Myocarditis Causing Premature Ventricular Contractions: Insights From the MAVERIC Registry

Diagnosis and treatment of myocarditis and inflammatory cardiomyopathy. Consensus document of the SEC-Working Group on Myocarditis

Myocarditis is defined as myocardial inflammation and its etiology is highly diverse, including infectious agents, drugs, and autoimmune diseases. The clinical presentation also varies widely, extending beyond the classic clinical picture of acute chest pain, and includes cases of cardiomyopathy of unknown cause whose etiology may be inflammatory. Because certain patients may benefit from targeted treatments, the search for the etiology should begin when myocarditis is first suspected. There remain several areas of uncertainty in the diagnosis and treatment of this disease. Consequently, this consensus document aims to provide clear recommendations for its diagnosis and treatment. Hence, a diagnostic algorithm is proposed, specifying when non-invasive diagnosis with cardiac MR is appropriate vs a noninvasive approach with endomyocardial biopsy. In addition, more novel aspects are discussed, such as when to suspect an underlying genetic etiology. The recommendations cover the management of myocarditis and inflammatory cardiomyopathy, both for general complications and specific clinical entities.

Targeting NLRP3 signaling reduces myocarditis-induced arrhythmogenesis and cardiac remodeling

BACKGROUND

Myocarditis substantially increases the risk of ventricular arrhythmia. Approximately 30% of all ventricular arrhythmia cases in patients with myocarditis originate from the right ventricular outflow tract (RVOT). However, the role of NLRP3 signaling in RVOT arrhythmogenesis remains unclear.

METHODS

Rats with myosin peptide-induced myocarditis (experimental group) were treated with an NLRP3 inhibitor (MCC950; 10 mg/kg, daily for 14 days) or left untreated. Then, they were subjected to electrocardiography and echocardiography. Ventricular tissue samples were collected from each rat's RVOT, right ventricular apex (RVA), and left ventricle (LV) and examined through conventional microelectrode and histopathologic analyses. In addition, whole-cell patch-clamp recording, confocal fluorescence microscopy, and Western blotting were performed to evaluate ionic currents, intracellular Ca2+ transients, and Ca2+-modulated protein expression in individual myocytes isolated from the RVOTs.

RESULTS

The LV ejection fraction was lower and premature ventricular contraction frequency was higher in the experimental group than in the control group (rats not exposed to myosin peptide). Myocarditis increased the infiltration of inflammatory cells into cardiac tissue and upregulated the expression of NLRP3; these observations were more prominent in the RVOT and RVA than in the LV. Furthermore, experimental rats treated with MCC950 (treatment group) improved their LV ejection fraction and reduced the frequency of premature ventricular contraction. Histopathological analysis revealed higher incidence of abnormal automaticity and pacing-induced ventricular tachycardia in the RVOTs of the experimental group than in those of the control and treatment groups. However, the incidences of these conditions in the RVA and LV were similar across the groups. The RVOT myocytes of the experimental group exhibited lower Ca2+ levels in the sarcoplasmic reticulum, smaller intracellular Ca2+ transients, lower L-type Ca2+ currents, larger late Na+ currents, larger Na+-Ca2+ exchanger currents, higher reactive oxygen species levels, and higher Ca2+/calmodulin-dependent protein kinase II levels than did those of the control and treatment groups.

CONCLUSION

Myocarditis may increase the rate of RVOT arrhythmogenesis, possibly through electrical and structural remodeling. These changes may be mitigated by inhibiting NLRP3 signaling.

Bilateral Cardiac Sympathetic Denervation for Refractory Multifocal Premature Ventricular Contractions in Patients With Nonischemic Cardiomyopathy

BACKGROUND

Bilateral cardiac sympathetic denervation (BCSD) for refractory life-threatening ventricular arrhythmias is a neuromodulatory intervention targeting sympathetically driven focal or re-entrant ventricular arrhythmias.

OBJECTIVES

This study sought to provide a more complete and successful option for intervention in patients in whom premature ventricular contraction (PVC) ablation is not feasible or has been unsuccessful.

METHODS

A total of 43 patients with >5% PVC burden and concomitant nonischemic cardiomyopathy (NICM) who previously failed medical and ablation therapies were referred for BCSD. All patients underwent bilateral video-assisted thoracoscopic surgical approach with T1-T4 sympathectomy. Primary effectiveness endpoints were postprocedural PVC burden resolution, improvement in left ventricular ejection fraction (LVEF), and cessation of antiarrhythmic drugs (AADs). Safety endpoints included peri- and postprocedural complications. Outcomes were assessed over a 1-year follow-up period.

