Trastornos inespecíficos de la repolarización ventricular: un lobo con piel de oveja / Nonspecific ventricular repolarization abnormalities: A wolf in sheep's clothing

El término trastornos inespecíficos de la repolarización ventricular se refiere a un conjunto de alteraciones menores del segmento ST y/o la onda T. Durante mucho tiempo han sido de escaso interés clínico al no traducir diagnósticos específicos. De forma extrema, se ha aseverado que constituyen hallazgos electrocardiográficos benignos. Su presencia se ha reportado en diversos estados patológicos cardiovasculares y no cardiovasculares. Sin embargo, con frecuencia se identifica en personas asintomáticas aparentemente sanas. Un creciente número de estudios demuestran su importancia como predictores de morbimortalidad cardiovascular, expandiendo su espectro hacia la prevención cardiovascular. A la luz de las evidencias científicas acumuladas se impone un cambio en la visión tradicional que se ha tenido con los trastornos inespecíficos de la repolarización ventricular. (AU)

The term nonspecific ventricular repolarization abnormalities refers to a set of minor alterations of the ST segment and/or the T wave. For a long time, they have been of little clinical interest as they do not translate into specific diagnoses. It has even been asserted that they constitute benign electrocardiographic findings. Their presence has been reported in various cardiovascular and non-cardiovascular diseases. However, it is frequently identified in apparently healthy asymptomatic people. A growing number of studies demonstrate their importance as predictors of cardiovascular morbidity and mortality, expanding their spectrum towards cardiovascular prevention. In light of the body of scientific evidence, it is imperative that the traditional view of nonspecific ventricular repolarization abnormalities changes. (AU)

Trauma, a Matter of the Heart-Molecular Mechanism of Post-Traumatic Cardiac Dysfunction.

Trauma remains a leading global cause of mortality, particularly in the young population. In the United States, approximately 30,000 patients with blunt cardiac trauma were recorded annually. Cardiac damage is a predictor for poor outcome after multiple trauma, with a poor prognosis and prolonged in-hospitalization. Systemic elevation of cardiac troponins was correlated with survival, injury severity score, and catecholamine consumption of patients after multiple trauma. The clinical features of the so-called "commotio cordis" are dysrhythmias, including ventricular fibrillation and sudden cardiac arrest as well as wall motion disorders. In trauma patients with inappropriate hypotension and inadequate response to fluid resuscitation, cardiac injury should be considered. Therefore, a combination of echocardiography (ECG) measurements, echocardiography, and systemic appearance of cardiomyocyte damage markers such as troponin appears to be an appropriate diagnostic approach to detect cardiac dysfunction after trauma. However, the mechanisms of post-traumatic cardiac dysfunction are still actively being investigated. This review aims to discuss cardiac damage following trauma, focusing on mechanisms of post-traumatic cardiac dysfunction associated with inflammation and complement activation. Herein, a causal relationship of cardiac dysfunction to traumatic brain injury, blunt chest trauma, multiple trauma, burn injury, psychosocial stress, fracture, and hemorrhagic shock are illustrated and therapeutic options are discussed.

Use of the modified myocardial performance index for evaluating fetal cardiac functions in pregestational diabetic pregnancy babies.

The aim of this study is assessment of importance of use of the modified myocardial performance index (Mod-MPI) for the evaluation of foetal cardiac function in foetuses of women with pregestational diabetes mellitus (PDM). In this study, data of 30 pregnant patients aged 18-45 years diagnosed with PDM and 30 pregnant women aged 18-45 years with normal pregnancy and their babies were evaluated. Foetal echocardiographic and doppler measurements, foetal biometric measurements, umbilical artery and ductus venosus pulsatility indexes were measured in both PDM and control groups. The Mod-MPI was significantly higher in foetuses of PDM women. Many influences especially cardiac and postpartum complications are observed in infants of PDM women. The Mod-MPI is a simple and useful method for assessing foetal ventricular function. Our study has shown that PDM is associated with foetal ventricular dysfunction.Impact statementWhat is already known on this subject? Although MPI is frequently used in routine clinical assessment of neonates, it is not used adequately in foetuses. Many influences especially cardiac and postpartum complications are observed in infants of PDM women. However, there are few studies focussed specifically on the assessment of foetal cardiac function in PDM.What do the results of this study add? MPI, which shows both diastolic and systolic functions is independent of ventricular anatomy and foetal heart rate, was found significantly higher in diabetic mother foetuses, can be said to be a valuable parameter in evaluating foetal cardiac functions globally.What are the implications of these findings for clinical practice and/or further research? Our study has shown that foetuses PDM are associated with foetal ventricular dysfunction. For this MPI measurement can be routinely performed at foetal cardiac measurements in foetuses of PDM mothers.

