Quantification of left ventricular fibrosis in arrhythmic mitral valve prolapse patients: comparison of different semi-automated techniques assessed by cardiac magnetic resonance

Background

Left ventricular (LV) fibrosis has a key role in arrhythmogenesis in mitral valve prolapse (MVP) patients. Cardiac magnetic resonance (CMR) demonstrated able to clearly identify LV fibrosis with the post-contrast late gadolinium enhancement (LGE) images. Despite the pivotal role of LV fibrosis in the arrhythmogenesis, a quantification and identification of reproducible method able to accurately measure LGE in arrhythmic MVP patients has not been recognized.

Purpose

We aimed to measure and compare different semi-quantitative methods for LGE quantification assessed by CMR, in order to identify the most reproducible one, in arrhythmic MVP patients.

Methods

66 arrhythmic MVP patients with normal systolic function and without significant regurgitation were enrolled. Semi-automated gray-scale thresholding technique using full with at half maximum (FWHM) and 2, 3 and 5 standard deviation (SD) above the remote myocardium were used and compared with visual assessment (Fig. 1).

Results

LGE was identified in 41 arrhythmic MVP patients (62%) and quantified (Fig. 2). The mean quantity of LGE visually assessed was 2.40±1.07% or 1.40±0.82 g. With FWHM, LGE resulted 3.56±1.23% or 1.99±1.13 g. Using thresholding, the mean LGE quantity was 9.2±3.1% or 4.82±2.28 g for 2-SD, 5.72±1.75% or 3.06±1.47 g for 3-SD and 2.36±0.99% or 1.29±0.79 g for 5-SD. The 5-SD measurement in percentage demonstrated a good correlation with LGE quantification visually assessed (2.402±1.075 vs 2.363±0.9909, p: 0.543). Despite all semi-quantitative methods for LGE quantification demonstrated a good intra and inter-observer agreement, the 5-SD threshold quantification, both in percentage and in grams, revealed the less intra-observer (respectively, ICC: 0.976 and 0.966) and inter-observer variability (respectively ICC: 0.948 and 0.935) when compared with visual assessment.

Conclusion

This is the first study that quantified and compared different CMR semi-automated methods for LGE assessment in a population of arrhythmic MVP patients. The 5-SD gray-scale threshold technique in percentage revealed the best correlation with the visual assessment and an optimal reproducibility.

Funding Acknowledgement

Type of funding sources: None.

P12 SUBCUTANEOUS IMPLANTABLE CARDIOVERTER–DEFIBRILLATOR AFTER TRANSVENOUS LEAD EXTRACTION: SAFETY, EFFICACY AND OUTCOME

Background

Subcutaneous implantable cardioverter defibrillator (S–ICD) is a suitable alternative for trans–venous–ICD (TV–ICD) patients underwent transvenous lead extraction (TLE) for any reason, but limited data are available about outcome of s–ICD patients implanted after TLE.

Methods

Thirty–six consecutive patients underwent TLE of TV–ICD and subsequent S–ICD implantation in our center were included in this prospective single–center observational study (72.2% male, median age 52 years–old).

Results

During a median follow-up of 31 months, 3 patients (8.3%) experienced appropriate therapy and 7 patients (19.4%) experienced complications including innapropriate therapy (IAT) (n = 4; 11.1%), pulse generator decubitus with no evidence of infection (n = 2; 5.5%) and ineffective therapy (n = 1; 2.7%). Reasons of IAT were: T–wave oversensing in one patient and extracardiac signals in the remaining 3 patients. Of note, 2 patients who experienced IAT had a left–ventricular assist device (LVAD) for refractory heart failure (HF). Premature device explantation and TV–ICD re–implantation occurred in 4 patients (11%) for pulse generator decubitus despite surgical pocket revisions (n = 2), for recurrent IAT despite reprogramming (n = 1) and ineffective therapy during arrhythmic storm (n = 1). Eight patients (22.2%) died, 3 patients (9%) underwent LVAD implantation due refractory HF during follow-up. Six patients died because of refractory HF, 1 patient died due to intracerebral hemorrhage and 1 due to sarcoidosis. There were no documented deaths associated with the procedure or the S–ICD system itself. No patient had the device removed because of a perceived need for antitachycardia pacing (ATP) or the necessity of pacing or cardiac resynchronization therapy despite 9 patients (25%) after TLE of a two–chamber ICD and one patient (3%) after TLE of a CRT–D. Univariate predictors of death included hypertension (HR 22.72; p = 0.02), diabetes (HR 10.64; p = 0.001), ischemic heart disease (HR 5.92; p = 0.01) and NYHA class > = II (p = 0.04). We did not observed any predictors for complications including IATs and device-related complications requiring surgical revision.

