A percutaneous treatment strategy of an adult patient with a bicuspid aortic valve, coarctation of the aorta, and an exceptionally large aneurysm of a collateral artery: Case report and literature overview

Coarctation of the aorta (CoA) is a congenital heart defect that is associated with a bicuspid aortic valve (BAV), ascending aorta dilatation, intracerebral aneurysms, and premature atherosclerotic disease. The first presentation during late adulthood is rare and is frequently driven by late sequelae. Hypertrophic collateral arteries can develop aneurysms which are at risk for spontaneous rupture, however, treatment recommendations for these aneurysms are scarce. Here, we describe the clinical course and percutaneous treatment strategy of a patient with a late diagnosis of a pin-point CoA, a BAV with moderate regurgitation, and an exceptionally large aneurysm of a collateral artery. A 59-year-old woman was diagnosed with Streptococcus bovis endocarditis of a BAV with moderate aortic valve regurgitation and small vegetation (<5 mm) on the non-coronary cusp. Work-up revealed hypertension and adenocarcinoma in situ of the ascending colon, considered the bacteremia porte d'entrée, for which a curative hemicolectomy was performed. Echocardiography showed a narrowing of the aorta distal from the origin of the left subclavian artery with the antegrade diastolic flow with a pathognomonic "sawtooth" pattern and an estimated pressure gradient of >70 mmHg. Computed tomography angiography (CTA) showed a network of well-developed collateral arteries and a levoatriocardinal vein. One of the collateral arteries arising from the left subclavian artery revealed an exceptionally large aneurysmatic dilation (29 × 24 × 24 mm). The invasive assessment confirmed a hemodynamically significant CoA. Treatment involved balloon dilatation and placement of a covered stent at the site of the pin-point CoA and a percutaneous coronary intervention (PCI) of the stenosis in the left anterior descending artery. No residual gradient over the CoA was observed. Antihypertensive drugs could be discontinued, and CTA performed 4 months later showed regression and thrombosis of the numerous collaterals and, importantly, thrombosis of the large aneurysm. This case illustrates the late diagnosis of CoA with associated congenital heart defects and late sequelae including hypertension, BAV endocarditis, coronary artery disease, and aneurysm formation of the extensive collateral network. The patient underwent pharmacological and percutaneous treatment, ultimately resulting in the alleviation of the CoA, normalization of the blood pressure, reduction of collateral flow, and thrombosis of the large aneurysm of the collateral artery.

A novel method for visualization and quantification of nerve density in transmural biopsies after myocardial infarction

Introduction

Abnormal cardiac innervation plays an important role in arrhythmogenicity after myocardial infarction (MI). To study the innervation state after cardiac damage and ventricular arrhythmias, accurate quantification of nerve density is important. However, as cardiac nerves are very small structures, the histological quantification of nerves requires high resolution images, thus far proved extremely challenging and has never been performed transmurally.

Aim

To develop a method to analyze nerve density in large transmural biopsies after MI.

Method

Transmural myocardial biopsies from 4 swine, 3 months after MI, were stained with Picrosirius Red (fibrosis) and Beta-III-Tubulin (autonomic nerves). Fibrosis cut-offs were used to classify the biopsies into MI core (&gt;59.8%), borderzone (BZ) (14.3–59.8%) or remote zone (RZ) (&lt;14.3%). Each biopsy was quantified with a custom software pipeline, involving Python, Matlab and ImageJ. The biopsy was graphically divided into a 1x1mm grid. Using fixed values, nerve and myocardial tissue areas were thresholded and subjected to a quality check and artefact removal, followed by further division into 0.1x0.1mm squares. The nerve density per square was calculated and classified into denervation, hypoinnervation, normal innervation and hyperinnervation according to cut-offs (5th, 95th percentile) derived from 3 control swine. Finally, squares were located back to the original position within the biopsy allowing visualization and quantification of the different innervation types. Currently these steps are being integrated into an easy-to-use framework.

Results

In all 121 analyzed biopsies (experimental swine n=83, control n=38), areas with variable nerve densities were observed, although the areas with denervation, hypo- and hyperinnervation were largest in the MI core and BZ. Normal innervation was observed in 94.9% (93.8–96.0%) of the total biopsy area in the RZ, decreased in the BZ biopsies, 87.9% (85.1–92.4%, p&lt;0.001), and even lower in the MI core, 72.8% (66.3–75.8%, p&lt;0.001). The percentage of denervation and hypoinnervation per biopsy was highest in the core biopsies, 16.7% (13.5–23.5%) and 3.8% (2.9–5.0%) respectively, lower in the BZ, 2.6% (1.6–6.5%, p&lt;0.008) and 1.2% (0.8–1.7%, p=0.015) and even lower in the RZ, 1.2% (0.7–1.8%, p&lt;0.001), 0.6% (0.3–1.3, p&lt;0.001). Hyperinnervation was observed mainly in the BZ, 5.3% (3.7–9.4%) and remarkably, also in the core, 5.3% (3.7–9.4%, p&gt;0.999), whilst being low in the RZ 2.6% (1.7–4.3%, p=0.002 and p=0.038 respectively).

Conclusion

This novel method allows successful visualization and quantification of nerve density after cardiac damage in transmural biopsies. Strikingly, alternating areas of different innervation types could be identified within the same biopsy after MI, indicating a potentially heterogenous substrate for arrhythmias. This method has the potential to be broadly applied to any research involving high resolution imaging of nerves in large tissues.

Funding Acknowledgement

Type of funding sources: None.

A novel method to identify an intramural segment in interarterial anomalous coronary arteries on CT-angiography

Background/Introduction

An anomalous coronary artery originating from the opposite sinus of Valsalva (ACAOS) with an interarterial course can be assessed using Computed Tomography Angiography (CTA) for the presence of high-risk characteristics associated with sudden cardiac death. These features include a slit-like ostium, acute angle take-off, and degree of proximal luminal narrowing. However, no robust CTA criteria currently exist to determine the presence of an intramural segment.

Purpose

The aim of this study is to deduct a method to accurately identify an intramural course of interarterial ACAOS on CTA imaging.

Methods

All consecutive adult patients with an interarterial ACAOS that were evaluated at the two academic hospitals between January 2010 and July 2019 were screened for inclusion. Inclusion criteria were availability of a preoperative CTA-scan (0.5–1mm slice-thickness) and peroperative confirmation of the intramural segment. Using multiplanar reconstruction of the CTA, the distance between the lumen of the aorta and the lumen of the ACAOS (defined as “interluminal space” (ILS)) was assessed at 2mm intervals along the intramural segment (Figure 1).

