Mechanisms, prevalence and management of cardiac arrhythmias in cancer patients: a comprehensive review.

Recently, prognosis and survival of cancer patients has improved due to progression and refinement of cancer therapies; however, cardiovascular sequelae in this population augmented and now represent the second cause of death in oncological patients. Initially, the main issue was represented by heart failure and coronary artery disease, but a growing body of evidence has now shed light on the increased arrhythmic risk of this population, atrial fibrillation being the most frequently encountered. Awareness of arrhythmic complications of cancer and its treatments may help oncologists and cardiologists to develop targeted approaches for the management of arrhythmias in this population. In this review, we provide an updated overview of the mechanisms triggering cardiac arrhythmias in cancer patients, their prevalence and management.

Valor pronóstico del intervalo Tpeak-Tend en el desarrollo de arritmias ventriculares subagudas intrahospitalarias en el síndrome de tako-tsubo / Prognostic value of the Tpeak-Tend interval for in-hospital subacute ventricular arrhythmias in tako-tsubo syndrome

Introducción y objetivos El valor de los parámetros del electrocardiograma (ECG) de repolarización asociados al riesgo de arritmias ventriculares (AVs) en el síndrome de tako-tsubo es controvertido. Nuestro objetivo fue identificar predictores ECG de AVs subagudas, definidas como aquellas ocurridas después de las primeras 48 horas desde el ingreso. Métodos Estudio observacional unicéntrico de pacientes ingresados en el servicio de cardiología entre 2012 y 2018 con diagnóstico de síndrome de tako-tsubo. La recogida de datos incluyó el ECG de 12 derivaciones al ingreso y a las 48 horas, registros de telemetría continua, analíticas, ecocardiografía transtorácica y angiografía coronaria durante la hospitalización. Los eventos de AVs se definieron como: extrasístoles ventriculares ≥ 2.000 en registros de telemetría de 24 horas, fibrilación ventricular, taquicardia ventricular (TV) sostenida, TV polimórfica y TV no sostenida. Resultados Se incluyeron 87 pacientes (edad 72±12 años). Durante una hospitalización mediana de 8 días se registraron AVs subagudas en 22 pacientes (25%) tras una mediana de 91 horas desde el ingreso. Las AVs subagudas se asociaron a aumento de la mortalidad hospitalaria (p=0,030). El intervalo Tpeak-Tend corregido global (promedio de las 12 derivaciones del ECG) a las 48 horas del ingreso fue un predictor independiente de AVs subagudas, superior al intervalo QT corregido (p=0,040). Un valor de corte 108ms en el Tpeak-Tend corregido global mostró una sensibilidad del 71% y especificidad del 72% para AVs subagudas. Conclusiones En pacientes con síndrome de tako-tsubo, las AVs subagudas se asocian a alteraciones de la repolarización que pueden detectarse en el ECG convencional mediante el intervalo Tpeak-Tend (AU)

Introduction and objectives The clinical value of electrocardiogram (ECG) repolarization parameters associated with ventricular arrhythmias (VAs) in tako-tsubo syndrome is still under debate. We aimed to evaluate ECG predictors of subacute VAs, defined as those occurring after the first 48hours from admission. Methods This single-center observational study enrolled patients admitted to the cardiology department between 2012 and 2018 with a confirmed diagnosis of tako-tsubo syndrome. Data collection included a 12-lead ECG on admission and at 48hours, continuous telemetry monitoring, blood testing, transthoracic echocardiography, and coronary angiography during hospitalization. VAs events were defined as: premature ventricular contractions ≥ 2000 within a 24-hour window of telemetry monitoring, ventricular fibrillation, sustained ventricular tachycardia (VT), polymorphic VT, and non-sustained VT. Results A total of 87 patients (age 72±12 years) were enrolled. During a median of 8 days of hospitalization, subacute VAs were documented in 22 patients (25%) after a median of 91hours from admission. Subacute VAs were associated with an increase in mortality during hospitalization (P=.030). The corrected global (mean of the 12-lead ECG values) Tpeak-Tend interval at 48hours from admission was an independent predictor of subacute VAs and was statistically superior to the standard corrected QT interval (Z test, P=.040). A cut-off of 108 msec for the corrected global Tpeak-Tend yielded a 71% sensitivity and 72% specificity for subacute VAs. Conclusions In patients with tako-tsubo syndrome, subacute VAs are associated with repolarization alterations that can be identified on conventional ECG using the Tpeak-Tend interval (AU)

Clinical Impact of Cardiac Fibrosis on Arrhythmia Recurrence after Ablation in Adults with Congenital Heart Disease.

