Accuracy of hand-carried ultrasound

Hand-carried ultrasound introduces a new group of devices, operators and usage patterns to echocardiography. This may have significant impact on the accuracy of the findings obtained with hand-carried ultrasound. Although reasonable agreement can be obtained with standard echocardiography in certain circumstances, limitations in imaging modes, device image quality, operator experience, and study completeness may significantly limit the diagnostic accuracy of hand carried ultrasound. Despite this, hand-carried ultrasound has the potential to improve significantly upon the data obtained by physical examination.     

Screening for left ventricular dysfunction using a hand-carried cardiac ultrasound device

BACKGROUND: The hand-carried cardiac ultrasound (HCU) device is a recently introduced imaging device, which may be potentially useful in the primary care setting. AIM: To test the screening potential of a HCU for the detection of left ventricular (LV) dysfunction by evaluating LV ejection fraction (LVEF) and inferior vena cava (IVC) collapse. Standard echocardiographic system (SE) and plasma brain natriuretic peptide (BNP) measurements were used as a reference. METHODS: Eighty-eight consecutive patients (56 male, aged 59+/-12 years) with suspected LV dysfunction were enrolled in the study. The HCU-LVEF was visually estimated and the SE-LVEF was derived by the Simpson's biplane method. A LVEF <40% represented LV dysfunction. An IVC collapse of <50% and BNP levels > or =15 pmol/l were considered abnormal. The correlation of HCU-LVEF, HCU-IVC and BNP to the SE-LVEF and SE-IVC was analysed independently using 2x2 tables. RESULTS: Six patients were excluded because of poor echo images. 19/82 patients had LV dysfunction. The HCU and BNP could identify 17 and 18 out of these 19 patients, respectively. The agreement for LVEF and IVC collapse between SE and HCU was 96% for both parameters. The sensitivity of IVC collapse, HCU-LVEF and BNP in identifying patients with LV dysfunction was 26, 89 and 94%, respectively. CONCLUSION: A HCU device can reliably be used as a screening tool for LV dysfunction.     

Italian chapter of the International Society of cardiovascular ultrasound expert consensus document on training requirements for noncardiologists using hand-carried ultrasound devices

Hand-carried ultrasound devices (HCDs), also named personal use echo, are pocket-size, compact, and battery-equipped echocardiographic systems. They have limited technical capabilities but offer some advantages compared with standard echocardiographic devices due to their simplicity of use, immediate availability at the patient's bedside, transportability, and relatively low cost. Current HCDs are considered as screening tools and are used to complement the physical examination by cardiologists. Many noncardiologic subspecialists, however, have adopted this technologic advancement rapidly raising the concern of an inappropriate use of HCD by health professionals who do not have any specific training. In keeping with the mission of the International Society of Cardiovascular Ultrasound to advance the science and art of cardiovascular ultrasound and encourage the knowledge of this subject, the purpose of this Expert Consensus document is to focus on the training for all health care professionals considering the use of HCD. Accordingly, this paper summarizes general aspects of HCD, such as technical characteristics and clinical indications, and then details the specific training requirements for noncardiologists (i.e., training program, minimum case load, duration, and certification of competence).     

A pilot study of the clinical impact of hand-carried cardiac ultrasound in the medical clinic

BACKGROUND: Small, hand-carried ultrasound devices have become widely available, making point-of-care echocardiograms (echos) accessible to all medical personnel as a means to augment and improve the increasingly inefficient physical examination. This study was designed to determine the clinical utility of hand-carried echo by medical residents in clinical decision making. METHODS: Nine residents underwent brief, practical echo training to perform and interpret a limited hand-carried echo as an integral component of their office examination. The residents' hand-carried echo consisting of four basic views to define left ventricular (LV) function and wall thickness, valvular disease, and any pericardial effusions was compared to one performed by a level III echocardiographer. RESULTS: Seventy-two consecutive medical clinic patients were enrolled with an average image acquisition time of 4.45 minutes. Residents obtained diagnostic images in 94% of the cases and interpreted them correctly 93% of the time. They correctly identified 92% of the major echo findings and 78% of the minor findings. Their diagnosis of LV dysfunction, valvular disease, and LV hypertrophy improved by 19%, 39%, and 14% with hand-carried echo compared to history and physical alone. Management decisions were reinforced in 76% and changed in 40% of patients with the use of hand-carried echo. CONCLUSION: This study demonstrates that it is possible to train medical residents to perform an effective and reasonably accurate hand-carried echo during their physical examination, which can impact clinical management.     