Conclusions

S–ICD implantaion after TLE of TV–ICD is safy and effective. Baseline clinical characterisctics including ischemic heart disease, diabetes, hypertension and NYHA class > = II are associated with worse survival.

Left ventricular thrombosis following apical myocardial infarction: may CMR strain analysis tell us something?

Funding Acknowledgements

Type of funding sources: None.

Background

 Left ventricular thrombosis (LVT) is a possible complication following myocardial infarction (MI). Besides infarct size, risk factors for LVT include ST-elevated MI (STEMI), anterior and apical location, reduced left ventricular ejection fraction (LVEF) and the presence of microvascular obstruction. Echocardiography quantified myocardial strain has been associated with LVT following MI. Recently, global longitudinal strain, calculated with feature tracking (FT) - CMR, emerged as an independent predictor of major cardiovascular events following MI. Anyway, the relationship between abnormalities on FT-CMR and LVT following MI is still unexplored. Aim of our study is to investigate the possible association between abnormal strain on FT-CMR and LVT following apical STEMI.

Methods

 We performed a retrospective analysis including all patients with a previous apical STEMI, who underwent CMR at our Institute between August 2013 and October 2020. Patients with ongoing anticoagulant therapy were excluded. Differences in global and segmental strain on CMR between patients with and without LVT were tested in a propensity-matched sample, using LVEF, age, gender, time from MI diagnosis and number of LV segments with transmural late gadolinium enhancement (LGE) as covariates to assign propensity score. Furthermore, difference in terms of apical to global radial strain percentual deviation (AGD), calculated as [(Global Radial Strain – Apical Radial Strain)/Global Radial Strain] * 100, was tested. 

Results

 Of 356 patients with apical STEMI undergoing CMR at our center, 37 (10.4%) were diagnosed with LVT. After performing a propensity score matching, we obtained a sample of 36 pairs, with a mean age of 65 (SD 11) years, and a median EF of 35% (IQR 27-42); 59 (82%) of them were male. A significant difference in terms of apical radial strain was found between the two groups, with a median strain of 10.75 (IQR 6.8–16.5) in patients without LVT compared to a value of 5.25 (IQR 2.7–9-6) in patients with LVT (p = 0.007). No differences were found in terms of global longitudinal, radial and circumferential strain (p = 0.19, p= 0.2 and p= 0.49 respectively) and segmental circumferential and longitudinal strain. When considering the AGD parameter, a significant difference was found between the two groups, with a median deviation of 12% (IQR -20; +48) in patients without LVT and 51% (IQR +47; +75) in patients with LVT (p= 0.0003). Furthermore, an AGD value of 26% was found to be the most accurate in terms of sensitivity and specificity applying a Receiver Operating Characteristic (ROC) curve analysis (AUC 0.74; CI 0.62-0.85).

Conclusions

 Among patients with transmural MI involving LV apex, reduced apical radial strain on FT-CMR is associated with the presence of LV thrombosis. Furthermore, among patients developing LV thrombi, a greater apical radial strain deviation from the global one was found, with a threshold value of 26% at ROC curve analysis.

Left ventricular myocardial deformation abnormalities in arrhythmic mitral valve prolapse: which comes first?

Funding Acknowledgements

Type of funding sources: None.

