Arrhythmic Mitral Valve Prolapse and Sports Activity: Pathophysiology, Risk Stratification, and Sports Eligibility Assessment.

Although mitral valve prolapse (MVP) is the most prevalent valvular abnormality in Western countries and generally carries a good prognosis, a small subset of patients is exposed to a significant risk of malignant ventricular arrhythmias (VAs) and sudden cardiac death (SCD), the so-called arrhythmic MVP (AMVP) syndrome. Recent work has emphasized phenotypical risk features of severe AMVP and clarified its pathophysiology. However, the appropriate assessment and risk stratification of patients with suspected AMVP remains a clinical conundrum, with the possibility of both overestimating and underestimating the risk of malignant VAs, with the inappropriate use of advanced imaging and invasive electrophysiology study on one hand, and the catastrophic occurrence of SCD on the other. Furthermore, the sports eligibility assessment of athletes with AMVP remains ill defined, especially in the grey zone of intermediate arrhythmic risk. The definition, epidemiology, pathophysiology, risk stratification, and treatment of AMVP are covered in the present review. Considering recent guidelines and expert consensus statements, we propose a comprehensive pathway to facilitate appropriate counseling concerning the practice of competitive/leisure-time sports, envisioning shared decision making and the multidisciplinary "sports heart team" evaluation of borderline cases. Our final aim is to encourage an active lifestyle without compromising patients' safety.

Microelectrode voltage mapping for substrate assessment in catheter ablation of ventricular tachycardia: A dual-center experience.

INTRODUCTION: The assessment of the ventricular myocardial substrate critically depends on the size of mapping electrodes, their orientation with respect to wavefront propagation, and interelectrode distance. We conducted a dual-center study to evaluate the impact of microelectrode mapping in patients undergoing catheter ablation (CA) of ventricular tachycardia (VT). METHODS: We included 21 consecutive patients (median age, 68 [12], 95% male) with structural heart disease undergoing CA for electrical storm (n = 14) or recurrent VT (n = 7) using the QDOT Micro catheter and a multipolar catheter (PentaRay, n = 9). The associations of peak-to-peak maximum standard bipolar (BVc ) and minibipolar (PentaRay, BVp ) with microbipolar (BVµMax ) voltages were respectively tested in sinus rhythm with mixed effect models. Furthermore, we compared the features of standard bipolar (BE) and microbipolar (µBE) electrograms in sinus rhythm at sites of termination with radiofrequency energy. RESULTS: BVµMax was moderately associated with both BVc (ß = .85, p < .01) and BVp (ß = .56, p < .01). BVµMax was 0.98 (95% CI: 0.93-1.04, p < .01) mV larger than corresponding BVc , and 0.27 (95% CI: 0.16-0.37, p < .01) mV larger than matching BVp in sinus rhythm, with higher percentage differences in low voltage regions, leading to smaller endocardial dense scar (2.3 [2.7] vs. 12.1 [17] cm2 , p < .01) and border zone (3.2 [7.4] vs. 4.8 [20.1] cm2 , p = .03) regions in microbipolar maps compared to standard bipolar maps. Late potentials areas were nonsignificantly greater in microelectrode maps, compared to standard electrode maps. At sites of VT termination (n = 14), µBE were of higher amplitude (0.9 [0.8] vs. 0.4 [0.2] mV, p < .01), longer duration (117 [66] vs. 74 [38] ms, p < .01), and with greater number of peaks (4 [2] vs. 2 [1], p < .01) in sinus rhythm compared to BE. CONCLUSION: microelectrode mapping is more sensitive than standard bipolar mapping in the identification of viable myocytes in SR, and may facilitate recognition of targets for CA.

Intraprocedural PRAETORIAN score for early assessment of S-ICD implantation: A proof-of-concept study.

