Changes In Ventricular Volume Research Articles

Subclinical changes in MRI-determined right ventricular volumes and function in subjects with prediabetes and diabetes.

The aim of this study was to assess subclinical changes in right ventricular volumes and function in subjects with prediabetes and diabetes and controls without a history of cardiovascular disease. Data from 400 participants in the KORA FF4 study without self-reported cardiovascular disease who underwent 3-T whole-body MRI were obtained. The right ventricle was evaluated using the short axis and a four-chamber view. Diabetes was defined according to WHO criteria. Associations between glucose tolerance and right ventricular parameters were assessed using multivariable adjusted linear regression models. Data from 337 participants were available for analysis. Of these, 43 (13%) had diabetes, 87 (26%) had prediabetes, and 207 (61%) were normoglycaemic controls. There was a stepwise decrease in right ventricular volumes in men with prediabetes and diabetes in comparison with controls, including right ventricular end-diastolic volume (β = -20.4 and β = -25.6, respectively; p ≤ 0.005), right ventricular end-systolic volume (β = -12.3 and β = -12.7, respectively; p ≤ 0.037) and right ventricular stroke volume (β = -8.1 and β = -13.1, respectively, p ≤ 0.016). We did not observe any association between prediabetes or diabetes and right ventricular volumes in women or between prediabetes or diabetes and right ventricular ejection fraction in men and women. This study points towards early subclinical changes in right ventricular volumes in men with diabetes and prediabetes. • MRI was used to detect subclinical changes in right ventricular parameters. • Diabetes mellitus is associated with right ventricular dysfunction. • Impairment of right ventricular volumes seems to occur predominantly in men.

Increase in callosal angle and decrease in ventricular volume after shunt surgery in patients with idiopathic normal pressure hydrocephalus.

OBJECTIVE Postoperative decrease in ventricle size is usually not detectable either by visual assessment or by measuring the Evans index in patients with idiopathic normal pressure hydrocephalus (iNPH). The aim of the present study was to investigate whether the angle between the lateral ventricles (the callosal angle [CA]) increases and ventricular volume decreases after shunt surgery in patients with iNPH. METHODS Magnetic resonance imaging of the brain was performed before and 3 months after shunt surgery in 18 patients with iNPH. The CA and Evans index were measured on T1-weighted 3D MR images, and ventricular volume contralateral to the shunt valve was measured with quantitative MRI. RESULTS The CA was larger postoperatively (mean 78°, 95% CI 69°-87°) than preoperatively (mean 67°, 95% CI 60°-73°; p < 0.001). The volume of the lateral ventricle contralateral to the shunt valve decreased from 73 ml (95% CI 66-80 ml) preoperatively to 63 ml (95% CI 54-72 ml) postoperatively (p < 0.001). The Evans index was 0.365 (95% CI 0.35-0.38) preoperatively and 0.358 (95% CI 0.34-0.38) postoperatively (p < 0.05). Postoperative change of CA showed a negative correlation with change of ventricular volume (r = -0.76, p < 0.01). CONCLUSIONS In this sample of patients with iNPH, the CA increased and ventricular volume decreased after shunt surgery. The relative difference was most pronounced for the CA, indicating that this accessible, noninvasive radiological marker should be evaluated further as an indirect method to determine shunt function in patients with iNPH.

Passive Self Resonant Skin Patch Sensor to Monitor Cardiac Intraventricular Stroke Volume Using Electromagnetic Properties of Blood.

This paper focuses on the development of a passive, lightweight skin patch sensor that can measure fluid volume changes in the heart in a non-invasive, point-of-care setting. The wearable sensor is an electromagnetic, self-resonant sensor configured into a specific pattern to formulate its three passive elements (resistance, capacitance, and inductance). In an animal model, a bladder was inserted into the left ventricle (LV) of a bovine heart, and fluid was injected using a syringe to simulate stoke volume (SV). In a human study, to assess the dynamic fluid volume changes of the heart in real time, the sensor frequency response was obtained from a participant in a 30° head-up tilt (HUT), 10° HUT, supine, and 10° head-down tilt positions over time. In the animal model, an 80-mL fluid volume change in the LV resulted in a downward frequency shift of 80.16 kHz. In the human study, there was a patterned frequency shift over time which correlated with ventricular volume changes in the heart during the cardiac cycle. Statistical analysis showed a linear correlation n}{}{R} ^{2} = 0.98n and 0.87 between the frequency shifts and fluid volume changes in the LV of the bovine heart and human participant, respectively. In addition, the patch sensor detected heart rate in a continuous manner with a 0.179% relative error compared to electrocardiography. These results provide promising data regarding the ability of the patch sensor to be a potential technology for SV monitoring in a non-invasive, continuous, and non-clinical setting.

