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Journal of Imaging Informatics in... Jun 2024Cardiac amyloidosis (CA) is characterized by the deposition of amyloid fibrils within the myocardium, resulting in a restrictive physiology. Although microvascular...
Cardiac amyloidosis (CA) is characterized by the deposition of amyloid fibrils within the myocardium, resulting in a restrictive physiology. Although microvascular dysfunction is a common feature, it is difficult to assess. This study aimed to explore myocardial transit time (MyoTT) by cardiovascular magnetic resonance (CMR) as a potential novel parameter of microcirculatory dysfunction in CA. This prospective study enrolled 20 CA patients and 20 control subjects. CMR acquisition included cine imaging, pre- and post-contrast T1 mapping, and MyoTT assessment, which was calculated from the time delay in contrast agent arrival between the aortic root and coronary sinus (CS). Compared to the control group, patients with CA exhibited significantly reduced left ventricular (LV) ejection fraction and myocardial strain, an increase in LV global peak wall thickness (LVGPWT), extracellular volume fraction (ECV), and prolonged MyoTT (14.4 ± 3.8 s vs. 7.7 ± 1.5 s, p < 0.001). Moreover, patients at Mayo stage III had a significantly longer MyoTT compared to those at stage I/II. MyoTT showed a positive correlation with the ECV, LVGPWT, and LV global longitudinal strain (LV-GLS) (p < 0.05). The area under the curve (AUC) for MyoTT was 0.962, demonstrating diagnostic performance comparable to that of the ECV (AUC 0.995) and LV-GLS (AUC 0.950) in identifying CA. MyoTT is significantly prolonged in patients with CA, correlating with fibrosis markers, remodeling, and dysfunction. As a novel parameter of coronary microvascular dysfunction (CMD), MyoTT has the potential to be an integral biomarker in multiparametric CMR assessment of CA.
PubMed: 38940890
DOI: 10.1007/s10278-024-01179-7 -
European Heart Journal. Cardiovascular... Jun 2024Left ventricular (LV) diastolic dysfunction, atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF) share common risk factors and are...
Left ventricular (LV) diastolic dysfunction, atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF) share common risk factors and are closely related to each other and to adverse cardiovascular events. Exertional dyspnea in patients with AF should trigger comprehensive LV diastolic function evaluation since AF frequently precedes incident HFpEF. Echocardiographic assessment of LV diastolic function in patients with AF is challenging, mainly because of variability in cycle length, the absence of atrial contraction, and the frequent occurrence of LA enlargement regardless of LV filling pressures (LVFP). The algorithm of the 2016 recommendations for the evaluation of LV diastolic function cannot be directly applied in this setting. This review discusses the modalities available for diastolic function assessment and HFpEF diagnosis in patients with AF. Based on currently available data, a reasonable clinical target of diastolic function evaluation in AF would be to reach a binary conclusion: LVFP elevated or not. Recently, a two-step algorithm that combined several echocardiographic parameters plus inclusion of body mass index, has been proposed to differentiate normal from elevated LVFP in patients with AF. The echocardiographic evaluation must be complemented by a thorough clinical evaluation along with natriuretic peptides and cardiac catheterization in selected cases. If a diagnosis of HFpEF cannot be ascertained, a close follow up for timely identification of diastolic dysfunction markers along with monitoring and correction of modifiable risk factors are recommended.
PubMed: 38940621
DOI: 10.1093/ehjci/jeae160 -
Biomeditsinskaia Khimiia Jun 2024Type 1 diabetes mellitus (T1DM) is the most severe form of diabetes, which is characterized by absolute insulin deficiency induced by the destruction of pancreatic beta...