BACKGROUND: Adults with congenital heart disease (ACHD) are often affected by cardiac arrhythmias requiring catheter ablation. Catheter ablation in this setting represents the treatment of choice but is flawed by frequent recurrencies. Predictors of arrhythmia relapse have been identified, but the role of cardiac fibrosis in this setting has not been investigated. The aim of this study was to determine the role of the extension of cardiac fibrosis, detected by electroanatomical mapping, in predicting arrhythmia recurrencies after ablation in ACHD. MATERIALS AND METHODS: Consecutive patients with congenital heart disease and atrial or ventricular arrhythmias undergoing catheter ablation were enrolled. An electroanatomical bipolar voltage map was performed during sinus rhythm in each patient and bipolar scar was assessed according to the current literature data. During follow-up, arrhythmia recurrences were recorded. The relationship between the extent of myocardial fibrosis and arrhythmia recurrence was assessed. RESULTS: Twenty patients underwent successful catheter ablation of atrial (14) or ventricular (6) arrhythmias, with no inducible arrhythmia at the end of the procedure. During a median follow-up period of 207 weeks (IQR 80 weeks), eight patients (40%; five atrial and three ventricular arrhythmias) had arrhythmia recurrence. Of the five patients undergoing a second ablation, four showed a new reentrant circuit, while one patient had a conduction gap across a previous ablation line. The extension of the bipolar scar area (HR 1.049, CI 1.011-1.089, p = 0.011) and the presence of a bipolar scar area >20 cm2 (HR 6.101, CI 1.147-32.442, p = 0.034) were identified as predictors of arrhythmia relapse. CONCLUSION: The extension of the bipolar scar area and the presence of a bipolar scar area >20 cm2 can predict arrhythmia relapse in ACHD undergoing catheter ablation of atrial and ventricular arrhythmias. Recurrent arrhythmias are often caused by circuits other than those previously ablated.

Ventricular tachycardia ablation through radiation therapy (VT-ART) consortium: Concept description of an observational multicentric trial via matched pair analysis.

Introduction: Monomorphic ventricular tachycardia (VT) is a life-threatening condition often observed in patients with structural heart disease. Ventricular tachycardia ablation through radiation therapy (VT-ART) for sustained monomorphic ventricular tachycardia seems promising, effective, and safe. VT-ART delivers focused, high-dose radiation, usually in a single fraction of 25 Gy, allowing ablation of VT by inducing myocardial scars. The procedure is fully non-invasive; therefore, it can be easily performed in patients with contraindications to invasive ablation procedures. Definitive data are lacking, and no direct comparison with standard procedures is available. Discussion: The aim of this multicenter observational study is to evaluate the efficacy and safety of VT-ART, comparing the clinical outcome of patients undergone to VT-ART to patients not having received such a procedure. The two groups will not be collected by direct, prospective accrual to avoid randomization among the innovative and traditional arm: A retrospective selection through matched pair analysis will collect patients presenting features similar to the ones undergone VT-ART within the consortium (in each center independently). Our trial will enroll patients with optimized medical therapy in whom endocardial and/or epicardial radiofrequency ablation (RFA), the gold standard for VT ablation, is either unfeasible or fails to control VT recurrence. Our primary outcome is investigating the difference in overall cardiovascular survival among the group undergoing VT-ART and the one not exposed to the innovative procedure. The secondary outcome is evaluating the difference in ventricular event-free survival after the last procedure (i.e., last RFA vs. VT-ART) between the two groups. An additional secondary aim is to evaluate the reduction in the number of VT episodes comparing the 3 months before the procedure to the ones recorded at 6 months (from the 4th to 6th month) following VT-ART and RFA, respectively. Other secondary objectives include identifying the benefits of VT-ART on cardiac function, as evaluated through an electrocardiogram, echocardiographic, biochemical variables, and on patient quality of life. We calculated the sample size (in a 2:1 ratio) upon enrolling 149 patients: 100 in the non-exposed control group and 49 in the VT-ART group. Progressively, on a multicentric basis supervised by the promoting center in the VT-ART consortium, for each VT-ART patient enrollment, a matched pair patient profile according to the predefined features will be shared with the consortium to enroll a patient that has not undergone VT-ART. Conclusion: Our trial will provide insight into the efficacy and safety of VT-ART through a matched pair analysis, via an observational, multicentric study of two groups of patients with or without VT-ART in the multicentric consortium (with subgroup stratification into dynamic cohorts).