Results

Twenty-five patients (64% female, mean age 46 years, 88% right ACAOS) were included. Analysis showed a mean ILS of 0.69mm±0.15mm at 2mm from the ostium. At the end of the intramural segment where the ACAOS becomes non-intramural, the mean ILS was significantly larger (1.27±0.29mm, p&lt;0.001) (Figure 2). Interobserver agreement evaluation showed good reproducibility of ILS (intraclass correlation coefficient 0.77, p&lt;0.001). ROC-analysis demonstrated that at a cut-off ILS of ≤0.95mm, an intramural segment can be diagnosed with 100% sensitivity and 84% specificity.

Conclusion(s)

The ILS is introduced as novel and robust CTA parameter to identify an intramural course of interarterial ACAOS. An ILS of ≤0.95mm is indicative of an intramural segment with 100% sensitivity and 84% specificity.

Funding Acknowledgement

Type of funding sources: None.

Non-invasive identification of slow conducting anatomical isthmuses in patients with tetralogy of Fallot by 3D late gadolinium enhancement cardiovascular magnetic resonance

Funding Acknowledgements

Type of funding sources: None.

Background

Patients with repaired tetralogy of Fallot (rTOF) remain at risk of sudden cardiac death due to reentrant sustained monomorphic ventricular tachycardia (SMVT). Slow conducting anatomical isthmuses (SCAI), in particular SCAI3 at the outlet septum, bordered by the pulmonary annulus and the ventricular septal defect patch, are the dominant substrate for SMVT. Electroanatomical mapping (EAM) is the invasive gold standard to identify SCAIs, and transection of SCAI by catheter ablation has been correlated with favorable long-term outcome. Non-invasive identification of SCAI for risk stratification and treatment planning is needed but has not been established yet. Three-dimensional (3D) late gadolinium-enhanced (LGE) cardiovascular magnetic resonance (CMR) facilitates accurate visualization of morphologically complex hearts with high-spatial resolution.

Objective

The study thought to determine whether 3D LGE-CMR can identify SCAIs.

Methods

Consecutive patients with rTOF who underwent right ventricular (RV) EAM and 3D LGE-CMR were included. LGE-CMR-derived 3D RV reconstructions were created (ADAS-3D) and merged with 3D RV EAM data. Mapping points were superimposed on the CMR-derived 3D reconstruction allowing for direct comparison of EAM data and local signal intensity (SI). The optimal SI cut-off to identify low bipolar voltage (LBV, BV&lt;1.76mV) was determined by receiver operating characteristic carve. An abnormal AI on LGE-CMR was defined as AI with continuous SI above the obtained cut-off connecting AI borders.

Results

Forty-eight rTOF patients (34±16 years, 58% male) were included. At EAM, 21 patients had normal AI, and 20 and 7 had a SCAI (&lt;0.5m/s) or blocked AI, which was AI3 in all. Patients with SCAI showed low BV of AI3 (median 0.7 [range 0.25-2.59] mV). In 11 patients, 14 SMVTs could be induced, all related to SCAI3.

A total of 9240 points were analyzed, showing a significant correlation between BV and SI (R=0.4, P&lt;0.001). The optimal SI cut-off to identify LBV was 42% of the maximal SI (MSI) (AUC 0.80; sensitivity, 74%; specificity, 78%). Using this cut-off of MSI, a SCAI or blocked AI3 could be correctly identified by LGE-CMR in all 27 patients, and a normal AI3 could be correctly confirmed by LGE-CMR in 14/21 patients with normal EAM findings (Figure). The sensitivity and specificity of 3D LGE-CMR for identifying SCAI or blocked AI3 were 100% and 67%, respectively. Of note, among patients with normal EAM findings, those with abnormal AI3 on LGE-CMR had significantly lower BV of AI3 than those with normal AI3 on LGE-CMR (2.06 [Range, 1.62-2.60] vs. 3.53 [2.22-5.67] mV, P&lt;0.01).

Conclusion

3D LGE-CMR can identify SCAI with 100% sensitivity and may identify diseased AI3 even before critical conduction delay occurs. This technique may allow for non-invasive risk stratification of VT and can refine patient selection for invasive EAM.

The effects of high-degree AV block requiring chronic ventricular pacing after tricuspid valve surgery in patients with a systemic right ventricle

Funding Acknowledgements

Type of funding sources: None.

Background

Patients with transposition of the great arteries(TGA) after atrial switch or congenitally corrected TGA(ccTGA) are prone to systemic right ventricular(sRV) failure. Atrioventricular(AV)-conduction disturbances requiring chronic ventricular pacing and tricuspid valve(TV) regurgitation aggravate sRV dysfunction. Timely TV surgery stabilizes sRV function, yet is a risk factor for AV-block, potentially contributing to sRV failure due to pacing-induced dyssynchrony. The aim of this study is to explore the incidence, timing and functional consequences of AV-block requiring ventricular pacing after TV surgery in sRV patients.

Methods

Consecutive adolescent and adult patients with a sRV who underwent TV surgery in the period 1989-2020 and follow-up at our centre were included in this observational cohort study. Demographic and clinical data was collected from patient records.

Results

Data of 28 patients(54% female, 57% ccTGA, mean age at surgery 38±13 years) was analysed. Mean follow-up duration was 9.7±6.8 years. Five patients(18%) already had chronic(&gt;40%) subpulmonary left ventricular pacing preoperatively, of which 2 received cardiac resynchronization therapy(CRT) upgrade prior to surgery. One patient received CRT during TV surgery. Of the remaining 22 patients at risk for AV-block after surgery, 9(41%) developed an indication for chronic pacing during follow-up, of which 3(33%) before hospital discharge and a total of 5(56%) within 24 months postoperatively, Figure 1. Five(20%) patients received CRT during follow-up due to progressive heart failure(HF). In one patient with transvenous upgrade, effective resynchronization was not attained due to suboptimal lead position. Of the patients receiving chronic pacing, 9(75%) died, underwent ventricular assist device(VAD) implantation or required CRT due to progressive HF. Only 4(31%) patients with native AV-conduction reached this composite endpoint(p=0.027). QRS duration, a surrogate marker for dyssynchrony, was significantly higher in patients with chronic pacing than with native AV-conduction(217±24 vs 116±23msec, p=0.000), as was NT-pro-BNP(2746[1242–6879] vs 495[355–690]ng/L, p=0.004) and the percentage of patients with ≥1 class of deterioration of systolic sRV function(p=0.001), Figure 2.

Conclusions

Patients with a failing sRV who undergo TV surgery are prone to AV-conduction abnormalities with 41% developing an indication for chronic ventricular pacing during follow-up. The patient group with chronic pacing has significantly more events of the composite endpoint of death, VAD implantation or upgrade to CRT, higher percentage of ≥1 grade deterioration of systolic sRV function and higher levels of HF biomarker NT-pro-BNP. Implantation of an epicardial sRV lead at the time of TV surgery for future CRT may be considered to attenuate the detrimental effects of subpulmonary ventricular pacing in this HF prone patient group with complex anatomy that limits transvenous possibilities.

