Marga B. Rominger

Occurrence of late gadolinium enhancement is associated with increased left ventricular wall stress and mass in patients with non-ischaemic dilated cardiomyopathy.

Occurrence of late gadolinium enhancement (LGE) as assessed by cardiac magnetic resonance (CMR) imaging has been attributed to various myocardial injuries. We hypothesized that LGE is associated with left ventricular (LV) wall stress.

Increased enddiastolic wall stress precedes left ventricular hypertrophy in dilative heart failure—Use of the volume-based wall stress index

INTRODUCTION To examine a potential interrelation of left ventricular (LV) wall stress and hypertrophy, we assessed increased wall stress in patients with suspected non-ischemic dilative cardiomyopathy and addressed the question whether increased LV wall stress is involved in the development of LV hypertrophy. METHODS We studied 502 consecutive patients in whom LV mass, LV enddiastolic (LVEDV) and endsystolic volume (LVESV) was determined using cardiac magnetic resonance (CMR). Based on a thick-walled sphere, we introduced a myocardial and cavity volume-based wall stress index. Follow up CMR examinations were obtained in a representative subgroup of 71 patients. RESULTS LV mass was correlated with LVEDV (r=0.517, P<0.001) and LVESV (r=0.510, P<0.001). Despite LV hypertrophy, LV mass was not sufficient to compensate for LV dilatation resulting in an increased wall stress. Increased LV enddiastolic wall stress was found in 227 patients (45 %) and increased endsystolic wall stress in 198 (39 %). In patients with normal LV enddiastolic wall stress ≤ 4 kPa at time of enrolment, no changes of LV mass occurred during follow up (142 ± 46 g vs. 141 ± 47 g). In contrast, patients with initially increased LV enddiastolic wall stress >4 kPa developed greater LV hypertrophy (141 ± 48 g vs. 158 ± 60 g, P=0.0247). CONCLUSIONS LV wall stress can be derived from CMR measurements of LV myocardium and cavity using the volume-based wall stress index. Increased LV enddiastolic wall stress leads to LV hypertrophy. Beyond a certain degree of LV dilatation, the extent of hypertrophy does not compensate LV dilatation. The ensuing increased wall stress promotes dilatation and consecutively hypertrophy with an unfavorable prognosis. It is proposed to use the volume-based wall stress index as new diagnostic criterion in heart failure.

Association of hyperhomocysteinemia with left ventricular dilatation and mass in human heart.

Abstract Background: Hyperhomocysteinemia is a risk factor for ischemic heart disease. Several other mechanisms apply also to dilative types of heart failure of various, non-ischemic etiologies. We hypothesized that hyperhomocysteinemia is associated with left ventricular (LV) dilatation and hypertrophy in dilative cardiomyopathy. Methods: Homocysteine was measured in 66 individuals with suspected cardiomyopathy. Cardiac magnetic resonance imaging was used to assess LV volume, mass, and wall stress. Results: Hyperhomocysteinemia (>12 μmol/L) was found in 45 patients (68%). LV mass was greater in these patients compared with individuals with normal homocysteine (83±27 vs. 67±19 g/m2; p<0.02). Homocysteine was increased in patients with increased brain natriuretic peptide ≥100 pg/mL (18.3±5.9 vs. 14.9±5.1 μmol/L; p=0.018). LV mass, LV end-diastolic and end-systolic volume (LVEDV, LVESV) were significantly increased in individuals in the upper quartile compared with the lower quartile (90±25 vs. 65±18 g/m2, p=0.021; 114±50 vs. 71±23 mL/m2, p=0.042; 76±51 vs. 36±22 mL/m2, p=0.045). LV dilatation (LVEDV≥90 mL/m2) was more common in hyperhomocysteinemia (>12 μmol/L, p=0.0166). Normalized LV mass was correlated with homocysteine (r=0.346, p=0.065). Homocysteine was not significantly correlated with LVEDV (r=0.229, p=0.065), LV end-diastolic wall stress (r=0.226, p=0.069) and LV ejection fraction. Conclusions: Hyperhomocysteinemia appears to be, at least in part, involved in a disproportional LV dilatation, where the ensuing hypertrophy is not sufficient to compensate for the increased wall stress. A potential mechanism is the hyperhomocysteinemia associated increase in oxidative stress that favors muscle fiber slippage. Clin Chem Lab Med 2010;48:555–60.

Right ventricular cardiac myxoma. Diagnostic usefulness of cardiac magnetic resonance imaging.