Prognostic value of the Tpeak-Tend interval for in-hospital subacute ventricular arrhythmias in tako-tsubo syndrome.

INTRODUCTION AND OBJECTIVES: The clinical value of electrocardiogram (ECG) repolarization parameters associated with ventricular arrhythmias (VAs) in tako-tsubo syndrome is still under debate. We aimed to evaluate ECG predictors of subacute VAs, defined as those occurring after the first 48hours from admission. METHODS: This single-center observational study enrolled patients admitted to the cardiology department between 2012 and 2018 with a confirmed diagnosis of tako-tsubo syndrome. Data collection included a 12-lead ECG on admission and at 48hours, continuous telemetry monitoring, blood testing, transthoracic echocardiography, and coronary angiography during hospitalization. VAs events were defined as: premature ventricular contractions ≥ 2000 within a 24-hour window of telemetry monitoring, ventricular fibrillation, sustained ventricular tachycardia (VT), polymorphic VT, and non-sustained VT. RESULTS: A total of 87 patients (age 72±12 years) were enrolled. During a median of 8 days of hospitalization, subacute VAs were documented in 22 patients (25%) after a median of 91hours from admission. Subacute VAs were associated with an increase in mortality during hospitalization (P=.030). The corrected global (mean of the 12-lead ECG values) Tpeak-Tend interval at 48hours from admission was an independent predictor of subacute VAs and was statistically superior to the standard corrected QT interval (Z test, P=.040). A cut-off of 108 msec for the corrected global Tpeak-Tend yielded a 71% sensitivity and 72% specificity for subacute VAs. CONCLUSIONS: In patients with tako-tsubo syndrome, subacute VAs are associated with repolarization alterations that can be identified on conventional ECG using the Tpeak-Tend interval.

Ultra-high-resolution assessment of lesion extension after cryoballoon ablation for pulmonary vein isolation.

Introduction: Unrecognized incomplete pulmonary vein (PV) isolation during the index procedure, can be a major cause of clinical recurrences of atrial fibrillation (AF) after cryoballoon (CB) ablation. We aimed to characterize the extension of the lesions produced by CB ablation and to assess the value of using an ultra-high resolution electroanatomic mapping (UHDM) system to detect incomplete CB lesions. Materials and methods: Twenty-nine consecutive patients from the CHARISMA registry undergoing AF ablation at four Italian centers were prospectively evaluated. The Rhythmia™ mapping system and the Orion™ (Boston Scientific) mapping catheter were used to systematically map the left atrium and PVs before and after cryoablation. Results: A total of 116 PVs were targeted and isolated. Quantitative assessment of the lesions revealed a significant reduction of the antral surface area of the PV, resulting in an ablated area of 5.7 ± 0.7 cm2 and 5.1 ± 0.8 cm2 for the left PV pair and right PV pair, respectively (p = 0.0068). The mean posterior wall (PW) area was 22.9 ± 2 cm2 and, following PV isolation, 44.8 ± 6% of the PW area was ablated. After CB ablation, complete isolation of each PV was documented by the POLARMap™ catheter in all patients. By contrast, confirmatory UHDM and the Lumipoint™ tool unveiled PV signals in 1 out of 114 of the PVs (0.9%). Over 30-day follow-up, no major procedure-related adverse events were reported. After a mean follow-up of 333 days, 89.7% of patients were free from arrhythmia recurrence. Conclusion: The lesion extension achieved by the new CB ablation system involved the PV antrum, with less than 50% of the PW remaining untouched. The new system, with short tip and circular mapping catheter, failed to achieve PV isolation in only 0.9% of all PVs treated. Clinical trial registration: [http://clinicaltrials.gov/], identifier [NCT03793998].

