Loira Leoni

Implantable Cardioverter-Defibrillator Therapy for Prevention of Sudden Death in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia

Background—Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a condition associated with the risk of sudden death (SD). Methods and Results—We conducted a multicenter study of the impact of the implantable cardioverter-defibrillator (ICD) for prevention of SD in 132 patients (93 males and 39 females, age 40±15 years) with ARVC/D. Implant indications were a history of cardiac arrest in 13 patients (10%), sustained ventricular tachycardia in 82 (62%), syncope in 21 (16%), and other in 16 (12%). During a mean follow-up of 39±25 months, 64 patients (48%) had appropriate ICD interventions, 21 (16%) had inappropriate interventions, and 19 (14%) had ICD-related complications. Fifty-three (83%) of the 64 patients with appropriate interventions received antiarrhythmic drug therapy at the time of first ICD discharge. Programmed ventricular stimulation was of limited value in identifying patients at risk of tachyarrhythmias during the follow-up (positive predictive value 49%, negative predictive value 54%). Four patients (3%) died, and 32 (24%) experienced ventricular fibrillation/flutter that in all likelihood would have been fatal in the absence of the device. At 36 months, the actual patient survival rate was 96% compared with the ventricular fibrillation/flutter-free survival rate of 72% (P <0.001). Patients who received implants because of ventricular tachycardia without hemodynamic compromise had a significantly lower incidence of ventricular fibrillation/flutter (log rank=0.01). History of cardiac arrest or ventricular tachycardia with hemodynamic compromise, younger age, and left ventricular involvement were independent predictors of ventricular fibrillation/flutter. Conclusions—In patients with ARVC/D, ICD therapy provided life-saving protection by effectively terminating life-threatening ventricular arrhythmias. Patients who were prone to ventricular fibrillation/flutter could be identified on the basis of clinical presentation, irrespective of programmed ventricular stimulation outcome.

Three-Dimensional Electroanatomic Voltage Mapping Increases Accuracy of Diagnosing Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia

Background—Three-dimensional electroanatomic voltage mapping offers the potential to identify low-voltage areas that correspond to regions of right ventricular (RV) myocardial loss and fibrofatty replacement in patients with arrhythmogenic RV cardiomyopathy/dysplasia (ARVC/D). Methods and Results—Thirty-one consecutive patients (22 men and 9 women; mean age, 30.8±7 years) who fulfilled the criteria of the Task Force of the European Society of Cardiology and International Society and Federation of Cardiology (ESC/ISFC) for ARVC/D diagnosis after noninvasive clinical evaluation underwent further invasive study including RV electroanatomic voltage mapping and endomyocardial biopsy (EMB) to validate the diagnosis. Multiple RV endocardial, bipolar electrograms (175±23) were sampled during sinus rhythm. Twenty patients (group A; 65%) had an abnormal RV electroanatomic voltage mapping showing ≥1 area (mean 2.25±0.7) with low-voltage values (bipolar electrogram amplitude <0.5 mV), surrounded by a border zone (0.5 to 1.5 mV) that transitioned into normal myocardium (>1.5 mV). Low-voltage electrograms appeared fractionated with significantly prolonged duration and delayed activation. In 11 patients (group B; 35%), electroanatomic voltage mapping was normal, with preserved electrogram voltage (4.4±0.7 mV) and duration (37.2±0.9 ms) throughout the RV. Low-voltage areas in patients from group A corresponded to echocardiographic/angiographic RV wall motion abnormalities and were significantly associated with myocyte loss and fibrofatty replacement at EMB (P<0.0001) and familial ARVC/D (P<0.0001). Patients from group B had sporadic disease and histopathological evidence of inflammatory cardiomyopathy (P<0.0001). During the time interval from onset of symptoms to the invasive study, 11 patients (55%) with electroanatomic low-voltage regions received an implantable cardioverter/defibrillator because of life-threatening ventricular arrhythmias, whereas all but 1 patient with a normal voltage map remained stable on antiarrhythmic drug therapy (P=0.02). Conclusions—Three-dimensional electroanatomic voltage mapping enhanced accuracy for diagnosing ARVC/D (1) by demonstrating low-voltage areas that were associated with fibrofatty myocardial replacement and (2) by identifying a subset of patients who fulfilled ESC/ISFC Task Force diagnostic criteria but showed a preserved electrogram voltage, an inflammatory cardiomyopathy mimicking ARVC/D, and a better arrhythmic outcome.

