Optimal left ventricular diameter measurement in subjects with sigmoid septum: comparison with three-dimensional left ventricular volume

BACKGROUND

The purpose of this study was to determine the most appropriate measurement of left ventricular (LV) end-diastolic diameter for subjects with the sigmoid septum (SS) by measuring the LV end-diastolic diameter at the base and mid-ventricle and by examining the relationship between these measurements and the three-dimensional (3D) echocardiographic LV end-diastolic volume.

METHODS

In 91 patients who underwent echocardiography for screening cardiovascular abnormalities, the aorto-septal angle (ASA) was measured as an index of the sigmoid septum. LV end-diastolic diameter was measured at the base and mid-ventricular level (DDbase and DDmid, respectively), and their average value was calculated (DDavg). By using 3D echocardiography, LV end-diastolic volume (EDV3D) was measured.

RESULTS

Among 91 patients, 48 patients had narrow ASA (< 120 degrees) and were divided into the sigmoid septum (SS) group, and the remaining 43 patients were divided into the non-SS group. In the SS group, all DDbase, DDmid, and DDavg were significantly correlated with EDV3D (r = 0.59, 0.80, and 0.76, respectively), and the correlation coefficient between DDbase and EDV3D was significantly lower than that between DDmid and EDV3D (p < 0.01). On the other hand, in the non-SS group, all DDbase, DDmid, and DDavg were significantly correlated with EDV3D (r = 0.77, 0.85, and 0.84, respectively), and the correlation coefficient between DDbase and EDV3D was statistically comparable to that between DDmid and EDV3D (p = 0.12). ASA was significantly correlated with the difference of DDmid minus DDbase (r =  - 0.71, p < 0.001).

CONCLUSIONS

In patients with SS, DDmid and DDavg were well reflected the 3D echocardiographic LV end-diastolic volume.

Left Ventricle Size Correlates with Peak Exercise Capacity in Pediatric Cancer Survivors Exposed to Anthracycline Chemotherapy

Cancer survivors exposed to anthracycline chemotherapy are at risk for developing cardiomyopathy, which may have delayed clinical manifestation. In a retrospective cross-sectional study, we evaluated the utility of cardiopulmonary exercise testing (CPET) for detecting early cardiac disease in 35 pediatric cancer survivors by examining the associations between peak exercise capacity (measured via percent predicted peak VO2) and resting left ventricular (LV) function on echocardiography and cardiac magnetic resonance imaging (cMRI). We additionally assessed the relationships between LV size on resting echocardiography or cMRI and percent predicted peak VO2 since LV growth arrest can occur in anthracycline-exposed patients prior to changes in LV systolic function. We found reduced exercise capacity in this cohort, with low percent predicted peak VO2 (62%, IQR: 53-75%). While most patients in our pediatric cohort had normal LV systolic function, we observed associations between percent predicted peak VO2 and echocardiographic and cMRI measures of LV size. These findings indicate that CPET may be more sensitive in manifesting early anthracycline-induced cardiomyopathy than echocardiography in pediatric cancer survivors. Our study also highlights the importance of assessing LV size in addition to function in pediatric cancer survivors exposed to anthracyclines.

The impact of left ventricular size on outcomes after centrifugal-flow left ventricular assist device implantation

OBJECTIVES

The influence of preoperative left ventricular size in outcomes following centrifugal-flow left ventricular assist device (LVAD) implantation has not been well characterized.

METHODS

A cohort of 313 patients who received a centrifugal-flow LVAD at a single institution was analysed. Using a maximally selected log-rank statistic, we investigated whether a left ventricular end-diastolic dimension (LVEDD) cut-off point was associated with worse outcomes. The cohort was then divided in 2 groups based on the LVEDD cut-off point.

