The use of small personal ultrasound devices by internists without formal training in echocardiography.

AIMS: Hand-held ultrasound devices will probably be used for bedside cardiac diagnoses by internists without formal training in echocardiography. We compared the accuracy of hand-held ultrasound devices studies performed by expert echocardiographers vs internal medicine residents with brief training in echocardiography. METHODS AND RESULTS: Three internal medicine residents participated in an organized training program in echocardiographic principles, image acquisition, and interpretation. Subsequently, these residents and three echocardiographers imaged 300 patients with a hand-held ultrasound device. Sensitivity, specificity, positive and negative predictive values for internist- and echocardiographer-performed studies for the detection of cardiac abnormalities were compared using a full-featured exam as the gold standard. Resident- and echocardiographer-performed scans had similar overall sensitivity and specificity. There was a higher positive predictive value for the echocardiographer-performed scans. For clinically important findings (likely to affect patient care), sensitivity was slightly but significantly higher for the echocardiographer-performed scans. Clinically important findings most often missed by residents included regional wall motion abnormalities, intra-cardiac thrombus, right ventricular dysfunction and non-trivial pericardial effusions. CONCLUSION:Hand-held ultrasound devices provide useful screening tools for cardiac disease but should not replace a standard platform study. Training guidelines and competency evaluation are needed if these devices are to be used by non-echocardiographers for clinical decision-making.     

Heavy chain diseases

Heavy chain diseases (HCDs) are rare B-cell lymphoplasma-cell proliferative disorders characterized by production of truncated monoclonal immunoglobulin heavy chains without associated light chains. HCDs involving the three main immunoglobulin classes have been described; alpha-HCD is the most common and has the most uniform presentation, gamma- and mu-HCDs have variable clinical presentations and histopathologic features. HCDs can be thought of as variant types of non-Hodgkin lymphoma: alpha-HCD presents as an extranodal marginal-zone lymphoma of mucosa-associated lymph-node tissue, gamma-HCD as lymphoplasmacytoid non-Hodgkin lymphoma, and mu-HCD as small lymphocytic non-Hodgkin lymphoma or chronic lymphocytic leukemia. Diagnosis of HCD requires documentation of a deleted immunoglobulin heavy chain without a bound light chain in the serum or urine. Prognosis is variable, and no standardized effective treatment programs are available except for alpha-HCD, which in its early stage may respond to antibiotics.     

Assessment of echocardiography in clinical practice

Echocardiography should be viewed as a technique that can be very useful in certain specific situations. It is important for the clinician to know which patients can profit most from this examination. Because the technique is apparently harmless, there will be an obvious tendency to use echocardiography to screen all patients with heart disease or suspected heart disease. Such an approach would be improper. The referring physician should have a specific reason for obtaining each examination. The cost of the test is not insignificant, and with the development of newer, more expensive echocardiographic equipment, future costs will probably be even higher. Thus, indiscriminate use of any diagnostic examination, including echocardiography, should be avoided.The echocardiographic examination should also be considered as evolving. Improvements are constantly being made, and the current examination is certainly not perfected. There are many technical details involved in doing this examination. This fact is the basis for the problem in training people to provide echocardiographic services. Although the examination may be reasonably harmless and painless for the patient, the technique is by no means simple. Because of the intricacies of the examination, the subtleties of the interpretation, and the knowledge explosion in the field, an increasing amount of training and experience is necessary to perform and interpret echocardiograms.Despite its many problems and limitations, the popularity of echocardiography testifies to the fact that this tool can be extremely helpful in many patients. This examination can provide information which is most difficult to obtain in any other manner. Unlike many other noninvasive cardiologic tests that provide graphic recordings of physical findings, echocardiography gives information that cannot be obtained at the bedside. In some respects, the use of ultrasound to examine the heart is more natural than any other imaging technique that relies on the interpretation of radiographic or isotopic shadows or silhouettes. Echocardiography is not dissimilar to sonar used by several animals, such as bats and dolphins. Anyone who has seen these animals use their sonar must be impressed with the fact that ultrasound can be very effective in sensing one's environment. Although we will probably never approach the skill with which these animals use ultrasound, there will undoubtedly be important improvements and advances in echocardiographic technology. Thus, from all indications, echocardiography should play an increasingly important role as a diagnostic tool in cardiology.     