Type 1 diabetes mellitus (T1DM) is the most severe form of diabetes, which is characterized by absolute insulin deficiency induced by the destruction of pancreatic beta cells. The aim of this study was to evaluate the effect of a structural analogue of apelin-12 ((NαMe)Arg-Pro-Arg-Leu-Ser-His-Lys-Gly-Pro-Nle-Pro-Phe-OH, metilin) on hyperglycemia, mitochondrial (MCh) respiration in permeabilized cardiac left ventricular (LV) fibers, the myocardial energy state, and cardiomyocyte membranes damage in a model of streptozotocin (STZ) diabetes in rats. Metilin was prepared by solid-phase synthesis using the Fmoc strategy and purified using HPLC. Four groups of animals were used: initial state (IS); control (C), diabetic control (D) and diabetic animals additionally treated with metilin (DM). The following parameters have been studied: blood glucose, MCh respiration in LV fibers, the content of cardiac ATP, ADP, AMP, phosphocreatine (PCr) and creatine (Cr), the activity of creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH) in blood plasma. Administration of metilin to STZ-treated rats decreased blood glucose, increased state 3 oxygen consumption, the respiratory control ratio in MCh of permeabilized LV fibers, and increased the functional coupling of mitochondrial CK (mt-CK) to oxidative phosphorylation compared with these parameters in group D. In STZ-treated animals metilin administration caused an increase in the PCr content and prevention of the loss of total creatine (ΣCr=PCr+Cr) in the diabetic hearts, as well as restoration of the PCr/ATP ratio in the myocardium and a decrease in the activity of CK-MB and LDH in plasma to initial values. Thus, metilin prevented energy disorders disturbances in cardiomyocytes of animals with experimental T1DM.
Topics: Animals; Diabetes Mellitus, Experimental; Rats; Male; Diabetes Mellitus, Type 1; Energy Metabolism; Intercellular Signaling Peptides and Proteins; Rats, Wistar; Myocytes, Cardiac; Mitochondria, Heart; Blood Glucose; Myocardium; Streptozocin
PubMed: 38940202
DOI: 10.18097/PBMC20247003135 -
Circulation Research Jun 2024Thoracic epidural anesthesia (TEA) has been shown to reduce the burden of ventricular tachycardia in small case series of patients with refractory ventricular...
BACKGROUND
Thoracic epidural anesthesia (TEA) has been shown to reduce the burden of ventricular tachycardia in small case series of patients with refractory ventricular tachycardia and cardiomyopathy. However, its electrophysiological and autonomic effects in diseased hearts remain unclear, and its use after myocardial infarction is limited by concerns for potential right ventricular dysfunction.
METHODS
Myocardial infarction was created in Yorkshire pigs (N=22) by left anterior descending coronary artery occlusion. Six weeks after myocardial infarction, an epidural catheter was placed at the C7-T1 vertebral level for injection of 2% lidocaine. Right and left ventricular hemodynamics were recorded using Millar pressure-conductance catheters, and ventricular activation recovery intervals (ARIs), a surrogate of action potential durations, by a 56-electrode sock and 64-electrode basket catheter. Hemodynamics and ARIs, baroreflex sensitivity and intrinsic cardiac neural activity, and ventricular effective refractory periods and slope of restitution (S) were assessed before and after TEA. Ventricular tachyarrhythmia inducibility was assessed by programmed electrical stimulation.
RESULTS
TEA reduced inducibility of ventricular tachyarrhythmias by 70%. TEA did not affect right ventricular-systolic pressure or contractility although left ventricular-systolic pressure and contractility decreased modestly. Global and regional ventricular ARIs increased, including in scar and border zone regions post-TEA. TEA reduced ARI dispersion specifically in border zone regions. Ventricular effective refractory periods prolonged significantly at critical sites of arrhythmogenesis, and S was reduced. Interestingly, TEA significantly improved cardiac vagal function, as measured by both baroreflex sensitivity and intrinsic cardiac neural activity.
CONCLUSIONS
TEA does not compromise right ventricular function in infarcted hearts. Its antiarrhythmic mechanisms are mediated by increases in ventricular effective refractory period and ARIs, decreases in S, and reductions in border zone electrophysiological heterogeneities. TEA improves parasympathetic function, which may independently underlie some of its observed antiarrhythmic mechanisms. This study provides novel insights into the antiarrhythmic mechanisms of TEA while highlighting its applicability to the clinical setting.