Short-Term Atrioventricular Dysfunction Recovery after Post-TAVI Pacemaker Implantation.

Permanent pacemaker implantation (PPI) represents a frequent complication after transcatheter aortic valve implantation (TAVI) due to atrio-ventricular (AV) node injury. Predictors of early AV function recovery were investigated. We analyzed 50 consecutive patients (82 ± 6 years, 58% males, EuroSCORE: 7.8 ± 3.3%, STS mortality score: 5 ± 2.8%). Pacemaker interrogations within 4−6 weeks from PPI were performed to collect data on AV conduction. The most common indication of PPI was persistent third-degree (44%)/high-degree (20%) AV block/atrial fibrillation (AF) with slow ventricular conduction (16%) after TAVI. At follow-up, 13 patients (26%) recovered AV conduction (i.e., sinus rhythm with stable 1:1 AV conduction/AF with a mean ventricular response >50 bpm, associated with a long-term ventricular pacing percentage < 5%). At multivariate analysis, complete atrio-ventricular block independently predicted pacemaker dependency at follow-up (p = 0.019). Patients with persistent AV dysfunction showed a significant AV conduction time prolongation after TAVI (PR interval from 207 ± 50 to 230 ± 51, p = 0.02; QRS interval from 124 ± 23 to 147 ± 16, p < 0.01) compared to patients with recovery, in whom AV conduction parameters remained unchanged. Several patients receiving PPI after TAVI have recovery of AV conduction within a few weeks. Longer observation periods prior to PPI might be justified, and algorithms to minimize ventricular pacing should be utilized whenever possible.

Atrioventricular conduction in PM recipients after transcatheter aortic valve implantation: Implications using Wenckebach point measurement.

Background: Atrioventricular (AV) conduction disturbances requiring permanent pacemaker implantation (PPI) are a common complication after transcatheter aortic valve implantation (TAVI). However, a significant proportion of patients might recover AV conduction at follow-up. Objectives: The aim of our study was to evaluate the recovery of AV conduction by determination through Wenckebach point in patients with PPI and therefore identify patients who could benefit from device reprogramming to avoid unnecessary RV pacing. Methods: We enrolled 43 patients that underwent PM implantation after TAVI at our Department from January 2018 to January 2021. PM interrogation was performed at follow-up and patients with native spontaneous rhythm were further assessed for AV conduction through WP determination. Results: A total of 43 patients requiring a PM represented the final study population, divided in patients with severely impaired AV conduction (no spontaneous valid rhythm or WP < 100; 26) and patients with valid AV conduction (WP ≥ 100; 17). In the first group patients had a significantly higher number of intraprocedural atrioventricular block (AVB) (20 vs. 1, p < 0.005), showed a significant higher implantation depth in LVOT (7.7 ± 2.2 vs. 4.4 ± 1.1, p < 0.05) and lower ΔMSID (-0.28 ± 3 vs. -3.94 ± 2, p < 0.05). Conclusion: AV conduction may recover in a significant proportion of patients. In our study, valve implantation depth in the LVOT and intraprocedural AV block are associated with severely impaired AV conduction. Regular PM interrogation and reprogramming are required to avoid unnecessary permanent right ventricular stimulation in patients with AV conduction recovery.

Successful ventricular tachycardia radioablation in a patient with previous chemical pleurodesis: A case report.