Fetal cardiac dysfunction in intrahepatic cholestasis of pregnancy is associated with elevated serum bile acid concentrations.

BACKGROUND & AIMS: Intrahepatic cholestasis of pregnancy (ICP) is associated with an increased risk of stillbirth. This study aimed to assess the relationship between bile acid concentrations and fetal cardiac dysfunction in patients with ICP who were or were not treated with ursodeoxycholic acid (UDCA). METHODS: Bile acid profiles and NT-proBNP, a marker of ventricular dysfunction, were assayed in umbilical venous serum from 15 controls and 76 ICP cases (36 untreated, 40 UDCA-treated). Fetal electrocardiogram traces were obtained from 43 controls and 48 ICP cases (26 untreated, 22 UDCA-treated). PR interval length and heart rate variability (HRV) parameters were measured in 2 behavioral states (quiet and active sleep). RESULTS: In untreated ICP, fetal total serum bile acid (TSBA) concentrations (r = 0.49, p = 0.019), hydrophobicity index (r = 0.20, p = 0.039), glycocholate concentrations (r = 0.56, p = 0.007) and taurocholate concentrations (r = 0.44, p = 0.039) positively correlated with fetal NT-proBNP. Maternal TSBA (r = 0.40, p = 0.026) and alanine aminotransferase (r = 0.40, p = 0.046) also positively correlated with fetal NT-proBNP. There were no significant correlations between maternal or fetal serum bile acid concentrations and fetal HRV parameters or NT-proBNP concentrations in the UDCA-treated cohort. Fetal PR interval length positively correlated with maternal TSBA in untreated (r = 0.46, p = 0.027) and UDCA-treated ICP (r = 0.54, p = 0.026). Measures of HRV in active sleep and quiet sleep were significantly higher in untreated ICP cases than controls. HRV values in UDCA-treated cases did not differ from controls. CONCLUSIONS: Elevated fetal and maternal serum bile acid concentrations in untreated ICP are associated with an abnormal fetal cardiac phenotype characterized by increased NT-proBNP concentration, PR interval length and HRV. UDCA treatment partially attenuates this phenotype. LAY SUMMARY: The risk of stillbirth in intrahepatic cholestasis of pregnancy (ICP) is linked to the level of bile acids in the mother which are thought to disrupt the baby's heart rhythm. We found that babies of women with untreated ICP have abnormally functioning hearts compared to those without ICP, and the degree of abnormality is closely linked to the level of harmful bile acids in the mother and baby's blood. Babies of women with ICP who received treatment with the drug UDCA do not have the same level of abnormality in their hearts, suggesting that UDCA could be a beneficial treatment in some ICP cases, although further clinical trials are needed to confirm this.

Mechanistic validation of the 2016 American Society of Echocardiography/European Association of Cardiovascular Imaging Guidelines for the assessment of diastolic dysfunction in heart failure with reduced ejection fraction.

BACKGROUND: The American Society for Echocardiography/European Association of Cardiovascular Imaging (ASE/EACVI) 2016 guidelines for assessment of diastolic dysfunction (DD) are based primarily on the effects of diastolic dysfunction on left ventricular filling hemodynamics. However, these measures do not provide quantifiable mechanistic information about diastolic function. The Parameterized Diastolic Filling (PDF) formalism is a validated theoretical framework that describes DD in terms of the physical properties of left ventricular filling. AIMS: We hypothesized that PDF analysis can provide mechanistic insight into the mechanical properties governing higher grade DD. METHODS: Patients referred for echocardiography showing reduced left ventricular ejection fraction (< 45%) were prospectively classified into DD grade according to 2016 ASE/EACVI guidelines. Serial E-waves acquired during free breathing using pulsed wave Doppler of transmitral blood flow were analyzed using the PDF formalism. RESULTS: Higher DD grade (grade 2 or 3, n = 20 vs grade 1, n = 30) was associated with increased chamber stiffness (261 ± 71 vs 169 ± 61 g/s2, p < 0.001), increased filling energy (2.0 ± 0.9 vs 1.0 ± 0.5 mJ, p < 0.001) and greater peak forces resisting filling (median [interquartile range], 18 [15-24] vs 11 [8-14] mN, p < 0.001). DD grade was unrelated to chamber viscoelasticity (21 ± 4 vs 20 ± 6 g/s, p = 0.32). Stiffness was inversely correlated with ejection fraction (r = - 0.39, p = 0.005). CONCLUSIONS: Higher grade DD was associated with changes in the mechanical properties that determine the physics of poorer left ventricular filling. These findings provide mechanistic insight into, and independent validation of the appropriateness of the 2016 guidelines for assessment of DD.

