Focused cardiac ultrasound is feasible in the general practice setting and alters diagnosis and management of cardiac disease.

BACKGROUND: Ultrasound-assisted examination of the cardiovascular system with focused cardiac ultrasound by the treating physician is non-invasive and changes diagnosis and management of patient's with suspected cardiac disease. This has not been reported in a general practice setting. AIM: To determine whether focused cardiac ultrasound performed on patients aged over 50 years changes the diagnosis and management of cardiac disease by a general practitioner. DESIGN AND SETTING: A prospective observational study of 80 patients aged over 50years and who had not received echocardiography or chest CT within 12months presenting to a general practice. METHOD: Clinical assessment and management of significant cardiac disorders in patients presenting to general practitioners were recorded before and after focused cardiac ultrasound. Echocardiography was performed by a medical student with sufficient training, which was verified by an expert. Differences in diagnosis and management between conventional and ultrasound-assisted assessment were recorded. RESULTS AND CONCLUSION: Echocardiography and interpretation were acceptable in all patients. Significant cardiac disease was detected in 16 (20%) patients, including aortic stenosis in 9 (11%) and cardiac failure in 7 (9%), which were missed by clinical examination in 10 (62.5%) of these patients. Changes in management occurred in 12 patients (15% overall and 75% of those found to have significant cardiac disease) including referral for diagnostic echocardiography in 8 (10%), commencement of heart failure treatment in 3 (4%) and referral to a cardiologist in 1 patient (1%).Routine focused cardiac ultrasound is feasible and frequently alters the diagnosis and management of cardiac disease in patients aged over 50years presenting to a general practice.

Ultrasound simulator-assisted teaching of cardiac anatomy to preclinical anatomy students: A pilot randomized trial of a three-hour learning exposure.

Ultrasound simulation allows students to virtually explore internal anatomy by producing accurate, moving, color, three-dimensional rendered slices from any angle or approach leaving the organs and their relationships intact without requirement for consumables. The aim was to determine the feasibility and efficacy of self-directed learning of cardiac anatomy with an ultrasound simulator compared to cadavers and plastic models. After a single cardiac anatomy lecture, fifty university anatomy students participated in a three-hour supervised self-directed learning exposure in groups of five, randomized to an ultrasound simulator or human cadaveric specimens and plastic models. Pre- and post-tests were conducted using pictorial and non-pictorial multiple-choice questions (MCQs). Simulator students completed a survey on their experience. Four simulator and seven cadaver group students did not attend after randomization. Simulator use in groups of five students was feasible and feedback from participants was very positive. Baseline test scores were similar (P = 0.9) between groups. After the learning intervention, there was no difference between groups in change in total test score (P = 0.37), whether they were pictorial (P = 0.6) or non-pictorial (P = 0.21). In both groups there was an increase in total test scores (simulator +19.8 ±12.4%% and cadaver: +16.4% ± 10.2, P < 0.0001), pictorial question scores (+22.9 ±18.0%, 19.7 ±19.3%, P < 0.001) and non-pictorial question scores (+16.7 ±18.2%, +13 ±15.4%, P = 0.002). The ultrasound simulator appears equivalent to human cadaveric prosections for learning cardiac anatomy.

Ultrasound-guided haemodynamic state assessment.

The haemodynamic state refers to the integration of myocardial and vascular systems, and involves both left and right hearts, and systolic and diastolic phases. The assessment of the haemodynamic state can be performed with echocardiography, and provides a higher level of diagnosis than conventional pressure- and flow-based monitoring. Whilst hypotension alerts the practitioner about the existence of haemodynamic abnormality, it does not provide sufficient information to identify the cause or the underlying haemodynamic state. The premise of haemodynamic state monitoring is that better diagnosis will lead to more rational therapy, which in turn may improve the outcome. The haemodynamic state can be classified into seven broad categories: normal, empty, vasodilation, systolic failure, primary diastolic failure, systolic and diastolic failure and right ventricular failure. These are identified as patterns based upon ventricular size, ventricular function and left atrial (LA) filling pressure. Patients may have an abnormal haemodynamic state (such a systolic failure), but may not need active treatment if they are haemodynamically stable. However, if treatment is required, it can be directed according to the underlying haemodynamic state. For example, a patient with systolic failure may benefit from inotrope support, whereas an empty state acquires volume infusion and vasodilation requires vasopressor support.