A study on change in ejection fraction during simulated diving in humans

Background: It has been observed that complex cardiovascular changes including cardiac rhythm and conduction occur during simulated diving in humans. As the study requires technical expertise, not many studies are conducted in this field. Two-dimensional (2D) echocardiography is a feasible method to study the cardiovascular changes during breath-hold immersion of the face in water. There is well-documented evidence for changes in left ventricular (LV) end-diastolic volume, stroke volume, and cardiac output. LV ejection fraction (LV EF) which is an important cardiac parameter that determines the amount of oxygenated blood each organ receives has not gained much attention. Hence, the present study was focused on the changes in LV EF with breath-hold immersion of the face in water. Aims and Objective: The objective of the study is to observe the change in LV EF during breath-hold immersion of the face in water using 2D echocardiography. Materials and Methods: The study was conducted in 15 male swimmers of age group 25–35 years, who are used to active breath-hold swimming. Results: There was a statistically significant reduction in LV EF during breath-hold immersion of the face in water. Conclusion: Cardiovascular changes during breath-hold immersion of the face in water are important as a majority of our population is involved with water-related activities for leisure, sports, or livelihood. The change in the cardiac parameter, LV EF, can be extrapolated to the case of actual swimming.

Change in Right Ventricular Volume and Function After Pulmonary Valve Replacement

Change in Right Ventricular Volume and Function After Pulmonary Valve Replacement

Establishing pathological cut-offs for lateral ventricular volume expansion rates.

BackgroundA percent brain volume change (PBVC) cut-off of −0.4% per year has been proposed to distinguish between pathological and physiological changes in multiple sclerosis (MS). Unfortunately, standardized PBVC measurement is not always feasible on scans acquired outside research studies or academic centers. Percent lateral ventricular volume change (PLVVC) is a strong surrogate measure of PBVC, and may be more feasible for atrophy assessment on real-world scans. However, the PLVVC rate corresponding to the established PBVC cut-off of −0.4% is unknown.ObjectiveTo establish a pathological PLVVC expansion rate cut-off analogous to −0.4% PBVC.MethodsWe used three complementary approaches. First, the original follow-up-length-weighted receiver operating characteristic (ROC) analysis method establishing whole brain atrophy rates was adapted to a longitudinal ventricular atrophy dataset of 177 relapsing-remitting MS (RRMS) patients and 48 healthy controls. Second, in the same dataset, SIENA PBVCs were used with non-linear regression to directly predict the PLVVC value corresponding to −0.4% PBVC. Third, in an unstandardized, real world dataset of 590 RRMS patients from 33 centers, the cut-off maximizing correspondence to PBVC was found. Finally, correspondences to clinical outcomes were evaluated in both datasets.ResultsROC analysis suggested a cut-off of 3.09% (AUC = 0.83, p < 0.001). Non-linear regression R2 was 0.71 (p < 0.001) and a − 0.4% PBVC corresponded to a PLVVC of 3.51%. A peak in accuracy in the real-world dataset was found at a 3.51% PLVVC cut-off. Accuracy of a 3.5% cut-off in predicting clinical progression was 0.62 (compared to 0.68 for PBVC).ConclusionsVentricular expansion of between 3.09% and 3.51% on T2-FLAIR corresponds to the pathological whole brain atrophy rate of 0.4% for RRMS. A conservative cut-off of 3.5% performs comparably to PBVC for clinical outcomes.

