Arrhythmic CArdiac DEath in MYotonic dystrophy type 1 patients (ACADEMY 1) study: the predictive role of programmed ventricular stimulation.

AIMS: Myotonic dystrophy type 1 (DM1) predisposes to the development of life-threatening arrhythmias and sudden cardiac death. Our study aimed to evaluate the prognostic value of programmed ventricular stimulation (PVS) in DM1 patients with conduction system disease. METHODS AND RESULTS: Arrhythmic CArdiac DEath in MYotonic dystrophy type 1 patients (ACADEMY 1) is a double-arm non-randomized interventional prospective study. Myotonic dystrophy type 1 patients with permanent cardiac pacing indication were eligible for the inclusion. The study population underwent to pacemaker (PM) or implantable cardioverter-defibrillator (ICD) implantation according to the inducibility of ventricular tachyarrhythmias at PVS. Primary endpoint of the study was a composite of appropriate ICD therapy and cardiac arrhythmic death. The secondary study endpoint was all-cause mortality. Seventy-two adult-onset DM1 patients (51 ± 12 years; 39 male) were enrolled in the study. A ventricular tachyarrhythmia was induced in 25 patients (34.7%) at PVS (PVS+) who underwent dual chambers ICD implantation. The remaining 47 patients (65.3%) without inducible ventricular tachyarrhythmia (PVS-) were treated with dual-chamber PM. During an average observation period of 44.7 ± 10.2 months, nine patients (12.5%) met the primary endpoint, four in the ICD group (16%) and five (10.6%) in the PM group. Thirteen patients died (18.5%), 2 in the ICD group (8%) and 11 in PM group (23.4%). The Kaplan-Meier analysis did not show a significantly different risk of both primary and secondary endpoint event rates between the two groups. CONCLUSIONS: The inducibility of ventricular tachyarrhythmias has shown a limited value in the arrhythmic risk stratification among DM1 patients.

RenalGuard system in high-risk patients for contrast-induced acute kidney injury.

BACKGROUND: High urine flow rate (UFR) has been suggested as a target for effective prevention of contrast-induced acute kidney injury (CI-AKI). The RenalGuard therapy (saline infusion plus furosemide controlled by the RenalGuard system) facilitates the achievement of this target. METHODS: Four hundred consecutive patients with an estimated glomerular filtration rate ≤30 mL/min per 1.73 m(2) and/or a high predicted risk (according to the Mehran score ≥11 and/or the Gurm score >7%) treated by the RenalGuard therapy were analyzed. The primary end points were (1) the relationship between CI-AKI and UFR during preprocedural, intraprocedural, and postprocedural phases of the RenalGuard therapy and (2) the rate of acute pulmonary edema and impairment in electrolytes balance. RESULTS: Urine flow rate was significantly lower in the patients with CI-AKI in the preprocedural phase (208 ± 117 vs 283 ± 160 mL/h, P < .001) and in the intraprocedural phase (389 ± 198 vs 483 ± 225 mL/h, P = .009). The best threshold for CI-AKI prevention was a mean intraprocedural phase UFR ≥450 mL/h (area under curve 0.62, P = .009, sensitivity 80%, specificity 46%). Performance of percutaneous coronary intervention (hazard ratio [HR] 4.13, 95% CI 1.81-9.10, P < .001), the intraprocedural phase UFR <450 mL/h (HR 2.27, 95% CI 1.05-2.01, P = .012), and total furosemide dose >0.32 mg/kg (HR 5.03, 95% CI 2.33-10.87, P < .001) were independent predictors of CI-AKI. Pulmonary edema occurred in 4 patients (1%). Potassium replacement was required in 16 patients (4%). No patients developed severe hypomagnesemia, hyponatremia, or hypernatremia. CONCLUSIONS: RenalGuard therapy is safe and effective in reaching high UFR. Mean intraprocedural UFR ≥450 mL/h should be the target for optimal CI-AKI prevention.

The Role of the Atrial Electromechanical Delay in Predicting Atrial Fibrillation in Myotonic Dystrophy Type 1 Patients.

