Portable spectral Doppler echocardiographic device: overcoming limitations

Comparison of hand-held acoustic Doppler with point-of-care portable color Doppler ultrasound in the assessment of venous reflux disease

OBJECTIVE

Diagnostic-quality portable color Doppler ultrasound (PCD) offers convenient point-of-care venous reflux disease (VRD) diagnosis. Philips Lumify (Philips N.V., Best, The Netherlands), a high-fidelity broadband linear array transducer (4-12 MHz frequency), connects through a web-enabled smartphone or tablet to cloud software and offers B-mode and color Doppler imaging without pulsed wave Doppler capability. The aims of the study were to compare hand-held acoustic Doppler (HHD) vs PCD diagnostic performance using conventional duplex ultrasound (DUP) as the "gold standard" for VRD assessment, to assess effects of body mass index (BMI) and disease severity on diagnostic performance of HHD and PCD, and to determine whether PCD offers any diagnostic improvement over HHD in VRD assessment.

METHODS

There were 241 patients (65 male, 176 female; mean age, 55.5 ± 15.5 years; mean BMI, 32.2 ± 7.9 kg/m²). DUP (447 legs), PCD (262 legs), and HHD (217 legs) studied the great saphenous vein at above-knee (AK) and below-knee (BK) levels. A phlebologist performed HHD, whereas PCD and DUP were performed sequentially (PCD first) by an experienced technologist and interpreted independently. PCD was done blinded to DUP results. DUP findings were analyzed blinded to HHD and PCD results. Venous reflux was dichotomously assessed as <2 seconds and >2 seconds.

RESULTS

HHD improves from moderate to good sensitivity from AK level (68%) to BK level (94%) but suffers poor specificity that declines significantly from AK level (50%) to BK level (12%; P < .05). HHD positive predictive value exceeds its negative predictive value (NPV) and remains unchanged from AK level (71%) to BK level (72%). HHD NPV remains consistently poor at AK (48%) and BK (42%) levels. PCD has similar sensitivity from AK level (69%) to BK level (74%), better AK level (79%) vs BK level (58%) specificity (P < .05), similar positive predictive value for AK (76%) and BK levels (78%), and better NPV for AK level (72%) vs BK level (53%; P < .05). BMI range (<30 kg/m² vs ≥ 30 kg/m²) did not influence diagnostic performance of HHD and PCD significantly. HHD and PCD specificity was higher for Clinical, Etiology, Anatomy, and Pathophysiology (CEAP) class <4 compared with CEAP class ≥4 (P < .05).

CONCLUSIONS

The relative diagnostic performance of HHD and PCD is highly dependent on insonation level. PCD advantages compared with HHD are marginally greater specificity at AK and BK levels and better NPV at AK level. Compared with HHD, PCD's disadvantage is lower sensitivity at BK level. Both HHD and PCD have higher specificity at AK level than at BK level. Overall, PCD offers only moderate sensitivity and specificity, making it inadequate for exclusion of significant venous reflux. Neither obesity nor CEAP class significantly influenced the general diagnostic performance of PCD or HHD.

Cardiovascular Ultrasound Combined With Non-invasive Screening for the Detection of Undiagnosed Cardiovascular Disease: A Literature Review

Non-invasive screenings have been widely utilized in the United States and worldwide to provide early identification of cardiovascular disease, allowing for earlier diagnosis and treatment. Screening sonography detects valve disease, cardiac dysfunction, and carotid disease in 5% to 20% of the population. This review discusses the current data regarding cardiovascular screening, the methodologies, and the resources required for performance of screenings. Cardiac and carotid sonography is highly accurate and discovers cardiovascular diseases that impact quality of life and risk of future events. Screenings are performed in a variety of settings and accuracy depends on the quality of personnel performing the non-invasive testing, the equipment utilized, and the personnel interpreting the studies. Despite the potential benefit for disease detection, population screening to detect cardiovascular disease is not widely supported by national organizations due to the theoretical cost of further testing and lack of cost versus benefit data. Additional studies are necessary to compare costs and benefits of non-invasive cardiovascular screening in the community setting.

