Conduction System Pacing versus Conventional Biventricular Pacing for Cardiac Resynchronization Therapy: Where Are We Heading?

Over the last few years, pacing of the conduction system (CSP) has emerged as the new standard pacing modality for bradycardia indications, allowing a more physiological ventricular activation compared to conventional right ventricular pacing. CSP has also emerged as an alternative modality to conventional biventricular pacing for the delivery of cardiac resynchronization therapy (CRT) in heart failure patients. However, if the initial clinical data seem to support this new physiological-based approach to CRT, the lack of large randomized studies confirming these preliminary results prevents CSP from being used routinely in clinical practice. Furthermore, concerns are still present regarding the long-term performance of pacing leads when employed for CSP, as well as their extractability. In this review article, we provide the state-of-the-art of CSP as an alternative to biventricular pacing for CRT delivery in heart failure patients. In particular, we describe the physiological concepts supporting this approach and we discuss the future perspectives of CSP in this context according to the implant techniques (His bundle pacing and left bundle branch area pacing) and the clinical data published so far.

Clinical presentation of calmodulin mutations: the International Calmodulinopathy Registry

AIMS

Calmodulinopathy due to mutations in any of the three CALM genes (CALM1-3) causes life-threatening arrhythmia syndromes, especially in young individuals. The International Calmodulinopathy Registry (ICalmR) aims to define and link the increasing complexity of the clinical presentation to the underlying molecular mechanisms.

METHODS AND RESULTS

The ICalmR is an international, collaborative, observational study, assembling and analysing clinical and genetic data on CALM-positive patients. The ICalmR has enrolled 140 subjects (median age 10.8 years [interquartile range 5-19]), 97 index cases and 43 family members. CALM-LQTS and CALM-CPVT are the prevalent phenotypes. Primary neurological manifestations, unrelated to post-anoxic sequelae, manifested in 20 patients. Calmodulinopathy remains associated with a high arrhythmic event rate (symptomatic patients, n = 103, 74%). However, compared with the original 2019 cohort, there was a reduced frequency and severity of all cardiac events (61% vs. 85%; P = .001) and sudden death (9% vs. 27%; P = .008). Data on therapy do not allow definitive recommendations. Cardiac structural abnormalities, either cardiomyopathy or congenital heart defects, are present in 30% of patients, mainly CALM-LQTS, and lethal cases of heart failure have occurred. The number of familial cases and of families with strikingly different phenotypes is increasing.

CONCLUSION

Calmodulinopathy has pleiotropic presentations, from channelopathy to syndromic forms. Clinical severity ranges from the early onset of life-threatening arrhythmias to the absence of symptoms, and the percentage of milder and familial forms is increasing. There are no hard data to guide therapy, and current management includes pharmacological and surgical antiadrenergic interventions with sodium channel blockers often accompanied by an implantable cardioverter-defibrillator.

Recurrences after stereotactic arrhythmia radioablation for refractory ventricular tachycardia

Introduction

Stereotactic arrhythmia radioablation (STAR) has been recently introduced for the management of ventricular tachycardia (VT) refractory to antiarrhythmic drugs (AADs) and catheter ablation (CA). VT recurrences were recently reported after STAR but the mechanisms remain poorly known.

Purpose

We analyzed VT recurrences after STAR for refractory VT in order to assess the characteristics and delivered dose at sites of VT relapse.

Methods

From 09.2017 to 01.2020, 12 consecutive patients (pts) (66±8y, LVEF 40±14%) suffering from refractory VT were enrolled. The underlying cardiopathy was ischemic in 3, inflammatory in 3 and idiopathic in 6 pts. Nine (75%) out of 12 pts had a history of at least 1 electrical storm. Before STAR, an invasive electro-anatomical mapping (Carto3) of the VT substrate (VT-sub) was performed. A mean dose of 22±2Gy was delivered to the VT-sub using the Cyberknife® system.