Common genetic variants improve risk stratification after atrial switch operation for transposition of the great arteries

Background

Current clinical risk scores are able to predict late complication risk in adults after atrial switch operation (AtrSO) for transposition of the great arteries (TGA), but a large heterogeneity in clinical course remains.

Purpose

To study whether common genetic factors are predictive of outcome and provide added value to an existing clinical risk score in TGA-AtrSO patients.

Methods

This multicenter study examined the association of genome-wide single-nucleotide polymorphisms (SNPs) in TGA-AtrSO patients with a combined clinical endpoint: time to symptomatic ventricular arrhythmia, heart failure hospitalization, ventricular assist device implantation, heart transplantation, or mortality. Furthermore, we evaluated whether a polygenic risk score (PRS) constructed of independent single-nucleotide polymorphisms (SNPs) with a p&lt;1x10–5 could be of added value to a recently published clinical risk score (included clinical factors: age &gt;30 years, prior ventricular arrhythmia, age &gt;1 year at repair, ≥moderate right ventricular dysfunction, severe tricuspid regurgitation, and ≥mild left ventricular dysfunction).

Results

We followed 133 patients (age at inclusion 28 [IQR 24–35] years, 59% male) for 13 [IQR 8–16] years. Thirty-two patients (24%) reached the endpoint. The genome-wide association study yielded one locus that reached genome-wide significance (p&lt;1x10–8) and 18 loci marked by 20 SNPs that reached the suggestive threshold (p&lt;1x10–5). The constructed PRS remained an independent predictor after correction for the clinical score (HR=1.21/point increase [95% CI 1.13–1.29], p=3x10–10). While the clinical risk score indicated intermediate (5–20%) 5-year risk of events in 52 patients (39%), the combined risk score (clinical score + PRS) reclassified 35 patients to low (&lt;5%) and 6 to high (&gt;20%) risk. Observed 5-year event-free survival based on the combined score remained 100% for low-risk patients, compared to 23% and 64% in intermediate and high-risk patients, respectively. This resulted in improved risk stratification with the combined risk score vs the clinical risk score alone (p=2x10–16, C-statistic 0.95 vs 0.85).

Conclusions

Genetic factors explain some of the variation in clinical course of TGA-AtrSO patients and improve risk stratification. In the heterogeneous group of patients with a clinical score indicating intermediate risk, the combined model could classify 67% of patients more accurately to &lt;5% or &gt;20% risk. These data argue for more research into the impact of genetics on clinical outcome in adult congenital heart disease.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Dutch Heart Foundation Figure 1. Risk stratification of predicted 5-year risk of events based on the clinical model versus the combined model (clinical risk score + polygenic risk score).

Clinical decision making in frequently encountered anomalous aortic origin of coronary arteries, the impact of IVUS

Introduction

The aim in the diagnostic work-up of patients with an anomalous aortic origin of coronary arteries (AAOCA) is to determine whether the course of the coronary artery is benign or malignant. In patients with AAOCA with an interarterial course the guidelines on diagnostics are concise. Recommended CT-scan imaging does not evaluate stress-induced functional consequences like external compression by the pulmonary artery as the scan is performed in a resting state. Non-invasive ischemia detection techniques often lack sufficient sensitivity. To improve functional stratification, exploration of new diagnostic modalities in the diagnostic workup of AAOCA is mandatory.

Purpose

The purpose is to explore the potential role of intravascular ultrasound (IVUS) in the diagnostic workup of patients with AAOCA.

Methods

Nine patients with an anomalous right coronary artery with an interarterial course were analyzed. A cardiologist evaluated the complaints. Anatomical features of the AAOCA were assessed with CT-scan imaging. Further analyses included ischemia detection and coronary angiography. To assess stress-induced ischemia IVUS and invasive measurements – fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) – were performed at rest and during adrenaline-induced stress. A slit-like orifice was classified as a width/length (W/L) ratio of ≤0.50, an oval orifice as 0.51–0.9 and a round orifice as &gt;0.91.

Results

Potential cardiac complaints were present in seven patients. In 8 (89%) patients CT-images showed an acute angle, in 8 (89%) proximal narrowing and an aortic take-off above the pulmonary valve in 4 (44%). In 7 (78%) patients a slit-like orifice and in two (22%) an oval orifice were observed (table 1). IVUS at rest showed a slit-like orifice in one patient classified as an oval orifice on the CT-images and vice versa in another patient (table 2). The patients classified as an oval orifice with IVUS showed no external compression during adrenaline-induced stress. In 4 (57%) out of 7 patients with an slit-like orifice on IVUS, the width remained unchanged or increased during adrenaline infusion. In 2 patients the width decreased slightly, however, these patients were asymptomatic and no ischemia was detected. In 1 (14%) patient the width remained 1.4mmm and the length increased from 3.2mm to 4.7mm. In this case the vessel ostium was fully engaged with the IVUS catheter, hence, the width could not decrease during adrenaline infusion. This was regarded as external compression. In addition, in this patient ischemia was detected.

Conclusion(s)

In two (22%) out of 9 patients IVUS gave a better insight of the shape of the orifice than CT. Additionally, the anatomic and functional-dynamic components of compression could be defined with adrenaline-induced stress. Therefore, IVUS can contribute to a better understanding of the functional consequences of the anatomical features and of potential stress-induced external compression.

Funding Acknowledgement

Type of funding sources: None. Table 1Table 2

The coronary arteries in adults after arterial switch: a systematic review

Background

Coronary artery status in adults longterm after the arterial switch operation (ASO) is unclear. As a consequence, current follow-up strategies for coronary assessment remain controversial. We conducted a systemic review to provide an overview of coronary complications during adulthood and to evaluate the value of coronary imaging in adults after ASO, in light of current guidelines.

Material and method

Studies describing coronary complications or coronary imaging after ASO in adults were considered eligible for review and analysis. Articles were screened for the inclusion of adult ASO patients and data on coronary complications and findings of coronary imaging were collected. In cohort studies with both adults (≥18 years) and non-adults (&lt;18 years) only outcomes in identifiable adults were analyzed.

Results

A total of 993 adults were followed with a median follow-up of 2.0 years after reaching adulthood. Myocardial ischemia was suspected in 16/192 patients (6.8%). The number of coronary interventions was 4 (0.4%) and coronary death was reported in 4 (0.4%) patients. The following coronary abnormalities were found by routine coronary computer tomography CT (cCT): stenosis (4%), acute angle (40%), kinking (24%) and interaterial course (11%). No coronary events were reported during pregnancy (n=45).