RESULTS

Among the 43 patients who underwent BCSD, the mean age was 52.3 ± 14.7 years, 69.8% of whom were male patients. Presenting mean LVEF was 38.7% ± 7.8%, and PVC burden was 23.7% ± 9.9%. There were significant reductions in PVC burden postprocedurally (1.3% ± 1.1% post-BCSD, compared with 23.7% ± 9.9% pre-BCSD, P < 0.001) and improvements in LVEF (46.3% ± 9.5% post-BCSD, compared with 38.7% ± 7.8% pre-BCSD, P < 0.001). The rate of ICD therapies decreased from 81.4% (n = 35) to 11.6% (n = 5) (P < 0.001), leading to a significant reduction in use of AADs (100.0% to 11.6%, P < 0.001) and improvement in mean NYHA functional class (2.5 ± 0.5 to 1.4 ± 0.2, P < 0.001). Major intraoperative complications were seen in 4.7% of patients (hemothorax and chylothorax). Of the patients, 81.4% (n = 35) experienced no mortality or major complications over a 1-year follow-up period, with the remaining still within their first year postprocedure.

CONCLUSIONS

BCSD is effective for the management of refractory PVCs and ventricular tachycardia who have failed previous ablation therapy.

Diagnostic Approach for Suspected Acute Myocarditis: Considerations for Standardization and Broadening Clinical Spectrum

Myocarditis is most recognized in patients with moderate to severe, recent-onset heart failure. However, less typical presentations including myocardial infarction with normal coronary arteries and arrhythmias are important manifestations but less commonly recognized to be caused by myocarditis. Most cases of myocarditis can be self-limiting without specific treatment; however, appropriate identification of risk during the diagnostic process of myocarditis and once a diagnosis is established is of primordial importance to identify patients in need for more specific follow-up and management. We propose a flexible, multitiered approach to the diagnostic process, allowing for capturing of the spectrum of myocarditis at an early time-point, individualized use of diagnostic resources through disease severity phenotyping, and providing structured follow-up care once myocarditis is confirmed. Such diagnostic processes allow for identification of specific etiologies with potential therapeutic consequences or allows for the comprehension of disease chronicity by understanding genetic contributions or elements of persistent immune dysregulation and degree of cardiac damage. The article highlights the evolving field of immunophenotyping in myocarditis, generating a potential for the development of targeted therapeutic approaches. Currently long-term follow-up should be titrated to the refined risk assessments of patients with a diagnosis of myocarditis and includes arrhythmia monitoring and imaging when the results will likely impact management. Genetic testing should be considered in selected cases, and histologic diagnosis may be considered in nonresponders even at later stages.

Clinical predictors and implications of cardiac inflammation detected on positron emission tomography (PET) in patients referred for premature ventricular complex (PVC) ablation

BACKGROUND

Positron emission tomography computed tomography (PET-CT) is not routinely used for premature ventricular complexes (PVCs). Whether specific clinical factors are associated with abnormal PET-CT results is not clear.

METHODS

The treatment courses and baseline characteristics of consecutive patients in a single center between 2012 and 2021, age > 18 years old, and who received ¹⁸F-fluorodeoxyglucose (FDG) PET-CT imaging for evaluation of PVCs were retrospectively analyzed.

RESULTS

A total of 102 patients was included. Of these, 27 patients (26.4%) had abnormal PET-CT and 61 (59.8%) had normal imaging. Abnormal PET-CT findings were associated with non-sustained ventricular tachycardia (NSVT) (95.2% vs. 52.6%, p = 0.001), higher number of PVC morphologies (2.29 ± 0.7 vs. 1.31 ± 0.6, p < 0.001), greater PVC coupling interval dispersion (72.47 ± 66.4 ms vs. 13.42 ± 17.9 ms, p < 0.001), and greater likelihood of fast heart rate dependent PVCs (78.5% vs. 38.2%, p = 0.017). Fourteen (51.8%) patients had an abnormal PET-CT and abnormal late gadolinium enhancement (LGE). Patients with abnormal PET-CT were more frequently treated with immunosuppression (81.4% vs. 3.2%, p < .0001) than with catheter ablation (11.1% vs. 45.9%, p = 0.002) compared to the normal PET-CT group. Over a median follow-up of 862 days (IQR 134, 1407), PVC burden decreased in both groups [from 23 ± 16% to 9 ± 10% (p < 0.001) in abnormal PET-CT group and from 21 ± 15% to 7 ± 10% (p < 0.001) in normal PET-CT group].

