Myocardial extracellular volume by T1 mapping: a new marker of arrhythmia in mitral valve prolapse.

We aimed to evaluate the relationship between mitral annular disjunction (MAD) severity and myocardial interstitial fibrosis at the left ventricular (LV) base in patients with mitral valve prolapse (MVP), and to assess the association between severity of interstitial fibrosis and the occurrence of ventricular arrhythmic events. In MVP, MAD has been associated with myocardial replacement fibrosis and arrhythmia, but the importance of interstitial fibrosis remains unknown. In this retrospective study, 30 patients with MVP and MAD (MVP-MAD) underwent cardiovascular magnetic resonance (CMR) with assessment of MAD length, late gadolinium enhancement (LGE), and basal segments myocardial extracellular volume (ECVsyn). The control group included 14 patients with mitral regurgitation (MR) but no MAD (MR-NoMAD) and 10 patients with normal CMR (NoMR-NoMAD). Fifteen MVP-MAD patients underwent 24 h-Holter monitoring. LGE was observed in 47% of MVP-MAD patients and was absent in all controls. ECVsyn was higher in MVP-MAD (30 ± 3% vs 24 ± 3% MR-NoMAD, p < 0.001 and vs 24 ± 2% NoMR-NoMAD, p < 0.001), even in MVP-MAD patients without LGE (29 ± 3% vs 24 ± 3%, p < 0.001 and vs 24 ± 2%, p < 0.001, respectively). MAD length correlated with ECVsyn (rho = 0.61, p < 0.001), but not with LGE extent. Four patients had history of out-of-hospital cardiac arrest; LGE and ECVsyn were equally performant to identify those high-risk patients, area under the receiver operating characteristic (ROC) curve 0.81 vs 0.83, p = 0.84). Among patients with Holter, 87% had complex ventricular arrhythmia. ECVsyn was above the cut-off value in all while only 53% had LGE. Increase in ECVsyn, a marker of interstitial fibrosis, occurs in MVP-MAD even in the absence of LGE, and was correlated with MAD length and increased risk of out-of-hospital cardiac arrest. ECV should be includedin the CMR examination of MVP patients in an effort to better assess fibrous remodelling as it may provide additional value beyond the assessment of LGE in the arrhythmic risk stratification

Lithium-induced ECG modifications: navigating from acute coronary syndrome to Brugada syndrome.

Lithium is frequently used in the treatment of bipolar disorders and is known to induce ECG alterations. This case study describes various patterns of lithium-induced ECG modifications in a patient with acute-on-chronic lithium intoxication. Clinicians should be familiar with this problem as it can have life-threatening consequences and lead to important changes in patient's management. Our patient was admitted for acute delirium with an ECG showing atrial fibrillation with wide QRS and ST-segment elevation. These modifications were first mistaken for an acute myocardial infarction and a diagnosis of Brugada syndrome was finally reached. Treatment after the acute phase implied changes in the therapeutic modality and required frequent monitoring

From trivial to severe arrhythmias: the diagnostic role of multimodality imaging in inflammatory cardiomyopathy through a case series.

The diagnosis of inflammatory cardiomyopathy remains challenging in cases presenting with arrhythmia as sole manifestation. An early diagnosis is critical as it may prevent life-threatening complications such as sudden cardiac death and atrioventricular block (AVB). The diagnostic workup of suspected cases includes multimodality imaging that requires an adequate interpretation in order to limit the risk of overdiagnosis. Herein, we report three cases presenting with various new-onset arrhythmias. The first patient was admitted for a third-degree AVB. The second patient suffered from a supraventricular tachycardia which degenerated into ventricular fibrillation. The third case was investigated for symptomatic premature ventricular complexes. No apparent heart disease was observed on standard exams (clinical, biological examinations, and echocardiography). However, cardiac magnetic resonance imaging (MRI) and nuclear imaging ( <sup>68</sup> Ga-DOTATOC and/or <sup>18</sup> F-FDG PET/CT) suggested an inflammatory substrate that seemed to correlate with the arrhythmic phenotype. Cardiac inflammation disappeared on immunotherapy for the first case and spontaneously for the third case. These cases emphasize the incremental diagnostic yield of multimodality imaging to highlight myocardial inflammation. Nuclear imaging modalities may complement MRI by enabling the detection of active inflammation. The <sup>18</sup> F-FDG PET/CT is well established for the diagnosis of cardiac sarcoidosis but its role remains to be clarified for the diagnosis of myocarditis. An alternative radiotracer, <sup>68</sup> Ga-DOTATOC, appears promising by overcoming the main limitation of <sup>18</sup> F-FDG but its specificity is not yet well established. The role of functional investigations is discussed as well as the benefit of immunosuppressive treatments