Conclusion

The reported number of coronary interventions (0.4%) and of coronary death (0.4%) during a median follow-up of 2 years in 993 ASO adults is low. Coronary abnormalities including acute angle, kinking and interarterial course were commonly found by cCT. The 2020 European Society of Cardiology (ESC) guidelines state that routine screening for coronary pathologies is questionable. However, based on current findings and in line with the 2018 American ACC/AHA guidelines we suggest a baseline assessment of the coronary arteries in all adult ASO patients. Thereafter, an individualized coronary follow-up strategy, based upon coronary findings, is advisable.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Hartstichting Freedom from coronary complications

Assessment of the intramural segment of interarterial anomalous coronary arteries originating from the opposite sinus of Valsalva on CT angiography

Background

Of the coronary anomaly variants, an anomalous coronary artery originating from the opposite sinus (AAOCA) with an interarterial course poses the highest the risk of sudden cardiac death. Assessment of high risk anatomical characteristics can be done with Computed Tomography Angiography (CTA). High risk features are a slit-like ostium, acute angle take-off, proximal narrowing and an intramural course. For an intramural course no clear-cut CT parameters exist.

Purpose

To deduct new CTA criteria to identify an intramural course as well as the length of the intramural segment based on peroperative findings.

Material and methods

Twenty patients were included that received unroofing surgery of the right or left AAOCA between 2010 and 2019. All patients had a pre-operative CTA (0.5–1mm slice-thickness) performed. The presence of the intramural segment was measured peroperatively by the surgeon and used as indicator for CTA evaluation. Using multiplanar reconstructions, CTA images were rotated perpendicular to the horizontal plane of the aortic valve annulus and AAOCA to assess the distance between the aortic and AAOCA lumen and the shape of the AAOCA. This was done at every 2mm for the length of the intramural course as described by the surgeon (Figure 1).

Results

Analysis of 20 patients (40% male, AAORCA n=17, age at diagnosis AAOCA 45.6±10.5 years), showed a mean intramural length of 11.5±2.4mm at surgery. The median distance between the aortic and AAOCA lumen was 0.76mm (IQR 0.72–0.97mm) for the intramural segment. At the distal end of the intramural part (indicated by no. 5 in Figure 1), the mean distance was 1.20mm±0.27mm. The median ratio between the antero-posterior and transverse diameter of the AAOCA lumen at the distal end of the intramural part was 0.94 (IQR 0.88–0.99). Along the intramural part (Figure 1, no. 1–4) this ratio was 0.56mm±0.11mm, indicating a more flattened ostial shape along the course of the vessel.

Conclusions

Results indicate that an aortic to AAOCA lumen distance of ≤0.76mm on CTA is suggestive of an intramural course. A distance between the aorta and AAOCA of ≥1.2mm combined with an antero-posterior to transverse diameter ratio of 0.94 of the AAOCA indicates that the intramural trajectory has ended.

Funding Acknowledgement

Type of funding sources: None.

Atrioventricular-block necessitating ventricular pacing after tricuspid valve surgery in patients with a systemic right ventricle: long term follow-up

Background

Patients with transposition of the great arteries (TGA) after atrial switch or congenitally corrected TGA (ccTGA) are prone to systemic right ventricular (sRV) failure. Atrioventricular (AV)-conduction disturbances and tricuspid regurgitation aggravate the course of sRV dysfunction. Timely tricuspid valve (TV) surgery stabilizes sRV function. However, TV surgery is an independent risk for AV-block and ventricular pacing in non-congenital cardiothoracic surgery patients. Chronic subpulmonary ventricular pacing-induced dyssynchrony further contributes to sRV failure, potentially reducing the beneficial effects of the tricuspid valve surgery.

Purpose

The aim of this study is to explore the incidence, timing and functional consequences of AV-conduction block requiring ventricular pacing after TV surgery in sRV patients.

Methods

Consecutive adolescent and adult patients with a sRV who underwent TV surgery in the period 1989–2020 and follow-up at our tertiary care center were included in this observational cohort study. Patients who were &lt;10 years of age at the time of operation and/or died in perioperative, in-hospital, setting were excluded from analysis (n=5). Demographic and clinical data was collected from the patient records.

Results

Data of 28 patients (54% female, 57% ccTGA) was analysed (Figure). The mean age at surgery was 38±13 years, 5 patients (18%) received chronic ventricular pacing preoperatively. Mean follow-up was 9.7±6.8 years, during which 7 patients (25%) died and 3 (11%) underwent ventricular assist device implantation (VAD). Two patients died awaiting VAD/HTx, one patient died awaiting CRT upgrade. Seven (25%) patients underwent a re-operation, of which 3 (11%) TV replacement, 3 (11%) VAD and 1 (4%) pulmonary valve replacement. Of the 23 patients at risk of developing AV-block, 11 (48%) developed an indication for chronic ventricular pacing, of which 6 within 24 months postoperatively (4 before hospital discharge). Of the 21 patients with a device, 7 (25%) had successful resynchronization therapy (2 before TV surgery). Patients with chronic ventricular pacing had a wider QRS-duration (mean 121 ms vs 194 ms in those without pacing, p&lt;0.001) and 43% had a severely reduced sRV function (vs 36% in those without pacing) at latest follow-up.

Conclusions

Patients with a failing sRV who undergo TV surgery are prone to AV-conduction abnormalities with 48% of this group developing an indication for chronic ventricular pacing during follow-up. Pacing-induced dyssynchrony can further contribute to sRV dysfunction. Implantation of an epicardial sRV lead at the time of TV surgery for future CRT may be considered to attenuate the detrimental effects of subpulmonary ventricular pacing in this heart failure prone patient group with complex anatomy, limiting transvenous possibilities.

Funding Acknowledgement

Type of funding sources: None.

Aortic stenosis: correlation of prenatal echocardiography to postmortem histology

Background

Foetal aortic stenosis (AS) is a challenging congenital heart disease considering its potential to progress during the course of pregnancy. Especially at midgestation, it remains extremely difficult to distinguish the cases that end up biventricular from the cases that will develop into an hypoplastic left heart syndrome.

Purpose

To test the hypothesis that the degree of myocardial maturation is a possible predictor of biventricular outcome, we present 4 cases of foetal AS with a varying degree of severity and uniquely correlate differences in myocardial function based on prenatal echocardiography to their post-mortem histopathologic maturation.

Methods

We selected 4 cases with midgestational AS from our tertiary foetal cardiology service between 2018–2020. Speckle tracking recordings of the cardiac four-chamber view were performed during routine foetal echocardiography to quantify myocardial wall motion as a marker for myocardial function. Three cases decided to terminate the pregnancy and donated the cardiac specimen. Immunohistochemical labelling (ICH) against key markers for myocardial maturation (troponin-I, N-cadherin, connexin-43, MLC2A, MLC2V and α-SMA) and fibrosis (Sirius Red) were compared with 2 normal foetal cardiac specimens.