PubMed: 38939925
DOI: 10.1161/CIRCRESAHA.123.324058 -
Journal of Arrhythmia Jun 2024Patients with atrial fibrillation (AF) and heart failure (HF) have high stroke risk owing to left atrial dysfunction. However, anticoagulation is a concern in patients...
BACKGROUND
Patients with atrial fibrillation (AF) and heart failure (HF) have high stroke risk owing to left atrial dysfunction. However, anticoagulation is a concern in patients with high bleeding risk. We aimed to identify independent predictors of stroke in HF patients with AF.
METHODS
We retrospectively examined 320 patients (mean age 79 ± 12 years, 163 women) hospitalized with acute HF complicated by AF between January 2014 and December 2018. Patients were followed from admission until ischemic stroke or systemic embolism (SSE) onset or death or were censored at the last contact date or September 2023.
RESULTS
SSE occurred in 40 patients (median follow-up of 528 days). Multivariate Cox regression analysis identified age (hazard ratio [HR] 1.04, 95% confidence interval [CI] 1.00-1.07, = .034), direct oral anticoagulant (DOAC) use (HR 0.26, 95% CI 0.11-0.60, = .002), and early diastolic peak flow velocity to early diastolic peak annular velocity (E/e'; HR 1.05, 95% CI 1.02-1.08, < .001) to be independent predictors of SSE, whereas left atrial reservoir strain was not. After determining an appropriate E/e' cutoff by receiver-operating characteristic curve analysis and adjusting the multivariate Cox model, E/e' ≥17.5 (HR 3.30, 95% CI 1.56-6.83, = .001) independently predicted SSE. The results were consistent with no interaction in the subanalysis except for gender.
CONCLUSION
Elderly patients not on DOACs with elevated E/e' may be at higher risk of stroke, suggesting that DOACs should be the first choice for patients with elevated E/e' and aggressive additional prophylaxis and careful follow-up are needed.
PubMed: 38939759
DOI: 10.1002/joa3.13031 -
JACC. Advances May 2024It is not known whether the transition from obesity and severe obesity, as 2 different metabolic disease entities, affect flow-mediated and, thus, endothelium-dependent...
BACKGROUND
It is not known whether the transition from obesity and severe obesity, as 2 different metabolic disease entities, affect flow-mediated and, thus, endothelium-dependent epicardial vasodilation.
OBJECTIVES
The purpose of this study was to investigate the effect of obesity and severe obesity on flow-mediated epicardial vasomotion with positron emission tomography/computed tomography-determined longitudinal decrease in myocardial blood flow (MBF) from the base-to-apex direction of the left ventricle or gradient.
METHODS
N-ammonia positron emission tomography/computed tomography evaluated global MBF during pharmacologically induced hyperemia and at rest for assessment of coronary microvascular function. In addition, the Δ longitudinal MBF gradient (hyperemia minus rest) was determined. Patients were then grouped according to the body mass index (BMI) into normal weight (NW) (BMI 20.0-24.9 kg/m, n = 27), overweight (OW) (BMI 25.0-29.9 kg/m, n = 29), obesity (OB) (BMI 30.0-39.9 kg/m, n = 53), and severe obesity (morbid obesity: BMI ≥40 kg/m, n = 43).
RESULTS
Compared to NW, left ventricular Δ longitudinal MBF gradient progressively declined in OW and OB (0.04 ± 0.09 mL/g/min vs -0.11 ± 0.14 mL/g/min and -0.15 ± 0.11 mL/g/min; ≤ 0.001, respectively) but not significantly in SOB (-0.01 ± 0.11 mL/g/min, = 0.066). Regadenoson-induced global hyperemic MBF was lower in OB than in NW (1.88 ± 0.40 mL/g/min vs 2.35 ± 0.32 mL/g/min; ≤ 0.001), while comparable between NW and SOB (2.35 ± 0.32 mL/g/min vs 2.26 ± 0.40 mL/g/min; = 0.302). The BMI of the study population was associated with the Δ longitudinal MBF gradient in a U-turn fashion (r = 0.362, standard error of the estimate = 0.124; < 0.001).