Transthoracic echocardiographic findings in patients admitted with SARS-CoV-2 infection.

INTRODUCTION: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)-infected patients commonly have elevated troponin and D-dimer levels, but limited imaging exists to support most likely etiologies in efforts to avoid staff exposure. The purpose of this study was to report transthoracic echocardiographic (TTE) findings in SARS-CoV-2 patients with correlating troponin and D-dimer levels. METHODS: We identified 66 SARS-CoV-2 patients (mean age 60 ± 15.7 years) admitted within a large, eight-hospital healthcare system over a 6-week period with a TTE performed. TTE readers were blinded to laboratory data with intra-observer and inter-observer analysis assessed. RESULTS: Sixty-six of 1780 SARS-CoV-2 patients were included and represented a high-risk population as 38 (57.6%) were ICU-admitted, 47 (71.2%) had elevated D-dimer, 41 (62.1%) had elevated troponin, and 25 (37.9%) died. Right ventricular (RV) dilation was present in 49 (74.2%) patients. The incidence and average D-dimer elevation was similar between moderate/severe vs. mild/no RV dilation (69.6% vs 67.6%, P = 1.0; 3736 ± 2986 vs 4141 ± 3351 ng/mL, P = .679). Increased left ventricular (LV) wall thickness was present in 46 (69.7%) with similar incidence of elevated troponin and average troponin levels compared to normal wall thickness (66.7% vs 52.4%, P = .231; 0.88 ± 1.9 vs 1.36 ± 2.4 ng/mL, P = .772). LV dilation was rare (n = 6, 9.1%), as was newly reduced LV ejection fraction (n = 2, 3.0%). CONCLUSION: TTE in SARS-CoV-2 patients is scarce, technically difficult, and reserved for high-risk patients. RV dilation is common in SARS-CoV-2 but does not correlate with elevated D-dimer levels. Increased LV wall thickness is common, while newly reduced LV ejection fraction is rare, and neither correlates with troponin levels.

Intraventricular Hemorrhage and Posthemorrhagic Ventricular Dilation: Current Approaches to Improve Outcomes.

Intraventricular hemorrhage (IVH) and posthemorrhagic ventricular dilation (PHVD) are important complications of prematurity with short- and long-term implications for the patient and for nursing care. Several approaches have been shown to reduce the incidence of IVH and, more recently, mitigate the impact of IVH on long-term neurodevelopment. This article discusses the pathophysiology of IVH, with a focus on prevention strategies. Posthemorrhagic ventricular dilation is a common complication of severe IVH and has implications for neurodevelopmental sequelae. Both surgical and nonsurgical interventions for PHVD are described.

Fragmented QRS is associated with intraventricular dyssynchrony and independently predicts nonresponse to cardiac resynchronization therapy-Systematic review and meta-analysis.

BACKGROUND: Fragmented QRS (fQRS) is postulated to be associated with ventricular dyssynchrony and might be able to predict a nonresponse to cardiac resynchronization therapy (CRT) implantation. In this systematic review and meta-analysis, we aim to assess whether fQRS can be a marker of intraventricular dyssynchronies in patients with ischemic and nonischemic cardiomyopathy and whether it is an independent predictor of nonresponse in patients receiving CRT. METHODS: We performed a comprehensive search on topics that assesses fQRS and its association with intraventricular dyssynchrony and nonresponse to CRT up until September 2019. RESULTS: Fragmented QRS is associated with intraventricular dyssynchrony (OR 10.34 [3.39, 31.54], p < .001; I2 : 80% with sensitivity 76.8%, specificity 77%, LR+ 3.3, and LR- 0.3). Subgroup analysis showed that fQRS is associated with intraventricular dyssynchrony in patients with narrow QRS complex (OR 20.92 [12.24, 35.73], p < .001; I2 : 0%) and nonischemic cardiomyopathy (OR of 19.97 [12.12, 32.92], p < .001; I2 : 0%). Fragmented QRS was also associated with a higher time-to-peak myocardial sustained systolic (Ts-SD) (OR 15.19 [12.58, 17.80], p < .001; I2 : 0% and positive Yu index (OR 15.61 [9.07, 26.86], p < .001; I2 : 0%). Fragmented QRS has a pooled adjusted OR of OR of 1.70 [1.35, 2.14], p < .001; I2 : 62% for association with a nonresponse to CRT. QRS duration is found to be higher in nonresponders group mean difference -8.54 [-13.38, -3.70], p < .001; I2 : 70%. CONCLUSION: Fragmented QRS is associated with intraventricular dyssynchrony and is independently associated with nonresponse to cardiac resynchronization therapy.