Professional Education,Training and Role of the Cardiac Sonographer in Different Countries

Performing a good echocardiographic examination requires intensive training and highly qualified technical staff personnel, which, in many countries, is represented by the Cardiac Sonographer. Being an operator-dependent diagnostic method, a long debate has been held to help identifying the most appropriate curriculum for the training of this professional profile. Although guidelines for the education of the Cardiac Sonographers have been suggested by the American Society of Echocardiography (ASE) several years ago and many scientific publications have given credibility, trust and enhance to this professional profile in Italy, this figure is not yet recognized by the National Health System. It is encouraging that in the last decade, national authorities, such as the SIEC (Società Italiana di Ecografia Cardiovascolare), have expressed interest in recognizing the Cardiac Sonographers as professionals in our country. Per their guidelines, the Cardiocirculatory Physiopathology Cardiovascular Perfusion technicians (TFCPCs) seem to be, among the professionals, the most suitable, due to their educational training and the role they play. Taking inspiration from the positive experience of this professional figure in the USA and in the Anglo Saxon countries, it could aims to be a valid support in terms of cost and quality for the Italian health system.     

The hand-carried echocardiographic device as an aid to the physical examination

Physical examination skills have been declining over the past several decades while technology has made diagnostic testing increasingly sophisticated. For patients with cardiovascular disease, the best approach to bedside diagnosis would be one that combines both physical examination and ready access to technology at the time of the patient encounter. Most cardiac testing is not performed at the bedside due to equipment size and time limitations for these tests. Small hand-carried echocardiographic devices are now available for rapid bedside examination. These devices compare well to full-featured systems when used in cardiology outpatient settings and in hospitalized patients who are not critically ill. Compared with physical examination by board certified cardiologists, these devices decrease diagnostic error. Early use of hand-carried echocardiographic devices after physical examination has been demonstrated to impact patient triage and treatment as well as uncover otherwise undetected cardiac disease. The degree of training required for responsible use of these devices is as yet unclear. However, organized training sessions have resulted in modest agreement with standard echocardiography and point-of-care echocardiography performed by expert echocardiographers. It is conceivable that the hand-carried echocardiographic devices will be used in medical school curriculum to enhance medical student education in the future.     

Technology insight: hand-carried ultrasound cardiac assessment--evolution, not revolution

Hand-carried ultrasound devices can enhance the art of bedside physical examination by increasing diagnostic accuracy, detecting disease at an earlier stage, and improving triage and referral of patients. Although limitations of device cost and portability can be overcome with technologic advances, the shortage of standardized imaging and training opportunities now needs to be addressed to move the technique forward. Cardiologists are the best-qualified subspecialists to design and teach a simplified training program for bedside use of hand-carried ultrasound devices to assess the cardiovascular system.     

Portable echocardiographs: useful or futile?

Echocardiographic systems which are the size of a laptop computer are currently available. These hand-held ultrasound units are very easy to use at patient bedside in various clinical settings. According to the miniaturized devices, spectral Doppler may not be available and power Doppler may replace true color Doppler. Validation studies of hand-held echocardiography have been conducted in critically ill patients, in patients hospitalized in ward, but also in outpatients and as a screening tool for the detection of cardiac abnormalities in the community. Hand-held echocardiography appears to have important limitations in specific clinical settings, such as shock, pulmonary hypertension, assessment of valvulopathy or valvular prosthesis, dynamic left outflow tract obstruction, left ventricular restriction or construction. The miniaturized system with spectral Doppler capability has not yet been properly validated in these indications. At its present stage of development, hand-carried ultrasound units do not allow to perform a comprehensive examination which relies on the use of a full-feature system, especially when a precise hemodynamic evaluation is required. Diagnostic ability of hand-held echocardiography is similar to that of upper-end platforms for diagnoses based on two-dimensional imaging: left ventricular systolic function, detection of wall motion abnormalities, size of cardiac chambers, identification of pericardial or pleural effusions. Hand-carried ultrasound devices may be considered as a "visual stethoscope" which provides an extension of the physical examination, but not as a potential alternative to standard transthoracic echocardiography. Its large potential clinical field of use raises the concern of taylored training programs to intensivists which could be focused on goal-directed echocardiographic examinations.     

The physiologic basis for the management of ventricular assist devices

Mechanical ventricular assist devices are now approved as destination therapy for terminal heart failure. It is the purpose of this review to discuss the physiology of this technology that is considered in outpatient care. The currently available pulsatile devices are solely dependent of preload volume and, when placed in the automatic mode, can maintain physiologic cardiac outputs with exercise. However, because of their dependence on preload volume, there are unique physiologic consequences; device bradycardia represents volume depletion, device tachycardia reflects volume overload. The differential diagnosis of left ventricular assist device dysfunction includes native right ventricular failure, native left ventricular recovery, or other technical considerations. The management of biventricular mechanical support as well as arrhythmia management and the role of echocardiographic assessment in this unique patient population will be discussed. Expertise in outpatient management of such devices is now a requisite for subspecialists in heart failure, In the future, technical innovations may simplify management for professionals, patients, and their families.     