Prophylactic Implantable Defibrillator in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia and No Prior Ventricular Fibrillation or Sustained Ventricular Tachycardia

Background— The role of implantable cardioverter-defibrillator (ICD) in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia and no prior ventricular fibrillation (VF) or sustained ventricular tachycardia is an unsolved issue. Methods and Results— We studied 106 consecutive patients (62 men and 44 women; age, 35.6±18 years) with arrhythmogenic right ventricular cardiomyopathy/dysplasia who received an ICD based on 1 or more arrhythmic risk factors such as syncope, nonsustained ventricular tachycardia, familial sudden death, and inducibility at programmed ventricular stimulation. During follow-up of 58±35 months, 25 patients (24%) had appropriate ICD interventions and 17 (16%) had shocks for life-threatening VF or ventricular flutter. At 48 months, the actual survival rate was 100% compared with the VF/ventricular flutter–free survival rate of 77% (log-rank P=0.01). Syncope significantly predicted any appropriate ICD interventions (hazard ratio, 2.94; 95% confidence interval, 1.83 to 4.67; P=0.013) and shocks for VF/ventricular flutter (hazard ratio, 3.16; 95% confidence interval, 1.39 to 5.63; P=0.005). The positive predictive value of programmed ventricular stimulation was 35% for any appropriate ICD intervention and 20% for shocks for VF/ventricular flutter, with a negative predictive value of 70% and 74%. None of the 27 asymptomatic patients with isolated familial sudden death had appropriate ICD therapy. Twenty patients (19%) had inappropriate ICD interventions, and 18 (17%) had device-related complications. Conclusions— One fourth of patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia and no prior sustained ventricular tachycardia or VF had appropriate ICD interventions. Syncope was an important predictor of life-saving ICD intervention and is an indication for ICD. Prophylactic ICD may not be indicated in asymptomatic patients because of their low arrhythmic risk regardless of familial sudden death and programmed ventricular stimulation findings. Programmed ventricular stimulation had a low predictive accuracy for ICD therapy.

Incidence, Predictors, and Outcome of Conduction Disorders After Transcatheter Self-Expandable Aortic Valve Implantation

The aims of the present study were to investigate the incidence and characteristics of conduction disorders (CDs) after transcatheter aortic valve implantation (TAVI), to analyze the predictors of permanent pacemaker (PPM) implantation, and to evaluate the outcomes of CDs over time. In particular, we sought to investigate whether the depth of deployment and other technical aspects of valve implantation might predict the need for PPM implantation after TAVI. TAVI has been reported to favor the onset or worsening of CDs often requiring PPM implantation. A total of 70 patients with aortic stenosis due to dystrophic calcification underwent TAVI with third-generation CoreValve Revalving System from May 2007 to April 2009. We collected electrocardiograms at baseline, during TAVI, during hospitalization and at the 1-, 3-, 6-, and 12-month follow-up visits thereafter. The clinical, anatomic, and procedural variables were tested to identify the predictors of PPM implantation. The PPM dependency at follow-up was analyzed. Six patients were excluded from the analysis because of a pre-existing PPM. Of the 64 patients, 32 (50%) had one or more atrioventricular-intraventricular CDs at baseline. TAVI induced a worsening in the CDs in 49 (77%) of the 64 patients, with 25 (39%) requiring in-hospital PPM implantation. On multivariate analysis, the independent predictors of PPM implantation were the depth of the prosthesis implantation (p = 0.039) and the pre-existing right bundle branch block (p = 0.046). A trend in the recovery of the CDs over time was recorded, although 2 patients required PPM implantation 1 month after discharge for late complete atrioventricular block. In conclusion, TAVI often induces or worsens CDs, requiring PPM in more than one third of patients, although a trend in the recovery of CDs during the midterm was recorded. The independent predictors of PPM implantation were the depth of prosthesis implantation and pre-existing right bundle branch block.