Background. Arrhythmic mitral valve prolapse (MVP) is characterized by left ventricular (LV) fibrosis in the basal inferolateral wall and papillary muscles. We hypothesized that LV fibrosis are driven by excessive mechanical forces acting on myocardial susceptible cells, representing the last step in the MVP-induced myocardial stretch process. Purpose. We aimed to evaluate the LV myocardial deformation, using strain assessed with cardiac magnetic resonance (CMR), in arrhythmic MVP patients with normal LV ejection fraction (LVEF) and absent/trivial mitral regurgitation (MR) and its correlation with the presence of LV fibrosis, detected by late gadolinium enhancement (LGE) in post-contrast CMR images. Methods. We enrolled consecutive arrhythmic MVP patients with normal LVEF and no/trivial MR. Sixty-nine (39 female; median age: 40 years) patients without MVP, arrhythmias or cardiovascular history served as control group. All patients underwent CMR for identification of LGE and evaluation of LV myocardial deformation. Results. A total of 66 patients were enrolled (47 female; median age: 44 years). In the overall MVP population, LGE was present in 41 patients (62.1%). MVP patients without LGE (25 patients, 37.9%) presented a higher global radial (median: 42.19 vs 33; p: <0.0001) and higher global longitudinal strain (median: -21.61 vs -18.10; p: <0.0001), compared to the control group. A reduction of regional basal posterolateral radial (BPL median: 50.60 vs 67.30; p: 0.0015) and longitudinal strain (BPL median: -23.50 vs -26.70; p: 0.0186) were observed in the MVP patients as compared with controls (Figures A-D). Conversely to the basal region, mid anterolateral and posterolateral region presented a higher radial (MAL median: 52.60 vs 31.10; p: < 0.0001 and MPL median: 52.80 vs 21.50; p: < 0.0001) and longitudinal strain (MAL median: -24.80 vs -18.30; p: < 0.0001 and MPL median: -25.30 vs -14.80; p: < 0.0001), when compared to control group. MVP patients with LGE had a lower global radial (median: 36.48 vs 42.19; p: <0.0047), longitudinal (median: -19.18 vs -21.61; p: 0.0013) and circumferential strain (median: -17.80 vs -19.28; p: 0.0134) compared with those without fibrosis. According to MVP patients without LGE, the presence of fibrosis is associated with a lower regional radial (BAL median: 64.40 vs 82.80; p: 0.0481; MAL median: 42.60 vs 52.60; p: 0.0287) and circumferential strain (BAL median: -21.90 vs -24.20; p: 0.0174; BPL median: -16.80 vs -18.80; p: 0.0411; MPL median: -15.50 vs -19.40; p: 0.0077) in the LV basal-mid lateral walls (Figures E-I). Conclusions. Arrhythmic MVP patients with normal LV systolic function and absent/trivial MR presented an abnormal myocardial deformation pattern. The reduced strain in BPL wall of MVP patients without LGE could be considered as an early marker of MVP-induced myocardial stress, that could promote, time by time, LV fibrosis and arrhythmias in MVP patients.

Relationship between papillary muscles abnormalities and apparently unexplained infero-lateral T-wave inversion in athletes

Aims

To evaluate by cardiac magnetic resonance (CMR) if left ventricle papillary muscle abnormalities, such as hypertrophy and abnormal location, may be the anatomo-functional substrates responsible for TWI inversion in lateral or infero-lateral leads in otherwise healthy athletes.

Methods

We included competitive athletes with TWI in lateral or infero-lateral leads in the absence of cardiac diseases detected by CMR. The control population included healthy athletes with normal ECG, matched for age and gender. We compared thickness, volume (both absolute and relative to the cardiac mass) and position of the papillary muscles between cases and controls.

Results

We included 53 athletes with apparently unexplained TWI in the lateral or infero-lateral leads (median age 20 years (17–42), 86.8% males) and 53 athletes with no TWI matched for age and gender. 4 patients (7.6%) had family history for cardiomyopathy or sudden cardiac death. Athletes with TWI showed more hypertrophic papillary muscles compared to controls, with statistically significant difference in diameter, area and volume (p<0.01). The median ratio between the papillary muscles and the left ventricular mass was 4.4% among athletes with TWI versus 3% among those without TWI (p<0.001). Papillary muscles showed apical displacement in 47% of cases, compared to 17% in the control group (p=0.001).

Conclusions

Idiopathic TWI in lateral or infero-lateral leads is associated with left ventricle papillary muscle hypertrophy and their apical displacement detected by CMR. The comprehension of clinical and prognostic significance of papillary muscle abnormalities responsible for these ventricular repolarization alterations requires further studies.