Results

Two cases with critical AS presented extremely decreased global and segmental longitudinal strain (GLS and SLS) values (GLS −2% and −0.9%) in the left ventricle (LV), indicating an impaired myocardial wall deformation. Post-mortem ICH showed overt endocardial fibro-elastosis (EFE) and pathological fibrosis patterns in the subendocardial layer which was remarkably spatially correlated to the EFE. The cardiomyocytes were disorganised with reduced expression of troponin-I and disturbed expression of connexin-43. The remaining 2 cases had normal LV appearance on foetal echocardiography, showing a mild reduction in left ventricular GLS and SLS (GLS −11.8% and −14.2%). Post-mortem ICH of 1 of these cases showed mild EFE with a milder fibrosis pattern. Cardiomyocytes were less disorganised but also showed a disturbed expression of connexin-43. The 4th case continued the pregnancy and had a biventricular outcome.

Conclusions

This is a unique case series showing that myocardial function correlates with high extent to histology. The degree of the reduction in myocardial function corresponded with the amount of pathological fibrosis patterns and disorganisation of the cardiomyocyte network. Myocardial wall motion on foetal echocardiography seems to hold promise as a possible marker for cardiac maturation.

Funding Acknowledgement

Type of funding sources: None. Speckle tracking and fibrosis patterns

Global cardiac sympathetic denervation is associated with diffuse myocardial fibrosis in non-ischemic cardiomyopathy

Funding Acknowledgements

Type of funding sources: None.

Background

 

Occurrence of ventricular tachycardias (VT) has been related to changes in sympathetic innervation and myocardial tissue in ischemic cardiomyopathy. In non-ischemic cardiomyopathy (NICM) patients with VT, the relation between global cardiac sympathetic innervation and non-ischemic fibrosis is less clear. The current gold standard in electrophysiology to identify non-ischemic fibrosis relies on unipolar endocardial voltage mapping.

Objective

To establish the relationship between global cardiac sympathetic innervation and global fibrosis.

Methods

29 patients (93% male, 58 ± 14 years, mean LVEF 38%±13) from the ‘Leiden Nonischemic Cardiomyopathy Study’ undergoing VT ablation between 2011-2018 were included. Endocardial voltage mapping was performed and the mean endocardial unipolar voltage (UV) was taken as a surrogate for global fibrosis. Global cardiac sympathetic innervation was analyzed by 123-I-MIBG imaging using heart-to-mediastinum ratio (HMR). A cut-off of 1.8 was used to delineate between normal (&gt;1.8) and denervated (&lt;1.8). HMR was correlated with mean UV.

Results

For patients with global cardiac sympathetic denervation a linear relationship was present between HMR and mean UV (R = 0.5278, P = 0.0431. There was no significant linear relationship for patients with normal cardiac sympathetic innervation between HMR and mean UV (R=-0.1696, P = 0.5795).

Conclusion

Global cardiac sympathetic denervation is related to myocardial fibrosis in patients with NICM and VT. The data support an interplay between denervation and fibrosis which may contribute to arrhythmogeneity, as observed in ICM. Abstract Figure.

Sympathetic innervation pattern in NICM patients with ventricular tachycardia -anteroseptal versus inferolateral substrates-

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation - Projektnummer 447558597)

Background

Among patients with non-ischemic cardiomyopathy (NICM) two dominant ventricular tachycardia (VT) substrate locations, namely anteroseptal (AS) and inferolateral (IL), have been identified. The poor outcome after catheter ablation of AS substrates (ASS) compared to IL substrates (ILS) has been attributed to its deep intramural location. However, region specific tissue charateristics, including sympathetic innervation, as important determinant of arrhythmogeneity, may also contribute to the outcome disparity.

Aim

To evaluate the association between regional sympathetic denervation, myocardial fibrosis and VT substrates according to two dominant VT substrate locations.

Methods

Twenty-nine patients from the ‘Leiden Nonischemic Cardiomyopathy Study’, who underwent electroanatomical substrate mapping and radiofrequency catheter ablation (RFCA), LGE-CMR and 123-I-MIBG imaging between 2011-2018 were included. The 16-segment model was used to describe the distribution of endocardial low unipolar voltage (UV &lt;25th IQR) (=electroanatomical surrogate for fibrosis), the location of abnormal local electrograms and VT related sites (= surrogate for VT substrate) and the presence of LGE. Regional cardiac sympathetic innervation was determined by 123-I-MIBG imaging and analyzed according to the 16-segment model. Regions with sympathetic denervation were correlated with low UV areas, VT substrate location and LGE. Patients were categorized according to the dominant VT substrate location in ASS or ILS.

Results

Ten patients had a dominant ASS, 12 patients a dominant ILS and 1 patient had ASS and ILS; 6 patients had other VT substrate locations. All but one patient with ASS and one with ILS also showed corresponding low UV (=surrogate for fibrosis) in segments with VT substrates. Eight patients with IL VT substrates but only 4 with AS substrates showed corresponding LGE in the VT related segments. All patients with inferolateral VT substrates showed sympathetic denervation in IL segments (100% matching segments), but only 3/11 (27%) with anteroseptal substrates had sympathetic denervation in AS segments (P = 0.0002). UV was not significantly different between matching (VT substrate and denervation) and not matching ASS segments (5.74 ± 2.69 mV vs. 4.64 ± 1.85 mV, P = 0.78) and between matching ASS and ILS segments (5.74 ± 2.69 mV vs. 7.61 ± 2.91, P = 0.43). LGE location was matching with sympathetic denervation in all patients with ILS but only in 33% of patients with ASS.

Conclusion

Despite low endocardial UV (=surrogate for fibrosis) for AS and IL segments harboring VT substrates, regional sympathetic denervation coincided with fibrosis only for IL VT substrates. The mismatch between regional fibrosis and preserved innervation for AS VT substrates may contribute to a VT substrate difficult to control by RFCA.

The first multicentre study on coronary anomalies in the Netherlands: MuSCAT

Background

Current guidelines on coronary anomalies are primarily based on expert consensus and a limited number of trials. A gold standard for diagnosis and a consensus on the treatment strategy in this patient group are lacking, especially for patients with an anomalous origin of a coronary artery from the opposite sinus of Valsalva (ACAOS) with an interarterial course.

Aim

To provide evidence-substantiated recommendations for diagnostic work-up, treatment and follow-up of patients with anomalous coronary arteries.

Methods

A clinical care pathway for patients with ACAOS was established by six Dutch centres. Prospectively included patients undergo work-up according to protocol using computed tomography (CT) angiography, ischaemia detection, echocardiography and coronary angiography with intracoronary measurements to assess anatomical and physiological characteristics of the ACAOS. Surgical and functional follow-up results are evaluated by CT angiography, ischaemia detection and a quality-of-life questionnaire. Patient inclusion for the first multicentre study on coronary anomalies in the Netherlands started in 2020 and will continue for at least 3 years with a minimum of 2 years of follow-up. For patients with a right or left coronary artery originating from the pulmonary artery and coronary arteriovenous fistulas a registry is maintained.

Results

Primary outcomes are: (cardiac) death, myocardial ischaemia attributable to the ACAOS, re-intervention after surgery and intervention after initially conservative treatment. The influence of work-up examinations on treatment choice is also evaluated.