INTRODUCTION: The PRAETORIAN score (PS) was developed to assess the implant position and predict defibrillation success of the subcutaneous implantable cardioverter defibrillators (S-ICD). The main critique moved to the routine use of PS has been its postprocedural timing, that limits its usefulness on procedure guidance. The aim of this proof-of-concept study was to assess the feasibility of an intraprocedural use of PS. METHODS: Forty consecutive patients undergoing S-ICD implantation were enrolled. Intraprocedural PS (IP-PS) obtained with fluoroscopy before closure of the pocket and postprocedural PS (PP-PS) obtained with two-views chest X-ray were compared. Intraprocedural data and PS were compared with the historic cohorts of the involved institutions. RESULTS: When assessing IP-PS and PP-PS, a complete overall agreement was observed (100%, 1.00-κ; p < .001). When assessing a per-step agreement, a very high-degree of concordance in evaluating Step 1 of the PS was observed (95%, 0.81-κ; p < .001). A complete agreement in Step 2-3 (100%, 1.00-κ; p < .001) of the PS was reported. In comparison with our historical cohort, procedural time in the IP-PS cohort did not increase (45 [41-52] vs. 45 [39-49] min; p = .351) while the expected increase in fluoroscopy time resulted scarce (15 [10-15] s). CONCLUSION: An IP-PS can be reliably obtained using fluoroscopy guidance during S-ICD implantation, without a significant increase in procedural duration and may serve as guidance for implanting physicians, to avoid postprocedural S-ICD repositioning, leading to patient discomfort and significantly enhancing infective risks. IP-PS showed a very high agreement with the PP-PS obtained from two-views chest X-ray.

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.

Procedural sedation for direct current cardioversion: a feasibility study between two management strategies in the emergency department.

BACKGROUND: A cardiologist-only approach to procedural sedation with midazolam in the setting of elective cardioversion (DCC) for AF has already been proven as safe as sedation with propofol and anaesthesiologist assistance. No data exist regarding the safety of such a strategy during emergency procedures. The aim of this study is to compare the feasibility of sedation with midazolam, administered by a cardiologist, to an anaesthesiologist-assisted protocol with propofol in emergency DCC. METHODS: Single centre, prospective, open blinded, randomized study including all consecutive patients admitted to the Emergency Department requiring urgent or emergency DCC. Patients were randomized in a 1:1 fashion to either propofol or midazolam treatment arm. Patients in the midazolam group were managed by the cardiologist only, while patients treated with propofol group underwent DCC with anaesthesiologist assistance. RESULTS: Sixty-nine patients were enrolled and split into two groups. Eighteen patients (26.1%) experienced peri-procedural adverse events (bradycardia, severe hypotension and severe hypoxia), which were similar between the two groups and all successfully managed by the cardiologist. No deaths, stroke or need for invasive ventilation were registered. Patients treated with propofol experienced a greater decrease in systolic and diastolic blood pressure when compared with those treated with midazolam. As the procedure was shorter when midazolam was used, the median cost of urgent/emergency DCC with midazolam was estimated to be 129.0 € (1st-3rd quartiles 114.6-151.6) and 195.6 € (1st-3rd quartiles 147.3-726.7) with propofol (p < .001). CONCLUSIONS: Procedural sedation with midazolam given by the cardiologist alone was feasible, well-tolerated and cost-effective in emergency DCC.

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.

Long-term follow-up analysis of a highly characterized arrhythmogenic cardiomyopathy cohort with classical and non-classical phenotypes-a real-world assessment of a novel prediction model: does the subtype really matter.