Epiaortic ultrasound assessment of the aorta in cardiac surgery.

The dislodgement of atheroma from the ascending aorta and proximal arch is a major cause of stroke and neurological injury following cardiac surgery. The accurate detection of atheroma prior to aortic manipulation is necessary to facilitate surgical strategies to reduce the risk of embolisation. The traditional method for atheroma detection is manual palpation by the surgeon. This technique misses about half the number of the atheroma lesions, as the soft (non-calcified) lesions offer little resistance to the surgeon's fingers. Trans-oesophageal echocardiography (TOE) is commonly used in cardiac surgery, but the interposition of the bronchus between the aorta and the oesophagus causes an ultrasound 'blind spot' in the ascending aorta and proximal arch, such that it does not offer improved detection compared to manual palpation. Accurate detection of atheroma requires direct ultrasound assessment using epiaortic scanning, with a high-frequency, linear-array probe. This allows the surgeon to correctly assess and localise any atheroma. In this article, a suggested epiaortic examination sequence is described and strategies for surgeons to avoid atheroma are discussed.

Persistent depression of contractility and vasodilation with propofol but not with sevoflurane or desflurane in rabbits.

BACKGROUND: Propofol, sevoflurane, and desflurane may cause hemodynamic compromise during anesthesia and critical care management. The aim of the study was to compare these anesthetics during increased dose and recovery to maintenance level. METHODS: Anesthetized, open-chest New Zealand White rabbits were used to acquire dose-response curves with sevoflurane, desflurane, and propofol, followed by reduction to baseline infusion. Simultaneous high-fidelity left ventricular pressure and volume data were acquired during caval occlusion with a dual-field conductance catheter inserted via an apical stab. The preload recruitable stroke work and the end-diastolic pressure-volume relationship were used as the primary measures of contractility and diastolic function. RESULTS: The time-matched controls were stable over time. Propofol and desflurane but not sevoflurane caused dose-dependent reductions in myocardial contractility, although sevoflurane reduced contractility more at 1 minimal alveolar concentration. All anesthetics reduced mean arterial pressure, and significant recovery occurred for sevoflurane and desflurane but not for propofol. The end-diastolic pressure-volume relationship was increased by sevoflurane. Ejection fraction decreased with sevoflurane only. All anesthetics caused dose-dependent vasodilation, with recovery for desflurane and sevoflurane but not propofol. Heart rate was decreased with propofol without significant recovery. Propofol plasma concentrations remained elevated after dose return to baseline infusion rate, suggestive of distribution compartment saturation. CONCLUSION: All three anesthetics caused dose-dependent decreases in cardiovascular function. Recovery of cardiovascular function occurred rapidly with sevoflurane and desflurane, but persistent depression of contractility, vasodilation, mean arterial pressure, and heart rate occurred with propofol during a 30-min recovery period.

Myocardial stiffness and the timing difference between tissue Doppler imaging Ea and peak mitral valve opening can distinguish physiological hypertrophy in athletes from hypertrophic cardiomyopathy.

AIM: To differentiate between physiological and pathological left ventricular hypertrophy in athletes using echocardiography. METHODS AND RESULTS: Eleven patients with mild hypertrophic cardiomyopathy were compared against 17 international rowers with mild left ventricular hypertrophy, and 30 age matched controls. The time difference between peak Ea (Doppler tissue imaging) and peak mitral valve opening (using M-mode) was measured simultaneously. A novel index (E/Ea)/LVEDD, as a measure of left ventricular stiffness was recorded. In athletes the peak Ea preceded peak mitral opening by: median (interquartile range) 20 ms (10,20), control group 15 ms (0,30), compared with HCM where Ea followed peak mitral opening by 10 ms (0,20), P<0.0001. In athletes the index of left ventricular stiffness was lower than controls 1.2 (0.93,1.4) versus 1.5 (1.3,1.6), and HCM 2.2 (2.0,2.3), P<0.0001. CONCLUSION: Physiological hypertrophy can be differentiated from hypertrophic cardiomyopathy in athletes using the Ea-peak mitral opening difference, and our index of ventricular stiffness.