Novel Mitochondria-Targeting Peptide in Heart Failure Treatment

Mitochondrial dysfunction and energy depletion in the failing heart are innovative therapeutic targets in heart failure management. Elamipretide is a novel tetrapeptide that increases mitochondrial energy; however, its safety, tolerability, and therapeutic effect on cardiac structure and function have not been studied in heart failure with reduced ejection fraction. In this double-blind, placebo-controlled, ascending-dose trial, patients with heart failure with reduced ejection fraction (ejection fraction, ≤35%) were randomized to either a single 4-hour infusion of elamipretide (cohort 1 [n=8], 0.005; cohort 2 [n=8], 0.05; and cohort 3 [n=8], 0.25 mg·kg-1·h-1) or placebo control (n=12). Safety and efficacy were assessed by clinical, laboratory, and echocardiographic assessments performed at pre-, mid- and end-infusion and 6-, 8-, 12- and 24-hours postinfusion start. Peak plasma concentrations of elamipretide occurred at end-infusion and were undetectable by 24 hours postinfusion. There were no serious adverse events. Blood pressure and heart rate remained stable in all cohorts. Compared with placebo, a significant decrease in left ventricular end-diastolic volume (-18 mL; P=0.009) and end-systolic volume (-14 mL; P=0.005) occurred at end infusion in the highest dose cohort. This is the first study to evaluate elamipretide in heart failure with reduced ejection fraction and demonstrates that a single infusion of elamipretide is safe and well tolerated. High-dose elamipretide resulted in favorable changes in left ventricular volumes that correlated with peak plasma concentrations, supporting a temporal association and dose-effect relationship. Further study of elamipretide is needed to determine long-term safety and efficacy. URL: https://www.clinicaltrials.gov. Unique identifier: NCT02388464.

Persistence of Infarct Zone T2 Hyperintensity at 6 Months After Acute ST-Segment-Elevation Myocardial Infarction: Incidence, Pathophysiology, and Prognostic Implications.

The incidence and clinical significance of persistent T2 hyperintensity after acute ST-segment-elevation myocardial infarction (STEMI) is uncertain. Patients who sustained an acute STEMI were enrolled in a cohort study (BHF MR-MI: NCT02072850). Two hundred eighty-three STEMI patients (mean age, 59±12 years; 75% male) had cardiac magnetic resonance with T2 mapping performed at 2 days and 6 months post-STEMI. Persisting T2 hyperintensity was defined as infarct T2 >2 SDs from remote T2 at 6 months. Infarct zone T2 was higher than remote zone T2 at 2 days (66.3±6.1 versus 49.7±2.1 ms; P<0.001) and 6 months (56.8±4.5 versus 49.7±2.3 ms; P<0.001). Remote zone T2 did not change over time (mean change, 0.0±2.7 ms; P=0.837), whereas infarct zone T2 decreased (-9.5±6.4 ms; P<0.001). At 6 months, T2 hyperintensity persisted in 189 (67%) patients, who were more likely to have Thrombus in Myocardial Infarction flow 0 or 1 in the culprit artery (P=0.020), incomplete ST-segment resolution (P=0.037), and higher troponin (P=0.024). Persistent T2 hyperintensity was associated with NT-proBNP (N-terminal pro-B-type natriuretic peptide) concentration (0.57 on a log scale [0.42-0.72]; P=0.004) and the likelihood of adverse left ventricular remodeling (>20% change in left ventricular end-diastolic volume; 21.91 [2.75-174.29]; P=0.004). Persistent T2 hyperintensity was associated with all-cause death and heart failure, but the result was not significant (P=0.051). ΔT2 was associated with all-cause death and heart failure (P=0.004) and major adverse cardiac events (P=0.013). Persistent T2 hyperintensity occurs in two thirds of STEMI patients. Persistent T2 hyperintensity was associated with the initial STEMI severity, adverse remodeling, and long-term health outcome. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02072850.