Bioeffects in echocardiography

Two mechanisms have been identified through which ultrasound as it is used clinically could produce biologically significant effects. One is heating that results from the absorption of ultrasonic energy by tissues. The other is cavitation, the ultrasonic activation of gas bodies including the potentially violent collapse of small gas bodies in or near tissue that is sometimes called transient or inertial cavitation. The heart, itself, is well perfused and the likelihood of significant heating of the heart tissues in the most extreme conditions known today is negligible. Lung also appears to be relatively immune to heating under diagnostic exposure conditions. In normal echocardiographic procedures, the only tissues that need serious consideration are the ribs. Under extreme conditions, ultrasonic heating of the bone might be as great as 6 degrees C. Nonthermal action of ultrasound has been demonstrated to cause lung hemorrhage at pressure levels on the order of 1 MPa. Although many diagnostic devices produce focal pressures greater than this amount, it appears unlikely that hemorrhage will occur in normal echocardiographic applications. Under certain conditions, pulsed ultrasound can either stimulate or modify the contraction of the heart but the exposures required are not used in normal echocardiographic applications. Since specific devices have been identified who's outputs approach levels required to produce thermal and nonthermal effects, the user should be aware of potential biological effects, particularly in pediatric or obstetric applications, as output levels increase.     

Therapeutic ultrasound in cardiology

Ultrasound can be exploited to derive therapeutic results by using its bioeffects such as creation of mechanical vibrations, localized cavitations, microstream formation, physicochemical changes and thermal energy. Extensive in vitro and animal investigations during the last 2 decades have laid a foundation for ultrasound energy to be used for treatment purposes in various medical specialties. In the area of cardiovascular diseases, ultrasound could be used for thrombolysis, adjunct to coronary interventions, drug delivery, local gene transfer, and creating therapeutic lesions. The dispensation approaches to therapeutic ultrasound are varied, from the use of low- to medium-range frequency, low to focused high intensity, and catheter-based to external devices. Catheter-based ultrasound could be useful for intracoronary thrombolysis, and external ultrasound instrument with transcutaneous delivery could be of use in applications such as creation of myocardial lesions, peripheral vessel thrombolysis, and drug and gene delivery. Adjunct administration of microbubbles has been found to enhance thrombolysis, and drug and gene therapy. Ongoing studies strongly suggest that therapeutic ultrasound could have an important role in cardiovascular disorders associated with thrombosis, inflammation, atherosclerotic disease, and arrhythmias.     

Handcarried Echocardiography to Assess Hemodynamics in Acute Decompensated Heart Failure

Heart failure is a major source of cardiovascular morbidity, including acute decompensations requiring hospitalization. Because most therapeutic interventions in acute heart failure target optimization of cardiac output and volume status, accurate assessment of these parameters at the point of care is critical to guide management. However, physician bedside assessments of left ventricular (LV) function and volume status have limited accuracy. Traditional echocardiographic platforms, while useful for assessing ventricular and valvular function and volume status, have limitations for bedside use or frequent serial evaluation. Handcarried cardiac ultrasound devices, with their substantially lower costs, portability, and ease of use, circumvent many of the limitations of traditional echocardiographic platforms. The diagnostic capabilities of handcarried devices provide the opportunity for ultrasound assessment of LV function and serial bedside evaluation of volume status in patients with acutely decompensated heart failure.     

The use of ultrasonography in obstetrics in developing countries

Ultrasonography in pregnancy is one of the most important advances in antenatal and obstetric emergency care. The benefits of diagnostic ultrasound in a resource-poor setting are well known and undisputed. Routine ultrasound can provide real benefit to patients when it is included in antenatal care programmes designed to improve maternal and neonatal health, and it should become a standard procedure in developing countries. Proper training of the antenatal ultrasound imager is very important. This should include training in ethics, use and misuse of ultrasonography as well as good technique and understanding of implications for clinical care to improve sensitivity. Training should be aimed not only at doctors but also at midwives who conduct most of the antenatal care and skilled deliveries in developing countries. Communication with patients and information about the limitations and benefits of ultrasound are essential to alleviate fear and to discourage irrational expectation and demand. Finally, routine antenatal ultrasound should be monitored closely for possible misuse, such as sex screening and selective abortion of normal female fetuses, and non-indicated overuse by health-care professionals for their own financial benefits.     