Measurement of peak aortic jet velocity in the perioperative period-machine variability: implications for assessment of aortic stenosis severity

Variation in echocardiography machines and probes are not well described in the perioperative period. We aimed to compare the estimation of severity of aortic stenosis with transthoracic echocardiography (TTE) using two semi-portable ultrasound machines. Experienced cardiac anaesthetists performed a limited transthoracic echocardiogram with two different semi-portable ultrasound machines in patients with known aortic stenosis. The peak aortic jet velocity with continuous-wave Doppler and the time taken to obtain an acceptable envelope were recorded. The Sonosite M Turbo often underestimated the peak jet velocities (median jet velocity [IQR] 2.25 m/s [1.95 to 3.4] versus 3.85 m/s (3 to 4.2); P <0.001) and required more time to get a satisfactory envelope than the GE Vivid I. There was no statistically or clinically significant difference between the velocities obtained from the Vivid I and those measured on the patient's formal cardiology preoperative transthoracic echocardiogram (median [IQR]: 3.95 m/s [3.0 to 4.7]; P=0.3). However, the velocities obtained by the M Turbo were significantly lower than those obtained by the formal preoperative transthoracic echocardiogram (P <0.001). With the expansion of transthoracic echocardiography amongst anaesthetists, underestimation of the peak aortic jet velocity can significantly underestimate the severity of aortic stenosis with potentially lethal clinical consequences. Semi-portable ultrasound machines with echocardiographic capability are not necessarily equivalent and can result in underestimation of severity of aortic stenosis.

Efficacy and learning curve of a hand-held echocardiography device in an oncology outpatient clinic: Expanding the use of echoscopic heart examination beyond cardiology

Certain chemotherapy drugs for breast cancer may induce cardiotoxicity and these patients should be echocardiographically monitored. The performance of a focused echocardiographic evaluation (echoscopy) at the patient's location by a non-cardiologist appears to be feasible. The aim of the present study was to assess the accuracy of echoscopy performed by medical oncologists in an outpatient clinic using hand-held echocardiography devices. The study cohort comprised consecutive unselected patients who attended an oncology outpatient clinic. Two medical oncologists attended a one-week training period, which included theoretical and practical teaching by an expert cardiologist. Every subject underwent two echo examinations. The first examination was performed by an oncologist using a hand-held echo device and the second was performed by a cardiologist using a 'premium' device. Out of the 101 enrolled patients, 32 were men (31.7%) and the mean age was 56.03±16.88 years. There was a good global agreement [intra-class correlation coefficient (ICC): 0.65 for left ventricular ejection fraction (LVEF)]. When the results were analyzed depending on the period of time when the echo studies were performed, a clear and short learning curve was observed: LVEF started at ICC=0.58 and increased to 0.66 and 0.77 in the second and third period, respectively. There were extremely few clinically significant differences and a learning curve was also evident. In conclusion, cardiac echoscopy performed by an oncologist with a hand-held device may lead to a similar clinical management as a study performed by an expert cardiologist with a 'premium' system in patients under chemotherapy following a short training period.

Usefulness of a new miniaturized echocardiographic system in outpatient cardiology consultations as an extension of physical examination

BACKGROUND

The aim of this study was to assess the usefulness of a new miniaturized echocardiographic system (MS) to perform bedside echocardiography in initial outpatient cardiology consultations, in addition to physical examination.

METHODS

One hundred eighty-nine patients referred for initial cardiology outpatient consultations at two tertiary hospitals in two countries were studied. Each patient was submitted to physical examination followed by MS assessment. Scanning time, the number of examinations with abnormal results after physical examination and the MS, and the information obtained by physical examination alone and followed by the MS (in terms of its importance in reaching a diagnosis, in the necessity of performing routine echocardiography, and in the decision to release the patient from the outpatient clinic) were assessed.

RESULTS

The scanning time with the MS was 180 ± 86 seconds. Its use after physical examination led to diagnoses in 141 patients (74.6%) and to an additional 37 patients (19.6%) being released from the outpatient clinic. After physical examination followed by MS assessment, only 64 patients (33.9%) were sent to the echocardiography lab. The MS modified the decision of whether to send a patient to the echocardiography lab, with referral determined by the MS in 27 patients (14.3%) and no referral determined by the MS in 58 patients (30.7%).

CONCLUSIONS

The new MS caused a negligible increase in the duration of consultations. It showed additive clinical value over physical examination, increasing the number of diagnoses, reducing the use of unnecessary routine echocardiography, increasing the number of adequate echocardiographic studies, and determining a large number of releases from the outpatient clinic.

Efficacy of Ultrasound-assisted Stress Testing Using a Hand-carried Ultrasound Device for Diagnosis of Coronary Artery Disease

BACKGROUND

Exercise echocardiography is an effective means of noninvasively detecting coronary artery disease (CAD), and hand-carried cardiac ultrasound (HCU) devices are now being used to diagnose CAD in emergency rooms and at bedsides.

