Three-Dimensional Late Gadolinium Enhancement Cardiovascular Magnetic Resonance Predicts Inducibility of Ventricular Tachycardia in Adults With Repaired Tetralogy of Fallot

BACKGROUND

Adults with repaired tetralogy of Fallot die prematurely from ventricular tachycardia (VT) and sudden cardiac death. Inducible VT predicts mortality. Ventricular scar, the key substrate for VT, can be noninvasively defined with late gadolinium enhancement (LGE) cardiovascular magnetic resonance but whether this relates to inducible VT is unknown.

METHODS

Sixty-nine consecutive repaired tetralogy of Fallot patients (43 male, mean 40±15 years) clinically scheduled for invasive programmed VT-stimulation were prospectively recruited for prior 3-dimensional LGE cardiovascular magnetic resonance. Ventricular LGE was segmented and merged with reconstructed cardiac chambers and LGE volume measured.

RESULTS

VT was induced in 22 (31%) patients. Univariable predictors of inducible VT included increased RV LGE (odds ratio [OR], 1.15; P=0.001 per cm³), increased nonapical vent LV LGE (OR, 1.09; P=0.008 per cm³), older age (OR, 1.6; P=0.01 per decile), QRS duration ≥180 ms (OR, 3.5; P=0.02), history of nonsustained VT (OR, 3.5; P=0.02), and previous clinical sustained VT (OR, 12.8; P=0.003); only prior sustained VT (OR, 8.02; P=0.02) remained independent in bivariable analyses after controlling for RV LGE volume (OR, 1.14; P=0.003). An RV LGE volume of 25 cm³ had 72% sensitivity and 81% specificity for predicting inducible VT (area under the curve, 0.81; P<0.001). At the extreme cutoffs for ruling-out and ruling-in inducible VT, RV LGE >10 cm³ was 100% sensitive and >36 cm³ was 100% specific for predicting inducible VT.

CONCLUSIONS

Three-dimensional LGE cardiovascular magnetic resonance-defined scar burden is independently associated with inducible VT and may help refine patient selection for programmed VT-stimulation when applied to an at least intermediate clinical risk cohort.

Abnormal aortic arch shape and vortical flow patterns are associated with descending aortic dilatation in patients with hypoplastic left heart syndrome

INTRODUCTION

The descending aorta (DAo) in patients with hypoplastic left heart syndrome (HLHS) after Norwood procedure is frequenty enlarged and exhibits increased stiffness. Such findings of previous studies still remain unexplained given the fact that the DAo is not involved in the Norwood operation.

METHODS

We studied five HLHS patients with DAo dilatation (aged: 2.9-15.1 years (y), median 9.0 y), four HLHS patients without DAo dilatation (aged: 3.5-9.7 years, median 6.45 y) and 7 healthy controls (aged 6.3-41.6 y, median 26.0 y) using cardiovascular magnetic resonance imaging with acquisition of cine images, contrast-enhanced angiograms and 4D flow. 4D flow data were analyzed based on in-house developed analysis software to quantify vortical flow patterns in terms of vorticity.

RESULTS

All patients with DAo dilatation presented with a caliber reduction between the proximal and distal aortic arch of more than 40% (median reduction 71%, range 43%-79%) and with increased z-scores of the DAo. Vorticity in the DAo of patients with DAo dilatation (median: -24 s^-1, range: -26 s^-1 - -8 s^-1) was significantly increased in magnitude compared to controls (median: 0 s^-1, range: -2 - +2) (p < 0.01). Vorticity in the DAo of patients without DAo dilatatation was not significantly increased compared to controls. DAo z-scores were associated with increased vorticity.

CONCLUSIONS

The findings of signficiantly increased vorticity and its association with increased DAo z-scores can potentially explain vascular alterations in the DAo of HLHS patients. This study gives motivation for further investigations and may ultimately lead to future Norwood procedure modifications.

Left Ventricular Twist Mechanics to Identify Left Ventricular Noncompaction in Childhood

BACKGROUND

Left ventricular noncompaction cardiomyopathy (LVNC) is associated with poor clinical outcome in childhood. Standard diagnostic criteria are still controversial, especially in young patients. Recent studies in adults demonstrated that left ventricular (LV) twist is abnormal in LVNC, but it has not been investigated in pediatric patients to date. Our aim was to assess LV cardiac mechanics, LV twist, and the prevalence of rigid body rotation, using 2-dimensional speckle tracking echocardiography, in young patients with LVNC and LV hypertrabeculation.