Results

The ablation volume was 24±7cc and involved the basal interventricular septum (IVS) in 10 (83%) pts. During the first 6 months after STAR, VT burden decreased by 93% (mean value, from 640 to 46 VT/semester). After a median follow-up of 32±11 months, 10/12 (83%) developed ≥1 recurrence as a sustained VT and underwent a redo CA. Two (17%) pts presented 2 distinct VT recurrences from clearly different areas. VT recurrence was located at the border zone (BZ) of the treated VT-sub in 6 (50%) cases, involved both the BZ and a larger substrate in 2 (17%) cases, and occurred remote from the VT-sub in 4 (33%) cases (see Table 1). The dose delivered at sites of VT recurrence was 8.4±8.6 Gy with a large heterogeneity ranging from 0.11 to 28.37 Gy, for some pts due to dose constraints near critical structures (coronary arteries). Voltage mapping showed a small but significant reduction in both unipolar and bipolar EGM voltage in the irradiated area after STAR (before vs after, Bipolar: 1.8±1.2 vs 1.1±1.2 mV and Unipolar: 4.4±2.0 vs 3.4±2.3 mV, p=0.02 and 0.01 respectively). Importantly no pts developed a high-grade AV block after STAR despite IVS irradiation.

Conclusion

STAR appears to be an efficient tool for the management of refractory VT, leading to a strong VT burden reduction and no new high-grade AV block. Recurrences were nevertheless common, often at the border zone of the irradiated volume.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): CHUV

The «Amish» NM_000256.3:c.3330+2T>G splice variant in MYBPC3 associated with hypertrophic cardiomyopathy is an ancient Swiss mutation

MYBPC3 is the most frequently mutated gene in hypertrophic cardiomyopathy (HCM). Several loss-of-function founder variants have been reported in MYBPC3 from various geographic regions, altogether suggestive of a modest or absent effect of these variants on reproductive fitness. One of them, a MYBPC3 splice variant, NM_000256.3:c.3330+2T > G, was first described in homozygous state in newborns presenting with a severe, recessive form of HCM among the Amish population and was later associated with adult-onset dominant HCM in heterozygous carriers. We here report this splice variant in heterozygous state in eight unrelated Swiss families with HCM, making it the most prevalent cardiomyopathy variant in western Switzerland. This variant was identified in patients using targeted (n = 5) or full-genome sequencing (n = 3). Given the prevalence of this variant in the Old Order Amish, Mennonites and Swiss populations, and given that both Amish and Mennonites founders originated from the Bern Canton in Switzerland, the MYBPC3, NM_000256.3:c.3330+2T > G variant appears to be of Swiss origin. Neighboring regions that hosted the first Amish settlements (Alsace, South Germany) should be on the lookout for that variant. The existence of MYBPC3 founder variants in different populations suggests that individuals with early-onset clinical disease may be the tip of the iceberg of a much larger number of asymptomatic carriers. Alternatively, reproductive fitness could even be slightly increased in some variant carriers to compensate for the reduction of fitness in the more severely affected ones, but this remains to be investigated.

Recurrences after stereotactic arrhythmia radioablation for refractory ventricular tachycardia

Funding Acknowledgements

Type of funding sources: None.

Introduction

Stereotactic arrhythmia radioablation (STAR) has been recently introduced for the management of ventricular tachycardia (VT) refractory to antiarrhythmic drugs and catheter ablation (CA). VT recurrences have been reported after STAR but the mechanisms remain poorly known. We analyzed recurrences in our patients (pts) after STAR for refractory VT.

Methods

From 09.2017 to 01.2020, 12 pts (66±8y, LVEF 40±14%) suffering from refractory VT were enrolled. The underlying cardiopathy was ischemic in 3, inflammatory in 3 and idiopathic in 6 pts. Nine out of 12 pts had a history of at least 1 electrical storm. Before STAR, an invasive electro-anatomical mapping of the VT substrate (VT-sub) was performed. A mean dose of 22±2Gy was delivered to the VT-sub using the Cyberknife system.

Results

The ablation volume was 24±7cc and involved the basal interventricular septum (IVS) in 10 pts. During the first 6 months after STAR, VT burden decreased by 95% (mean value, from 930 to 46 VT/semester). After a median follow-up of 14±10 months, 10/12 (83%) developed a recurrence as a sustained VT and underwent a redo CA. VT recurrence was located at the border zone (BZ) of the treated VT-sub in 6 cases, involved both the BZ and a larger substrate in 2 cases, and occurred remote from the VT-sub in 2 cases (see Table). The dose delivered at sites of VT recurrence was 9.9±8.6 Gy with a large heterogeneity ranging from 0.11 to 28.37 Gy, for some patients due to dose constraints near critical structures. Importantly no pts developed an AV block after STAR.

