Case series of mobile structures detected vividly by using superb microvascular imaging.

Background: Superb microvascular imaging (SMI) is a new imaging technique that can reveal low-velocity blood flow without use of a contrast agent. SMI is based on an original algorithm and effectively removes tissue motion artifacts (clutter motion) from the background, thereby preserving visibility of low-velocity blood flow. SMI is expected to be useful for the evaluation of heart diseases, as well as blood vessels. Case summary: Here, we report three cases in which a mobile structure in the heart or a blood vessel was detected easily by strong enhancement on SMI. In the heart, the entire mass was strongly enhanced by colour-SMI and had the appearance of 'a fire ball'. In the abdominal aorta and carotid artery, SMI captured a strongly enhanced echo image of a mass and revealed hyperechoic mobile plaque. It was hard to detect with the conventional echocardiography. Discussion: It is important to detect mobile intravascular and intracardiac structures as they are risk factors of thrombosis. Echo images are often strongly affected by the skill of the examiner, the patient's body habitus, and the presence of intestinal gas; thus, it is often difficult to detect a small mass with conventional echocardiography. With the use of SMI, even small mobile structures can be displayed at high intensity in comparison with the surrounding blood flow. Therefore, the non-invasive SMI was useful for the detection of mobile intravascular and intracardiac structures. Our findings of the current report may lead to new developments in SMI for imaging in the cardiac region.

Substitute parameters of exercise-induced pulmonary hypertension and usefulness of low workload exercise stress echocardiography in mitral regurgitation.

In asymptomatic patients with mitral regurgitation (MR), data of exercise-induced pulmonary hypertension (EIPH) are limited, and feasibility of evaluating EIPH is not high. We aimed to investigate prognostic impact of EIPH and its substitute parameters. Exercise stress echocardiography (ESE) were performed in 123 consecutive patients with moderate to severe degenerative MR. The endpoint was a composite of death, hospitalization for heart failure, and worsening of symptoms. EIPH [tricuspid regurgitation peak gradient (TRPG) at peak workload ≥ 50 mmHg] was shown in 57 patients (46%). TRPG at low workload was independently associated with TRPG at peak workload (ß = 0.67, p < 0.001). Early surgical intervention (within 6 months after ESE) was performed in 65 patients. Of the remaining 58 patients with the watchful waiting strategy, the event free survival was lower in patients with EIPH than in patients without EIPH (48.1 vs. 97.0% at 1-year, p < 0.001). TRPG at low workload ≥ 35.0 mmHg as well as EIPH were associated with poor prognosis in patients with the watchful waiting strategy. In conclusion, the importance of ESE and evaluating EIPH in patients with MR was re-acknowledged. TRPG at peak workload can be predicted by TRPG at low workload, and TRPG at low workload may be useful in real-world clinical settings.

Comparison of Clinical Characteristics, Natural History and Predictors of Disease Progression in Patients With Degenerative Mitral Stenosis Versus Rheumatic Mitral Stenosis.

Mitral annular calcification (MAC) is a common echocardiographic finding and an increasingly recognized cause of degenerative mitral stenosis (DMS). However, little is known about the clinical characteristics and disease progression in DMS, particularly in comparison with rheumatic mitral stenosis (RMS). We retrospectively reviewed 203 consecutive patients with mitral stenosis (113 with DMS and 90 with RMS) who underwent echocardiography at our institution between January 2014 and December 2017. We compared the clinical characteristics and disease progression between the 2 groups. In addition, we analyzed the predictors of disease progression (defined as annual progression rate of a mean gradient >0 mm Hg/year) among patients with DMS. Patients with DMS were significantly older and had higher prevalence of atherosclerotic comorbidities than those with RMS. During the median follow-up period of 2.2 years, the annual progression rates were comparable (0.8 ± 0.8 mm Hg/year in DMS vs 1.0 ± 1.2 mm Hg/year in RMS; p = 0.32) and were highly variable (0.0 to 3.5 mm Hg/year in DMS and 0.0 to 5.5 mm Hg/year in RMS) within both groups among disease progression. In DMS patients, atherosclerotic comorbidities and lower initial mean gradient were significantly associated with disease progression even after adjustment by age and sex. There was no significant difference in the disease progression according to the circumferential MAC severity determined by echocardiography among DMS. In conclusion, DMS disease progression was slow but highly variable, similar to that of RMS. In patients with DMS, the baseline MAC severity did not correlate with disease progression, suggesting the importance of follow-up echocardiography regardless of the MAC severity.

Prevalence, determinants, and prognostic significance of exercise-induced pulmonary hypertension in patients with hypertrophic cardiomyopathy.

Exercise-induced pulmonary hypertension (EIPH) is associated with worse outcomes in patients with heart failure or valvular heart disease. However, little is known regarding the implications of EIPH in hypertrophic cardiomyopathy (HCM) patients. We retrospectively reviewed data of consecutive HCM patients who underwent clinically indicated exercise echocardiography using a semi-supine bicycle ergometer at our hospital. EIPH was defined as pulmonary artery systolic pressure ≥ 60 mmHg during exercise. The incidences of HCM-related mortality and HCM-related morbidity during follow-up period were evaluated. Of 42 patients (mean age 59 ± 21 years; 4 with resting obstruction, 19 with provoked obstruction, and 19 without obstruction), 16 (38%) developed EIPH. Patients with EIPH had significantly longer resting E wave deceleration time (271 ± 116 vs. 213 ± 66 ms; P = 0.04), higher resting pulmonary artery systolic pressure (35 ± 6 vs. 31 ± 5 mmHg; P = 0.04), and higher B-type natriuretic peptide level (283 [222, 465] vs. 142 [54, 423] pg/ml; P = 0.04) than those without EIPH. Kaplan-Meier curve analysis demonstrated that EIPH was significantly associated with HCM-related morbidity (log-rank; P = 0.01). In Cox regression analysis, EIPH was a significant predictor of HCM-related morbidity (hazard ratio: 5.98, 95% confidence interval 1.36-41.07; P = 0.02). In conclusion, EIPH was documented in about one-third of HCM patients. EIPH was a significant predictor of HCM-related morbidity in patients with HCM.