AIMS: To provide long-term outcome data on arrhythmogenic cardiomyopathy (ACM) patients with non-classical forms [left dominant ACM (LD-ACM) and biventricular ACM (Bi-ACM)] and an external validation of a recently proposed algorithm for ventricular arrhythmia (VA) prediction in ACM patients. METHODS AND RESULTS: Demographic, clinical, and outcome data were retrieved from all ACM patients encountered at our institution. Patients were classified according to disease phenotype (R-ACM; Bi-ACM; LD-ACM). Overall and by phenotype long-term survival were calculated; the novel Cadrin-Tourigny et al. algorithm was used to calculate the a priori predicted VA risk, and it was compared with the observed outcome to test its reliability. One hundred and one patients were enrolled; three subgroups were defined (R-ACM, n = 68; Bi-ACM, n = 14; LD-ACM, n = 19). Over a median of 5.41 (2.59-8.37) years, the non-classical form cohort experienced higher rates of VAs than the classical form [5-year freedom from VAs: 0.58 (0.43-0.78) vs. 0.76 (0.66-0.89), P = 0.04]. The Cadrin-Tourigny et al. predictive model adequately described the overall cohort risk [mean observed-predicted risk difference (O-PRD): +6.7 (-4.3, +17.7) %, P = 0.19]; strafing by subgroup, excellent goodness-of-fit was demonstrated for the R-ACM subgroup (mean O-PRD, P = 0.99), while in the Bi-ACM and LD-ACM ones the real observed risk appeared to be underestimated [mean O-PRD: -20.0 (-1.1, -38.9) %, P < 0.0001; -22.6 (-7.8, -37.5) %, P < 0.0001, respectively]. CONCLUSION: Non-classical ACM forms appear more prone to VAs than classical forms. The novel prediction model effectively predicted arrhythmic risk in the classical R-ACM cohort, but seemed to underestimate it in non-classical forms.

The effects of gender on electrical therapies for the heart: procedural considerations, results and complications: A report from the XII Congress of the Italian Association on Arrhythmology and Cardiostimulation (AIAC).

Use of cardiac implantable devices and catheter ablation is steadily increasing in Western countries following the positive results of clinical trials. Despite the advances in scientific knowledge, tools development, and techniques improvement we still have some grey area in the field of electrical therapies for the heart. In particular, several reports highlighted differences both in medical behaviour and procedural outcomes between female and male candidates. Women are referred later for catheter ablation of supraventricular arrhythmias, especially atrial fibrillation, leading to suboptimal results. On the opposite females present greater response to cardiac resynchronization, while the benefit of implantable defibrillator in primary prevention seems to be less pronounced. Differences on aetiology, clinical profile, and development of myocardial scarring are the more plausible causes. This review will discuss all these aspects together with gender-related differences in terms of acute/late complications. We will also provide useful hints on plausible mechanisms and practical procedural aspects.

Simultaneous assessment of contact pressure and local electrical coupling index using robotic navigation.

PURPOSE: Contact with cardiac tissue is a determinant of lesion efficacy during atrial fibrillation (AF) ablation. The Sensei®X Robotic Catheter System (Hansen Medical, CA) has been validated for contact force sensing. The electrical coupling index (ECI) from the EnSite Contact™ system (St. Jude Medical, MN) has been validated as an indicator of tissue contact. We aimed at analyzing ECI behavior during radiofrequency (RF) pulses maintaining a stable contact through the robotic navigation contact system. METHODS: In 15 patients (age, 59 ± 12) undergoing AF ablation, pulmonary vein (PV) isolation was guided by the Sensei®X System, employing the Contact™ catheter. RESULTS: During the procedure, we assessed ECI changes associated with adequate contact based on the IntelliSense® force-sensing technology (Hansen Medical, CA. Baseline contact (27 ± 8 g/cm(2)) ECI value was 99 ± 13, whereas ECI values in a noncontact site (0 g/cm(2)) and in a light contact site (1-10 g/cm(2)) were respectively 66 ± 12 and 77 ± 10 (p < 0.0001). Baseline contact ECI values were not different depending on AF presentation (paroxysmal AF, 98 ± 9; persistent AF, 100 ± 9) or on cardiac rhythm (sinus rhythm, 97 ± 7; AF,101 ± 10). In all PVs, ECI was significantly reduced during and after ablation (ECI during RF, 56 ± 15; ECI after RF, 72 ± 16; p < 0.001). A mean reduction of 32.2% during RF delivery and 25.4% immediately after RF discontinuation compared with baseline ECI was observed. CONCLUSIONS: Successful PV isolation is associated with a significant decrease in ECI of at least 20 %. This may be used as a surrogate marker of effective lesion in AF ablation.