Introduction: Stereotactic arrhythmia radioablation (STAR) is a novel technique for the ablation of ventricular tachycardia in patients with contraindications to standard procedures, i.e., radiofrequency ablation. Case presentation: We report the case of a 73-year-old man with non-ischemic dilated cardiomyopathy and recurrent VT episodes. Electroanatomic mapping showed VT prevalently of epicardial origin, but direct epicardial access through subxyphoid puncture could not be performed due to pleuropericardial adhesions from a past history of chemical pleurodesis. STAR was performed, with no VT recurrence at 6 months follow-up. Conclusions: Previous experiences with STAR have demonstrated its importance in the management of patients with refractory VT in whom other ablation strategies were not successful. Our case report highlights the use of STAR as a second choice in a patient with an unfavorable VT anatomical location and technical limitations to an optimal radiofrequency ablation. Moreover, it confirms STAR's effectiveness in the ablation of complex transmural lesions, which are more often associated with non-ischemic structural heart disease.

Rapid resolution of severe pericardial effusion using anakinra in a patient with COVID-19 vaccine-related acute pericarditis relapse: a case report.

Background: Pericarditis, along with myocarditis, is being increasingly reported after the coronavirus disease 2019 (COVID-19) vaccine, but the best treatment strategy in this specific setting is still unclear. Case summary: We report a case of acute pericarditis after the second dose of mRNA COVID-19 vaccine with recurrence of large pericardial effusion after a previous pericardiocentesis and anti-inflammatory drugs tapering. The patient was successfully treated with the recombinant interleukin-1 receptor antagonist anakinra, with full reabsorption of the pericardial effusion and an abrupt drop of the inflammatory markers within 72 h. The patient was discharged a few days later, with a further decrease of the inflammatory markers and no residual symptoms. Discussion: Anakinra is being increasingly used in the treatment of recurrent pericarditis due to its capability to interrupt the autoinflammatory response leading to deleterious cytokine storms. On account of its high efficacy and rapid onset, it has been reported to rapidly reverse large inflammatory pericardial effusions. Pericarditis and myocarditis have been reported after the COVID-19 vaccine, but this is the first case of COVID-19 vaccine-related pericarditis and pericardial effusion successfully treated with anakinra, avoiding a second pericardiocentesis.

Severity of spleep apnea syndrome and life-threatening tachyarrhythmias in patients with implantable cardioverter defibrillator.

BACKGROUND: Sleep apnea syndrome (SAS) has been reported to be associated with a higher incidence of ventricular arrhythmias. The aim of this study was twofold: (1) to investigate whether in SAS patients receiving an implantable cardioverter defibrillator (ICD) the severity of SAS was associated with the occurrence of ventricular arrhythmias; (2) to assess whether changes in nocturnal apnoic/hypopnoic episodes may favor the occurrence of life-threatening arrhythmias, that is, sustained ventricular tachycardia (VT)/fibrillation (VF), requiring ICD intervention. METHODS: We enrolled 46 patients with documented SAS at polysomnography (apnea/hypopnea index [AHI] > 5) who also had a left ventricle ejection fraction (LVEF) < 35% and, according to primary prevention indications, implanted an ICD (Boston Scientific Incepta) able to daily monitor apnoic/hypopnoic episodes occurring during sleep. Patients were followed at 3-month intervals. RESULTS: At a mean follow-up of 18 months, 21 episodes of sustained VT/FV requiring ICD intervention were documented in eight patients (17.4%). Baseline AHI was significantly higher in patients with compared to those without ICD intervention. ICD interventions, however, were not preceded by any worsening of apnoic/hypopnoic episodes. The respiratory disturbance index (RDI) of the week during the event, indeed, was not different from that recorded during the previous 2 weeks (25.4 ± 11, 25.6 ± 10 and 25.1 ± 10, respectively; p = .9). CONCLUSIONS: In patients with SAS who received an ICD for primary prevention of sudden death, those with ICD interventions showed a more severe form of the disease at baseline. ICD interventions, however, were not preceded by any significant changes in SAS severity.

Diagnostic Workflow in Competitive Athletes with Ventricular Arrhythmias and Suspected Concealed Cardiomyopathies.

The diagnosis of structural heart disease in athletes with ventricular arrhythmias (VAs) and an apparently normal heart can be very challenging. Several pieces of evidence demonstrate the importance of an extensive diagnostic work-up in apparently healthy young patients for the characterization of concealed cardiomyopathies. This study shows the various diagnostic levels and tools to help identify which athletes need deeper investigation in order to unmask possible underlying heart disease.