Example

Funding Acknowledgement

Type of funding source: None

Predictors of left ventricular scar at cardiac magnetic resonance in athletes with apparently idiopathic ventricular arrhythmias

Introduction

In athletes with ventricular arrhythmias (VA) and otherwise unremarkable clinical findings, cardiac magnetic resonance (CMR) may reveal concealed pathological substrates. The aim of this multicentre study was to evaluate which VA characteristics were associated with CMR abnormalities.

Methods

We enrolled a consecutive series of 251 competitive athletes (74% males, mean age 28.5±14.5 years) who underwent CMR for evaluation of VA. We included athletes with >100 premature ventricular beats (PVBs)/24-hour or ≥1 repetitive VA (couplets, triplets or non-sustained ventricular tachycardia) on 12-lead 24-hour ambulatory ECG monitoring and negative family history, electrocardiogram and echocardiogram. Features of VA that were evaluated included number, morphology, repetitivity and response to exercise testing.

Results

Left-ventricular late gadolinium-enhancement (LGE) was documented in 28 (11%) athletes, mostly (N=25) with a subepicardial/midmyocardial (non-ischemic) distribution. On 24-hour ECG monitoring, PVBs with a right-bundle-branch-block and intermediate/superior axis configuration or multiple morphologies were documented in 24/28 (86%) athletes with versus 55/223 (25%) without LGE (p<0.001). More than 2000 PVBs were recorded in 6 (21%) athletes with versus 127 (57%) without positive CMR (p<0.001). At exercise testing, repetitive VA occurred at high work-load in 12 (43%) athletes with versus 26 (12%) without LGE (p<0.001). At multivariable analysis, all three VA features independently correlated with CMR abnormalities.

Conclusions

In athletes with apparently idiopathic VA, simple characteristics such as number and morphology of PVBs on 12-lead 24-hour ambulatory ECG monitoring and response to exercise testing predicted the presence of concealed myocardial abnormalities on CMR. These findings may help cost-effective CMR prescription.

Flow chart

Funding Acknowledgement

Type of funding source: None

P527Ultrasound-guided serratus anterior plane block for S-ICD implantation using the intermuscular technique

Funding Acknowledgements

NONE

Background

operative anesthetic requirements and peri-operative discomfort are barriers to wide adoption of the subcutaneous implantable cardioverter defibrillator (S-ICD) system expecially when the intermuscular technique is used due to the greater amount of tissue dissection. The procedure is most commonly performed under general anesthesia (GA). There is growing interest in transitioning away from the routine use of GA and towards several alternative anesthesia modalities implifying the anesthetic management of the S-ICD implant procedure without the involvement of an anesthesiologist.

Purpose

we assessed the feasibility of ultrasound-guided serratus anterior plane block (US-SAPB) in patients undergoing S-ICD implantation with the intermuscular two-incision technique. Methods: the study population included 38 consecutive patients (84% male; median, 53 [46-62] years) who received S-ICD implantation using the intermuscular two-incision technique. All procedures were performed under US-SAPB and sedoanalagesia without the involvement of an anesthesiologist.

Results

the average procedure time was 67 ± 14 minutes.No patient experienced significant hemodynamic changes or oxygen desaturation during the period of US- SAPB procedure and sedation; there was no need for pharmacological interventions. The whole procedute was well tollerated without discomfort and complications in the absence of needing GA except in one (2.6%) patient who required GA with laryngeal mask airway. Patients remained always able to respond appropriately to neurological monitoring during S-ICD implantation procedure. There were no procedure-related complications.

Conclusion

US-SAPB and the intermuscular two-incision technique may be a safe and feasible promising combination for S-ICD implantation overcoming potential barrier to wieder S-ICD adoption in the clinical practice.