Imaging Study of Ventricular Scar in Arrhythmogenic Right Ventricular Cardiomyopathy Comparison of 3D Standard Electroanatomical Voltage Mapping and Contrast-Enhanced Cardiac Magnetic Resonance

Background— The hallmark lesion of arrhythmogenic right ventricular cardiomyopathy (ARVC) is fibrofatty scar replacement. We compared endocardial voltage mapping (EVM) and contrast-enhanced cardiac magnetic resonance (CE-CMR) for imaging scar lesions in ARVC patients. Methods and Results— We studied 23 consecutive ARVC patients (16 males; mean age, 38±12 years) who underwent RV EVM and CE-CMR and 37 control subjects. In 21 (91%) of 23 ARVC patients, RV EVM was abnormal, with a total of 45 electroanatomical scars (EAS): 17 (38%) in the inferobasal region, 12 (26.6%) in the anterolateral region, 8 (17.7%) in the RV outflow tract (RVOT), and 8 (17.7%) in the apex. RV delayed contrast enhancement (DCE) was found in 9 (39%) of 23 patients, with a total of 23 RV DCE scars: 4 (17.4%) in the inferobasal region, 9 (39.1%) in the anterolateral region, 4 (17.4%) in the RVOT, and 6 (26.1%) in the apex. There was a mismatch in 24 RV scars, with 22 EAS not confirmed by DCE and 2 DCE scars (both in the RVOT) undetected by EVM. In 9 (75%) of 12 patients with abnormal RV EVM/normal RV DCE, ≥1 DCEs were identified in the left ventricle (LV). Overall, ventricular DCE was detected in 78% of patients. No control subjects showed either EAS or DCE. Conclusions— EVM and CE-CMR allow identification of RV scar lesions in most ARVC patients. CE-CMR is less sensitive than EVM in identifying RV scar lesions. The high prevalence of LV DCE confirms the frequent biventricular involvement and indicates the diagnostic relevance of LV scar detection by CE-CMR.Background— The hallmark lesion of arrhythmogenic right ventricular cardiomyopathy (ARVC) is fibrofatty scar replacement. We compared endocardial voltage mapping (EVM) and contrast-enhanced cardiac magnetic resonance (CE-CMR) for imaging scar lesions in ARVC patients. Methods and Results— We studied 23 consecutive ARVC patients (16 males; mean age, 38±12 years) who underwent RV EVM and CE-CMR and 37 control subjects. In 21 (91%) of 23 ARVC patients, RV EVM was abnormal, with a total of 45 electroanatomical scars (EAS): 17 (38%) in the inferobasal region, 12 (26.6%) in the anterolateral region, 8 (17.7%) in the RV outflow tract (RVOT), and 8 (17.7%) in the apex. RV delayed contrast enhancement (DCE) was found in 9 (39%) of 23 patients, with a total of 23 RV DCE scars: 4 (17.4%) in the inferobasal region, 9 (39.1%) in the anterolateral region, 4 (17.4%) in the RVOT, and 6 (26.1%) in the apex. There was a mismatch in 24 RV scars, with 22 EAS not confirmed by DCE and 2 DCE scars (both in the RVOT) undetected by EVM. In 9 (75%) of 12 patients with abnormal RV EVM/normal RV DCE, ≥1 DCEs were identified in the left ventricle (LV). Overall, ventricular DCE was detected in 78% of patients. No control subjects showed either EAS or DCE. Conclusions— EVM and CE-CMR allow identification of RV scar lesions in most ARVC patients. CE-CMR is less sensitive than EVM in identifying RV scar lesions. The high prevalence of LV DCE confirms the frequent biventricular involvement and indicates the diagnostic relevance of LV scar detection by CE-CMR.

Prognostic Value of Endocardial Voltage Mapping in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia

Background—Endocardial voltage mapping (EVM) identifies low-voltage right ventricular (RV) areas, which may represent the electroanatomic scar substrate of life-threatening tachyarrhythmias. We prospectively assessed the prognostic value of EVM in a consecutive series of patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D). Methods and Results—We studied 69 consecutive ARVC/D patients (47 males; median age 35 years [28–45]) who underwent electrophysiological study and both bipolar and unipolar EVM. The extent of confluent bipolar (<1.5 mV) and unipolar (<6.0 mV) low-voltage electrograms was estimated using the CARTO-incorporated area calculation software. Fifty-three patients (77%) showed ≥1 RV electroanatomic scars with an estimated burden of bipolar versus unipolar low-voltage areas of 24.8% (7.2–31.5) and 64.8% (39.8–95.3), respectively (P=0.009). In the remaining patients with normal bipolar EVM (n=16; 23%), the use of unipolar EVM unmasked ≥1 region of low-voltage electrogram affecting 26.2% (11.6–38.2) of RV wall. During a median follow-up of 41 (28–56) months, 19 (27.5%) patients experienced arrhythmic events, such as sudden death (n=1), appropriate implantable cardioverter defibrillator interventions (n=7), or sustained ventricular tachycardia (n=11). Univariate predictors of arrhythmic outcome included previous cardiac arrest or syncope (hazard ratio=3.4; 95% confidence interval, 1.4–8.8; P=0.03) and extent of bipolar low-voltage areas (hazard ratio=1.7 per 5%; 95% confidence interval, 1.5–2; P<0.001), whereas the only independent predictor was the bipolar low-voltage electrogram burden (hazard ratio=1.6 per 5%; 95% confidence interval, 1.2–1.9; P<0.001). Patients with normal bipolar EVM had an uneventful clinical course. Conclusions—The extent of bipolar RV endocardial low-voltage area was a powerful predictor of arrhythmic outcome in ARVC/D, independently of history and RV dilatation/dysfunction. A normal bipolar EVM characterized a low-risk subgroup of ARVC/D patients.

Acute biopsy-proven lymphocytic myocarditis mimicking Takotsubo cardiomyopathy

Endomyocardial biopsy (EMB), the diagnostic gold standard for myocarditis, has not been systematically performed in the reported case series of Takotsubo cardiomyopathy, although proposed Mayo Criteria specify exclusion of myocarditis. Moreover, there is no specific recommendation for infarct‐like acute myocarditis in the recently published guidelines on the role of EMB. Here we present a thoroughly documented case fulfilling both the proposed Mayo criteria for Takotsubo cardiomyopathy and the World Health Organization criteria for active, virus‐negative, immune‐mediated myocarditis. Since myocarditis can mimic acute myocardial infarction with normal coronary arteries, EMB should be performed to rule out myocarditis in patients presenting with LV apical ballooning syndrome (or Takotsubo cardiomyopathy).

Incidence, management, and prevention of right ventricular perforation by pacemaker and implantable cardioverter defibrillator leads.

Cardiac perforation of the right ventricle (RV) is a rare but potentially life‐threatening complication of both pacemaker (PM) and implantable cardioverter defibrillator (ICD) implant. Appropriate management is still uncertain. We assessed the incidence of subacute (24 hours–1 month) or delayed (>1 month) cardiac perforation by RV lead and the results of percutaneous lead extraction.

Clinical outcomes in patients with implantable cardioverter defibrillators and Sprint Fidelis leads

Objective The performances of implantable cardioverter defibrillators and leads are important issues for healthcare providers and patients. In 2007 Sprint Fidelis leads were found to be associated with an increased failure rate and so the purpose of the study was to evaluate long-term mortality and clinical outcomes in patients implanted with Sprint Fidelis leads compared with Sprint Quattro leads. Design, setting, patients 508 patients with Sprint Fidelis leads and 468 with Sprint Quattro leads were prospectively followed in 12 Italian cardiology centres. Main outcome measures Information on hospitalisations and other clinical events were collected during scheduled and unscheduled hospital visits. Deaths were identified from medical records or via phone contacts with patients’ family members or through the National Office of Vital Statistics. Results Over a mean follow-up of 27±18 months 141 deaths occurred in the overall population. No death was observed in patients with diagnosed failing lead. Kaplan-Meier patient survival differed between the two lead groups (80±2% in Fidelis leads vs 70±4% in the Sprint Quattro leads at 4 years, p=0.002). Multivariate analyses showed that mortality was neither associated with lead type nor with diagnosed failed lead. The annual rate of lead failure was 1.8% patient-year for Fidelis leads and 0.2% for the Sprint Quattro leads. Conclusions In our multicentre research, the clinical outcomes of patients with Fidelis leads differed from those of patients with Sprint Quattro leads. Nevertheless, neither mortality nor the combined endpoint of mortality and heart failure hospitalisations was associated with the lead type. http://clinicaltrials.gov/ct2/show/NCT01007474.

Pacemaker Remote Monitoring in the Pediatric Population: Is It A Real Solution?

Clinical utility of remote monitoring of implantable cardiac devices has been previously demonstrated in several trials in the adult population. The aim of this study was to assess the clinical utility of remote monitoring in a pediatric population undergoing pacemakers implantation.