Decreased biventricular function following thoracic endovascular aortic repair.

OBJECTIVES: Preclinical studies have suggested acute stiffening of the aorta following experimental thoracic endovascular aortic repair (TEVAR), resulting in acute elevated pulse pressure, hypertension and possibly heart failure. The aim of this study was to evaluate cardiac remodelling following TEVAR. METHODS: From 2005 to 2018, 519 TEVAR procedures were performed at a single centre. Transthoracic echocardiography was performed pre- and post-TEVAR in 31 patients without previous replacement of the thoracic aorta. Patient characteristics, drug information, radiographic and follow-up data were evaluated. Aortic details were measured in multiplanar reconstruction. RESULTS: Transthoracic echocardiography was performed 2 ± 2 years after TEVAR. At this time, patients received significantly more antihypertensive drugs compared to the pre-TEVAR intake (beta-blocker therapy: P = 0.037; calcium channel blocker: P = 0.022). Compared to pre-TEVAR, there was a significant reduction in the left ventricular ejection fraction (P = 0.008) and tricuspid annular plane systolic excursion (P = 0.013) post-TEVAR. A significant increase in the left ventricular mass was not detected in this study (P = 0.95). The mean distance of 163 ± 66 mm of the descending aorta was covered. CONCLUSIONS: This study suggests negative cardiac remodelling with a decrease in the left and right ventricular function following TEVAR despite an increase in oral antihypertensive medication. The impact of stiffer endovascular grafts compared with the native aortic wall should be considered by endovascular specialists and manufacturers.

Atrial Fibrillation-Mediated Cardiomyopathy.

AF-mediated cardiomyopathy (AMC) is an important reversible cause of heart failure that is likely underdiagnosed in today's clinical practice. AMC describes AF either as the sole cause for ventricular dysfunction or exacerbating ventricular dysfunction in patients with existing cardiomyopathy or heart failure. Studies suggest that irreversible ventricular and atrial remodeling can occur in AMC, making timely diagnosis and intervention critical to optimize clinical outcome. Clinical correlation between AF onset/burden and progression of cardiomyopathy/heart failure symptoms provides strong evidence for the diagnosis of AMC. Cardiac MRI, continuous cardiac monitoring, and biomarkers are important diagnostic tools. From the therapeutic standpoint, early data suggest that AF ablation may improve long-term outcomes in AMC patients compared with medical rate and rhythm control. Patients with more AF burden and less severe underlying structural heart disease are more likely to experience left ventricle function recovery with successful AF ablation. Despite recent advances, significant knowledge gaps exist in our understanding of the epidemiology, mechanisms, diagnosis, management strategies, and prognosis of AMC.

Utility of High-Sensitivity and Conventional Troponin in Patients Undergoing Transcatheter Aortic Valve Replacement: Incremental Prognostic Value to B-type Natriuretic Peptide.

High-sensitivity Troponin (hs-Tn) has emerged as a useful marker for patients with myocardial injury or heart failure. However, few studies have compared intermediate and hs-Tn in patients undergoing transcatheter aortic valve replacement (TAVR). Moreover, there remains uncertainty of which thresholds are the most useful for discriminating ventricular dysfunction or outcome. In this study we prospectively enrolled 105 patients with severe aortic stenosis (AS) who underwent TAVR as well as blood sampling for high-sensitivity (hs-TnI) and conventional troponin I (EXL-LOCI and RXL) assessment. Patients underwent comprehensive pre-procedure echocardiography. Ventricular dysfunction was defined using left ventricular mass index (LVMI), LV global longitudinal strain (LVGLS) and LV end-diastolic pressure. The mean age was 84.0 ± 8.7 years old and 60% were male sex with mean transaortic pressure gradient of 50.1 ± 16.0 mmHg and AVA of 0.63 ± 0.19 cm2. When using a threshold of 6 ng/L, 77% had positive hs-TnI while 27% had positive hs-TnI using recommended thresholds (16 ng/L for female and 34 ng/L for male). Troponin levels were higher in the presence of abnormal LV phenotypes. The strongest correlate of troponin was LVMI. During median follow-up of 375 days, 21 patients (20%) died. Lower threshold of hs-TnI and EXL-TnI was more discriminatory for overall mortality (Log-rank P = 0.03 for both), while higher threshold of hs-TnI (p = 0.75) and RXL-TnI were not (p = 0.30). Combining hs-TnI and BNP improved to predict long-term outcome (p = 0.004). In conclusion, hs-TnI levels correlated with the degree of LV dysfunction phenotypes. Furthermore, applying a lower threshold for hs-TnI performed better for outcome prediction than a recommended threshold in patients undergoing TAVR. Combining hs-TnI with BNP helped better risk stratification.