The Pocket Echocardiograph: Validation and Feasibility

Background: A new, miniaturized ultrasound device, the pocket echocardiograph (PE), is highly portable and can be carried inside a lab‐coat pocket. Studies of this device are limited and have not examined the use by novice echocardiographers. We hypothesize that a novice echocardiographer can use PE to produce interpretable cardiac images, and that both novice and expert echocardiographers can use PE to accurately quantify ejection fraction. Methods: Unselected subjects (n = 40) in an echocardiography laboratory underwent blinded formal transthoracic echocardiography (TTE) and PE (Acuson P10, Siemens, Mountain View, CA, USA). A cardiology fellow with 2 months of echocardiography training acquired PE images. The fellow and an experienced echocardiographer interpreted the PE studies offline in a blinded fashion. To assess adequacy, studies were graded as technically adequate, limited, or inadequate. A visual estimation of ejection fraction was made. Comparisons were made to the formal reported TTE. Results: Subjects were heterogeneous, 43% male; age 64 ± 17 years, and ejection fraction 52.4%± 12.3%. All PE studies were interpretable, and the vast majority of PE and TTE images were considered technically adequate (77.5% and 85% respectively; P = 0.32). Ejection fraction showed a good correlation, bias, and limits of agreement for the fellow's interpretation (r = 0.78, −5.9%, ±16.6%) with stronger association for the experienced echocardiographer (r = 0.88, −0.8%, ±11.4%). Conclusion: Novice echocardiographers using the PE can produce adequate quality images. Both expert and novice echocardiographers can use PE to quantify ejection fraction over a broad range of patients. The device's low cost and portability may greatly expand the availability of bedside echocardiography for routine or urgent cardiovascular assessment. (Echocardiography 2010;27:759‐764)     

The pocket echocardiograph: a pilot study of its validation and feasibility in intubated patients

Background: The clinical use of miniaturized echocardiograph devices is expanding due to the potential to rapidly assess cardiac function in the critically ill patient. Novice echocardiographers have used the pocket echocardiograph (PE) to estimate ejection fraction in ambulatory patients, but have not evaluated intubated patients. We hypothesize that a novice echocardiographer can use PE to acquire interpretable cardiac images, and provide an accurate tool for estimating ejection fraction. Methods: Subjects scheduled for cardiac surgery underwent blinded transesophageal echocardiography (TEE) and PE during a hemodynamically stable period after endotracheal intubation prior to incision. A single cardiology fellow acquired all PE images. The fellow and an experienced echocardiographer interpreted PE studies offline in a blinded fashion, visually estimating ejection fraction and assigning an image quality grade. Comparisons were made to the TEE study. Results: Subjects (n = 22) were 81% male; age 69 ± 9 years, and had a mean ejection fraction of 51%± 10.0%. Parasternal images were adequate in the vast majority of patients (77%), limited in 14%, and unacceptable in 9%, while apical (41%, 45%, and 14%) and subcostal (36%, 32%, and 32%) image quality was inferior. Ejection fraction showed fair correlation, bias, and limits of agreement for the fellow's interpretation (r = 0.50, 4.9%, ± 20.7%), with stronger association for the experienced echocardiographer (r = 0.76, 3.3%, ± 16.6%). Conclusion: A novice echocardiographer using PE can acquire interpretable images in the majority of intubated patients. Novice and expert echocardiographers can reasonably estimate ejection fraction using PE. PE may allow novice echocardiographers to rapidly assess cardiac function in intubated patients. (Echocardiography 2011;28:371‐377)     

Transesophageal echocardiographic evaluation of mechanical biventricular assist device

The usefulness of transesophageal echocardiography in the assessment of mechanical biventricular assist devices is described.     