Feasibility of adenosine stress cardiovascular magnetic resonance perfusion imaging in patients with MR-conditional transvenous permanent pacemakers and defibrillators.

The use of stress perfusion-cardiovascular magnetic resonance (CMR) imaging remains limited in patients with implantable devices. The primary goal of the study was to assess the safety, image quality, and the diagnostic value of stress perfusion-CMR in patients with MR-conditional transvenous permanent pacemakers (PPM) or implantable cardioverter-defibrillators (ICD). Consecutive patients with a transvenous PPM or ICD referred for adenosine stress-CMR were enrolled in this single-center longitudinal study. The CMR protocol was performed using a 1.5 T system according to current guidelines while all devices were put in MR-mode. Quality of cine, late-gadolinium-enhancement (LGE), and stress perfusion sequences were assessed. An ischemia burden of ≥ 1.5 segments was considered significant. We assessed the safety, image quality and the occurrence of interference of the magnetic field with the implantable device. In case of ischemia, we also assessed the correlation with the presence of significant coronary lesions on coronary angiography. Among 3743 perfusion-CMR examinations, 66 patients had implantable devices (1.7%). Image quality proved diagnostic in 98% of cases. No device damage or malfunction was reported immediately and at 1 year. Fifty patients were continuously paced during CMR. Heart rate and systolic blood pressure remained unchanged during adenosine stress, while diastolic blood pressure decreased (p = 0.007). Six patients (9%) had an ischemia-positive stress CMR and significant coronary stenoses were confirmed by coronary angiography in all cases. Stress perfusion-CMR is safe, allows reliable ischemia detection, and provides good diagnostic value

New Insights in Central Venous Disorders. The Role of Transvenous Lead Extractions.

Over the last decades, the implementation of new technology in cardiac pacemakers and defibrillators as well as the increasing life expectancy have been associated with a higher incidence of transvenous lead complications over time. Variable degrees of venous stenosis at the level of the subclavian vein, the innominate trunk and the superior vena cava are reported in up to 50% of implanted patients. Importantly, the number of implanted leads seems to be the main risk factor for such complications. Extraction of abandoned or dysfunctional leads is a potential solution to overcome venous stenosis in case of device upgrades requiring additional leads, but also, in addition to venous angioplasty and stenting, to reduce symptoms related to the venous stenosis itself, i.e., the superior vena cava syndrome. This review explores the role of transvenous lead extraction procedures as therapeutical option in case of central venous disorders related to transvenous cardiac leads. We also describe the different extraction techniques available and other clinical indications for lead extractions such as lead infections. Finally, we discuss the alternative therapeutic options for cardiac stimulation or defibrillation in case of chronic venous occlusions that preclude the implant of conventional transvenous cardiac devices

Fabry disease: development and progression of left ventricular hypertrophy despite long-term enzyme replacement therapy.