Hypertrophic Cardiomyopathy: The Time-Synchronized Relationship between Ischemia and Left Ventricular Dysfunction Assessed by Highly Sensitive Troponin I and NT-proBNP.

The aim of this study was to compare NT-proBNP using the absolute values and NT-proBNP/ULN values that were standardized by age and gender between three subgroups: those without ischemia (negative hs-troponin I and no anginal pain (hsTnI-/AP-)), those with painless ischemia (hsTnI+/AP-), and those with painful ischemia (hsTnI+/AP+). Additionally, echocardiographic parameters were compared in these three subgroups. The absolute value of NT-proBNP was significantly higher in the painful ischemia subgroup (hsTnI-/AP- vs. hsTnI+/AP- vs. hsTnI+/AP+: 502 (174-833) vs. 969 (363-1346) vs. 2053 (323-3283) pg/ml; p = 0.018 for the whole-model analysis). The standardized value of NT-proBNP/ULN was gradually increased (hsTnI-/AP- vs. hsTnI+/AP- vs. hsTnI+/AP+: 3.61 + 0.63 vs. 6.90 + 1.31 vs. 9.35 + 1.87; p = 0.001 for the whole-model analysis). In the comparison between subgroups (hsTnI-/AP- vs. hsTnI+/AP- vs. hsTnI+/AP+), two echocardiographic parameters increased significantly. The left ventricular maximum wall thickness (LVMWT) at diastole was 1.99 ± 0.08 cm vs. 2.28 ± 0.13 cm vs. 2.49 ± 0.15 cm (p = 0.004 for the whole-model analysis). The maximal gradient of the provoked left ventricular outflow tract (LVOT) gradient increased significantly in only the painful-ischemia subgroup (11 (7-30) mmHg vs. 12 (9.35-31.5) mmHg vs. 100 (43-120) mmHg). In conclusion, both painless ischemia and painful ischemia are associated with a gradual, significant increase in NT-proBNP/ULN in comparison to the double-negative hsTnI/AP subgroup. In contrast, NT-proBNP is significantly higher in only the subgroup with painful ischemia.

NT-proBNP as an Early Marker of Diastolic Ventricular Dysfunction in Very-Low-Birth-Weight Infants.

The objective is to examine the correlation between plasma levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) and tissue Doppler imaging (TDI) echocardiographic parameters in the first 28 days of life in very-low-birth-weight infants (VLBWI). VLBWI admitted to the Neonatal Intensive Care Unit (NICU) at Hospital Puerta del Mar, Spain, from January 2015 to January 2017 were prospectively enrolled. Weekly determination of plasma NT-proBNP (pg/mL), and echocardiograms were done during the first 28 days of life. 101 preterm infants with a mean GA of 28.85 weeks (± 1.85 SD) and mean birth weight of 1152 g (± 247.4 SD) were included. A total of 483 echocardiograms and 139 NT-proBNP determinations were performed. We found a negative correlation between plasma NT-proBNP levels and diastolic velocities: mitral A' (ρ = - 0.15, p = 0.04), mitral E' (ρ = - 0.17, p = 0.02), tricuspid A' (ρ = - 0.20, p = 0.006), tricuspid E' (ρ = - 0.24, p = 0.0009). In the first 24 h of life, NT-proBNP levels were strongly correlated with mitral A' and E' velocities in patients with no patent ductus arteriosus (PDA) (ρ = - 0.75, p = 0.04). In preterm patients, elevated NT-proBNP levels are related to worse diastolic myocardial function. In the first 24 h, this correlation is much stronger in the absence of PDA.

Changes in left and right ventricular two-dimensional echocardiographic speckle-tracking indices in pediatric LVAD population: A retrospective clinical study.