METHODS

Forty-seven children (age range: 0-18 years) were assessed for suspected LVNC. All patients underwent 2-dimensional speckle tracking echocardiography and cardiovascular magnetic resonance imaging at 1.5 Tesla (T). Twenty-three patients fulfilled the cardiovascular magnetic resonance imaging diagnostic criteria for LVNC (LVNC group), while the remaining 24 did not and were included in the LV hypertrabeculation group. Forty-seven age- and sex-matched healthy volunteers were used as controls.

RESULTS

The average LV twist was significantly reduced in LVNC compared with control and LV hypertrabeculation. Rigid body rotation was recognized in 13 (56%) children with LVNC and in 1 (4%) child with LV hypertrabeculation and a strong family history for LVNC. Multivariable analysis demonstrated that LV twist is an independent predictor of LVNC ( P=0.006; coefficient=0.462). The receiver operating characteristics curve showed that LV twist had optimal predictive value to discriminate patients with LVNC (cutoff value <5.8°; sensitivity, 82%; specificity, 92%; area under the curve=0.914).

CONCLUSIONS

LV twist has good predictive value in diagnosing LVNC in young patients. Our findings strongly support the routine use of 2-dimensional speckle tracking echocardiography in the evaluation of young patients with suspected LVNC.

Myocardial fibrosis and the effect of primary prophylactic defibrillator implantation in patients with non-ischemic systolic heart failure-DANISH-MRI

AIMS

Patients with non-ischemic systolic heart failure have an increased risk of sudden cardiac death (SCD). Myocardial fibrosis, detected as late gadolinium enhancement (LGE) with cardiac magnetic resonance (CMR), has been shown to predict all-cause mortality. We hypothesized that LGE can identify patients with non-ischemic heart failure who will benefit from ICD implantation.

METHODS AND RESULTS

In this prospective observational sub-study of the Danish Study to Assess the Efficacy of ICDs in Patients with Nonischemic Systolic Heart Failure on Mortality (DANISH), 252 patients underwent CMR. LGE was quantified by the full width/half maximum method. The primary endpoint was all-cause mortality. LGE could be adequately assessed in 236 patients, median age was 61 years and median duration of heart failure was 14 months; there were 108 patients (46%) randomized to ICD. Median follow-up time was 5.3 years. Median left ventricular ejection fraction on CMR was 35%. In all, 50 patients died. LGE was present in 113 patients (48%). The presence of LGE was an independent predictor of all-cause mortality (HR 1.82; 95% CI 1.002-3.29; P = .049) after adjusting for known cardiovascular risk factors. ICD implantation did not impact all-cause mortality, for either patients with LGE (HR 1.18; 95% CI 0.59-2.38; P = .63), or for patients without LGE (HR 1.00; 95% CI 0.39-2.53; P = .99), (P for interaction =0.79).

CONCLUSION

In patients with non-ischemic systolic heart failure, LGE predicted all-cause mortality. However, in this cohort, LGE did not identify a group of patients who survived longer by receiving an ICD.

Right ventricular outflow tract reconstruction with the Labcor® stentless valved pulmonary conduit

OBJECTIVES

The right ventricular outflow tract reconstruction is a common necessity in congenital cardiac surgery. As homograft availability is limited, alternatives need to be evaluated. The Labcor® conduit consists of a porcine tricomposite valve assembled inside a bovine pericardium tube. This study presents intermediate-term results for its utilization for right ventricular outflow tract reconstruction.

METHODS

Labcor conduits were implanted in 53 patients (February 2009-July 2016). We analysed perioperative data, freedom from conduit failure and risk factors for conduit dysfunction.

RESULTS

The most common diagnosis was Tetralogy of Fallot (n = 20, 37.7%). The median age at surgery was 10.0 [interquartile range (IQR) 4.9-14.3] years. Pulmonary artery plasty (n = 37, 69.8%) and augmentation of the right ventricular outflow tract (n = 16, 30.2%) were often part of the procedure. The median conduit size was 21 (range 11-25) mm. There was no in-hospital death. The median follow-up after surgery was 4.6 (IQR 3.4-5.6) years. Fourteen patients (27.5%) developed conduit failure with stenosis being the main cause. Freedom from conduit failure was 98.0% at 2 and 80.5% at 5 years. The median longevity of the conduit was 7.4 years (95% confidence interval 5.1-9.8 years). Younger age and smaller conduit size were related to conduit failure.