Conclusions

Structural evidence for the appropriate management of patients with coronary anomalies, especially (interarterial) ACAOS, is lacking. By means of a structured care pathway in a multicentre setting, we aim to provide an evidence-based strategy for the diagnostic evaluation and treatment of this patient group.

Supplementary Information

The online version of this article (10.1007/s12471-021-01556-9) contains supplementary material, which is available to authorized users.

Lack of diagnostic utility of the ECG-derived ventricular gradient in patients with suspected acute pulmonary embolism

INTRODUCTION

The YEARS algorithm was successfully developed to reduce the number of computed tomography pulmonary angiography (CTPA) investigations in the diagnostic management of patients with suspected pulmonary embolism (PE), although half of patients still needed to be referred for CTPA. We hypothesized that ECG derived ventricular gradient optimized for right ventricular pressure overload (VG-RVPO), an easy to use tool for detecting PE-induced pulmonary hypertension (PH), may further improve the efficiency of the YEARS algorithm.

METHODS

In this post-hoc analysis of the Years study, ECGs of 479 patients with suspected PE managed according to the YEARS algorithm were available for analysis. The diagnostic performance of VG-RVPO was assessed and likelihood ratios were calculated.

RESULTS

PE was diagnosed in 88 patients (18%). In patients with confirmed PE, 34% had an abnormal VG-RVPO versus 24% of those without PE (odds ratio 1.6; 95%CI 0.94-2.6). The mean VG-RVPO was -22 ± 13 and did not differ between the two patient groups (-22 versus -20; mean difference - 2, 95% CI -4.8 to 1.3). The sensitivity of VG-RVPO for PE was 24% (95%CI 34-45), the specificity 76% (95%CI 71-80) and the c-statistic 0.45 (95% CI 0.38-0.51). When combined with the YEARS algorithm, the likelihood ratios of VG-RVPO remained close to 1.0. Ruling out PE in patients with an indication for CTPA based on a normal VG-RVPO would have resulted in 58 missed cases.

CONCLUSIONS

The VG-RVPO has no diagnostic value for suspected acute PE, either as stand-alone diagnostic test or combined with the YEARS algorithm.

CONDENSED ABSTRACT

This post-hoc analysis of the YEARS study failed to demonstrate incremental diagnostic value of VG-RVPO for acute PE, either as stand-alone diagnostic test or combined with the YEARS algorithm. Nevertheless, the role of VG-RVPO recorded on admission could potentially be valuable in the risk stratification of PE during hospitalization, although this remains to be studied.

P5392Epicardium derived cells promote sympathetic ganglionic outgrowth towards myocardium in vitro

Background

The autonomic nerve system is essential to maintain homeostasis in the body. In the heart, autonomic innervation is important for adjusting the physiology to the continuously changing demands such as stress responses. After cardiac damage, excessive neurite outgrowth, referred to as autonomic hyperinnervation, can occur which is related to ventricular arrhythmias and sudden cardiac death. The cellular basis for this hyperinnervation is as yet unresolved. Here we hypothesize a role for epicardium derived cells (EPDCs) in stimulating sympathetic neurite outgrowth.

Purpose

To investigate the potential role of adult EPDCs in promoting sympathetic ganglionic outgrowth towards adult myocardium.

Method

Fetal murine superior cervical ganglia were dissected and co-cultured with activated adult mesenchymal epicardium-derived cells (EPDCs) or/and adult myocardium in a 3D collagen gel culture system. Four experiment groups were included: Group 1: Vehicle cultures (ganglia cultured without EPDC/myocardium) (n=48); Group 2: ganglia co-cultured with EPDCs (n=38); Group 3: ganglia co-cultured with myocardium (n=95); and group 4: ganglia co-cultured with both EPDCs and myocardium (n=96). The occurrence of neurite outgrowth was assessed in each group. The density of neurites that showed directional sprouting (i.e. sprouting towards myocardium) was assessed as well with a semi-automatic quantification method. Finally, sub-analyses were made by taking gender into account.

Results

Cervical ganglia cultured with EPDCs alone (group 2) showed increased neurite outgrowth compared to vehicle cultures (group 1), however the neurites did not show directional sprouting towards EPDCs. When co-cultured with myocardium (group 3), directional neurite outgrowth towards myocardium was observed. Compared to the ganglia-myocardium co-cultures, directional outgrowth was significantly increased in co-cultures combining myocardium and EPDCs (group 4), and the neurite density was also significantly augmented. Comparison between males and female ganglia demonstrated that more neurite outgrowth occurred in female-derived ganglia than in male-derived ganglia under the same co-culture conditions.

Conclusion

Activated adult EPDCs promote sympathetic ganglionic outgrowth in vitro. Sex differences exist in the response of ganglia to EPDCs, and female-derived ganglia appear more sensitive to EPDC-signalling. Results support a role of EPDCs in cardiac autonomic innervation and open avenues for exploring of their role in ventricular hyperinnervation after cardiac damage.

2402Reduced heart rate variability is linked to clinical status in patients with a systemic right ventricle

Background

Adult patients with congenital heart disease and a systemic right ventricle (sRV) are prone to develop heart failure. Decreased heart rate variability (HRV), a measure of autonomic dysfunction, is associated with morbidity and mortality in patients with congestive heart failure. The standard deviation of all intervals between normal sinus beats (SDNN) is a HRV parameter commonly reported as an indicator of autonomic function in these patients. Data about HRV and its clinical implications in patients with a sRV are scarce.

Purpose

To compare HRV parameters between patients with a sRV and healthy controls, and to assess their association with clinical status.

Methods

All available 24-hour Holter monitoring records of sRV patients under follow-up in our center and one record per healthy control subject were analysed. Holters with non-sinus rhythm were excluded. Time and frequency domain parameters were calculated and compared between both groups. Clinical landmarks such as arrhythmias or an episode of congestive heart failure, which occurred up until the time of the ambulatory ECG, were combined in a clinical event score. Determinants of SDNN were investigated with mixed model linear regression in the patients and with multivariate linear regression in the controls. Baseline characteristics, medication use, global longitudinal strain, validity as measured with bicycle exercise testing, and the clinical event score were taken into account.

Results

113 Holters of 43 patients and 39 Holters of healthy controls were analysed. The patient group included 30 patients (70%) late after Mustard or Senning correction for transposition of the great arteries, and 13 patients with congenitally corrected transposition of the great arteries (30%). Age and gender were comparable in patients and controls. Several HRV parameters were significantly worse in patients compared with controls, including SDNN (138 in patients vs. 161 in controls, p=0.021). In the patients, clinical event score was the only significant determinant of a lower SDNN (p<0.001). In the controls, age was the only significant determinant of a lower SDNN (p=0.039).

Conclusion

Contrary to the healthy population, in patients with a sRV, HRV is associated with clinical status rather than age. This indicates that disease progression affects autonomic function more than ageing in this group. Further research is needed to clarify the relation between clinical outcome and autonomic function in sRV patients.