RESULTS

An LVEDD cut-off point of 59 mm was found to predict worse survival. Smaller LVEDD patients (≤59 mm, N = 52) were older and more likely to have a history of coronary artery disease compared those with a larger LVEDD (>59 mm, N = 261). Smaller LVEDD patients had lower survival compared to larger LVEDD patients (71% vs 85% at 1 year and 58% vs 80% at 2 years, P = 0.003). The need for temporary right ventricular mechanical support was significantly higher in the smaller LVEDD cohort (11.5% vs 1.9%, P = 0.002). Pump flows at time of discharge were lower in the smaller LVEDD group (3.8 vs 4.2 l/min, P = 0.005), who also had a higher incidence of late right ventricular failure (23% vs 12%, P = 0.02), higher rates of gastrointestinal bleeding (0.416 vs 0.256 events per patient-year, P = 0.025) and higher readmissions secondary to low flow alarms (0.429 vs 0.240 events per patient-year, P = 0.007). Multivariable analysis demonstrated that smaller LVEDD, older age, high BUN and high bilirubin levels were independent predictors of worse survival.

CONCLUSIONS

In patients receiving a centrifugal-flow LVAD, smaller preoperative LVEDD (≤59 mm) was associated with lower survival and higher incidence of adverse outcomes.

Effect of isolated left bundle-branch block on biventricular volumes and ejection fraction: a cardiovascular magnetic resonance assessment

BACKGROUND

Left bundle branch block (LBBB) is associated with abnormal left ventricular (LV) contraction, and is frequently associated with co-morbid cardiovascular disease, but the effect of an isolated (i.e. in the absence of cardiovascular dissease) LBBB on biventricular volumes and ejection fraction (EF) is not well characterized. The objective of this study was to compare LV and right ventricular (RV) volumes and EF in adults with an isolated LBBB to matched healthy controls and to population-derived normative values, using cardiovascular magnetic resonance (CMR) imaging.

METHODS

We reviewed our clinical echocardiography database and the Framingham Heart Study Offspring cohort CMR database to identify adults with an isolated LBBB. Age-, sex-, hypertension-status, and body-surface area (BSA)-matched controls were identified from the Offspring cohort. All study subjects were scanned using the same CMR hardware and imaging sequence. Isolated-LBBB cases were compared with matched controls using Wilcoxon paired signed-rank test, and to normative reference values via Z-score.

RESULTS

Isolated-LBBB subjects (n = 18, 10F) ranged in age from 37 to 82 years. An isolated LBBB was associated with larger LV end-diastolic and end-systolic volumes (both p < 0.01) and lower LVEF (56+/- 7% vs. 68+/- 6%; p  <0.001) with similar myocardial contraction fraction. LVEF in isolated LBBB was nearly two standard deviations (Z = - 1.95) below mean sex and age-matched group values. LV stroke volume, cardiac output, and mass, and all RV parameters were similar (p = NS) between the groups.

CONCLUSIONS

Adults with an isolated LBBB have greater LV volumes and markedly reduced LVEF, despite the absence of overt cardiovascular disease. These data may be useful toward the clinical interpretation of imaging studies performed on patients with an isolated LBBB.

Left ventricular size as a predictor of outcome in patients of non-ischemic dilated cardiomyopathy with severe left ventricular systolic dysfunction

BACKGROUND

Limited data is available regarding prognosis of patients with severe left ventricular (LV) systolic dysfunction and varying LV dimensions. Purpose of this study was to compare outcomes of patients with non-ischemic dilated cardiomyopathy (DCM) with respect to LV size.

METHODS

145 patients of DCM cohort with LV ejection fraction <35% were divided into 3 groups. Group 1 with normal LV dimensions, group 2 with mild-moderately enlarged left ventricle and group 3 with severely dilated left ventricle. Primary endpoint was composite of all cause mortality and heart failure hospitalizations at end of follow-up.

RESULTS

Forty-four patients (30.3%) with normal LV diastolic diameter (51.9±5.3mm) were included in group 1, 57(39.3%) with mild-moderately enlarged LV (61.4±3.7mm) in group 2 and 44(30.3%) with severely enlarged LV (71.3±7.4mm) in group 3. Mean follow-up was 42.2±31.6months. Primary end point occurred in 4 patients (9.1%) in group 1, 8 patients (14%) in group 2 and 9 patients (20.5%) in group 3, p=0.23 by log-rank test. Hazard ratio for primary endpoint in group 2 as compared to group 1 was 1.71(95% CI, 0.51 to 5.67; p=0.39) and in group 3 as compared to group 1 was 1.61(95% CI, 0.89 to 2.91; p=0.11). Of patients with more than two years of follow-up, 2 of 29 patients(6.9%) died in group 1, 3 of 35 patients(8.6%) in group 2 and 3 of 34 patients(8.8%) died in group 3, p=0.95.