CONCLUSIONS

Utilization of the Labcor conduit revealed acceptable intermediate-term results. The conduit appeared to be functioning sufficiently well within the first 5 years in the majority of patients. The higher rate of failure concerning smaller conduits might be associated with somatic outgrowth; however, conduit degeneration as common and long-term outcome still needs to be evaluated.

Determinants of Left Ventricular Dysfunction and Remodeling in Patients With Corrected Tetralogy of Fallot

Background

The aim of this study was to identify in asymptomatic patients with repaired tetralogy of Fallot the prevalence and determinants of impaired left‐sided cardiac function and adverse ventricular remodeling and the relation of left ventricular (LV) dysfunction and remodeling with cardiopulmonary exercise capacity.

Methods and Results

In a cross‐sectional study, 103 patients with tetralogy of Fallot (median age, 16.3 years) in New York Heart Association class 1, with surgical repair at a median age of 1.1 years, and 63 age‐matched controls were studied. LV, right ventricular function and geometry, LV myocardial extracellular volume (n=57), and left atrial function were quantified with cardiac magnetic resonance. Peak oxygen consumption was measured by a standardized cardiopulmonary exercise test (n=70). Patients with tetralogy of Fallot had lower LV ejection fraction (P=0.001; 49% below age‐adjusted fifth percentile for controls), lower LV mass index (P=0.003), lower LV mass/volume ratio (P<0.01), and impaired left atrial function. Right ventricular mass/volume ratio was the best predictor for LV systolic dysfunction and for a lower LV mass/volume ratio. Compared with controls, LV extracellular volume was higher (P<0.001), particularly in female patients, and associated with subnormal peak oxygen consumption (P=0.037). A peak oxygen consumption below the third percentile reference level was more likely with decreasing LV ejection fraction (P=0.008), and lower LV mass index (P=0.024), but independent of right ventricular ejection fraction.

Conclusions

In New York Heart Association class 1 patients with tetralogy of Fallot, frequent impaired systolic and diastolic LV function, LV adverse remodeling with LV atrophy, a decreased mass/volume ratio, and extracellular matrix expansion suggest cardiomyopathic changes. The best predictor for LV systolic dysfunction was the right ventricular mass/volume ratio. The subnormal peak oxygen consumption indicates that monitoring of LV status may be important for long‐term prognosis.

Out-of-hospital cardiac arrest and survival in a patient with Noonan syndrome and multiple lentigines: a case report

Background

A 9-year-old Arabic boy attending middle school presented with an out-of-hospital cardiac arrest due to ventricular fibrillation recorded by Holter electrocardiographic monitoring. He had a background history of Noonan syndrome with multiple lentigines (also known as LEOPARD syndrome), a rare condition of autosomal dominant inheritance with approximately 200 cases reported worldwide.

Case presentation

Apart from characteristic features, the boy was known to have asymmetric septal hypertrophy with a maximum wall thickness of 24 mm measured by cardiovascular magnetic resonance imaging. A day prior to the event, he attended cardiology follow-up at our institution, and Holter monitoring was commenced. Following cardiopulmonary resuscitation by bystanders and paramedics, he reverted back into sinus rhythm after a total downtime of 24 min. He was initially treated in the intensive care unit and underwent implantable cardioverter defibrillator implantation. He has made a full recovery and remains at the top of his class.

Conclusion

This case demonstrates that sudden cardiac arrest in patients with secondary forms of hypertrophic cardiomyopathy is not necessarily protected by apparently favorable phenotypes and that events may be preceded by non-sustained ventricular tachycardia observed by Holter monitoring. Implantable cardioverter defibrillator implantation plays a critical role in both primary and secondary prevention in patients at high risk of out-of-hospital cardiac arrest.

Complicated coarctation repair: The importance of three-dimensional cross-sectional imaging in late postoperative assessment

Coarctation of the aorta (CoA) represents 5%–8% of congenital heart disease patients and is one of the most common causes of neonatal surgical intervention. These patients require close lifelong follow-up due to frequent long-term complications. Although transthoracic echocardiography is the first-line technique for its diagnosis and follow-up, cross-sectional imaging with cardiovascular magnetic resonance (CMR) gives excellent anatomical and functional information, especially in complex CoA. We present the case of a 17-year-old patient who underwent complicated neonatal CoA repair and demonstrate how CMR and thorough operative records helped to define the exact anatomy of repair many years after surgery. Furthermore, we conclude that keeping surgical drawings in the patient records can be of great importance, especially in complicated cases.