Acknowledgement/Funding

The Department of Cardiology of the LUMC received research grants from Medtronic, Biotronik, Boston Scientific and Edwards Lifesciences

P1797Prevalence of coronary anomalies in tetralogy of Fallot and its clinical implications, a meta-analysis

Background

In literature, anomalous coronary arteries from the opposite sinus of Valsalva or opposite coronary artery (ACAOS) are reported between 2% to 39% of patients with Tetralogy of Fallot (TOF). Knowledge of coronary anatomy prior to corrective surgery is vital to avoid damage to vessels crossing the right ventricular outflow tract (RVOT). The current range of reported prevalences is broad and a general overview comparing current knowledge on anomalous coronary arteries in TOF is lacking to date.

Purpose

In this meta-analysis, we aim to provide a detailed overview of current knowledge on prevalence of coronary anomalies in TOF and discuss the implications for patient management.

Methods

PubMed, Embase and Web of Science were searched for articles on TOF and coronary anomalies. Analysis was done using Revman 5.3 (Cochrane Community, London). The primary analysis focused on the origin and proximal course of the right and left coronary arteries. Also, the prevalences of large conus arteries and coronary arteriovenous fistulas were calculated.

Results

Twenty-nine studies, comprising 6977 patients all together, were included for primary meta-analysis of ACAOS. 6% of TOF patients have an ACAOS. Of these anomalous vessels, 72% crosses the RVOT. 6% of patients have a large conus artery and 4% a coronary arteriovenous fistula. Other incidentally reported coronary anomalies in TOF include a left or right coronary artery originating from the pulmonary artery, an accessory left anterior descending artery, hypoplasia of the entire coronary tree and anastomoses between coronary and bronchial arteries. CT-angiography is the imaging modality of preference because of its high spatial resolution. Transthoracic echocardiography can be used in younger children as well for discerning the coronary anatomy. Most surgical approaches can be adapted to an anomalous coronary artery coursing over the RVOT.

Overall prevalence of ACAOS in TOF

Conclusions

Coronary anomalies have a high prevalence in TOF. An ACAOS occurs in 6%, large conus arteries exist in 6% and coronary arteriovenous fistulas in 4% of cases. A substantial part crosses the RVOT. This has to be taken into account during surgery.

Ventricular assist device implantation in patients with a failing systemic right ventricle: a call to expand current practice

Ventricular assist device (VAD) implantation is an established treatment modality for patients with end-stage heart failure, and improves symptoms and survival. In the Netherlands, it is not yet routinely considered in patients with congenital heart disease and failing systemic right ventricle (SRV). Recently, a VAD was implanted in 2 SRV patients, one who underwent a Mustard procedure during infancy for transposition of the great arteries (male, 47 years old) and one with a congenitally corrected transposition of the great arteries (male, 54 years old). The first patient is doing well >1 year after implantation; the second patient will be discharged home soon. These examples and other reports demonstrate the feasibility of adopting VAD implantation into routine care for SRV failure. In conclusion, patients with SRV failure may be suitable candidates for VAD implantation: they are relatively young, usually have a preserved subpulmonary left ventricular function, and their specific anatomical and physiological characteristics often make them unsuitable for cardiac transplantation. Therefore it is important to recognise the possibility of VAD implantation early in the process of SRV failure, and to timely refer these patients to a heart failure clinic with experience in VAD implantation in this group of patients for optimisation, screening, and implantation.

Tailored circulatory intervention in adults with pulmonary hypertension due to congenital heart disease

BACKGROUND

Adults with pulmonary hypertension associated with congenital heart disease (PH-CHD) often have residual shunts. Invasive interventions aim to optimise pulmonary flow and prevent right ventricular failure. However, eligibility for procedures strongly depends on the adaptation potential of the pulmonary vasculature and right ventricle to resultant circulatory changes. Current guidelines are not sufficiently applicable to individual patients, who exhibit great diversity and complexity in cardiac anomalies.

METHODS AND RESULTS

We present four complex adult PH-CHD patients with impaired pulmonary flow, including detailed graphics of the cardiopulmonary circulation. All these patients had an ambiguous indication for shunt intervention. Our local multidisciplinary Grown-Ups with Congenital Heart Disease team reached consensus regarding a patient-tailored invasive treatment strategy, adjacent to relevant guidelines. Interventions improved pulmonary haemodynamics and short-term clinical functioning in all cases.

CONCLUSIONS

Individual evaluation of disease characteristics is mandatory for tailored interventional treatment in PH-CHD patients, adjacent to relevant guidelines. Both strict registration of cases and multidisciplinary and multicentre collaboration are essential in the quest for optimal therapy in this patient population.

The extent of the raphe in bicuspid aortic valves is associated with aortic regurgitation and aortic root dilatation

Background

The clinical course of bicuspid aortic valves (BAVs) is variable. Data on predictors of aortopathy and valvular dysfunction mainly focus on valve morphology.

Aim

To determine whether the presence and extent of the raphe (fusion site of valve leaflets) is associated with the degree of aortopathy and valvular dysfunction in patients with isolated BAV and associated aortic coarctation (CoA).

Methods

Valve morphology and aortic dimensions of 255 BAV patients were evaluated retrospectively by echocardiography.

Results

BAVs with a complete raphe had a significantly higher prevalence of valve dysfunction (especially aortic regurgitation) than BAVs with incomplete raphes (82.9 vs. 66.7 %, p = 0.01). Type 1A BAVs (fusion of right and left coronary leaflets) and complete raphe had larger aortic sinus diameters compared with the rest of the population (37.74 vs. 36.01, p = 0.031). Patients with CoA and type 1A BAV had significantly less valve regurgitation (13.6 vs. 55.8 %, p < 0.001) and smaller diameters of the ascending aorta (33.7 vs. 37.8 mm, p < 0.001) and aortic arch (25.8 vs. 30.2 mm, p < 0.001) than patients with isolated BAV.

Conclusions

Type 1A BAV with complete raphe is associated with more aortic regurgitation and root dilatation. The majority of CoA patients have incomplete raphes, associated with smaller aortic root diameters and less valve regurgitation.

Prosthetic valves in adult patients with congenital heart disease: Rationale and design of the Dutch PROSTAVA study

BACKGROUND

Data on long-term complications in adult patients with congenital heart disease (ACHD) and a prosthetic valve are scarce. Moreover, the influence of prosthetic valves on quality of life (QoL) and functional outcome in ACHD patients with prosthetic valves has not been studied.

OBJECTIVES

The primary objective of the PROSTAVA study is to investigate the relation between prosthetic valve characteristics (type, size and location) and functional outcome as well as QoL in ACHD patients. The secondary objectives are to investigate the prevalence and predictors of prosthesis-related complications including prosthesis-patient mismatch.