Intravascular ultrasound of the coronary arteries: Current applications and future directions

Although angiography is widely applied in the diagnosis of the coronary artery disease (CAD), studies have questioned the accuracy of radiographic methods. Miniaturized intravascular ultrasound devices offer several potential advantages, including a tomographic orientation and the ability to characterize atherosclerotic plaques. Two dissimilar technical approaches to transducer design have emerged: mechanically rotated devices and multi-element arrays, each yielding small coronary catheters (1.1–1.8 mm in diameter). Initial studies of coronary ultrasound have demonstrated few serious untoward effects. In most normal subjects, the vessel wall is laminar in appearance with an intimal leading edge and subintimal sonolucent layer averaging ≤0.20 mm in thickness. In most CAD patients, the thickness of the leading-edge or sonolucent zone is abnormally increased. Atherosclerotic abnormalities are frequently evident in segments with no angiographic lesion. At sites with a circular lumen shape, minimum diameter by ultrasound and angiography correlate closely, R = 0.93. At sites with an eccentric lumen, significant disagreement between angiography and ultrasound diameter is evident, R = 0.78. Correlation between angiography and ultrasound from percent stenosis is moderate, R = 0.63. Following balloon angioplasty percutaneous transluminal coronary angioplasty (PICA), morphologic findings include complex cracks, splits, and dissections, and minimum lumen diameter by angiography and intravascular ultrasound correlate poorly. Recent advances have improved the utility of coronary ultrasound, including smaller catheters and a device combining a miniature imaging transducer (1.16 mm) with a low profile balloon (0.028–0.033 inch). Important current limitations include inability to visualize the smallest coronaries and tight stensoses. The future of coronary ultrasound is promising, propelled by the unique capability of this modality to image atherosclerotic plaques directly.     

Usefulness of ultrasound lung comets as a nonradiologic sign of extravascular lung water

The "comet-tail" is an ultrasound sign detectable with ultrasound chest instruments; this sign consists of multiple comet-tails fanning out from the lung surface. They originate from water-thickened interlobular septa and would be ideal for nonradiologic bedside assessment of extravascular lung water. To assess the feasibility and value of ultrasonic comet signs, we studied 121 consecutive hospitalized patients (43 women and 78 men; aged 67 +/- 12 years) admitted to our combined cardiology-pneumology department (including cardiac intensive care unit); the study was conducted with commercially available echocardiographic systems including a portable unit. Transducer frequencies (range 2.5 to 3.5 MHz) were used. In each patient, the right and left chest was scanned by examining predefined locations in multiple intercostal spaces. Examiners blinded to clinical diagnoses noted the presence and numbers of lung comets at each examining site. A patient lung comet score was obtained by summing the number of comets in each of the scanning spaces. Within a few minutes, patients underwent chest x-ray, with specific assessment of extravascular lung water score by 2 pneumologist-radiologists blinded to clinical and echo findings. The chest ultrasound scan was obtained in all patients (feasibility 100%). The imaging time per examination was always <3 minutes. There was a linear correlation between echocardiographic comet score and radiologic lung water score (r = 0.78, p <0.01). Intrapatient variations (n = 15) showed an even stronger correlation between changes in echocardiographic lung comet and radiologic lung water scores (r = 0.89; p <0.01). In 121 consecutive hospitalized patients, we found a linear correlation between echocardiographic comet scores and radiologic extravascular lung water scores. Thus, the comet-tail is a simple, non-time-consuming, and reasonably accurate chest ultrasound sign of extravascular lung water that can be obtained at bedside (also with portable echocardiographic equipment) and is not restricted by cardiac acoustic window limitations.     

Hand-carried ultrasound improves the bedside cardiovascular examination

OBJECTIVES: We assessed the clinical utility of hand-carried cardiac ultrasound (HCU) devices to assist physicians in the diagnosis of cardiovascular disease. MATERIALS AND METHODS: We reviewed 42 articles published from 1978 to 2004. RESULTS: The capability and simplicity of the HCU device assist physicians in the diagnosis of cardiovascular disease at the initial patients contact. HCU is particularly useful in the setting of emergency or critical care, community screening, or in remote areas with limited access to health care. CONCLUSION: The inherent limitations of the physical examination as well as the reduced focus and training in physical diagnosis of current and recent medical school graduates has set the stage for the HCU device to modify traditional medical practices by complementing the physical examination with real-time cardiovascular imaging.     

Left ventricular hypertrophy screening using a hand-held ultrasound device.