Right Heart-Pulmonary Circulation Unit in Congenital Heart Diseases

The right ventricle plays a major role in congenital heart disease. This article describes the right ventricular mechanics in some selected congenital heart diseases affecting the right ventricle in different ways: tetralogy of Fallot, Ebstein anomaly, and the systemic right ventricle.

Erworbenes von-Willebrand-Syndrom bei Kindern mit hämodynamisch relevantem Vitium

Das erworbene von-Willebrand-Syndrom (VWS) ist eine seltene Gerinnungsstörung im Rahmen anderer (z. B. kardiovaskulärer) Erkrankungen, die bei operativen oder interventionellen Eingriffen zu starken Blutungen führen kann. Zur Verdachtsdiagnose führen die prädisponierende Grunderkrankung, die leere Blutungsanamnese und die pathologisch veränderten von-Willebrand-Faktor-Parameter. Wir berichten über zwei Patienten mit kongenitalen Vitien und negativer Blutungsanamnese, bei denen präoperativ durch erweiterte Gerinnungsdiagnostik die Diagnose eines erworbenen VWS gestellt wurde.

Phenotype and Clinical Outcomes of Titin Cardiomyopathy

BACKGROUND

Improved understanding of dilated cardiomyopathy (DCM) due to titin truncation (TTNtv) may help guide patient stratification.

OBJECTIVES

The purpose of this study was to establish relationships among TTNtv genotype, cardiac phenotype, and outcomes in DCM.

METHODS

In this prospective, observational cohort study, DCM patients underwent clinical evaluation, late gadolinium enhancement cardiovascular magnetic resonance, TTN sequencing, and adjudicated follow-up blinded to genotype for the primary composite endpoint of cardiovascular death, and major arrhythmic and major heart failure events.

RESULTS

Of 716 subjects recruited (mean age 53.5 ± 14.3 years; 469 men [65.5%]; 577 [80.6%] New York Heart Association function class I/II), 83 (11.6%) had TTNtv. Patients with TTNtv were younger at enrollment (49.0 years vs. 54.1 years; p = 0.002) and had lower indexed left ventricular mass (5.1 g/m² reduction; p_adjusted = 0.03) compared with patients without TTNtv. There was no difference in biventricular ejection fraction between TTNtv^+/- groups. Overall, 78 of 604 patients (12.9%) met the primary endpoint (median follow-up 3.9 years; interquartile range: 2.0 to 5.8 years), including 9 of 71 patients with TTNtv (12.7%) and 69 of 533 (12.9%) without. There was no difference in the composite primary outcome of cardiovascular death, heart failure, or arrhythmic events, for patients with or without TTNtv (hazard ratio adjusted for primary endpoint: 0.92 [95% confidence interval: 0.45 to 1.87]; p = 0.82).

CONCLUSIONS

In this large, prospective, genotype-phenotype study of ambulatory DCM patients, we show that prognostic factors for all-cause DCM also predict outcome in TTNtv DCM, and that TTNtv DCM does not appear to be associated with worse medium-term prognosis.

Myocardial Architecture, Mechanics, and Fibrosis in Congenital Heart Disease

Congenital heart disease (CHD) is the most common category of birth defect, affecting 1% of the population and requiring cardiovascular surgery in the first months of life in many patients. Due to advances in congenital cardiovascular surgery and patient management, most children with CHD now survive into adulthood. However, residual and postoperative defects are common resulting in abnormal hemodynamics, which may interact further with scar formation related to surgical procedures. Cardiovascular magnetic resonance (CMR) has become an important diagnostic imaging modality in the long-term management of CHD patients. It is the gold standard technique to assess ventricular volumes and systolic function. Besides this, advanced CMR techniques allow the acquisition of more detailed information about myocardial architecture, ventricular mechanics, and fibrosis. The left ventricle (LV) and right ventricle have unique myocardial architecture that underpins their mechanics; however, this becomes disorganized under conditions of volume and pressure overload. CMR diffusion tensor imaging is able to interrogate non-invasively the principal alignments of microstructures in the left ventricular wall. Myocardial tissue tagging (displacement encoding using stimulated echoes) and feature tracking are CMR techniques that can be used to examine the deformation and strain of the myocardium in CHD, whereas 3D feature tracking can assess the twisting motion of the LV chamber. Late gadolinium enhancement imaging and more recently T1 mapping can help in detecting fibrotic myocardial changes and evolve our understanding of the pathophysiology of CHD patients. This review not only gives an overview about available or emerging CMR techniques for assessing myocardial mechanics and fibrosis but it also describes their clinical value and how they can be used to detect abnormalities in myocardial architecture and mechanics in CHD patients.