METHODS

The PROSTAVA study, a multicentre cross-sectional observational study, will include approximately 550 ACHD patients with prosthetic valves. Primary outcome measures are maximum oxygen uptake during cardiopulmonary exercise testing and QoL. Secondary outcomes are the prevalence and incidence of valve-related complications including prosthesis-patient mismatch. Other evaluations are medical history, physical examination, echocardiography, MRI, rhythm monitoring and laboratory evaluation (including NT-proBNP).

IMPLICATIONS

Identification of the relation between prosthetic valve characteristics in ACHD patients on one hand and functional outcome, QoL, the prevalence and predictors of prosthesis-related complications on the other hand may influence the choice of valve prosthesis, the indication for more extensive surgery and the indication for re-operation.

Expression of Id2 in the second heart field and cardiac defects in Id2 knock-out mice

The inhibitor of differentiation Id2 is expressed in mesoderm of the second heart field, which contributes myocardial and mesenchymal cells to the primary heart tube. The role of Id2 in cardiac development is insufficiently known. Heart development was studied in sequential developmental stages in Id2 wildtype and knockout mouse embryos. Expression patterns of Id2, MLC-2a, Nkx2.5, HCN4, and WT-1 were analyzed. Id2 is expressed in myocardial progenitor cells at the inflow and outflow tract, in the endocardial and epicardial lineage, and in neural crest cells. Id2 knockout embryos show severe cardiac defects including abnormal orientation of systemic and pulmonary drainage, abnormal myocardialization of systemic and pulmonary veins, hypoplasia of the sinoatrial node, large interatrial communications, ventricular septal defects, double outlet right ventricle, and myocardial hypoplasia. Our results indicate a role for Id2 in the second heart field contribution at both the arterial and the venous poles of the heart.

Development of the cardiac conduction system and the possible relation to predilection sites of arrhythmogenesis

The cardiac conduction system (CCS) encompasses a complex system responsible for the coordinated contraction of the heart. In the developing heart, as well as in the adult heart, tissues of the (putative) CCS are characterized by different properties than the surrounding working myocardium, which can be observed on a histological level, as well as by the expression patterns of several immunohistological and molecular markers. In recent years, many markers have been studied that have helped to elucidate the processes involved in CCS development. It has become clear that multiple genes, cells and their interactions are involved in this complex process. In this article, an overview of the current knowledge of CCS development is supplied. Furthermore, several controversies regarding conduction system development are discussed, as well as the possible significance of embryologic development of the CCS for the development of arrhythmias later in life.

Contrast echocardiography as a useful additional diagnostic tool in evaluating a primary cardiac tumor

The current report describes a case of a primary cardiac lymphoma. For early and appropriate treatment of a cardiac mass it is not only important to determine its localization and extension but also to differentiate between malignant and benign lesions. This report demonstrates that not only transthoracic echocardiography but also the other different forms of echocardiography such as transesophageal echocardiography, as well as contrast and intracardiac echocardiography, are useful tools in the diagnostic workup of cardiac masses.

Development of the Right Ventricular Inflow Tract and Moderator Band

Atriofascicular accessory bundles with AV-node like conduction properties can sustain atrioventricular (AV) re-entrant tachycardia (Mahaim tachycardia). During early embryogenesis, the AV canal is situated above the primitive left ventricle (LV), and a right AV connection has not been achieved yet. We studied the formation of the right ventricular (RV) inflow tract in relation to the developing cardiac conduction system and hypothesized a morphological explanation for functional atriofascicular bypass tracts. Analysis of lacZ-expression during sequential stages of cardiogenesis was performed in CCS-lacZ transgenic mice (E9.5 to 15.5). Embryos were stained for β-galactosidase activity and the myocardial marker HHF35. At early stages CCS-lacZ expression was observed in a ring surrounding the AV canal, which connected at the inner curvature to the primary fold. The first sign of formation of the (CCS-lacZ negative) RV inlet component was a groove in the CCS-lacZ positive tissue of the primary fold. Outgrowth of the RV inlet tract resulted in division of the primary fold in a septal part, the trabecula septomarginalis and a lateral part, the moderator band, which extended laterally up to the right AV ring. Electrophysiological measurements in embryonic hearts (E15.5) in which the right atrium (RA) and RV were isolated from the left atrium (LA) and LV supported the functionality of this AV-connection via the moderator band, by demonstrating sequential atrial and ventricular activation in both RA/RV and LA/LV preparations. In conclusion, our observations may provide a possible morphological and functional explanation for atriofascicular accessory pathways via the moderator band, underlying Mahaim tachycardia.

Thrombus in the left atrial appendage detected by intracardiac echocardiography

Radiofrequency catheter ablation (RFCA) at the ostium of the pulmonary veins can potentially cure atrial fibrillation. Left-sided ablation procedures may carry a risk of thrombo-embolic events. Emboli from intracardiac thrombus originate from the left atrial appendage (LAA) in a substantial number of patients. The presence of spontaneous echo contrast in the left atrium (LA) and LAA peak emptying flow < or = 20 cm/s are also significantly related to thrombo-embolic events. Evaluation of the anatomy of the LA and LAA prior to left-sided procedures is therefore mandatory. Intracardiac echocardiography (ICE) appears an ideal technique to obtain this information during the RFCA-procedure. In the current report, we report on the use of ICE detecting a thrombus in the LAA in a patient planned to undergo RFCA of pulmonary veins for atrial fibrillation.

Radiofrequency catheter ablation of ventricular tachycardia guided by intracardiac echocardiography

AIMS

Ventricular tachycardia (VT) frequently has an anatomical substrate. Identification of areas prone to arrhythmogenicity facilitates radiofrequency catheter ablation (RFCA). Furthermore, direct monitoring of complications potentially increases safety of RFCA. The aim of this study was to evaluate the feasibility of guiding RFCA of VT with intracardiac echocardiography (ICE), in order to improve outcome and procedural safety.

METHODS AND RESULTS

Eleven patients (age 59 +/- 15 years) with drug-refractory VT of various etiologies were studied. VT mapping and ablation were performed using standard techniques. ICE was performed with a multifrequency (5-10 MHz) phased-array transducer positioned in the right ventricle. Twenty different VTs were treated (CL 352 +/- 120 ms, 2.0 +/- 0.9 VT per patient). LV a- or dyskinesia was identified in all post-infarct patients. In patients with arrhythmogenic right ventricular dysplasia, right ventricular aneurysms and dyskinesia could be identified. In all patients catheter position and tip-tissue contact could easily be monitored with ICE. Procedural success (non-inducibility of hemodynamically stable VT) was achieved in all patients. Complications did not occur.

CONCLUSION

ICE is feasible in guiding RFCA of VT of different etiologies. The use of ICE in adjunction with fluoroscopy and mapping procedures will facilitate treatment of VT and may contribute to the safety of the procedure.

Noncompaction cardiomyopathy

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