Cardiac assessment accuracy by students using palm-held ultrasound compared to physical examination by skilled cardiologists: a pilot study with a single medical student

For centuries, the physical examination (PE) has been the backbone of cardiovascular diagnosis. In the past few years, studies demonstrate that PE, with the stethoscope being in the forefront, carries significant limitations. Despite those limitations and the emergence of novel miniaturized imaging devices, the stethoscope has not yet been replaced [1].

The approach to a patient with known or suspected cardiovascular disease begins with a directed history and targeted PE, which is a time honored tradition. For the last two decades, there has been a gradual decline in PE skills, from student to faculty specialist levels [2]. This raises a great concern to both clinicians and medical educators. Today, only a minority of internal medicine and family physicians correctly recognize classic cardiac findings, and despite the popular belief, this performance does not improve with experience. Moreover, it has become more difficult to teach PE, as physicians become busier and devote less time to tutor students and residents. The declining quality of medical education (especially related to clinical reasoning and supervised training of medical skills) nowadays, especially in places where medical schools are being opened without criteria or supervision by health authorities, also account for the worsening accuracy of PE. The declining skills of PE derive not only from the busy agenda of physicians, but especially from suboptimal training. As a consequence there is an increasing reliance on noninvasive imaging devices to establish the presence and severity of cardiovascular disease [2]. Lack of confidence on PE, which results in ordering unnecessary tests, is another adverse outcome. Furthermore, cardiac abnormalities such as LV dysfunction, LV thrombus and valvular vegetations are findings that cannot be assessed using PE alone [1].

For the past 50 years, conventional echocardiography is routinely used to evaluate the structure and function of the heart. Even though the equipment has improved and became lighter, it still weighs more than a 100 kg, and it takes time to move it to the bedside [3]. Hand-carried ultrasound (HCU) is a portable imaging device, battery operated, lightweight (2–3 kg) and about the size of a laptop computer. The high image resolution, low-cost, and simplicity of the HCU may modify traditional medical practice and medical education by complementing the PE with a real-time cardiovascular imaging [4]. The portable HCU extends the physician’s diagnostic capabilities beyond the limits of the PE along with a potential for a more accurate and faster diagnosis, lower cost, while extends the physician’s need of an expert operator [5, 6].

In 2005, Kobal et al. hypothesized that medical students without clinical experience could accurately evaluate and diagnose cardiac abnormalities using HCU after short training. The study compared the accuracy of cardiovascular diagnosis by medical students using HCU to PE performed by cardiologists. Of the 239 abnormal findings identified by standard echocardiography, medical students recognized 75%, whereas cardiologists identified only 49% [7].

The V-scan (GE, USA) is a novel, smaller than HCU, pocket-sized palm-held ultrasound (PHU). It is so much smaller than the HCU that it can be carried in the physician's pocket. It enables medical professionals including cardiologists, general practitioners, OB/GYN, primary care, emergency physicians and intensivists to visualize the heart in two-dimensions and in a color Doppler imaging at the point of care.

We therefore hypothesized that a single medical student, following a brief training (two academic hours) with the PHU, will better identify abnormal findings including significant valvular diseases, pericardial effusion and reduced LV function, as compared to PE performed by senior cardiologists and cardiology fellows.

Our study demonstrates that a very short training period (2 h) allowed a medical student with no prior echocardiographic skills to perform basic cardiac evaluation using PHU and achieve results almost identical to a physical examination performed by a cardiology fellow or a senior physician using a stethoscope.

The use of ultraportable echocardiography devices has been an object of study in various clinical settings of cardiology and other medical specialties. Several studies have shown an incremental benefit when hand-handled ultrasonography compliments the routine general PE [9, 8, 3].

Moreover, these days, telemedicine is a rapidly evolving field in the medical arena. PHU can allow physicians from intern to senior level, both within the hospital and in the community clinic to consult a specialist while transmitting the test data in real-time or later by saving the information on the PHU. This will allow avoiding unnecessary follow-up tests due to lack of confidence or inexperience of the attending physician and will allow for a quicker and more accurate diagnosis.

Since the findings by PHU are very much similar to the ‘gold standard’ in this study, and since the study population has very high likelihood of showing abnormalities with PHU, the results shown in our study may in a way be very much obvious. However, we did not intend to demonstrate that PHU may be used as a screening tool to detect significant valvular disease, cardiomyopathy, or pericardial disease in daily clinical practice. In this case, the study population should be general population or patients who may present with shortness of breath. We mainly intended to prove its ability to detect cardiac abnormalities even by medical students after a brief training session.

Kobal et al. [7] utilized 18 h of training medical students, yet in their study they used the Optigo hand-carried device, which is a much larger device with a wider range of imaging capabilities. Moreover, the students who performed the studies were first-year students, with minimal knowledge in cardiac anatomy and physiology. Our students were 4^th year students, and we used a PHU with much more limited imaging capacbilities and much easier to use. Therefore we were able to reach sufficient skills with such a short training session. In addition, Stokke et al. [10] utilized only a 4 h training session in their study, using a PHU again, and reached similar results to ours.

As demonstrated in our study and previous studies, both the PHU and physical examination will probably not be able to replace standard echocardiography as a ‘gold standard’ in the very near future. However, it can be used as an excellent tool for rapid diagnosis of cardiac function, including LV function assessment, valvular disorders and pericardial fluid with high sensitivity and specificity.

Currently, students acquire comprehensive training on how to perform a physical examination that includes the use of a stethoscope as a tool for evaluating heart sounds and cardiac function. Our study and previous studies [4, 7, 5] point to the difficulty of skilled physicians these days to diagnose cardiac abnormalities by physical examination only. Thus we strongly recommend that the use of a PHU be integrated during the professional training phase of medical students in parallel with the study of the complete and comprehensive physical examination. Moreover, with future technical improvements (the addition of Doppler measurements, improved resolution), satellite communication, and the required short training period—PHUs can become a useful and inexpensive device for providing better standard of care in low-income and remote regions of the world.

The results of our study are hypothesis generating. The study topic should be validated in future studies with more medical students with a very brief training of cardiac ultrasound.