CONCLUSIONS

Intermediate term prognosis of patients with severe LVSD and severely dilated left ventricle is good, with outcomes similar to patients with normal or mild-moderately dilated left ventricle.

Determination and distribution of left ventricular size as measured by noncontrast CT in the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Left ventricular (LV) volume and mass have prognostic relevance. Overall size of the left ventricle as it appears in noncontrast CT is a composite of the ventricular volume and myocardial mass. We describe a method to estimate the LV size using a single cross-section in noncontrast CT and determined normal ranges on the basis of a large population cohort.

METHODS

The Multi-Ethnic Study of Atherosclerosis with 6814 participants from 4 ethnicities who were free of known cardiovascular disease and enrolled between 2000 and 2002 form the basis of our analysis. LV size was calculated from a single cross-sectional slice obtained by either nonenhanced electron beam or multidetector CT. LV size was adjusted to body surface area to obtain the LV size index, which was adjusted for age, sex, race or ethnicity, hypertension, hyperlipidemia, and diabetes.

RESULTS

There were significant differences in LV size index by race which were further influenced by age and sex. Higher values were noted in men in all ethnic groups across all age groups. Similarly, LV size index uniformly decreased with age across all ethnic and sex categories. Caucasians had the lowest and African Americans had the highest LV size index across all age and sex categories. In multivariate regression analyses adjusted for age, sex, race or ethnicity, hypertension, hyperlipidemia, smoking, and diabetes mellitus, the significant differences were noted between male vs female (median difference, 17.5 cc/m(2); P < .001), ethnic groups (Caucasian, reference group; Asian, 3.7 cc/m(2); African American, 8.3 cc/m(2); and Hispanic, 5.6 cc/m(2); P < .001), and age groups (45-54 years, reference group; 55-64 years, -5.2 cc/m(2); 65-74 years, -11.4 cc/m(2); and 74-84 years, -12.5 cc/m(2)).

CONCLUSIONS

This study provides normative values for LV size as determined from a single, nonenhanced CT cross-section and indexed to body surface area, and it demonstrates that the LV size index varies by age, sex, and ethnic background.

Does left ventricular size impact on intrinsic right ventricular function in hypoplastic left heart syndrome?

BACKGROUND

The size of the remnant left ventricle (LV) may influence right ventricular function and thus long-term outcome in palliated hypoplastic left heart syndrome (HLHS). We therefore sought to assess the impact of the size of the hypoplastic LV on intrinsic RV function in HLHS patients after Fontan surgery.

METHODS

Fifty-seven HLHS patients were studied 2.5 (range: 0.8-12.6) years after Fontan-type palliation with the pressure-volume conductance system. The patient cohort was divided into two groups according to the median LV area index (group 1: LV area index ≤ 1.33 cm(2)/m(2), n=29; group 2: LV area index>1.33 cm(2)/m(2), n=28).

RESULTS

The slopes of the end systolic elastance (Ees) and the preload recruitable stroke work relation (Mw) were not different between group 1 and 2 (Ees: 2.70 ± 1.92 vs. 3.68 ± 2.68 mmHg/ml; Mw: 52.75 ± 14.98 vs. 51.09 ± 16.63 mmHg x ml; P=NS for all). Furthermore, the systolic responses to dobutamine were not statistically different between groups. However, the slope of the end diastolic stiffness (Eed) was higher in group 2 and catecholaminergic stimulation resulted in a decrease in Eed in group 2 (group 1: 0.40 ± 0.26 vs. 0.52 ± 0.45; group 2: 0.68 ± 0.44 vs. 0.47 ± 0.38 mmHg/ml, P<0.01). Furthermore Eed was lowest in patients with mitral atresia/aortic atresia, the anatomic subgroup with the smallest LV remnant.

CONCLUSIONS

Intrinsic systolic RV function is not affected by the size of the hypoplastic LV in survivors of surgical palliation of HLHS. Diastolic stiffness, however, was higher in patients with a larger LV remnant.