Enzyme replacement therapy (ERT) may halt or attenuate disease progression in patients with Anderson-Fabry disease (AFD). However, whether left ventricular hypertrophy (LVH) can be prevented by early therapy or may still progress despite ERT over a long-term follow-up is still unclear. Consecutive patients with AFD from the Independent Swiss-Fabry Cohort receiving ERT who were at least followed up for 5 years were included. Cardiac progression was defined as an increase of >10 g/m <sup>2</sup> in left ventricular mass index (LVMI) between the first and the last available follow-up transthoracic echocardiography. 60 patients (35 (23-48) years, 39 (65%) men) were followed up for 10.5 (7.2-12.2) years. 22 had LVH at ERT start (LVMI of 150±38 g/m <sup>2</sup> ). During follow-up, 22 (36%, 34±15 years) had LVMI progression of 12.1 (7-17.6) g/m <sup>2</sup> per 100 patient-years, of these 7 (11%, 29±13 years) with no LVH at baseline. Three of them progressed to LVH. LVMI progression occurred mostly in men (17 of 39 (43%) vs 5 of 21 (24%), p<0.01) and after the age of 30 years (17 of 22 (77%)). LVH at ERT start was associated with LVMI progression (OR 1.3, 95% CI 1.1 to 2.6; p=0.02). A total of 19 (31%) patients experienced a major AFD-related event. They were predominantly men (17 of 19, 89%), older (45±11 vs 32±9 years) with baseline LVH (12 of 19, 63%), and 10 of 19 (52%) presented with LVMI progression. Over a median follow-up of >10 years under ERT, 36% of the patients still had LVMI cardiac progression, and 32%, predominantly older men, experienced major AFD-related events. LVH at treatment initiation was a strong predictor of LVMI progression and adverse events on ERT

SCN5A Overlap Syndromes: an open-minded approach.

SCN5A overlap syndromes are clinical entities that express a phenotype combining aspects of different canonical SCN5A-related arrhythmia syndromes or a variable arrhythmic phenotype among individuals carrying the same SCN5A mutation. We here review the literature addressing SCN5A overlap syndromes, as well as the principal mechanisms currently proposed. Among others, a multifactorial determination - encompassing an interaction between SCN5A variant(s), other genetic polymorphisms, and possibly environmental factors - seems the most plausible hypothesis

A combined "in vivo" noninvasive evaluation of carotid plaques using ultrasonography and high-resolution magnetic resonance - new insight into plaque burden and vulnerability.

Qualitative change in carotid plaques was prospectively evaluated by Gray Scale Median (GSM) analysis at repeated examinations "in vivo", in relation to quantitative change in carotid arterial geometry, as assessed by high-resolution magnetic resonance imaging (HR-MRI). Duplex ultrasound with GSM analysis and HR-MRI at the carotid level were performed at baseline and 1- and 2-year follow up in 30 patients with < 70% carotid stenosis. Changes in GSM values (ΔGSM) were evaluated as the intra-individual difference between 2-year and baseline values. HR-MRI studies were evaluated for lumen area (LA), total vessel area (TVA), vessel wall area (VWA = TVA-LA) and normalized wall index (NWI = VWA/TVA). ΔGSM value distribution was divided into quartiles. Predominantly echolucent plaques with ΔGSM value in the lowest quartile (ΔGSM ≤- 8) showed a significantly greater mean 2-year LA (28.62 ± 10.9 mm2 vs. 17.88 ± 4.8 mm2, p = 0.04) and a greater mean 2-year TVA (83.64 ± 19.4 mm2 vs. 63.26 ± 9.2 mm2, p = 0.02) than predominantly echogenic plaques with ΔGSM value in the highest quartile (ΔGSM ≥8). Increasing echolucency during the 2-year follow up was associated with a 2-year lower degree of stenosis and higher tendency toward lumen preservation. By corroborating that plaque vulnerability is highly independent of stenosis severity, our study provided a possible new combined "in vivo" noninvasive approach for the assessment of carotid plaque vulnerability

Dysfonction sinusale, syndrome de Brugada et syndrome du QT long chez un même patient - Quand la génétique y perd son latin [Sinus node dysfunction, Brugada syndrome and long QT syndrome affecting the same patient : when genetics can't make head or tail of it]

The gene SCN5A encodes the cardiac sodium channel which, through the conduction of Na+ current into the cell, generates the fast upstroke of the action potential of cardiomyocytes. Pathogenic variants of SCN5A have been causally associated to several hereditary cardiac diseases including, among others, Brugada syndrome, congenital long QT syndrome and sinus node dysfunction. Recently, overlap syndromes have been described that are characterized by the simultaneous expression of mixed clinical phenotypes among two or more hereditary cardiac diseases associated to the gene SCN5A (HCD-SCN5A). For this reason, it is time to rethink about HCD-SCN5A as different expressions of the same complex spectrum encompassing multiple clinical phenotypes with pronounced overlaps instead of as distinct clinical entities