CONCLUSIONS

Abnormal PET-CT findings were more commonly associated with NSVT, multiform PVCs, greater PVC coupling interval dispersion, and fast heart rate dependent PVCs. LGE was not sensitive for detecting inflammation. Immunosuppression was effective in managing PVCs with abnormal PET-CT.

Best Practices for the Catheter Ablation of Ventricular Arrhythmias

Techniques for catheter ablation have evolved to effectively treat a range of ventricular arrhythmias. Pre-operative electrocardiographic and cardiac imaging data are very useful in understanding the arrhythmogenic substrate and can guide mapping and ablation. In this review, we focus on best practices for catheter ablation, with emphasis on tailoring ablation strategies, based on the presence or absence of structural heart disease, underlying clinical status, and hemodynamic stability of the ventricular arrhythmia. We discuss steps to make ablation safe and prevent complications, and techniques to improve the efficacy of ablation, including optimal use of electroanatomical mapping algorithms, energy delivery, intracardiac echocardiography, and selective use of mechanical circulatory support.

Characteristics and Prognostic Relevance of Ventricular Arrhythmia in Patients with Myocarditis

Myocarditis is characterized by various clinical manifestations, with ventricular arrhythmia (VA) as a frequent symptom at initial presentation. Here, we investigated characteristics and prognostic relevance of VA in patients with myocarditis. The study population consisted of 76 patients with myocarditis, verified by biopsy and/or cardiac magnetic resonance (CMR) imaging, including 38 consecutive patients with VA (45 ± 3 years, 68% male) vs. 38 patients without VA (NVA) (38 ± 2 years, 84% male) serving as a control group. VA was monomorphic ventricular tachycardia in 55% of patients, premature ventricular complexes in 50% and ventricular fibrillation in 29%. The left ventricular ejection fraction at baseline was 47 ± 2% vs. 40 ± 3% in VA vs. NVA patients (p = 0.069). CMR showed late gadolinium enhancement more often in VA patients (94% vs. 69%; p = 0.016), incorporating 17.6 ± 1.8% vs. 8.2 ± 1.3% of myocardial mass (p < 0.001). Radiofrequency catheter ablation for VA was initially performed in nine (24%) patients, of whom five remained free from any recurrence over 24 ± 3 months. Taken together, in patients with myocarditis, reduced left ventricular ejection fraction does not predict VA occurrence but CMR shows late gadolinium enhancement more frequently and to a larger extent in VA than in NVA patients, potentially guiding catheter ablation as a reasonable treatment of VA in this population.

Immunomodulating Therapies in Acute Myocarditis and Recurrent/Acute Pericarditis

The field of inflammatory disease of the heart or "cardio-immunology" is rapidly evolving due to the wider use of non-invasive diagnostic tools able to detect and monitor myocardial inflammation. In acute myocarditis, recent data on the use of immunomodulating therapies have been reported both in the setting of systemic autoimmune disorders and in the setting of isolated forms, especially in patients with specific histology (e.g., eosinophilic myocarditis) or with an arrhythmicburden. A role for immunosuppressive therapies has been also shown in severe cases of coronavirus disease 2019 (COVID-19), a condition that can be associated with cardiac injury and acute myocarditis. Furthermore, ongoing clinical trials are assessing the role of high dosage methylprednisolone in the context of acute myocarditis complicated by heart failure or fulminant presentation or the role of anakinra to treat patients with acute myocarditis excluding patients with hemodynamically unstable conditions. In addition, the explosion of immune-mediated therapies in oncology has introduced new pathophysiological entities, such as immune-checkpoint inhibitor-associated myocarditis and new basic research models to understand the interaction between the cardiac and immune systems. Here we provide a broad overview of evolving areas in cardio-immunology. We summarize the use of new imaging tools in combination with endomyocardial biopsy and laboratory parameters such as high sensitivity troponin to monitor the response to immunomodulating therapies based on recent evidence and clinical experience. Concerning pericarditis, the normal composition of pericardial fluid has been recently elucidated, allowing to assess the actual presence of inflammation; indeed, normal pericardial fluid is rich in nucleated cells, protein, albumin, LDH, at levels consistent with inflammatory exudates in other biological fluids. Importantly, recent findings showed how innate immunity plays a pivotal role in the pathogenesis of recurrent pericarditis with raised C-reactive protein, with inflammasome and IL-1 overproduction as drivers for systemic inflammatory response. In the era of tailored medicine, anti-IL-1 agents such as anakinra and rilonacept have been demonstrated highly effective in patients with recurrent pericarditis associated with an inflammatory phenotype.