Transient cardiac dysfunction but elevated cardiac and kidney biomarkers 24\xa0h following an ultra-distance running event in Mexican Tarahumara

BackgroundThe Mexican Tarahumara are accustomed to running ultra-distance races. No data exist on the acute physiological changes following ultra-distance running and physiological-biomarker associations in this population. Thus, we aimed to investigate the acute impact (≤ 24 h) on functional and biochemical changes of the cardiac muscle and biochemical changes associated with kidney function following a 63-km ultra-distance race with an altitude difference of 1800 m in Mexican Tarahumara athletes.MethodsTen Tarahumara male athletes (mean ± SD age = 29.9 ± 6.6 years) volunteered to participate in the study. VO2max was assessed by a sub-maximal step test individually calibrated combining heart rate and accelerometry. Standard transthoracic echocardiography methodology and venipuncture blood tests were carried out at four time points: pre-race, immediately post-race, 6 h, and 24 h post-race.ResultsEstimated mean VO2max was 54.5 (± 8.8) mL O2 min−1 kg−1 and average physiological activity intensity was 746 (± 143) J min−1 kg −1 (~ 11.5 METs). When compared to pre-race values, significant changes in left ventricular ejection fraction (LVEF) and LV end-diastolic volume (− 15%, p < 0.001 for both parameters), cardiac output (39%, p < 0.001), and maximal longitudinal velocity (− 13%, p < 0.009) were seen post-race with LVEF also being decreased at < 6 h post-race (− 8%, p < 0.014). Plasma biomarkers mid-regional pro-atrial natriuretic peptide, copeptin-ultra sensitive, and high-sensitivity cardiac troponin T remained significantly elevated at 24 h post-race, and the two latter were inversely associated with LVEF (p < 0.04). Kidney dysfunction was indicated by increased post-race copeptin-ultra sensitive.ConclusionsThe athletes participating in this study had acute transient cardiac dysfunction as assessed by echocardiography but elevated cardiac and kidney biomarkers at 24 h following a 63-km race with extreme altitude variation.

Comparison of strain parameters in dyssynchronous heart failure between speckle tracking echocardiography vendor systems

BackgroundAlthough mechanical dyssynchrony parameters derived by speckle tracking echocardiography (STE) may predict response to cardiac resynchronization therapy (CRT), comparability of parameters derived with different STE vendors is unknown.MethodsIn the MARC study, echocardiographic images of heart failure patients obtained before CRT implantation were prospectively analysed with vendor specific STE software (GE EchoPac and Philips QLAB) and vendor-independent software (TomTec 2DCPA). Response was defined as change in left ventricular (LV) end-systolic volume between examination before and six-months after CRT implantation. Basic longitudinal strain and mechanical dyssynchrony parameters (septal to lateral wall delay (SL-delay), septal systolic rebound stretch (SRSsept), and systolic stretch index (SSI)) were obtained from either separate septal and lateral walls, or total LV apical four chamber. Septal strain patterns were categorized in three types. The coefficient of variation and intra-class correlation coefficient (ICC) were analysed. Dyssynchrony parameters were associated with CRT response using univariate regression analysis and C-statistics.ResultsTwo-hundred eleven patients were analysed. GE-cohort (n = 123): age 68 years (interquartile range (IQR): 61–73), 67% male, QRS-duration 177 ms (IQR: 160–192), LV ejection fraction: 26 ± 7%. Philips-cohort (n = 88): age 67 years (IQR: 59–74), 60% male, QRS-duration: 179 ms (IQR: 166–193), LV ejection fraction: 27 ± 8. LV derived peak strain was comparable in the GE- (GE: -7.3 ± 3.1%, TomTec: −6.4 ± 2.8%, ICC: 0.723) and Philips-cohort (Philips: −7.7 ± 2.7%, TomTec: −7.7 ± 3.3%, ICC: 0.749). SL-delay showed low ICC values (GE vs. TomTec: 0.078 and Philips vs. TomTec: 0.025). ICC’s of SRSsept and SSI were higher but only weak (GE vs. TomTec: SRSsept: 0.470, SSI: 0.467) (Philips vs. QLAB: SRSsept: 0.419, SSI: 0.421). Comparability of septal strain patterns was low (Cohen’s kappa, GE vs. TomTec: 0.221 and Philips vs. TomTec: 0.279). Septal strain patterns, SRSsept and SSI were associated with changes in LV end-systolic volume for all vendors. SRSsept and SSI had relative varying C-statistic values (range: 0.530–0.705) and different cut-off values between vendors.ConclusionsAlthough global longitudinal strain analysis showed fair comparability, assessment of dyssynchrony parameters was vendor specific and not applicable outside the context of the implemented platform. While the standardization taskforce took an important step for global peak strain, further standardization of STE is still warranted.