BACKGROUND: Paroxysmal atrial tachyarrhythmias frequently occur in myotonic dystrophy type 1 (DM1) patients. The aim of the current study was to evaluate the atrial electromechanical-delay (AEMD) in a DM1-population with normal cardiac function and its relationship to atrial fibrillation (AF) onset. METHODS AND RESULTS: Fifty DM1 patients (28 male; mean age 34.2 ± 11.4 years) and 50 healthy subjects used as controls, matched for age and gender, were studied for the occurrence of atrial fibrillation during a 4-year follow-up, through 30-day external loop recorder (ELR) monitoring performed every 6 months. Intra-AEMD and inter-AEMD of both atrium were measured through tissue-Doppler echocardiography. Compared to the healthy control group, the DM1 group showed a statistically significant increase in inter-AEMD and intraleft-AEMD. Dividing the DM1-group into 2 subgroups (patients with or without AF), the inter-AEMD and intraleft-AEMD were significantly higher in the subgroup with AF compared to the subgroup without AF. A cut off value of 39.2 milliseconds for intraleft-AEMD had a sensitivity of 90% and a specificity of 90% in identifying DM1 patients with AF risk. A cut off value of 57.7 milliseconds for inter-AEMD had a sensitivity of 84.2% and a specificity of 93.5% in identifying this category of patients. CONCLUSION: Our results showed that the echocardiographic atrial electromechanical delay indices (intraleft and inter-AEMD) were significantly increased in DM1 subjects with normal cardiac function. Intraleft and inter-AEMD represent noninvasive, inexpensive, useful and simple parameters to assess the AF risk in DM1 patients.

Which hemodynamic parameter predicts nitroglycerin-potentiated head-up tilt test response?

BACKGROUND: The aim of our study was to identify the early hemodynamic predictors of head-up tilt test (HUTT) outcome in healthy patients with recurrent unexplained syncope. METHODS AND RESULTS: The study involved 95 patients (mean age 38 ± 15; 42 male) who were referred for the evaluation of the syncopal episodes from October 2012 to May 2013. According to the nitroglycerin-potentiated diagnostic tilt test response, the study population was divided into two groups: HUTT+ Group (61 patients, mean age 37 ± 10; 27 male) and HUTT- Group (34 patients, mean age 38 ± 11; 15 male) with no tilt-induced syncope. Finger arterial blood pressure (BP) was recorded during tilt testing. Left ventricular stroke volume (SV), cardiac output (CO), and total peripheral resistance (TPR) were computed from the pressure pulsations. After nitroglycerin administration, the HUTT+ Group showed a significant increase in heart rate (92.0 ± 7.3 beats/min vs 68.9 ± 8.7 beats/min, P < 0.0001), with well-maintained systolic BP (111.6 ± 14.1 mm Hg vs 108.8 ± 11.5 mm Hg; P = 0.332) and diastolic BP (66.1 ± 8.5 mm Hg vs 63.1 ± 6.9 mm Hg; P = 0.0913); a significant decrease in SV (53.9 ± 8.0 mL vs 78.6 ± 8.2 mL; P < 0.0001) and CO (4.0 ± 0.5 L/min vs 5.8 ± 1.0 L/min; P < 0.001), and a significant increase in TPR (1.3 ± 0.3 U vs 0.9 ± 0.2 U, P < 0.0011). We tested three hemodynamic parameters (SV, CO, and TPR) as predictors of positive tilt test response with receiver-operating characteristic curve analysis. CONCLUSIONS: Our results show that, 2 minutes after nitroglycerin administration, a statistically significant decrease of SV values (<67 mL) strongly predicts (area under the curve, 0.985; P < 0.0001) the HUTT-positive response in healthy patients with recurrent unexplained syncope.

Atrial Septal Aneurysms and Supraventricular Arrhythmias: The Role of Atrial Electromechanical Delay.