AIMS: To test the diagnostic potential of a hand-held ultrasound device for screening for left ventricular hypertrophy in a hypertensive population using a standard echocardiographic system as a reference. METHODS: One hundred consecutive hypertensive patients were enrolled. An experienced investigator performed measurements of the thickness of the anterior septum and posterior wall using the parasternal 2D-long axis view and the end-diastolic dimension of the left ventricle with both imaging devices. Left ventricular hypertrophy was defined as an increase in left ventricular mass > or = 134 g x m(-2) for men and > or = 110 g x m(-2) for women, when indexed for body surface area and > or = 143 g x m(-1) for men and > or = 102 g x m(-1) for women, when indexed for height. RESULTS: Sixty-five men and 35 women were studied (age 60 +/- 11 years); mean duration of hypertension: 13 +/- 11 years; mean blood pressures: systolic 150 +/- 20 mmHg and diastolic 89 +/- 11 mmHg. The anterior septum and posterior wall were visualized in all patients with both imaging devices. The standard echocardiographic system identified left ventricular hypertrophy by body surface area in 18 (18%) patients and by height in 26 (26%) patients. The agreement between the standard echocardiographic system and the hand-held device for the assessment of left ventricular hypertrophy was 93%, kappa: 0.77 (left ventricular mass/body surface area) and 90%, kappa: 0.76 (left ventricular mass/height). CONCLUSIONS: We conclude that hand-held devices can be effectively applied for screening for left ventricular hypertrophy in hypertensive patients.     

Endobronchial ultrasound

The efficacy and technical aspects of endobronchial ultrasound (EBUS) are reviewed because this technology promises to revolutionise bronchoscopy. EBUS extends the endoscopist's view beyond the mucosal surface of the large airways to peri-bronchial structures and peripheral lung lesions. Guided biopsies and real-time transbronchial needle aspirations (TBNA) have been shown to increase the diagnostic yield over conventional bronchoscopic techniques. The technology is available in two forms: radial EBUS probes and linear EBUS–TBNA bronchoscopes. Radial EBUS utilizes higher frequencies and the transducer is inserted via a standard flexible bronchoscope. The higher ultrasound frequencies improve image resolution to <1 mm. Radial EBUS is used to assess airway walls, guide TBNA (diagnostic yield: 72–86%) and diagnose peripheral lung lesions (diagnostic yield: 61–80%). Linear EBUS–TBNA transducers are built into dedicated bronchoscopes to produce sector view images and permit real-time TBNA. The pooled sensitivity of real-time EBUS–TBNA in lung cancer is 90% but the false negative rate is 20%. Therefore, EBUS–TBNA is a viable alternative to cervical mediastinoscopy in the diagnosis and staging of mediastinal lymphadenopathy. However, negative results need either further confirmatory testing or adequate clinical follow-up. Complications are rare with either EBUS modality and are usually related to the underlying biopsy procedure rather than the use of ultrasound. Procedure duration is short enough to be incorporated into an outpatient setting and can performed under moderate sedation. Clear training standards are emerging to facilitate credentialing as EBUS is rapidly evolving to become a part of standard diagnostic bronchoscopy.     

Anatomy, histology, and pathology of coronary arteries: a review relevant to new interventional and imaging techniques--Part IV.

In the last 15 years, intense interest has focused on various interventional pharmacologic and mechanical forms of therapy for the treatment of atherosclerosis coronary artery disease. Many techniques and devices (dilating balloons, perfusion catheters, thermal probes and balloons, lasers, atherectomy devices, stents, intravascular ultrasound) have been used or are under study for future use. Many of these techniques and devices require an understanding of histologic and pathologic features of the coronary arteries and diseases which affect them. This article reviews selective areas of anatomy, histology, and pathology relevant to the use of various new interventional techniques. Part IV of this review will focus on congenital coronary artery anomalies, myocardial bridges, coronary aneurysm, emboli, and dissection and clinical implications regarding echocardiographic imaging techniques.     

Endoscopic ultrasound-guided biliary drainage

Endoscopic ultrasound (EUS)-guided biliary drainage has emerged as a minimally invasive alternative to percutaneous and surgical interventions for patients with biliary obstruction who had failed endoscopic retrograde cholangiopancreatography (ERCP). EUS-guided biliary drainage has become feasible due to the development of large channel curvilinear therapeutic echo-endoscopes and the use of real-time ultrasound and fluoroscopy imaging in addition to standard ERCP devices and techniques. EUS-guided biliary drainage is an attractive option because of its minimally invasive, single step procedure which provides internal biliary decompression. Multiple investigators have reported high success and low complication rates. Unfortunately, high quality prospective data are still lacking. We provide detailed review of the use of EUS for biliary drainage from the perspective of practicing endoscopists with specific focus on the technical aspects of the procedure.