OBJECTIVE

To compare the efficacies of exercise echocardiography with an HCU device (EchoCG-HCU) and exercise electrocardiography (ECG) in the diagnosis of CAD.

METHODS

Fifty-eight patients underwent symptom-limited treadmill exercise testing. Two-dimensional echocardiographic images were obtained from standard parasternal and apical windows at rest and immediately after exercise using an HCU device (180 PLUS SonoSite Inc, Bothell, Wash). Wall motion was scored for each of 16 left ventricular segments using a 5-point grading system. The development of new or worsening wall motion was considered to be indicative of ischemia.

RESULTS

When identifying CAD using exercise ECG, the sensitivity ws 63%, the specificity was 72%, and the diagnostic accuracy was 69%. By comparison, with exercise EchoCG-HCU the sensitivity was 68%, the specificity was 90%, and the diagnostic accuracy was 83%. Moreover, the specificity of exercise EchoCG-HCU was significantly higher than that of exercise ECG (p < .05).

CONCLUSION

Exercise EchoCG-HCU is at least as useful as exercise ECG for diagnosing CAD.

Hand-held echocardiography: added value in clinical cardiological assessment

BACKGROUND

The ultrasonic industry has recently produced echocardiographic Hand Held Devices (miniaturized, compact and battery-equipped echocardiographic systems). Their potential usefulness has been successfully assessed in a wide range of clinical conditions. The aim of the study was to verify if the routine use of a basic model of echocardiographic Hand Held Device (HHD) could be an important diagnostic tool during outpatient cardiologic consulting or in non-cardiologic hospital sections.

METHODS

87 consecutive patients were included in this study; they underwent routine physical examination, resting ECG and echocardiographic evaluation using a basic model of HHD performed by trained echocardiographists; the cardiologist, whenever possible, formulated a diagnosis. The percentage of subjects in whom the findings were judged reasonably adequate for final diagnostic and therapeutic conclusions was used to quantify the "conclusiveness" of HHD evaluation. Successively, all patients underwent a second echocardiographic evaluation, by an examiner with similar echocardiographic experience, performed using a Standard Echo Device (SED). The agreement between the first and the second echocardiographic exam was also assessed.

RESULTS

Mean examination time was 6.7 +/- 1.5 min. using HHD vs. 13.6 +/- 2.4 min. using SED. The echocardiographic examination performed using HHD was considered satisfactory in 74/87 patients (85.1% conclusiveness). Among the 74 patients for whom the examination was conclusive, the diagnosis was concordant with that obtained with the SED examination in 62 cases (83.8% agreement).

CONCLUSION

HHD may generally allow a reliable cardiologic basic evaluation of outpatient or subjects admitted to non-cardiologic sections, more specifically in particular subgroups of patients, with a gain in terms of time, shortening patient waiting lists and reducing healthy costs.

Evaluation of a hand carried cardiac ultrasound device in an outpatient cardiology clinic

OBJECTIVE

To determine the diagnostic potential of a hand carried cardiac ultrasound (HCU) device (OptiGo, Philips Medical Systems) in a cardiology outpatient clinic and to compare the HCU diagnosis with the clinical diagnosis and diagnosis with a full featured standard echocardiography (SE) system.

METHODS

300 consecutive patients took part in the study. The HCU examination was performed by an experienced echocardiographer before patients visited the cardiologist. The echocardiographer noted whether the HCU device was able to confirm or reject the referral diagnosis, which abnormality was detected, and whether SE investigation was necessary. Physical examination by a cardiologist followed and thereafter, whenever required, a complete study with an SE was carried out. The HCU data were compared with the clinical diagnosis of the cardiologist and the SE diagnosis in a blinded manner.

RESULTS

The cardiologist referred 203 of 300 patients for an SE study and 13 patients for transoesophageal echocardiography. In 84 patients no further examination was considered necessary. HCU echocardiography was able to confirm or reject the suspected clinical diagnosis in 159 of 203 (78%) patients. In 44 of 203 (22%) patients SE Doppler was needed. Agreement between the HCU device and the SE system for the detection of major abnormalities was excellent (98%). The HCU device missed 4% of the major findings. Among the 84 patients not referred for an SE, the HCU device detected unsuspected major abnormalities missed with the physical examination in 14 (17%).

CONCLUSION

Integration of an HCU device with the physical examination augments the yield of information.