BACKGROUND: Paroxysmal supraventricular arrhythmias (SVAs) frequently occur in patients with atrial septal aneurysm (ASA). The aim of the current study was to evaluate the electrocardiographic (P-wave duration and dispersion) and echocardiographic (atrial electromechanical delay, AEMD) noninvasive indicators of atrial conduction heterogeneity in healthy ASA subjects without interatrial shunt and to assess the AEMD role in predicting the SVAs onset in this population. MATERIALS AND METHODS: One hundered ASA patients (41 males, mean age of 32.5 ± 8 years) and 100 healthy subjects used as controls, matched for age and gender, were studied for the occurrence of SVAs during a 4-year follow-up, through 30-day external loop recorder (ELR) monitoring performed every 3 months. ASAs were diagnosed by transthoracic echocardiography based on the criteria of a minimal aneurismal base of ≥15 mm and an excursion of ≥10 mm. Intra-AEMD and inter-AEMD of both atria were measured through tissue Doppler echocardiography. P-wave dispersion (PD) was carefully measured using 12-lead electrocardiogram (ECG). RESULTS: Compared to the healthy control group, the ASA group showed a statistically significant increase in inter-AEMD, intra-left AEMD, maximum P-wave duration, and PD. Dividing the ASA group into 2 subgroups (patients with or without SVAs), the inter-AEMD, intra-left AEMD, P max, and PD were significantly higher in the subgroup with SVAs compared to the subgroup without SVAs. There were significant good correlations of intra-left AEMD and inter-AEMD with PD. A cutoff value of 40.1 msec for intra-left AEMD had a sensitivity of 82% and a specificity of 83% in identifying ASA patients at risk for SVA. CONCLUSION: Our results showed that the echocardiographic AEMD indices (intra-left and inter-AEMD) and the PD were significantly increased in healthy ASA subjects without interatrial shunt. PD and AEMD represent noninvasive, inexpensive, useful, and simple parameters to assess the SVAs' risk in ASA patients.

Incremental value of larger interventricular conduction time in improving cardiac resynchronization therapy outcome in patients with different QRS duration.

INTRODUCTION: The left ventricular (LV) pacing site and the magnitude of the electrical delay within the LV, as expressed by prolonged QRS duration, are major determinants of cardiac resynchronization therapy (CRT) efficacy. We investigated the incremental value of positioning the LV lead in areas of late activation in order to enhance the response to CRT in patients with different degrees of QRS complex lengthening. METHODS AND RESULTS: This analysis was performed on 301 heart failure patients who received a CRT defibrillator. On implantation, the right ventricular (RV)-to-LV interval was measured as the delay between local activations recorded through the RV and LV leads in the final position. After 1 year, 171 (57%) patients displayed reverse LV remodeling, as measured by a ≥15% reduction in the LV end-systolic volume. Both the RV-to-LV interval and its percentage value corrected for the QRS duration were significantly associated with a positive response to CRT. An RV-to-LV interval >80 milliseconds and an RV-to-LV interval/QRS >58% yielded the best prediction of reverse remodeling. Although the response to CRT decreased with shorter QRS duration in the overall population, patients with an RV-to-LV interval >80 milliseconds showed a response rate >65% in all QRS subgroups. CONCLUSION: A longer RV-to-LV interval is associated with reverse LV remodeling after CRT. On implantation attempts could be made to maximize it when selecting the LV lead position, especially in patients with shorter QRS duration, and thus less likely to respond positively to CRT.

Incidence and predictors of heart failure hospitalization and death in permanent pacemaker patients: a single-centre experience over medium-term follow-up.

AIM: The aim of this study was to assess the incidence and clinical predictors of the development of new-onset heart failure (HF) over medium-term follow-up, in patients treated with permanent pacing in daily clinical practice. METHODS AND RESULTS: We retrospectively enrolled all consecutive patients who underwent single- or dual-chamber pacemaker implantation at the study centre. Patients with a left ventricular ejection fraction (LVEF) ≤35% or a prior diagnosis of HF were excluded. Ventricular leads were routinely implanted in the right apex. Pacemakers were implanted in 490 patients with a standard pacemaker indication and LVEF >35%. Left bundle-branch block (LBBB) was reported in 30 (8%) patients, and an LVEF <50% in 64 (13%) patients. During a follow-up of 27 ± 21 months, 32 (7%) patients reached the combined endpoint of HF death or hospitalization. On multivariate analysis, LBBB (HR, 3.50; 95% CI, 1.1-11.1; P = 0.033) and LVEF <50% (HR, 5.1; 95% CI, 1.9-14.2; P = 0.002) were confirmed as independent predictors of HF death or hospitalization. Patients with LVEF <50% and/or LBBB displayed significantly higher rates of HF death or hospitalization (log-rank test, all P<0.001). CONCLUSION: The majority of patients with a standard indication for permanent pacing and normal LV function remained in a clinically stable condition after pacemaker implantation. However, ∼7% of patients developed new-onset HF over a period of follow-up of 27 months, and the presence of LBBB and LVEF <50% at the baseline predicted HF death or hospitalization.

Cardiac resynchronization therapy-defibrillator improves long-term survival compared with cardiac resynchronization therapy-pacemaker in patients with a class IA indication for cardiac resynchronization therapy: data from the Contak Italian Registry.