Conclusion

STAR appears to be an efficient tool for the management of IVS refractory VT, leading to a strong VT burden reduction and no AV block. Recurrences were nevertheless common, often at the border zone of the irradiated volume.

Genotype-phenotype correlation in hypertrophic cardiomyopathy: moving towards precision medicine?

Funding Acknowledgements

Type of funding sources: None.

Background

Hypertrophic cardiomyopathy (HCM) is the most prevalent inherited cardiomyopathy. In spite of approximately 50 mutations causally associated to HCM, pathogenic variants in the thick-filament genes, encoding myosin 7 (MYH7) and cardiac myosin-binding protein C (MYBPC3), are responsible for up to 50% of clinically diagnosed HCM cases and for about 80% of patients (pts) with a confirmed genetic aetiology. However, the complex model of inheritance, encompassing genetic modifiers and environmental causes, accounts for the typical incomplete penetrance and variable expressivity, and still hampers genotype-phenotype correlation.

Purpose

We present a series of pts clinically diagnosed with HCM at our tertiary university center and enrolled in the Institutional Prospective Registry of HCM (IPRHCM). We report the clinical presentation and outcome, according to specific genotype.

Methods

Based on clinical criteria for HCM, 65 consecutive pts (42 ± 17 years) were enrolled in the IPRHCM. The diagnosis was made after a cardiac assessment including, among others, echocardiography and cardiac stress test (CST). Among them, 28 pts (43%) underwent a genetic test. A genetic variant was detected in 23 patients (82%) including 11 MYBPC3 (48%), 10 MYH7 (43%), 1 MYL3 (4%) and 1 TNNI3 (4%) variants. According to genotypes, we divided pts into two groups: the MYH7 group (10/23 pts) and the non-MYH7 one (13/23 pts). Of note, no pathogenic variant was detected among the 5 remaining pts (18%).

Results

No significant difference was observed in age at diagnosis and gender distribution between the MYH7 and the non-MYH7 group. On standard ECG, the MYH7 group had a significant lower basal heart rate (60 ±3 vs 73 ±3 bpm, p=0.01) and a trend (p =0.09) towards a more frequent occurrence of left bundle branch block (30% vs 0%). Of note, no significant difference was observed between groups in terms of medical therapy (i.e., betablockers). Despite similar LV outflow tract pressure gradient (LVOTPG) at rest, MYH7 pts had a significantly higher LVOTPG during Valsalva manoeuvre (12 [9-80] vs 7 [7-8] mmHg, p=0.03) and a trend (p =0.08) towards a greater left atrium diameter (44 ±2 vs 39 ±2 mm). At CST, MYH7 pts had significant lower peak systolic blood pressure (149±10 vs 185 ±8 mmHg, p=0.01). We finally appreciated a significant difference between groups in term of outcome. MYH7 pts underwent more often septal myectomy (70% vs 55%, p =0.02) and showed a trend (p =0.07) towards a more frequent occurrence of heart failure or heart transplantation (30% vs 0%) as compared to non-MYH7 pts.

Conclusions

Our study supports the findings of a more severe phenotype with a worse prognosis in MYH7 pts than that of other CMH genotypes, as suggested by greater LVOTPG during Valsalva manoeuvre, greater left atrial enlargement, abnormal exercise pressure response and by a more frequent occurrence of septal myectomy and of heart failure/transplantation.

External validation study of the 2014 European Society of Cardiology Guidelines in relation to 2020 ACC/AHA guidelines on sudden cardiac death prevention in hypertrophic cardiomyopathy

Funding Acknowledgements

Type of funding sources: None.

Background

Strategies for reliable selection of high-risk hypertrophic cardiomyopathy (HCM) patients for prevention of sudden cardiac death (SCD) with implantable cardioverter-defibrillators (ICDs) are still debated.