Evaluation of spatial and temporal relationship between left ventricular volume and longitudinal strain in healthy subjects by 2D speckle-tracking echocardiography

Objective To evaluate the coupling relationship between segmental longitudinal strain and left ventricular volume at different phases of the cardiac cycle by two dimensional speckle tracking imaging. Methods 2D grey scale images of 41 healthy adults were acquired, and time curve of left ventricular volume (LVV), segmental longitudinal strain (LS) and segmental longitudinal strain rate (LSr) were outputed by analysis software. The correlations between LVV and LS or LSr in isovolumic relaxation time(IVRT), the rapid filling time(RFT), the atrial filling time(AFT) and the ejection time(ET) were analyzed respectively. Results ①IVRT: LS in basal segment, middle segment, apical segment of interventricular septum, in apical segment, basal segment of the lateral wall, and in middle segment of inferior wall were low-moderate negatively correlated with LVV; only LSr in middle segment of anterior wall was negatively correlated with LVV (P<0.05). ② RFT: LS in middle segment, apical segment of interventricular septum, in apical segment of the lateral wall were negatively correlated with LVV; LSr in basal segment, middle segment, apical segment of interventricular septum, in apical segment, middle segment, basal segment of lateral wall, in middle segment, basal segment of inferior wall were low-moderate negatively correlated with LVV (P<0.05). ③AFT: LS in basal segment of inferior wall, in apical segment, basal segment of the anterior wall were low negatively correlated wtih LVV (P<0.05). ④ET: LS in basal segment, middle segment, apical segment of interventricular septum, in apical segment, basal segment of the lateral wall were low negatively correlated with LVV (P<0.05); only LSr in apical segment of lateral wall was negatively correlated with LVV (P<0.05). Conclusions LS or LSr in special segments of interventricular septum, lateral wall, anterior wall and posterior wall are actively participate in the volume change of the left ventricle in healthy adults, specific myocardial segments of left ventricular wall are involved in left ventricular volume changes. Key words: Echocardiography; Ventricular function, left; Left ventricular volume; Longitudinal strain; Speckle tracking imaging

Cerebral blood volume and oxygen supply uniformly increase following various intrathoracic pressure strains

Intrathoracic pressure (ITP) swings challenge many physiological systems. The responses of cerebral hemodynamics to different ITP swings are still less well-known due to the complexity of cerebral circulation and methodological limitation. Using frequency-domain near-infrared spectroscopy and echocardiography, we measured changes in cerebral, muscular and cardiac hemodynamics in five graded respiratory maneuvers (RM), breath holding, moderate and strong Valsalva maneuvers (mVM/sVM) with 20 and 40 cmH2O increments in ITP, moderate and strong Mueller maneuvers (mMM/sMM) with 20 and 40 cmH2O decrements in ITP controlled by esophageal manometry. We found cerebral blood volume (CBV) maintains relative constant during the strains while it increases during the recoveries together with increased oxygen supply. By contrast changes in muscular blood volume (MBV) are mainly controlled by systemic changes. The graded changes of ITP during the maneuvers predict the changes of MBV but not CBV. Changes in left ventricular stroke volume and heart rate correlate to MBV but not to CBV. These results suggest the increased CBV after the ITP strains is brain specific, suggesting cerebral vasodilatation. Within the strains, cerebral oxygen saturation only decreases in sVM, indicating strong increment rather than decrement in ITP may be more challenging for the brain.

Association of Concentric Left Ventricular Hypertrophy With Subsequent Change in Left Ventricular End-Diastolic Volume: The Dallas Heart Study.

