treatment, that is, superiority trials. There is an increasing number of trials demonstrating a new treatment is non-inferior to standard treatment. The hypotheses, design and interpretation of non-inferiority trials are different to superiority trials. Non-inferiority trials are designed with the notion that the new treatment offers advantages over standard treatment in certain important aspects. The non-inferior margin is a predetermined margin of difference between the new and standard treatment that is considered acceptable or tolerable for the new treatment to be considered 'similar' or 'not worse'. Both relative difference and absolute difference methods can be used to define the non-inferior margin. Sequential testing for non-inferiority and superiority is often performed. Non-inferiority trials may be necessary in situations where it is no longer ethical to test any new treatment against placebo. There are inherent assumptions in non-inferiority trials which may not be correct and which are not being tested. Successive non-inferiority trials may introduce less and less effective treatments even though these treatments may have been shown to be non-inferior. Furthermore, poor quality trials favour non-inferior results. Intention-to-treat analysis, the preferred way to analyse randomised trials, may favour non-inferiority. Both intention-to-treat and per-protocol analyses should be recommended in non-inferiority trials. Clinicians should be aware of the pitfalls of non-inferiority trials and not accept non-inferiority on face value. The focus should not be on the p values but on the effect size and confidence limits.

An Unusual Cause of an Uncommon Condition: Pulmonary Vein Stenosis.

Pulmonary vein stenosis in adults is historically a rare condition, but is becoming a recognised complication, albeit an uncommon one, of radiofrequency ablation around the pulmonary veins for treatment of atrial fibrillation. It may also be due to infiltrating mediastinal processes such as neoplasm or sarcoidosis. In this case report, a 55-year old man underwent resection of a mediastinal phaeochromocytoma involving the left atrial wall and the right inferior pulmonary vein. One year later he subsequently presented with increasing dyspnoea and atypical chest pain. Transthoracic echocardiogram showed severe pulmonary hypertension, right ventricular dilatation and dysfunction. Transesophageal echocardiogram demonstrated severe bilateral pulmonary vein stenosis with peak/mean gradients across the left pulmonary veins of about 25/20mmHg. The diagnosis was also confirmed on CT pulmonary angiography with 3D reconstruction. Open pulmonary vein stenting was planned but unfortunately the patient died suddenly before the procedure. Pulmonary vein stenosis is an uncommon but serious condition and may present with signs and symptoms indistinguishable from other conditions and may easily be missed. Clinicians should have a high index of suspicion when patients present with unexplained respiratory symptoms, especially in the context of catheter ablation or mediastinal processes such as neoplasm. Transesophageal echocardiography played an indispensible part in the correct diagnosis in our patient.