Long-term Results of Drug and Interventional Treatment in Patients with Morphologically Verified Idiopathic Arrhythmias

Aim. To study the late results of medical and interventional treatment in patients with morphologically verified nature of idiopathic arrhythmias.

Methods. The prospective study included 20 patients (mean age 43.1±11.3 years, 10 female) with atrial fibrillation (AF), supraventricular and ventricular extrasystole, supraventricular and ventricular tachycardia, conduction disturbance without structural heart changes. In addition to the standard examination, the level of anti-heart antibodies was initially determined; endomyocardial biopsy (EMB) of the right ventricle with PCR study for the viral genome; DNA diagnostics (n=4), coronary angioraphy (n=6), skin biopsy (n=1) were performed. The median follow-up was 134 [128; 138] months.

Results. By EMB in the initial examination were diagnosed: active (n=8)/borderline (n=3) infectious immune myocarditis; parvovirus-positive endomyocarditis (n=1); undifferentiated vasculitis (n=2); myocardial vasculitis (n=1); Fabry disease (n=1); arrhythmogenic right ventricular dysplasia (n=1); unspecified cardiomyopathy (n=2). Anti-heart antibodies were the most important in myocarditis diagnosis and monitoring. All patients with myocarditis/vasculitis (n=15) received its basic therapy: acyclovir (n=10); immunoglobulin G 10-12.5 g (n=2); hydroxychloroquine 200 mg/day (n=15); glucocorticoids (n=14); azathioprine 150 mg/day (n=2). The late results were evaluated in all patients with myocarditis. Initially, in 62.5% of patients a resistance of AF to all antiarrhythmic drugs was noted. After treatment the average frequency of AF paroxysms decreased (from 8 [5; 8] to 3 [1,25; 7,75] points). By the end of the follow-up, six patients underwent radiofrequency ablation (RFA) for AF, the full effect was achieved once. All patients without RFA have AF partially or completely resistant to drugs. Two patients (without RFA) died from ischemic stroke/ pulmonary embolism.

Conclusion. Using EMB the causes of idiopathic arrhythmias (mainly AF) were diagnosed: immune inflammatory diseases in 75% and genetic in 25% of patients. As a result of complex treatment, the general burden of arrhythmias has decreased. But the presence of myocarditis and primary cardiomyopathy, without reducing the cardiac contractility and dilatation, does not allow achieving a stable antiarrhythmic effect. Lethality for 11 years was 10%. The causes of death were thromboembolic complications.

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.

Multi-Modality Imaging for the Identification of Arrhythmogenic Substrates Prior to Electrophysiology Studies

Noninvasive cardiac imaging is crucial for the characterization of patients who are candidates for cardiac ablations, for both procedure planning and long-term management. Multimodality cardiac imaging can provide not only anatomical parameters but even more importantly functional information that may allow a better risk stratification of cardiac patients. Moreover, fusion of anatomical and functional data derived from noninvasive cardiac imaging with the results of endocavitary mapping may possibly allow a better identification of the ablation substrate and also avoid peri-procedural complications. As a result, imaging-guided electrophysiological procedures are associated with an improved outcome than traditional ablation procedures, with a consistently lower recurrence rate.

Fulminant Eosinophilic Myocarditis and VT Storm

Eosinophilic myocarditis is a rare and frequently fatal disease that is often undiagnosed until autopsy. We report a case of eosinophilic myocarditis with an unusual initial presentation of palpitations that subsequently evolved into ventricular tachycardia storm and death within 4 days. (Level of Difficulty: Beginner.).