Background:Cardiac myxomas are the most common type of cardiac tumors. About 75–85% of cardiac myxomas originate in the left atrium, 15–20% in the right atrium. Most myxomas arise from the interatrial septum adjacent to the fossa ovalis. Only 3–4% are found in the left and right ventricle each. Although myxomas are histologically benign, they may be fatal because of their strategic position.Case Study:The authors report on a 24-year-old patient with stabbing thoracic pain and dyspnea due to pulmonary thromboembolism that was caused by an atypically localized myxoma at the right ventricular apex originating from the interventricular septum. The diagnosis was based on cardiac magnetic resonance (CMR) imaging. Superior to echocardiography, CMR could strengthen the diagnostic accuracy by additional information on tissue characterization using different imaging sequences. Typically for cardiac myxomas, contrast enhancement was moderate and delayed enhancement was found in the outer circumferential tumor margins only.Conclusion:High spatial resolution and multiplane imaging combined with different acquisition patterns of CMR achieve a global view of the heart that seems to be useful for diagnosing cardiac tumorous masses.ZusammenfassungHintergrund:Myxome sind die häufigsten kardialen Tumoren und zu 75–85% im linken sowie zu 15–20% im rechten Vorhof zu finden. Die linksatrialen Myxome entspringen üblicherweise von der Fossa ovalis. Nur 3–4% sind jeweils rechts- bzw. linksventrikulär lokalisiert. Obwohl Myxome histologisch benigne sind, können sie aufgrund ihrer Lokalisation erhebliche Folgeerscheinungen wie beispielsweise Thromboembolien oder mechanische Herzklappenbeeinträchtigungen, intrakavitäre Obstruktionen oder Herzrhythmusstörungen nach sich ziehen.Fallbericht:Die Autoren berichten den Fall eines 24-jährigen Patienten mit stechenden thorakalen Beschwerden und Dyspnoe, hervorgerufen durch eine Lungenembolie. Ursache war ein atypisch lokalisiertes Myxom im Bereich des rechtsventrikulären Apex mit Ursprung am interventrikulären Septum. Die kardiale Magnetresonanztomographie mit unterschiedlichen Bildgebungssequenzen wurde zur Charakterisierung der Raumforderung herangezogen. Es fand sich eine nur mäßige Kontrastmittelaufnahme in der First-Pass-Perfusion, wie dies für Myxome typisch ist. Ein „delayed enhancement“ 15 min nach Kontrastmittelapplikation wurde im äußeren Randbereich des Myxoms gefunden. Darüber hinaus grenzte sich das Myxom in ödemsensitiven Sequenzen deutlich von seiner Umgebung ab.Schlussfolgerung:Die kardiale Magnetresonanztomographie bietet durch ihre hohe räumliche Auflösung und die Möglichkeiten der multiplanaren Darstellung, kombiniert mit verschiedenen Aufnahmesequenzen, eine gute Möglichkeit zur morphologischen Erfassung und Gewebecharakterisierung kardialer Raumforderungen.

Wall stress determines systolic and diastolic function — Characteristics of heart failure

INTRODUCTION Heart failure can be caused by systolic or diastolic dysfunction. Diagnosing diastolic dysfunction remains challenging, although several criteria have been identified. Ventricular wall stress is crucially involved. It is hypothesized whether increased end-diastolic and end-systolic ventricular wall stress as assessed by the wall stress index is associated with cardiac dysfunction and thus provide novel diagnostic criteria. METHODS 1050 consecutive patients with suspected non-ischemic heart failure covering a broad spectrum from normal to severely impaired cardiac function were observed. Cardiac magnetic resonance imaging was performed to assess left ventricular (LV) volumes, myocardial mass, peak ejection (PER) and filling rate (PFR). RESULTS A reduced PFR was found in 348 patients (33.1%), which resulted from 275 of 422 patients (65.2%) with reduced and from 73 of 628 patients (11.6%) with preserved LVEF (p<0.0001). Increased LV volume and mass was correlated with reduced PER and PFR (p<0.0001). Increased end-diastolic wall stress was the strongest predictor of a reduced PER (OR 4.5 [2.6 to 7.8], p<0.0001) and increased end-systolic wall stress predicted a reduced PFR (OR 1.2 [1.1 to 1.3], p<0.0001). Increased end-systolic wall stress was correlated with increased pulmonary pressure (p<0.0001). Normal end-systolic wall stress<18 kPa had a favorable predictive value for the absence of an impaired filling and increased pulmonary capillary pressure. CONCLUSION Increased end-diastolic wall stress precedes a reduced ventricular ejection rate and increased end-systolic wall stress determines an impaired diastolic filling. It is thus suggested to add assessment of ventricular wall stress as diagnostic criterion of heart failure.

The missing link between heart failure and sleep disordered breathing: increased left ventricular wall stress.

I study, we observed that the infusion of the combination cell product did not elicit, both in control and treated patients, any significant change in LVEF (Table 2A). Likewise in both group of patients, SSS and SRS values after three months of follow up did not significantly differ to those at baseline. In turn, in the group of treated but not in control patients we noticed a statistically significant decrease (p: 0.03) in SDS values, at 3 months of follow up (Table 2B). These findings are suggestive of a noteworthy decrease in myocardial ischemic burden triggered by the infusion of the combination cell product. The above assumption correlates with an improvement in quality of life measurements and a decreased nitroglycerin consumption (data not shown). The observed change in myocardial ischemic burden following intracoronary infusion of the cell product, gives strength to the contention that the infusion of a combination of ECs andMSC promotes the development of mature and stable new blood vessels. The previous assumption is also in agreement with the observation that after an acute MI, while the number of circulating EC precursors is within acceptable limits the level of circulating MSC is extremely low [6]. Whether the results here reported prove to be momentous, the concurrent infusion of a source of EC and MSC gains strength as a novel therapeutic modality to treat MI.