In the conventional paradigm of the progression of left ventricular hypertrophy, a thick-walled left ventricle (LV) ultimately transitions to a dilated cardiomyopathy. There are scant data in humans demonstrating whether this transition occurs commonly without an interval myocardial infarction. Participants (n=1282) from the Dallas Heart Study underwent serial cardiac magnetic resonance ≈7 years apart. Those with interval cardiovascular events and a dilated LV (increased LV end-diastolic volume [EDV] indexed to body surface area) at baseline were excluded. Multivariable linear regression models tested the association of concentric hypertrophy (increased LV mass and LV mass/volume0.67) with change in LVEDV. The study cohort had a median age of 44 years, 57% women, 43% black, and 11% (n=142) baseline concentric hypertrophy. The change in LVEDV in those with versus without concentric hypertrophy was 1 mL (-9 to 12) versus -2 mL (-11 to 7), respectively, P<0.01. In multivariable linear regression models, concentric hypertrophy was associated with larger follow-up LVEDV (P≤0.01). The progression to a dilated LV was uncommon (2%, n=25). In the absence of interval myocardial infarction, concentric hypertrophy was associated with a small, but significantly greater, increase in LVEDV after 7-year follow-up. However, the degree of LV enlargement was minimal, and few participants developed a dilated LV. These data suggest that if concentric hypertrophy does progress to a dilated cardiomyopathy, such a transition would occur over a much longer timeframe (eg, decades) and perhaps less common than previously thought. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00344903.

THE ROLE OF CARDIOVASCULAR HEALTH IN MODERATING THE EFFECTS OF POSTMENOPAUSAL HORMONE THERAPY ON NEUROIMAGING OUTCOMES

Effects of menopausal hormone therapy (mHT) on neurological function may depend on the timing of initiation of mHT and the overall cardiovascular health of the woman. Effects of mHT on adverse cardiovascular events have been studied, but little is known of how cardiovascular health might interact with mHT to affect brain health. Our objective was to examine whether the effects of mHT on brain structure are modulated by the cardiovascular health status in women who were treated with mHT compared to placebo soon after menopause. Participants (mean age=52; 5–36 months past their last menses), were randomized to oCEE, tE2 (each with progesterone for 12 days/month).or placebo pills and patch for 48 months. MRI scans were obtained from participants (n=89) at baseline (prior to randomization) and months 18, 36, and 48 of randomization and 3 years after the end of treatments (month 84). To examine phenotypic heterogeneity in their cardiovascular health profiles, a mixture model was applied using 7 variables (Table 1) obtained at baseline. Using a multi-group structural model, we assessed the effect of mHT on changes in imaging outcomes longitudinally from baseline to 48 and 84 months within each latent class identified by the mixture analysis. Multiple imputation methods were used to handle missing data. The joint distribution of the 7 variables with a 2-class model adequately fit the data. In the latent Class 1 group (n=47) that was characterized by a low cardiovascular risk profile, we found no statistically significant effects of mHT on net changes in ventricular volume or white matter hyperintensity volume both at months 48 and 84 (Table 2). However, in the Class 2 group (n=42), ventricular volumes significantly increased in women randomized to either oCEE (p=0.020) or tE2 (p = 0.002) compared to placebo at month 48. This effect was not significantly different from placebo three years after stopping mHT. The cardiovascular health profile may modulate the effects of mHT on brain structure. Larger epidemiological studies that incorporate potential mediating or moderating variables are needed to gain a better understanding of the interactions among cardiovascular health, mHT and structural changes in the brain.

Ventricular volumes across stages of schizophrenia and other psychoses.

Ventricular enlargement is common in established schizophrenia; however, data from ultra high-risk for psychosis and first-episode psychosis studies are inconclusive. This study aims to investigate ventricular volumes at different stages of psychosis. Ventricular volumes were measured using a semi-automated and highly reliable method, for 89 established schizophrenia, 162 first-episode psychosis, 135 ultra high-risk for psychosis and 87 healthy controls using 1.5T magnetic resonance images. Clinical outcome diagnoses for ultra high-risk for psychosis were evaluated at long-term follow-up (mean: 7.5 years). Compared to controls, we identified significant ventricular enlargement of 36.2% in established schizophrenia ( p < 0.001). Ventricular enlargement was not significant in first-episode psychosis (6%) or ultra high-risk for psychosis (-3%). Examination across stages of schizophrenia-spectrum diagnoses subgroups revealed a significant linear trend ( p = 0.006; established schizophrenia = 36.2%, first-episode psychosis schizophrenia = 18.5%, first-episode psychosis schizophreniform = -4.2% and ultra high-risk for psychosis-schizophrenia converters = -18.5%). Ventricular enlargement is apparent in patients with established schizophrenia but is not a feature at the earliest stages of illness (ultra high-risk for psychosis and first-episode psychosis). Further research is needed to fully characterize the nature and timing of ventricular volume changes early in the course of illness and how these changes impact outcomes.