Purpose

Assess the sensitivity of sudden death risk strategies (2014 ESC SCD 5-year risk score and 2020 ACC/AHA risk factor strategy) in predicting lethal arrhythmic events (LAE), appropriate ICD shocks, SCD or out of hospital cardiac arrest among a cohort of HCM patients

Methods

Sixty-five patients (42±17 y) with a clinical diagnosis of HCM were enrolled in our institution from 1990 to 2021. Among them, 28 patients (43%) underwent a genetic test and a pathogenic/likely pathogenic sarcomeric variant was detected in 23 cases (82%). Patients were managed according to the best available treatment strategy for HCM in the different clinical eras.

Results

Of the 65 patients, 28 cases (43%) received an ICD, including 23 for primary and 5 for secondary prevention. During a follow-up period of 15 years (median, 15 [6, 21], range 1 to 33 years, 1014 patients/year), a total of 10 LAE were observed (0.98%/year). According to ESC SCD 5-year Risk Score, 7 (10%) were at high risk, 14 (22%) at intermediate to high risk, and 44 (68%) at low risk. Median SCD 5-year risk score of 3.5% ± 2.1. ACC/AHA risk factors categorized patients as 35 (54%) at high risk, 24 (37%) at intermediate to high risk, and 6 (9%) at low risk. A total of 4 (2.8%) patients experiencing SCD events were misclassified as low-risk patients by the ESC SCD Risk Score, whereas none by the ACC/AHA model. Of the 7 patients categorized as high risk by the ESC SCD Risk Score, 2 (29%) experienced a LAE, whereas of the 35 patients at high risk by the ACC/AHA, 9 (26%) suffered a LAE. No difference in the area under the curve was showed for the 2020 ACC/AHA SCD risk stratification strategies with respect to 2014 ESC SCD 5-year-risk score (0.72; 95% CI 0.60–0.83, 0.66; 95% CI 0.49–0.84, p =0.55).

Conclusions

In this HCM cohort followed up over an extended period of more than 15 years, LAE remained relatively low (0.98%/year). SCD risk stratification recommended by the 2014 ESC SCD 5 year risk score did not showed a better discrimination than that of 2020 ACC/AHA stratifications, despite the latter proved to be more sensible in the identification of the low risk patients. More than half of our cohort was classified with a recommendation by the 2020 ACC/AHA for an ICD implantation. A larger multicenter, independent, and prospective study with long-term follow-up is warranted to better elucidate these results.

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.

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

BACKGROUND

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).

METHODS

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.

RESULTS

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.

CONCLUSION

Stress perfusion-CMR is safe, allows reliable ischemia detection, and provides good diagnostic value.

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

Background 

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.

Case summary 

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 (68Ga-DOTATOC and/or 18F-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.

Discussion 

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 18F-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, 68Ga-DOTATOC, appears promising by overcoming the main limitation of 18F-FDG but its specificity is not yet well established. The role of functional investigations is discussed as well as the benefit of immunosuppressive treatments.

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

OBJECTIVES

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.

BACKGROUND

In MVP, MAD has been associated with myocardial replacement fibrosis and arrhythmia, but the importance of interstitial fibrosis remains unknown.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

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

Funding Acknowledgements

Type of funding sources: None.

Background

In MVP, MAD has been associated with myocardial replacement fibrosis and arrhythmia, but the importance of interstitial fibrosis remains unknown. 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

Methods

Thirty patients with MVP and MAD (MVP-MAD) underwent Cardiac Magnetic Resonance (CMR) with assessment of MAD length, late gadolinium enhancement (LGE), and basal segments myocardial extracellular volume (ECV). The control group included 14 patients with mitral regurgitation but no MAD (MR-NoMAD) and 10 patients with normal CMR (NoMR-NoMAD). Fifteen MVP-MAD patients underwent 24h-Holter monitoring.

Results

LGE was observed in 47% of MVP-MAD patients and absent in controls. ECV was higher in MVP-MAD (30 ± 3% vs 24 ± 3% MR-NoMAD, p &lt; 0.0001 and vs 24 ± 2% NoMR-NoMAD, p &lt; 0.0001), even in MVP-MAD patients without LGE (29 ± 3% vs 24 ± 3%, p &lt; 0.0001 and vs 24 ± 2%, p &lt; 0.0001, respectively), Fig.1. MAD length was correlated with ECV (rho = 0.61, p = 0.0003), but not with LGE extent. Four patients had history of OHCA; LGE and ECV were equally performant to identify those high-risk patients (area under the ROC curve 0.81 vs 0.83, p = 0.84). Among patients with Holter, 87% had complex ventricular arrhythmia. ECV was above the cut-off value in all while only 53% had LGE.