CONCLUSIONS
Increased body weight associates with abnormalities in coronary circulatory function that advances from an impairment flow-mediated, epicardial vasodilation in overweight and obesity to coronary microvascular dysfunction in obesity, not observed in severe obesity. The U-turn of flow-mediated epicardial vasomotion outlines obesity and severe obesity to affect epicardial endothelial function differently.
PubMed: 38939628
DOI: 10.1016/j.jacadv.2024.100936 -
JACC. Advances Feb 2024Previous studies have linked cardiovascular risk factors during midlife to cognitive function in later life. However, few studies have looked at the association between...
BACKGROUND
Previous studies have linked cardiovascular risk factors during midlife to cognitive function in later life. However, few studies have looked at the association between cardiac function, brain structure, and cognitive function and even less have included diverse middle-aged populations.
OBJECTIVES
The objective of this study was to determine associations between cardiac and brain structure and function in a multiethnic cohort of middle-aged adults.
METHODS
A cross-sectional study was conducted in participants of the Dallas Heart Study phase 2 (N = 1,919; 46% Black participants). Left ventricular (LV) mass, LV ejection fraction, LV concentricity, and peak systolic strain (LV E) were assessed by cardiac magnetic resonance imaging. White matter hyperintensities (WMH) volume was measured by fluid attenuated inversion recovery magnetic resonance imaging. The Montreal Cognitive Assessment was used to measure cognitive functioning. Associations between cardiac and brain measures were determined using multivariable linear regression after adjusting for cardiovascular risk factors, education level, and physical activity.
RESULTS
LV ejection fraction was associated with total Montreal Cognitive Assessment score (β = 0.06 [95% CI: 0.003-0.12], = 0.042) and LV E was associated with WMH volume (β = 0.08 [95% CI: 0.01-0.14], = 0.025) in the overall cohort without significant interaction by race/ethnicity. Higher LV mass and concentricity were associated with larger WMH volume in the overall cohort (β = 0.13 [95% CI: 0.03-0.23], = 0.008 and 0.10 [95% CI: 0.03-0.17], = 0.005). These associations were more predominant in Black than White participants (β = 0.17 [95% CI: 0.04-0.30] vs β = -0.009 [95% CI: -0.16 to 0.14], = 0.036 and β = 0.22 [95% CI: 0.13-0.32] vs β = -0.11 [95% CI: -0.21 to -0.01], < 0.0001, for LV mass and concentricity, respectively).
CONCLUSIONS
Subclinical cardiac dysfunction indicated by LVEF was associated with lower cognitive function. Moreover, LV mass and concentric remodeling were associated with higher WMH burden, particularly among Black individuals.
PubMed: 38939405
DOI: 10.1016/j.jacadv.2023.100777 -
JACC. Advances Feb 2024Systemic right ventricle (RV) dysfunction is associated with lower transplant-free survival (TFS) in hypoplastic left heart syndrome (HLHS), but the likelihood of...
BACKGROUND
Systemic right ventricle (RV) dysfunction is associated with lower transplant-free survival (TFS) in hypoplastic left heart syndrome (HLHS), but the likelihood of functional improvement and utility of heart failure (HF) medications is not understood.
OBJECTIVES
The authors aimed to describe TFS, HF medication use, and surgical interventions in HLHS patients with RV dysfunction with and without subsequent improvement in function.
METHODS
The SickKids HF Database is a retrospective cohort that includes all pediatric HLHS patients with RV dysfunction lasting >30 days. We compared TFS, HF medications, and surgical interventions in HLHS patients with and without functional normalization.