Dynamic Relation of Changes in Weight and Indices of Fat Distribution With Cardiac Structure and Function: The Dallas Heart Study.

BackgroundObesity may increase heart failure risk through cardiac remodeling. Cross‐sectional associations between adiposity and cardiac structure and function have been elucidated, but the impact of longitudinal changes in adiposity on cardiac remodeling is less well understood.Methods and ResultsParticipants in the Dallas Heart Study without cardiovascular disease or left ventricular dysfunction underwent assessment of body weight, anthropometrics, and cardiac magnetic resonance imaging at baseline and 7 years later. Associations between changes in indices of generalized and central adiposity with changes in left ventricular mass, volume, mass/volume ratio (concentricity), wall thickness, and ejection fraction were assessed using multivariable linear regression. The study cohort (n=1262) mean age was 44 years with 57% women, 44% black, and 36% obese participants. At follow‐up, 41% had ≥5% weight gain, and 15% had ≥5% weight loss. Greater weight gain was associated with younger age, lower risk factor burden, and lower body mass index at baseline. In multivariable models adjusting for age, sex, race, comorbid conditions at baseline and follow‐up, baseline adiposity, and cardiac measurement, increasing weight was associated with increases in left ventricular mass (β=0.10, P<0.0001), wall thickness (β=0.10, P<0.0001), and concentricity (β=0.06, P=0.002), with modest effects on end‐diastolic volume (β=0.04, P=0.044) and ejection fraction (β=0.05, P=0.046). Similar results were seen with other adiposity indices.ConclusionsConcentric left ventricular remodeling is the predominant phenotype linked to increasing adiposity in middle age. Our findings support the importance of weight management to prevent secular changes in adiposity, concentric remodeling, and eventual heart failure over time.

Multiple Comorbidities and Response to Cardiac Resynchronization Therapy: MADIT-CRT Long-Term Follow-Up

BackgroundData regarding cardiac resynchronization therapy (CRT) in patients with multiple comorbidities are limited. ObjectivesThis study evaluated the association of multiple comorbidities with the benefits of CRT over implantable cardioverter-defibrillator (ICD) alone. MethodsWe examined 1,214 MADIT-CRT (Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy) study patients with left bundle branch block (LBBB) and 0, 1, 2, or ≥3 comorbidities, including renal dysfunction, hypertension (HTN), diabetes, coronary artery disease, history of atrial arrhythmias, history of ventricular arrhythmias, current smoking, and cerebrovascular accident. In an adjusted analysis, we analyzed risk of heart failure (HF) events or death by comorbidity group in all patients and in patients with CRT with defibrillator (CRT-D) versus ICD. Then we examined percent change in left ventricular (LV) end-diastolic volume, LV end-systolic volume, LV ejection fraction, left atrial volume, and LV dyssynchrony at 1-year in CRT-D patients by comorbidity group. ResultsThere was an inverse relationship between comorbidity burden and improvements in LV end-systolic volume, LV end-diastolic volume, left ventricular ejection fraction, left atrial volume, and LV dyssynchrony. In an adjusted model, there was an increasing risk of death or nonfatal HF events with increasing comorbidity burden regardless of treatment group (p < 0.001). During a mean follow-up of 4.65 years, there was no interaction with respect to comorbidity burden and the benefit of CRT-D versus ICD only for death or nonfatal HF events (interaction p = 0.943). In the groups with greatest comorbidity burden (2 and ≥3), the absolute risk reduction associated with CRT-D over ICD alone appeared greater than that seen for groups with less comorbidity burden (0 and 1). ConclusionsDuring long-term follow-up of MADIT-CRT study patients with LBBB randomized to CRT-D, there were differences in HF or death risk and in the degree of reverse remodeling among comorbidity groups. However, the burden of comorbidity does not appear to compromise the clinical benefits of CRT-D compared with ICD alone.