Depression of Heart Rate Variability in Patients with Increased Ventricular Wall Stress

Background: Heart failure is characterized by neurohumoral dysfunction that can be assessed by measurement of heart rate variability (HRV). Depression of HRV is related to several hemodynamic parameters. We hypothesized that an increased left ventricular (LV) wall stress is related to a depressed HRV in patients with LV dilatation or dysfunction.

Economical sponge phantom for teaching, understanding, and researching A- and B-Line reverberation artifacts in lung ultrasound

This project evaluated a low‐cost sponge phantom setup for its capability to teach and study A‐ and B‐line reverberation artifacts known from lung ultrasound and to numerically simulate sound wave interaction with the phantom using a finite‐difference time‐domain (FDTD) model. Both A‐ and B‐line artifacts were reproducible on B‐mode ultrasound imaging as well as in the FDTD‐based simulation. The phantom was found to be an easy‐to‐set up and economical tool for understanding, teaching, and researching A‐ and B‐line artifacts occurring in lung ultrasound. The FDTD method–based simulation was able to reproduce the artifacts and provides intuitive insight into the underlying physics.

Accuracy of MRI volume measurements of breast lesions: comparison between automated, semiautomated and manual assessment

The aim of this study was to investigate the efficacy of a dedicated software tool for automated and semiautomated volume measurement in contrast-enhanced (CE) magnetic resonance mammography (MRM). Ninety-six breast lesions with histopathological workup (27 benign, 69 malignant) were re-evaluated by different volume measurement techniques. Volumes of all lesions were extracted automatically (AVM) and semiautomatically (SAVM) from CE 3D MRM and compared with manual 3D contour segmentation (manual volume measurement, MVM, reference measurement technique) and volume estimates based on maximum diameter measurement (MDM). Compared with MVM as reference method MDM, AVM and SAVM underestimated lesion volumes by 63.8%, 30.9% and 21.5%, respectively, with significantly different accuracy for benign (102.4%, 18.4% and 11.4%) and malignant (54.9%, 33.0% and 23.1%) lesions (p < 0.05). Inter- and intraobserver reproducibility was best for AVM (mean difference ± 2SD, 1.0 ± 9.7% and 1.8 ± 12.1%) followed by SAVM (4.3 ± 25.7% and 4.3 ± 7.9%), MVM (2.3 ± 38.2% and 8.6 ± 31.8%) and MDM (33.9 ± 128.4% and 9.3 ± 55.9%). SAVM is more accurate for volume assessment of breast lesions than MDM and AVM. Volume measurement is less accurate for malignant than benign lesions.

Breast-density assessment with hand-held ultrasound: A novel biomarker to assess breast cancer risk and to tailor screening?

ObjectivesTo assess feasibility and diagnostic accuracy of a novel hand-held ultrasound (US) method for breast density assessment that measures the speed of sound (SoS), in comparison to the ACR mammographic (MG) categories.MethodsACR-MG density (a=fatty to d=extremely dense) and SoS-US were assessed in the retromamillary, inner and outer segments of 106 women by two radiographers. A conventional US system was used for SoS-US. A reflector served as timing reference for US signals transmitted through the breasts. Four blinded readers assessed average SoS (m/s), ΔSoS (segment-variation SoS; m/s) and the ACR-MG density. The highest SoS and ΔSoS values of the three segments were used for MG-ACR whole breast comparison.ResultsSoS-US breasts were examined in <2 min. Mean SoS values of densities a-d were 1,421 m/s (SD 14), 1,432 m/s (SD 17), 1,448 m/s (SD 20) and 1,500 m/s (SD 31), with significant differences between all groups (p<0.001). The SoS-US comfort scores and inter-reader agreement were significantly better than those for MG (1.05 vs. 2.05 and 0.982 vs. 0.774; respectively). A strong segment correlation between SoS and ACR-MG breast density was evident (rs=0.622, p=<0.001) and increased for full breast classification (rs=0.746, p=<0.001). SoS-US allowed diagnosis of dense breasts (ACR c and d) with sensitivity 86.2 %, specificity 85.2 % and AUC 0.887.ConclusionsUsing hand-held SoS-US, radiographers measured breast density without discomfort, readers evaluated measurements with high inter-reader agreement, and SoS-US correlated significantly with ACR-MG breast-density categories.Key Points• The novel speed-of-sound ultrasound correlated significantly with mammographic ACR breast density categories.• Radiographers measured breast density without women discomfort or radiation.• SoS-US can be implemented on a standard US machine.• SoS-US shows potential for a quantifiable, cost-effective assessment of breast density.