P173 When the heart doesn"t want to grow up

Background

Blood cysts of heart valves are uncommon and, usually, incidental findings in pediatric population. Rarely seen in adults, blood cysts are normally asymptomatic, even though several cases of embolization, valvular disfunction and left ventricle outflow tract (LVOT) obstruction have been described. Clinical Presentation. We report the case of a 23 year-old woman, with history of a small nodular mass of the mitral valve, found on a previous cardiac magnetic resonance (CMR) at the age of thirteen, who was admitted to our emergency department complaining atypical chest pain. She denied shortness of breath, syncope, tachycardia and fever. She was hemodynamically stable and a fast regression of symptoms was observed. The physical examination was unremarkable. Both the electrocardiogram (ECG) and blood tests were normal. A chest radiography showed normal heart size, without other abnormalities. After having ruled out an acute coronary syndrome, the patient was discharged with the indication to undergo further cardiological assessments. Diagnostic techniques and their most important findings. Therefore, a trans-thoracic echocardiogram was performed revealing normal biventricular function, no aortic root dilation, no pericardial effusion, no valvular regurgitation or stenosis. A round (7x11 mm) mass with hyperechogenic borders and hypoechogenic content was detected on the ventricular side of the anterior mitral valve leaflet consistent with a valvular blood cyst (figure 1: a,b,c). Only trivial mitral valve regurgitation without LVOT obstruction was present. The 3D echo reconstruction allowed to confirm the suspicion of blood cyst and detect a cleft of the posterior mitral valve leaflet, located in the P2 scallop (figure 1: d,e). A repeated CMR showed no contrast enhancement of the mass. Due to the clinical stability and the absence of complications, the patient was suggested to continue an echocardiographic follow-up. Discussion. Cardiac blood cysts are a rare condition with uncertain origin, usually found in infants in the first six months of life. A natural regression after that age has been described, making this condition very unusual in adults. Despite its benign features, when persistent beyond the childhood, the blood cyst can grow and reach even huge dimensions, potentially impairing the valvular function and/or causing LVOT obstruction. Another potential complication of blood cysts may be the arterial embolization. In all these situations surgical resection must be considered. In our patient, the contribution of trans-thoracic echocardiogram and in particular the 3D reconstruction, were pivotal to address the correct diagnosis.

Abstract P173 Figure 1

4252Additional value of stress testing for evaluation of ventricular arrhythmias in athletes undergoing preparticipation screening

Introduction

The optimal protocol of athletes pre-participation screening is a matter of debate. The aim of this study is to test the additional value of exercise testing (ET) for evaluation of ventricular arrhythmias (VA) in athletes with otherwise normal findings.

Methods

The study included 10,975 competitive athletes who underwent preparticipation screening including ECG and stress testing. Athletes with ≥3 isolated premature ventricular beats or ≥1 repetitive VA underwent second-line investigations (echocardiography and 24-hour ambulatory ECG monitoring with a training session) and, in case of frequent, complex or exercise-induced VA or echocardiographic abnormalities, also cardiac magnetic resonance (CMR).

Results

451 (4,1%) athletes were excluded for abnormalities at history, physical examination and baseline ECG. Among the remaining 10524 athletes, 524 (5%)showed VA at ET, 87 of whom underwent CMR.Echocardiography identified major cardiac abnormalities in 5 athletes and regional ventricular systolic dysfunction in 7, which were confirmed by CMR in 6. Other 12 patients with normal echocardiography had a positive CMR. In particular, in 16 subjects the CMR showed left ventricular late gadolinium enhancement suggesting myocardial fibrosis with a non-ischemic distribution. At multivariate analysis, VA observed at high work load at ET, the presence of complex VA at ET and the presence of a morphology other than infundibular or fascicular predicted an underlying pathological myocardial substrate while the presence of frequent (>500/24-hour) premature ventricular beats did not.

Predictors of underlying pathological myocardial substrate Substrate Univariate Multivariable YES (n=23) NO (n=501) OR (95% IC) P OR (95% IC) P Age 17 [13–43] 15 [14–17] 1.03 [0.98 -1.06] 0.18 – Male gender 15 (65%) 184 (37%) 3.2 [1.3–7.7] <0.001 1.6 [0.7–4.8] 0.28 >500 PVBs/24-hour 7 (30%) 98 (20%) 1.8 [0.7–4.5] 0.21 – VA at high work-load 10 (44%) 78 (16%) 4.2 [1.8–9.8] <0.001 1.6 [1.1–4.7] 0.02 Couplets/NSVT at ET 14 (61%) 117 (23%) 6.2 [2.5–15] <0.001 8.5 [2.5–29] 0.01 PVBs other than infundibular/fascicular 17 (74%) 118 (24%) 6.1 [2.4–16] <0.001 3.9 [1.4–11] 0.008

Conclusions

VA at ET may represent the only sign of a pathological myocardial abnormalities, such as the “isolated nonischemic left ventricular scar”, that could be the substrate for life-threatening ventricular arrhythmias. Addition of ET to baseline ECG may increase the sensitivity of PPE of competitive athletes.

