BACKGROUND: Non-invasive high-resolution echocardiography to evaluate cardiovascular function of small animals is increasingly being used due to availability of genetically engineered murine models. Even though guidelines and standard values for humans were revised by the American Society of Echocardiography, evaluations on murine models are not performed according to any standard protocols. These limitations are preventing translation of preclinical evaluations to clinical meaningful conclusions. We have assessed the right heart of two commonly used murine models according to standard clinical guidelines, and provided the practical guide and sample values for cardiac assessments. METHODS: Right heart echocardiography evaluations of CD1 and C57BL/6 mice were performed under 1–3% isoflurane anesthesia using Vevo® 2100 Imaging System with a high-frequency (18–38 MHz) probe (VisualSonics MS400). We have provided a practical guide on how to image and assess the right heart of a mouse which is frequently used to evaluate development of right heart failure due to pulmonary hypertension. RESULTS: Our results show significant differences between CD1 and C57BL/6 mice. Right ventricle structural assessment showed significantly larger (p < 0.05) size, and pulmonary artery diameter in CD1 mice (n = 11) compared to C57BL/6 mice (n = 15). Right heart systolic and diastolic functions were similar for both strains. CONCLUSION: Our practical guide on how to image and assess the right heart of murine models provides the first comprehensive values which can be used for preclinical research studies using echocardiography. Additionally, our results indicate that there is a high variability between mouse species and experimental models should be carefully selected for cardiac evaluations.
Anesthesia ; Animals ; Echocardiography* ; Heart ; Heart Failure ; Heart Ventricles* ; Humans ; Hypertension, Pulmonary ; Isoflurane ; Mice ; Models, Theoretical ; Pulmonary Artery

BACKGROUND: Currently there is no noninvasive imaging modality used to risk stratify patients requiring lead extractions. We report the novel use of superior vena cava (SVC) echocardiography to identify lead fibrosis and complex cardiac implantable electronic device (CIED) lead extraction. With an aging population and expanding indications for cardiac device implantation, the ability to deal with the complications associated with chronically implanted device has also increased. METHODS: This was a retrospective analysis of Doppler echocardiography recorded in our outpatient Electrophysiology/Device Clinic office over 6 months. Images from 109 consecutive patients were reviewed. RESULTS: 62% (68/109) did not have a CIED and 38% (41/109) had a CIED. In patients without a CIED, 6% (4/68) displayed turbulent color flow by Doppler in the SVC, while 22% (9/41) of patients with a CIED displayed turbulent flow. Fisher's exact test found a statistically significant difference between the two groups (p value < 0.05). The CIED group was subdivided into 2 groups based on device implant duration (< 2 years vs. > or = 2 years). Of the CIED implanted for > or = 2 years, 27% (9/33) had turbulent flow in the SVC by Doppler, while no patients (0/8) with implant durations < 2 years demonstrated turbulent flow. Nine patients underwent subsequent lead extraction. A turbulent color pattern successfully identified all 3 patients that had significant fibrosis in the SVC found during extraction. CONCLUSION: Our data suggests that assessing turbulent flow using color Doppler in the SVC may be a valuable noninvasive screening tool prior to lead extraction in predicting complex procedures.
Aging ; Echocardiography* ; Echocardiography, Doppler ; Fibrosis* ; Humans ; Mass Screening* ; Outpatients ; Retrospective Studies ; Vena Cava, Superior*