Role of cardiac imaging in patients undergoing catheter ablation of ventricular tachycardia

Ventricular tachycardia is a major health issue in patients with structural heart disease (SHD). Implantable cardioverter defibrillator (ICD) therapy has significantly reduced the risk of sudden cardiac death (SCD) in such patients, but on the other hand, it has led to frequent ICD shocks as an emerging problem, being associated with poor quality of life, frequent hospitalizations and increased mortality. Myocardial scar plays a central role in the genesis and maintenance of re-entrant arrhythmias, as the coexistence of surviving myocardial fibres within fibrotic tissue leads to the formation of slow conduction pathways and to a dispersion of activation and refractoriness that constitutes the milieu for ventricular tachycardia circuits. Catheter ablation has repeatedly proven to be well tolerated and highly effective in treating VT and in the last two decades has benefited from continuous efforts to determine ventricular tachycardia mechanisms by integration with a wide range of invasive and noninvasive imaging techniques such as intracardiac echocardiography, cardiac magnetic resonance, multidetector computed tomography and nuclear imaging. Cardiovascular imaging has become a fundamental aid in planning and guiding catheter ablation procedures by integrating structural and electrophysiological information, enabling the ventricular tachycardia arrhythmogenic substrate to be characterized and effective ablation targets to be identified with increasing precision, and allowing the development of new ablation strategies with improved outcomes. In this review, we provide an overview of the role of cardiac imaging in patients undergoing catheter ablation of ventricular tachycardia.

Ventricular arrhythmia during rehabilitation of cervical spinal cord injury

Patients with cervical spinal cord injury have a high incidence of cardiac arrhythmias, especially in the first 14 to 30 days after traumatic event (acute phase). Electrophysiological abnormalities described in the acute phase are most often bradycardia, which is spontaneous or triggered by various stimuli. In the chronic phase, varied arrhythmias are described, but ventricular arrhythmias as a result of autonomic dysregulation in chronic SCI are rare and isolated. We present the case of a patient with a C5-C6 incomplete spinal cord injury (ASIA-B grade) in which symptomatic ventricular arrhythmia is described one year after the traumatic event.

Secondary prevention of sudden cardiac death

The prevention and treatment of sudden cardiac death (SCD) remains a significant public health challenge. For patients with a history of sudden death attributable to ventricular arrhythmia, implantable cardioverter-defibrillator (ICD) therapy is a mainstay of treatment, although these patients remain at high risk for recurrent ventricular arrhythmia and defibrillator therapies. In this review, we summarize landmark clinical trials evaluating the efficacy of ICD therapy in secondary prevention patients, review clinical outcomes including mode of death in survivors of SCD, and highlight the role for systematic diagnostic evaluation. We additionally discuss the invasive electrophysiological management of these patients, including ICD selection and programming as well as the role and timing of antiarrhythmic drug therapy and catheter ablation. Finally, we frame future challenges and needs to advance the care for secondary prevention patients.

Treatment with corticosteroids is associated with an increase in ventricular arrhythmia burden in patients with clinically manifest cardiac sarcoidosis: Insights from implantable cardioverter-defibrillator diagnostics

INTRODUCTION

We sought to explore the relationship between ventricular tachycardia (VT) and premature ventricular complex (PVC) burden (from implantable cardioverter-defibrillator diagnostics), before and during corticosteroid use in patients with newly diagnosed clinically manifest cardiac sarcoidosis (CS).

METHODS

A single-centre, prospective cohort study was performed in consecutive patients who met all of the following criteria: (1) presentation with clinically manifest CS, (2) abnormal myocardial fluoro-deoxyglucose (FDG) uptake on positron emission tomography scan, (3) plan for implantation with implantable cardioverter-defibrillator device that reports accurate PVC count, (4) plan to initiate corticosteroids after the device healing period. Data were collected during each device interrogation visit for all patients in the study. For each inter-visit period the total number of episodes of VT-sustained and nonsustained, and the number of PVCs was obtained. Each inter-visit period was classified into one of the following three periods: (1) New diagnosis of treatment-naive active disease without corticosteroids during the period. (2) Known treatment-naive active disease with corticosteroids initiated during the inter-visit period. (3) On corticosteroid therapy during the entire period.