[One or more functional somatic syndromes? Comparison of the health status of fibromyalgia and electro-hypersensitive people]

INTRODUCTION

Functional somatic syndromes, grouping somatic symptoms without an organic explanation, are defined either by their predominant symptoms or by an attribution to an, often hypothetical, cause. Due to many similarities, some authors consider that there is only one FSS due to a general phenomenon of "somatization". The objective of this work was to compare two functional somatic syndromes, one defined by its symptoms, fibromyalgia, and the other by a specific contested attribution, electro-hypersensitivity.

METHOD

Fibromyalgia or electro-hypersensitive participants (EHS) were recruited from September 2016 to April 2017 through associations of patients in Auvergne-Rhône-Alpes. Home interviews included the collection of medical, psychopathological, and symptom histories. The assessment of psychological distress, quality of life and the search for other functional somatic syndromes was performed through structured questionnaires, self-administrated scales, and clinical examination.

RESULTS

Sixteen fibromyalgia subjects and sixteen EHS subjects were included. There are differences in symptomatology, although many symptoms are common to both conditions. Lifetime history of psychiatric disorders and current psychological distress and psychopathology are frequent in both groups but more prevalent in fibromyalgia subjects. The experience of the symptoms, their interpretation, the diagnostic itineraries and the therapeutic behaviours differ radically according to the group, even if for all socio-professional impact is high and quality of life are altered.

CONCLUSION

The health status of fibromyalgia persons is overall worse than the health status of electro-hypersensitive individuals in this small sample. Despite the overlap in symptoms and a similar impact on daily functioning, this exploratory study suggests that heterogeneous mechanisms of "somatization" may be at stake in functional somatic syndromes.

Plasma-beam traps and radiofrequency quadrupole beam coolers

Two linear trap devices for particle beam manipulation (including emittance reduction, cooling, control of instabilities, dust dynamics, and non-neutral plasmas) are here presented, namely, a radiofrequency quadrupole (RFQ) beam cooler and a compact Penning trap with a dust injector. Both beam dynamics studies by means of dedicated codes including the interaction of the ions with a buffer gas (up to 3 Pa pressure), and the electromagnetic design of the RFQ beam cooler are reported. The compact multipurpose Penning trap is aimed to the study of multispecies charged particle samples, primarily electron beams interacting with a background gas and/or a micrometric dust contaminant. Using a 0.9 T solenoid and an electrode stack where both static and RF electric fields can be applied, both beam transport and confinement operations will be available. The design of the apparatus is presented.

Serum Bone Gla-Protein in Hypercalcemia of Primary Hyperparathyroidism and Malignancy

Serum bone GLA-protein, a modem and sensitive marker of bone turnover, was measured in 15 patients with primary hyperparathyroidism, 18 patients with hypercalcemia of malignancy, 41 patients with bone metastasis without hypercalcemia, and 29 healthy subjects. Serum bone GLA-protein was increased in primary hyperparathyroidism (17.6 ± 3.9 ng/ml) and normal in hypercalcemia of malignancy (5.2 ± 2.8 ng/ml; p < 0.001 vs hyperparathyroidism) and in normocalcemic patients with bone metastases. In primary hyperparathyroidism parathyroid hormone correlated positively with urinary calcium excretion (p < 0.05) and with urinary hydroxyproline excretion (p < 0.001). The sensitivity of serum bone GLA-protein measurements in differentiating between primary hyperparathyroidism and hypercalcemia of malignancy was 91 % and the specificity 84 %. Thus this marker appears to be a useful tool for the differential diagnosis of hypercalcemias.