Preimplant transthoracic echocardiographic assessment of continuous flow left ventricular assist device

For many patients with end-stage heart failure, heart transplantation is the only remaining option to prolong survival and provide symptom relief. Transthoracic echo is the modality of choice in assessing a patient for potential left ventricular assist device (LVAD) insertion. There are currently no guidelines available, and assessing this specific patient population can prove extremely challenging. As such, an understanding of LVAD mechanism, the important physiological consequences of device implantation together with the related echocardiographic examination is vital to accurately and effectively gauge correct patient selection and also improve implantation success. This review aims to highlight the common devices implanted, how these devices affect cardiac physiology and hemodynamics, and therefore discuss the major echocardiographic variables that should be assessed predevice implantation. (Echocardiography 2012;29:52-58).     

Rapid assessment of cardiac anatomy and function with a new hand-carried ultrasound device (OptiGo): a comparison with standard echocardiography.

AIMS: The aim of this study was to evaluate image quality and accuracy of a new hand-carried ultrasound device, OptiGo (Agilent Technologies) when compared to standard echocardiography in the setting of a focused examination in the assessment of cardiac anatomy and function. METHODS AND RESULTS:One-hundred and twenty-one patients were prospectively enrolled. Image quality and accuracy in assessment of chamber sizes, left ventricular (LV) wall thickness and contractility, right ventricular (RV) function, mitral and aortic leaflet thickening, mitral annular calcification, pericardial effusion and valvular regurgitation were assessed. Two-dimensional (2D) findings were graded on a four-point scale, except for LV function (six-point) and valvular leaflet opening (two-point). Colour Doppler assessment of valvular regurgitation was graded on a seven-point scale. A one-point difference was considered minor; a two or more point difference was considered major. There was no statistically significant difference in image quality between the two devices. For 2D data, the number of total (minor and major) differences between the hand-carried and standard echocardiograph examinations was significantly greater than the inter-observer variability (14.3% vs 10.7%, P< 0.05), however, major differences alone were not statistically different. For the colour Doppler assessment of regurgitation there was a significant difference between the devices for total (minor and major) differences, (40.0% vs 31.8%,P < 0.007) however, the number of major differences is explained by inter-observer variability. CONCLUSIONS: Image quality and diagnostic accuracy of the hand-carried device, OptiGo, was adequate for the purpose of performing a focused assessment of a limited number of 2D and Doppler parameters for the evaluation of cardiac anatomy and function.     

经胸B超指导Amplatzer封堵器在治疗成人房间隔缺损中的应用

目的　评价经胸B超 (TTE)指导Amplatzer封堵器治疗成人继发孔型房间隔缺损 (ASD)的价值。方法　 30例ASD行Amplatzer封堵术的患者 ,年龄 13～ 6 5岁 ,平均 (32± 15 )岁 ,术前及术中采用TTE指导封堵 ,术后即刻及术后 1个月 ,3个月分别行TTE检查评价治疗效果。结果　 2 4例 (80 % )患者术前和术中直接采用TTE指导封堵成功 ,总有效率为 80 % ;5例 (16 7% )患者术前加做食管B超(TEE)选择适应证 ;1例 (3 3% )患者术中加做TEE指导封堵成功。术中未发生任何重要并发症 ,无急症手术病例。术后即刻TTE彩色多普勒显示 2例 (6 7% )存在微 /少量残余分流 ,术后 1月TTE显示30例患者的ASD完全闭合 ,封堵器形态、位置良好 ,未对毗邻结构产生影响 ,且未见封堵器移位及ASD再通。结论　TTE可用于指导大多数ASD患者行经导管Amplatzer封堵器治疗。     

Spontaneous echocardiographic contrast in the ascending aorta mimicking the appearance of aortic dissection in a patient with a left ventricular assist device

We describe a patient with a previously implanted Jarvik 2000 left ventricular assist device (LVAD), who presented with bacteraemia and with features suspected for aortic dissection at the CT scan. However, transesophageal echocardiography showed competition in the ascending aorta between the retrograde pump flow and the anterograde transaortic output, which mimicked true aortic dissection and could be resolved by lowering the pump speed. As patients with LVAD are increasing in number, clinicians should be aware of this possible effect. (ECHOCARDIOGRAPHY, Volume 21, February 2004)     