Echocardiographic strain and strain-rate imaging is a promising tool for the evaluation of myocardial segmental function, for the early detection of myocardial dysfunction, and for the prediction of reverse remodeling. We aimed at studying the changes in left and right ventricular function in pulsatile left ventricular assist device pediatric patients by two-dimensional echocardiography and two-dimensional speckle-tracking echocardiography. Echocardiographic and clinical data of patients implanted with a pulsatile-flow left ventricular assist device from 2011 to 2018 were retrospectively reviewed before and after implantation at 1, 3, and 6 months. A total of 18 patients were enrolled. Median age and weight at implantation were 9 months (5-23 months) and 5.85 kg (4.85-8.75 kg), respectively; median left ventricular assist device support was 181 (114.5-289.5) days. 13 patients (73%) were transplanted and 5 patients (27%) died. At follow-up: left ventricular ejection fraction increase at 1 month (p = 0.001) and 3 months (p = 0.01), left ventricular global longitudinal strain improvement at 1 month (p = 0.0008) and 3 months (p = 0.02), and right ventricular free-wall longitudinal strain increase at 1 month (p = 0.01). At short term after left ventricular assist device implantation, both left ventricular and right ventricular mechanics improved. The temporary benefit seems to decrease over time. The worsening of left ventricular function has been followed by a worsening of right ventricular function probably due to the ventricular interdependence.

Reduced Biventricular Volumes and Myocardial Dysfunction Long-term After Pediatric Heart Transplantation Assessed by CMR.

BACKGROUND: Long-term cardiac remodeling after heart transplantation (HT) in children has been insufficiently characterized. The aim of our study was to evaluate ventricular size in HT patients using cardiovascular magnetic resonance (CMR) imaging, to find underlying factors related to potentially abnormal cardiac dimensions and to study its impact on functional class and ventricular function. METHODS: Seventy-five pediatric HT recipients (age 14.0 ± 4.2 y) were assessed by using CMR 11.2 ± 5.4 years after HT. Right ventricular (RV) and left ventricular (LV) volumes and mass were derived from short-axis cine images and myocardial strain/strain rate was assessed using myocardial feature tracking technique. Results were compared with a healthy reference population (n = 79, age 13.7 ± 3.7 y). RESULTS: LV end-diastolic ventricular volumes were smaller (64 ± 12 versus 84 ± 12 mL/m; P < 0.001) while mass-to-volume ratio (0.86 ± 0.18 versus 0.65 ± 0.11; P < 0.001) and heart rate (92 ± 14 versus 78 ± 13 beats/min; P < 0.001) were higher in HT patients. LV-ejection fraction (EF) was preserved (66% ± 8% versus 64% ± 6%; P = 0.18) but RV-EF (58 ± 7 versus 62% ± 4%, P = 0.004), LV systolic longitudinal strain (-12 ± 6 versus -15% ± 5%; P = 0.05), diastolic strain rate (1.2 ± 0.6 versus 1.5 ± 0.6 1/s; P = 0.03), and intra and interventricular synchrony were lower in the HT group. Smaller LV dimensions were primarily related to longer follow-up time since HT (ß = -0.38; P < 0.001) and were associated with worse functional class and impaired ventricular systolic and diastolic performance. CONCLUSIONS: Cardiac remodeling after pediatric HT is characterized by reduced biventricular size and increased mass-to-volume ratio. These adverse changes evolve gradually and are associated with impaired functional class and ventricular dysfunction suggesting chronic maladaptive processes affecting allograft health.

Diastology for the clinician.

Diastolic filling of the heart is a complex sequence of multiple inter-related events consisting of processes such as ventricular relaxation, erectile coronary effect, visco-elastic forces of the myocardium, ventricular interaction, myocardial stress strain relationships, pericardial restraint, passive filling, and atrial contraction. However, in order to understand diastolic filling from a clinical aspect, a simplified foundation can be used which divides the cardiac cycle into contraction, relaxation, passive filling, and filling at atrial contraction. The mitral flow velocity curves are representative of the relative driving pressure between left atrium and left ventricle and allow one to grade the progression of diastolic dysfunction which occurs in disease states. Doppler tissue imaging is necessary as a surrogate of ventricular relaxation to further determine the stages of diastolic dysfunction in patients with preserved ejection fraction. These Doppler flow velocity curves can be applied to understanding diastolic filling of the heart in patients with both reduced ejection fraction and preserved ejection fraction.