Stroke Volume Ratio Predicts Redilatation of the Right Ventricle After Pulmonary Valve Replacement

This study aimed to identify the prognostic value of the preoperative stroke volume ratio (right ventricular stroke volume/left ventricular stroke volume) for redilatation of the right ventricle after pulmonary valve replacement in patients with repaired tetralogy of Fallot. From April 2004 to November 2013, 20 patients with repaired tetralogy of Fallot underwent pulmonary valve replacement for pulmonary valve regurgitation and right ventricular dilatation. Serial changes in ventricular volume were examined by cardiac magnetic resonance or computed tomography imaging. The redilatation ratio was calculated for right ventricular end-diastolic and end-systolic volume indices by dividing the increment in right ventricular volume from the first (median, 1.1 years) to the second (median, 3.2 years) evaluations after pulmonary valve replacement by the first evaluation. The relationships between the stroke volume ratio and redilatation ratio were assessed. The degree of right ventricular myocardial fibrosis was examined in 13 patients and compared with the stroke volume ratio. Right ventricular volume (redilatation) significantly increased from a median of 1.1 to 3.2 years after pulmonary valve replacement. Significant positive correlations were detected between the stroke volume ratio and redilatation ratio of the right ventricular end-diastolic (r=0.50. p= 0.02) and end-systolic volume indices (r=0.49, p= 0.03). The stroke volume ratio also showed a significant positive correlation with the degree of right ventricular myocardial fibrosis (r= 0.73, p= 0.005). The preoperative stroke volume ratio can predict redilatation of the right ventricle after pulmonary valve replacement and the degree of right ventricular myocardial fibrosis.

Echocardiographic Predictors of Long-Term Survival in Patients Undergoing Cardiac Resynchronization Therapy: What Is the Optimal Metric?

Multiple definitions of reverse ventricular remodeling (RVR) employing various changes in left ventricular end-systolic (LVESV) or diastolic volumes (LVEDVs) or left ventricular ejection fraction (LVEF) have been used in determining cardiac resynchronization therapy (CRT) response, making comparability across studies difficult. We compared different metrics to each other, and in combination, in terms of association with long-term outcomes. We collected clinical and echocardiographic data on 436 patients undergoing CRT. LVEF was assessed via a combined volumetric and visual assessment. Volumes were manually traced. Using a nested multivariate model of a priori determined predictors of long-term survival free of left ventricular assist device (LVAD) or heart transplant, multiple definitions of RVR were added to the model individually to determine which provided the best model fit. Over a mean follow-up of 5.4 ± 2.3 years, there were 198 endpoints (10 LVADs, 15 heart transplants, and 173 deaths). When added to a nested model controlling for multiple potential confounders, all definitions of RVR were significantly associated with improved survival. Changes in LVEF and LVESV were superior to changes in LVEDV. A combination metric of an LVEF improvement ≥ 5% and LVESV reduction ≥ 10% was the best overall metric for model fit. Changes in LVESV and LVEF are better predictors of long-term outcome following CRT compared to changes in LVEDV. Adding an assessment of LVEF to reduction in LVESV ≥ 10% provided the best overall definition for RVR in predicting CRT outcomes.

IN-SILICO MODELING OF LEFT VENTRICLE TO SIMULATE DILATED CARDIOMYOPATHY AND CF-LVAD SUPPORT

Numerical modeling of the left ventricle dynamics plays an important role in testing different physiological scenarios and treatment techniques before the in vitro and in vivo assessments. However, utilized left ventricle model becomes vital in the simulations because validity of the results depends on the response of the numerical model to the parameter changes and additional sub-models for the applied treatment techniques. In this study, it is aimed to evaluate different numerical left ventricle models describing healthy and failing ventricle dynamics as well as the response of these models under continuous flow left ventricular assist device support. Six different numerical left ventricle models which include time varying elastance and single fiber contraction approaches are selected and applied in combination with a closed loop electric analogue of the circulation to achieve this purpose. The time varying elastace models relate ventricular pressure and volume changes in a simplistic way while the single fiber contraction models combine different scales ranging from protein to organ level. Change of the hemodynamic signals at the organ level for healthy, failing and CF-LVAD supported left ventricle models shows functionality of these models and helps to understand usability of them for different purposes.