Conclusion

Increase in ECV, a marker of interstitial fibrosis, occurs in MVP-MAD even in the absence of LGE, and was correlated with MAD length and OHCA. ECV should be part of 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.

Feasibility and prognostic value of adenosine stress perfusion cardiovascular magnetic resonance in patient with implantable device

Funding Acknowledgements

Type of funding sources: None.

Background

stress CMR has a limited use in patients with implantable device, in order to the possible artefacts due to the metallic component and to the risk of adenosine interaction with cardiac pacing. The aim of the study was to assess the global feasibility and to assess the prognostic value of stress perfusion CMR in patients with implantable device.

Materials and Methods

we conducted a retrospective single-center longitudinal analysis of consecutive patients with an implantable device referred for stress CMR, performed using a 1.5 Tesla unit (Siemens Healthcare,MAGNETOM Aera, Erlangen-Germany). Protocol was adapted according to current guidelines. Cardiac follow-up [6 months to 7 years] was obtained by medical records of direct contact with patient’s cardiologist referral. 

Results

44 patients were enrolled. 34 patients needed a continuous pacing during adenosine stress, that was settled in DOO in 14 (32%) and in VOO in 20 (45%). Device integrity was not compromised by CMR and not competitive atrial or ventricular stimulation was observed during examination. Image quality was good in 95% cases. 26% cases had a perfusion deficit corresponding to a previous scar, while 12% of patients had a positive stress test. All of them needed continuous pacing during stress test and underwent to a coronary angiography who confirmed the coronary stenosis.  In patients without inducible ischemia 2 patients experienced a Non-ST-elevation Myocardial Infarction after 6 and 2 years while no other cardiac symptoms or cardiac hospitalisation was remarkable during follow up.

Conclusion

adenosine stress CMR in patient who are pacemaker dependent during scanner is feasible, with an overall good image quality, proving an excellent diagnostic and prognostic value in a long term follow up even. Adenosine administration is safe and no the magnetic field interference with the correct functioning of the device have been shown in short or long term follow-up.

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.

[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.

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

BACKGROUND

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).

PATIENTS AND METHODS

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).

RESULTS

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).

CONCLUSIONS

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.

[Cardiac sarcoidosis: seven keypoints to remind in order to avoid misdiagnosis]

Early diagnosis of cardiac sarcoidosis remains difficult in the absence of specific symptoms. The evolution and prognosis of the disease are strongly correlated to an early and appropriate treatment. The multi-modality assessment based on cardiac MRI and positron emission tomography associated with computed tomography (PET/CT) has significantly improved the detection of cardiac sarcoidosis over the last two decades. These approaches appear as useful and suitable imaging strategy for the early diagnosis, the assessment of the disease extent as well as the management and therapeutic follow-up. This article is a didactic review on cardiac sarcoidosis, with a special focus on recent diagnostic and therapeutic modalities, prognosis and interest of imaging techniques.

Ranolazine: Drug overview and possible role in primary microvascular angina management

Ranolazine is a novel well-tolerated anti-ischemic drug, which selectively inhibits late sodium current and exerts metabolic properties without any hemodynamic effect. Ranolazine has been approved as a second-line medical treatment for symptomatic stable coronary artery disease. Primary microvascular angina (MVA) is suspected when angina symptoms occur in patients with demonstrated myocardial ischemia, absence of myocardial disease and normal coronary artery angiography. Recent clinical data suggest that MVA represents a complex entity, which has been increasingly recognized as a significant cause of morbidity. High variability and low response to traditional anti-anginal treatment characterize primary MVA. Despite the fact that clinical and preclinical evidence provides information regarding ranolazine usefulness in primary MVA management, only three recent small randomized trials have investigated this issue. By selecting peer-reviewed literature in Pubmed and Cochrane Library, this review provides an overview on ranolazine pharmacology and efficacy, focusing on recent evidence suggesting its usefulness in management of primary MVA.