RESULTS
Of 99 patients with HLHS and RV dysfunction, 52% had normalized function for ≥30 days. TFS at 2 years after dysfunction onset was lower in those without normalization (14% vs 78%, < 0.001). Patients without normalization were less likely to reach target dosing (TD) of HF medications (27% vs 47% on 1 medication at TD, < 0.001) and undergo Fontan completion (7% vs 53%, < 0.001). Clinical factors associated with improved TFS were normalization of function for ≥30 days, onset of dysfunction after bidirectional Glenn, and exposure to ACE inhibition.
CONCLUSIONS
Our cohort of HLHS patients with systemic RV dysfunction demonstrated a novel finding of improved TFS in those with functional normalization for ≥30 days. Achieving TD of HF medications was associated with improved outcomes. This may reflect patient stability and tolerance for HF medication more than its therapeutic effect, but it can help inform decisions to proceed with surgical palliation or list for transplant.
PubMed: 38939382
DOI: 10.1016/j.jacadv.2023.100811 -
Cureus May 2024Reverse takotsubo cardiomyopathy is a rare variant of the classic stress-induced takotsubo cardiomyopathy. It is associated with transient left ventricular (LV) systolic...
Reverse takotsubo cardiomyopathy is a rare variant of the classic stress-induced takotsubo cardiomyopathy. It is associated with transient left ventricular (LV) systolic dysfunction characterized by basal hypokinesis and apical hyperkinesis. We present a case of a 27-year-old woman who presented to an outside facility for a scheduled cesarean section and developed perioperative chest tightness, hypoxemia, and hypotension. Her electrocardiogram (ECG) showed sinus rhythm with marked ST segment depressions in leads V4-V6. High sensitivity troponin was elevated to 474 ng/L. Transthoracic echocardiography revealed an LV ejection fraction of 52% (Simpson's) with hypokinesis of the basal myocardial segments and hyperdynamic systolic function of the apical segments. Subsequent coronary angiography showed angiographically normal epicardial coronaries. Left ventriculography showed ballooning of the basal segments with apical hyperkinesis. She was subsequently diagnosed with reverse takotsubo cardiomyopathy and managed conservatively with beta-blockers. In this case, we highlight the need for collaboration between the cardiology and obstetric teams for tailored management strategies to ensure the well-being of both mother and baby.
PubMed: 38939286
DOI: 10.7759/cureus.61225 -
JACC. Advances Mar 2024Left ventricular noncompaction (LVNC) is characterized by excessive trabeculations of the left ventricular (LV) wall.
BACKGROUND
Left ventricular noncompaction (LVNC) is characterized by excessive trabeculations of the left ventricular (LV) wall.
OBJECTIVES
The authors aimed to examine changes in LV function and morphology in 2 to 4-year-old children with and without LVNC at birth and to describe the prevalence of LVNC in first-degree relatives.
METHODS
Echocardiograms in children with and without LVNC (matched 1:4) were performed at 2 to 4 years and in first-degree relatives. LVNC was blindly assessed and defined as a ratio of non-compact to compact myocardium of ≥2 in ≥1 LV segment. Trabeculations were expressed as a percentage of the number of segments with LVNC out of the total number of segments.
RESULTS
In total, 14 (median age 3 years, 71% male) of 16 children with LVNC at birth and 56 children without (median age 4 years, 71% male), 37 first-degree relatives of children with LVNC (median age 31 years, 46% male) and 146 first-degree relatives of children without (median age 33 years, 50% male) were included. In children with LVNC, trabeculation (8% vs 13%, = 0.81) and LV ejection fraction (50% vs 49%, = 0.91) were unchanged from birth to follow-up but LV ejection fraction was lower compared to children without LVNC (49% vs 60%, < 0.001). In relatives of children with LVNC, 11 of 37 (30%) fulfilled LVNC criteria compared to no relatives to children without LVNC ( < 0.001).
CONCLUSIONS
At 2 to 4 years, children with LVNC diagnosed at birth had reduced systolic function compared to children without but did not have progression of LV dysfunction or extent of trabeculations. In first-degree relatives to children with LVNC, 30% fulfilled criteria.
PubMed: 38938835
DOI: 10.1016/j.jacadv.2024.100829