Assessment of patients presenting with life-threatening ventricular arrhythmias and suspected myocarditis: The key role of endomyocardial biopsy.

BACKGROUND: Life-threatening ventricular tachyarrhythmias (VAs) represent a significant cause of death in myocarditis. OBJECTIVE: The purpose of this study was to identify predictors of sustained VAs in patients with myocarditis and ventricular phenotype diagnosed by workflow including endomyocardial biopsy (EMB) guided by 3D electroanatomic mapping (3D-EAM). METHODS: We prospectively enrolled patients with suspected myocarditis and VAs, undergoing cardiac magnetic resonance imaging, coronary angiography, 3D-EAM, and EMB guided by 3D-EAM. At follow-up, sustained VAs were detected by device interrogation and 24-hour electrocardiographic Holter monitoring. RESULTS: We enrolled 54 consecutive patients (mean age 41 ± 14 years; 32(59%) men) with normal ventricular function; left ventricular and right ventricular (RV) late gadolinium enhancement was present, respectively, in 21 (46%) and 6 (13%) of the 46 patients who underwent cardiac magnetic resonance. In 31 patients, the histological diagnosis was myocarditis, while in 14 patients, focal replacement myocardial fibrosis (FRMF); in 9 patients, specimens were inadequate (diagnostic yield of EMB 83%). 3D-EAM showed a larger endocardial scar area for both ventricles in myocarditis than in FRMF (RV bipolar mean scar area 22 ± 16 cm2 vs 3 ± 2 cm2; P = .02; left ventricular bipolar mean scar area 13 ± 5 cm2 vs 4 ± 2 cm2; P = .02, respectively). At a follow-up of 21 months, freedom from sustained VAs was 58% in myocarditis and 92% in FRMF (log-rank, P = .008). Histological diagnosis of myocarditis and RV endocardial scar were independent predictors of sustained VAs (P = .02 for both). CONCLUSION: Our data highlight the need for 3D-EAM-guided EMB in apparently healthy young patients with suspected myocarditis and VAs.

Ventricular arrhythmias in Takotsubo Syndrome: incidence, predictors and clinical outcomes.

AIMS: To investigate predictors of the occurrence of subacute ventricular arrhythmias (VAs), defined as any VAs presenting after 48 h from admission in patients with Takotsubo Syndrome (TTS), and to evaluate the related in-hospital mortality. METHODS: This is a retrospective single-center study enrolling patients admitted between 2012 and 2017 with TTS according to International Takotsubo diagnostic criteria. Data collection included ECG on admission and at 48 h, telemetry monitoring and transthoracic echocardiogram. RESULTS: We enrolled 93 patients; during in-hospital stay (mean 14 ±â€Š16 days) subacute VAs occurred in 25% of patients (VAs group). Life-threatening VAs occurred in 6% of patients (3 sustained ventricular tachycardia, 1 torsade de pointes, 1 ventricular fibrillation) and not life-threatening VAs in 19% (6 non-sustained ventricular tachycardia and 12 premature ventricular contractions > 2000 in 24 h). Mortality was higher in the VAs than in the non-VAs group (P = 0.03), without differences in terms of life-threatening and not life-threatening subacute VAs (P = 0.65) and VAs on admission (P = 0.25). Logistic regression identified the following independent predictors of subacute VAs occurrence: VAs on admission {odds ratio [OR] 22.5 (3.9-131.8), P = 0.001]}, New York Heart Association (NYHA) class III-IV on admission [OR 6.7 (1.3- 34.0), P = 0.021] and QTc at 48 h [OR 1.01 (1.00-1.03), P = 0.046]. CONCLUSION: TTS patients with VAs and NYHA class III-IV on admission and higher QTc at 48 h are at increased risk of subacute VAs occurrence, associated with higher in-hospital mortality. Awareness of this potential complication is critical for proper patients management.

Case Report: A Case Report of Stereotactic Ventricular Arrhythmia Radioablation (STAR) on Large Cardiac Target Volume by Highly Personalized Inter- and Intra-fractional Image Guidance.