RESULTS

A total of 20 patients with a mean age of 59.7 ± 7.7 years were recruited and 82 inter-visit periods were analyzed. All patients were corticosteroid responders based on FDG uptake. The maximum left ventricular standardized uptake value was 11.14 ± 5.19 before corticosteroid initiation and 4.07 ± 0.88 after (p < .001). Patients with active untreated CS had an average of 496.4 ± 879.1 PVCs per day. After treatment with corticosteroids, the average PVC count increased to 1332.4 ± 1865.7/day during Period 2 (p = .036) and to 1590.1 ± 2362.2 per day during Period 3 (p = .008). There was also a statistically significant increase in episodes of nonsustained ventricular tachycardia (NSVT) before and after treatment with corticosteroids (p = .017). There were too few episodes of sustained ventricular arrhythmia to analyze. Overall, 18 out of 20 patients (90%) had an increase in PVC burden after corticosteroid initiation.

CONCLUSION

This study demonstrated, on average, a threefold increase in daily PVC count in clinically manifest CS patients during treatment with corticosteroids compared to pretreatment. There was also a significant increase in episodes of NSVT. Clinicians and patients with active manifest CS should be aware that corticosteroids are unlikely to lead to a reduction in the burdens of PVC and NSVT.

Impaired left ventricular global longitudinal strain improves with radiofrequency catheter ablation in patients with PVC-induced cardiomyopathy

BACKGROUND

In our study, we aimed to evaluate left ventricular global longitudinal strain (LV-GLS) value in patients with premature ventricular contractions (PVCs) and reduced LV ejection fraction (LVEF) and to determine the effect of radiofrequency catheter ablation (RFA) procedure on LV-GLS.

METHODS

In this cross-sectional study, 150 patients who underwent three-dimensional RFA with the diagnosis of PVCs were included. LV-GLS was measured with strain echocardiography in all patients before RFA and in the sixth-month control. Patients included in the study were grouped as LVEF <50% (Group I) and LVEF ≥50% (Group II) according to baseline LVEF, and patients within Group I were grouped as LVEF <50% (Group A) and LVEF ≥50% (Group B) according to the sixth-month LVEF.

RESULTS

There were 39 patients (26%) with baseline LVEF <50%. In 14 (36%) of these patients, LVEF <50% was observed to continue during the sixth-month controls. Both the baseline and sixth-month LV-GLS values were significantly lower in Group I patients (<0.01). RFA treatment significantly increased both LVEF and LV-GLS (<0.01). It was found that age, N-terminal pro-brain natriuretic peptide, LV diameters, and baseline LVEF were higher, and baseline LV-GLS level was lower in Group A patients (P < .01). Baseline LVEF and LV-GLS values were found to independently determine the patients in Group A (P < .01). In receiver operator characteristic analysis, when the limit value is accepted as 40% for baseline LVEF and 18% for baseline LV-GLS, it can determine Group A with acceptable sensitivity and specificity.

CONCLUSIONS

LV-GLS decreases significantly in patients with reduced LVEF and PVCs. In these patients, RFA treatment significantly increases both LVEF and LV-GLS.

Concealed structural heart disease discovered at cardiac magnetic resonance in patients with ventricular extrasystoles from ventricular outflow tract and apparently normal hearts

BACKGROUND

Outflow tract (OT) premature ventricular contractions (PVCs) are commonly found in clinical practice; in most cases, PVCs are benign and observed in structurally normal hearts, not requiring any therapeutic intervention. In this study, we therefore sought to evaluate with cardiac magnetic resonance (CMR) patients with PVC and apparently normal heart at echocardiographic examination, in order to identify possible substrates linked with higher prevalence of arrhythmias or structural heart disease.

METHODS

Thirty-three consecutive patients with frequent PVCs originating from the ventricular OT (right and left) were enrolled in the study and assessed by echocardiography and CMR. All patients had normal baseline electrocardiogram.

RESULTS

CMR showed structural changes in 5 patients out of 33; in 3 cases, areas of fibrosis limited in one case to the middle basal segments of the interventricular septum and in two patients to the middle basal segments of the inferior-lateral wall were found. In 2 other cases, however, late gadolinium enhancement showed significant anomalies characterized in one patient by extensive areas of subepicardial fibrosis of the left ventricle, suitable with arrhythmogenic left dominant dysplasia; in another patient, a marked trabeculation of left ventricular medium apical segments suitable with non-compaction myocardium was present.

CONCLUSIONS

CMR may identify cases of structural heart disease in subjects with OT PVCs and apparently normal electrocardiogram and echocardiogram examinations. A preliminary screening with CMR may be considered before any further invasive electrophysiology assessment and therapeutic planning.