Rapid screening of cardiac patients with a miniaturized hand-held ultrasound imager--comparisons with physical examination and conventional two-dimensional echocardiography

BACKGROUND: Rapid screening of cardiac patients with a hand-held ultrasound imager (SonoHeart [SH]) could provide valuable clinical information. HYPOTHESIS: Whether the use of this device yields additional information to a carefully conducted physical examination and comparable findings to those of conventional two-dimensional echocardiography (2-D) during inpatient rounds is not well established and is the subject of this study. METHODS: In all, 100 consecutive telemetry patients underwent rapid screening with 2-D and color Doppler SH during inpatient rounds. SonoHeart findings were compared with results from conventional 2-D and physical examination conducted by an attending cardiologist. RESULTS: All patients had interpretable images. Mean scanning time with SH was 5.0 +/- 1.2 min; 2-D and SH findings were comparable. The parameters studied included chamber sizes, left ventricular (LV) systolic function, presence of LV hypertrophy (LVH), wall motion abnormalities (WMA), pericardial effusion (PE), and valvular regurgitations. Mild to moderate valvular regurgitation and LV systolic dysfunction were reliably diagnosed by SH in a number of patients whose symptoms were unrelated to the abnormalities detected. CONCLUSIONS: Rapid screening with SH provides accurate and valuable information that would otherwise be undetected during physical examination. Its introduction into clinical practice may redefine the initial approach to patients with cardiovascular disease.     

Three-dimensional and four-dimensional transesophageal echocardiographic imaging of the heart and aorta in humans using a computed tomographic imaging probe

We evaluated the clinical applicability of a prototype tomographic transesophageal echocardiographic (TEE) system, which not only provides conventional TEE images but also three-dimensional tissue reconstruction and four-dimensional display capabilities. The probe was used in 16 patients in the echocardiographic laboratory, intensive care unit, and the operating room. The instrument is a 5-MHz, 64-element, phased array unit mounted on a sliding carriage within a casing. After appropriate probe placement within the esophagus, the probe is straightened, a balloon surrounding the probe is inflated, and data acquisition begun with ECG and respiration gating. With computer controlled transducer movement at 1-mm increments, a complete cardiac cycle is recorded at each tomographic level. These are processed using a dedicated four-dimensional software, and displayed as a dynamic three-dimensional tissue image of the heart. We were able to see the dynamic motion of the ventricles and all the valves in the four-dimensional format. In addition to four-dimensional display, we were able to cut and visualize the heart in dynamic mode in any desired plane and also in multiple planes. Patients tolerated the procedure well. We conclude that this tomographic four-dimensional approach, which does not require tedious off-line processing, can easily be performed in patients and has a strong clinical potential.     

Pocket ultrasound device as a complement to physical examination for ascites evaluation and guided paracentesis

The pocket ultrasound device (PUD) is a new tool that may be of use in the early detection of ascites. Abdominal ultrasound-guided paracentesis has been reported to decrease the rate of complications due to the procedure, but must be performed in a healthcare setting; this new tool may be a useful on an ambulatory basis. The aim of this study was to determine the diagnostic usefulness of the PUD in the diagnosis of ascites and the safety of guided paracentesis. We conducted a retrospective study that included adult patients suspected of having ascites and in whom an evaluation was performed with the PUD to identify it. Concordance with abdominal ultrasound (AUS) was determined with the Kappa coefficient. Sensitivity (Se), specificity (Sp) and likelihood ratios (LR) were determined and compared with physical examination, AUS, computed tomography and procurement of fluid by paracentesis. Complications resulting from the guided paracentesis were analyzed. 89 participants were included and 40 underwent a paracentesis. The PUD for ascites detection had 95.8 % Se, 81.8 % Sp, 5.27 +LR and 0.05 ?LR. It had a concordance with AUS of 0.781 (p < 0.001). Technical problems during the guided paracentesis were present in only two participants (5 %) and three patients (7.5 %) developed minor complications that required no further intervention. There were no severe complications or deaths. This study suggests that the PUD is a reliable tool for ascites detection as a complement to physical examination and appears to be a safe method to perform guided paracentesis.