Introduction: Although catheter ablation is the current gold standard treatment for refractory ventricular arrhythmias, sometimes its efficacy is not optimal and it's associated with high risks of procedural complication and death. Stereotactic arrhythmia radioablation (STAR) is increasingly being adopted for such clinical presentation, considering its efficacy and safety. Case Presentation: We do report our experience managing a case of high volume of left ventricle for refractory ventricular tachycardia in advanced heart failure patient, by delivering a single fraction of STAR through an highly personalization of dose delivery applying repeated inter- and continuous intra-fraction image guidance. Conclusion: According to the literature reports, we recommend considering increasing as much as possible the personalization features and safety technical procedure as long as that is not significantly affecting the STAR duration. Moreover, the duration in itself shouldn't be the main parameter, but balanced into the frame of possibly obtainable outcome improvement. At best of our knowledge, this is the first report applying such specific technology onto this clinical setting. Future studies will clarify these issues.

Long-Term Arrhythmic Risk Assessment in Biopsy-Proven Myocarditis.

OBJECTIVES: This study sought to assess long-term arrhythmic risk in patients with myocarditis who received an implantable cardioverter-defibrillator (ICD). BACKGROUND: The arrhythmic risk of patients with myocarditis overtime remains poorly known. METHODS: The study enrolled 56 patients with biopsy-proven myocarditis who received an ICD for either primary (57%) or secondary prevention (43%) according to current guidelines. Clinical characteristics, biopsy findings, electrophysiological data from endocardial 3-dimensional electroanatomic voltage mapping, and device interrogation data were analyzed to detect arrhythmic events overtime. Coronary angiography excluded significant coronary artery disease in all patients. RESULTS: At a mean follow-up of 74 ± 60 months (median 65 months), 25 (45%) patients had major ventricular arrhythmias treated by ICD intervention (76% being terminated by ICD shock and 24% by antitachyarrhythmia burst pacing). At multivariable analysis, the presence of sustained ventricular tachycardia on admission (hazard ratio: 13.0; 95% confidence interval: 2.0 to 35.0; p = 0.032) and the extension of the areas of low potentials at the bipolar endocardial mapping (hazard ratio: 1.19; 95% confidence interval: 1.04 to 1.37; p = 0.013) were the only independent predictors of appropriate ICD interventions. A cutoff value of 10% of abnormal bipolar area at electroanatomical ventricular mapping discriminated patients with appropriate ICD interventions with a sensitivity of 89% and a specificity of 85%. CONCLUSIONS: The study demonstrates that the prevalence of life-threatening ventricular arrhythmias in patients with myocarditis receiving an ICD according to current guidelines is high and the arrhythmic risk persists late overtime. Electroanatomical ventricular mapping may be a useful tool to identify patients at greater arrhythmic risk.

Role of extensive diagnostic workup in young athletes and nonathletes with complex ventricular arrhythmias.

BACKGROUND: Ventricular arrhythmias (VAs) are the most common cause of death in athletes. The differences in the electroanatomic substrate in athletes and nonathletes with complex VA are unknown. OBJECTIVE: The purpose of this study was to compare the electroanatomic substrate of complex VA in athletes vs nonathletes. METHODS: The study prospectively enrolled young athletes and nonathletes with VA. Patients underwent 2-dimensional echocardiography, cardiac magnetic resonance (CMR) imaging, coronary angiography, 3-dimensional electroanatomic mapping (3D-EAM), and 3D-EAM-guided endomyocardial biopsy (EMB). Follow-up included 24-hour electrocardiographic Holter or implantable cardioverter-defibrillator/loop recorder interrogation for VA recurrence. RESULTS: Thirty-three patients were enrolled: 18 competitive athletes (56%) and 15 nonathletes (44%). Left ventricular and right ventricular (RV) findings by echocardiography and CMR did not show structural disease. Nine athletes (50%) were asymptomatic compared to 1 nonathlete (7%; P <.05). Unifocal origin of VA was reported in 14 athletes (93%) and 17 nonathletes (94%). Athletes showed a larger RV unipolar than bipolar scar (18 ± 17 cm2 vs 3 ± 3.8 cm2; P = .04). Diagnostic yield of EMB was 50% in athletes and 40% in nonathletes. Among athletes, the final diagnosis was myocarditis in 2, arrhythmogenic ventricular right cardiomyopathy in 1, and focal replacement fibrosis in 1. Among nonathletes, EMB revealed focal replacement fibrosis in 4 cases. At median follow-up of 18.7 months, Kaplan-Meier curves showed lower VA recurrence in detrained athletes than nonathletes (53% vs 6%; P = .02). CONCLUSION: This study showed the need for extensive diagnostic workup in apparently healthy young patients with complex VA in order to characterize concealed cardiomyopathies.

Prognostic significance of non-sustained ventricular tachycardia on stored electrograms in pacemaker recipients.

BACKGROUND: Little is known about the prognostic significance of non-sustained ventricular tachycardia (NS-VT) in outpatients scheduled for routine pacemaker controls. We therefore sought to investigate the prognostic significance of non-sustained ventricular tachycardia on stored electrograms in pacemaker recipients. METHODS: We enrolled patients implanted with dual chamber pacemaker for atrioventricular block or sinus node dysfunction from 2010 to 2016, with LVEF> 45%, older than 18 years, with at least 3 device interrogations at follow-up. Data were collected about medical history, pharmacological therapy at implantation, pacemaker programming, NS-VT occurrence, long-term survival. RESULTS: A total of 308 patients were included in the final analysis, with median follow-up time of 56 months. No ventricular arrhythmic episodes were documented in 221 patients (Group 1), whereas 87 had at least 1 episode of NS-VT during follow-up (Group 2). As a whole, 282 episodes of NS-VT were documented. There was a higher prevalence of previous myocardial infarction and slightly lower left ventricular ejection fraction (LVEF) in Group 2. The primary endpoint (all-cause mortality) occurred in 50 patients (22%) of Group 1 and 12 (14%) patients of Group 2 (p = 0.07). Clinical predictors of all-cause mortality at univariate analysis included age, LVEF and coronary artery disease (CAD). Only age and CAD, however, remained as predictors of mortality at multivariable analysis. A sizeable, but not statistically significant, portion of patients who died had a de novo occurrence of NS-VT at the last pacemaker check. CONCLUSION: Our data do not support a prognostic role for the detection of NS-VT during pacemaker controls.

Use of T-wave alternans in identifying patients with coronary artery disease.

AIMS: Microvolt T-wave alternans (MTWA) has been found to predict fatal events in patients with coronary artery disease (CAD). In a previous study, we found that MTWA values are higher in patients with CAD, compared with apparently healthy individuals. In this study, we assessed the relation between CAD and MTWA in patients with a diagnosis based on coronary angiography results. METHODS: We studied 98 consecutive patients undergoing coronary angiography for suspected CAD. All patients underwent a maximal exercise stress test (EST), and MTWA was measured in the precordial ECG leads. Patients were divided into three groups: 40 patients without any significant (>50%) stenosis (group 1); 47 patients with significant stenosis (group 2); and 11 patients with a previous percutaneous coronary intervention (PCI) who had no evidence of restenosis (group 3). EST was repeated after 1 month in 24 group 2 patients who underwent PCI and in 17 group 1 patients. RESULTS: MTWA was significantly higher in group 2 (58.7 ±â€Š24 µV) compared with group 1 (34.2  ±â€Š15 µV, P < 0.01) and group 3 (43.2 ±â€Š24 µV, P < 0.05). An MTWA greater than 60 µV had 95% specificity and 82% positive predictive value for obstructive CAD. At 1-month follow-up, MTWA decreased significantly in patients treated with PCI (from 61.3 ±â€Š22 to 43.5 ±â€Š17 µV; P < 0.001), but not in group 1 patients (from 50.5 ± 22 to 44.3 ±â€Š19 µV, P = 0.19). CONCLUSION: MTWA is increased in patients with obstructive CAD and is reduced by coronary revascularization. An assessment of MTWA can be helpful in identifying which patients with suspected CAD are likely to show obstructive CAD on angiography.