AIMS: In candidates for cardiac resynchronization therapy (CRT), the choice between pacemaker (CRT-P) and defibrillator (CRT-D) implantation is still debated. We compared the long-term prognosis of patients who received CRT-D or CRT-P according to class IA recommendations of the European Society of Cardiology (ESC) and who were enrolled in a multicentre prospective registry. METHODS AND RESULTS: A total of 620 heart failure patients underwent successful implantation of a CRT device and were enrolled in the Contak Italian Registry. This analysis included 266 patients who received a CRT-D and 108 who received a CRT-P according to class IA ESC indications. Their survival status was verified after a median follow-up of 55 months. During follow-up, 73 CRT-D and 44 CRT-P patients died (rate 6.6 vs. 10.4%/year; log-rank test, P = 0.020). Patients receiving CRT-P were predominantly older, female, had no history of life-threatening ventricular arrhythmias, and more frequently presented non-ischaemic aetiology of heart failure, longer QRS durations, and worse renal function. However, the only independent predictor of death from any cause was the use of CRT-P (hazard ratio, 1.97; 95% confidence interval, 1.21-3.16; P = 0.007). CONCLUSION: The implantation of CRT-D, rather than CRT-P, may be preferable in patients presenting with current class IA ESC indications for CRT. Indeed, CRT-D resulted in greater long-term survival and was independently associated with a better prognosis.

Effects of COVID-19 lockdown on arrhythmias in patients with implantable cardioverter-defibrillators in southern Italy.

Background: The effects of lockdown on non-COVID patients are varied and unexpected. The aim is to evaluate the burden of cardiac arrhythmias during a lockdown period because of COVID-19 pandemics in a population implanted with cardiac defibrillators and followed by remote monitoring. Methods: In this retrospective, multicentre cohort study, we included 574 remotely monitored implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy-defibrillator (CRT-D) recipients implanted before January 1, 2019, at seven hospitals in the Campania region, comparing the burden of arrhythmias occurred during the lockdown period because of COVID-19 epidemics (from March 9 to May 1, 2020) with the arrhythmias burden of the corresponding period in 2019 (reference period). Data collection was performed through remote monitoring. Results: During the lockdown period, we observed ventricular tachyarrhythmias (ventricular tachycardia or fibrillation) in 25 (4.8%) patients while in seasonal reference period we documented ventricular tachyarrhythmias in 12 (2.3%) patients; the comparison between the periods is statistically significant (P < .04). Atrial arrhythmias were detected in 38 (8.2%) subjects during the lockdown period and in 24 (5.2%) during the reference period (P < .004). Conclusion: In seven hospitals in the Campania region, during the pandemic lockdown period, we observed a higher burden of arrhythmic events in ICD/CRT-D patients through device remote monitoring.

Usefulness of Hemodynamic Device-Based Optimization in Heterogeneous Patients Implanted with Cardiac Resynchronization Therapy Defibrillator.

Optimization of the atrioventricular (AV) and interventricular (VV) timings of the CRT is the most supposed correctable variable to improve the rate of CRT responder. The aim of the present study has been to evaluate if there is a specific subgroup of patients who can actually benefit the most from a hemodynamic optimization of AV. This is a prospective, observational single-center study that enrolled consecutive patients with clinical indication for CRT; all patients were implanted with CRT-D devices with SonR technology, able to automatically adjust AV and VV delay on a weekly basis. Among 57 patients, 39 (69%) showed a LVESV reduction > 15%. The SonR was able to modify the pacing parameters, but an increase of left atrial diameter was associated to a reduced AV variability, suggesting that an impaired left atrial function could potentially reduce the ability of the SonR algorithm to adjust the correct timing of pacing. Graphical abstract Patients with respectively a high (A) and low (B) AV timing variability, among several parameters that could potentially influence the AV timing, only left atrial dimensions demonstrated a significant impact. In fact an increase of left atrial diameter was associated to a reduced AV variability, suggesting that an impaired left atrial function could potentially reduce the ability of the SonR algorithm to adjust the correct timing of pacing.

Long-term outcomes of CRT-PM versus CRT-D recipients.

OBJECTIVE: To compare the rates of all-cause mortality in recipients of cardiac resynchronization therapy devices without (CRT-PM) versus with defibrillator (CRT-D). METHODS: Between February 1999 and July 2004, 233 patients (mean age = 69 +/- 8 years, 180 men) underwent implantation of CRT-PM or CRT-D devices. New York Heart Association (NYHA) heart failure functional class II was present in 11%, class III in 69%, and class IV in 20% of patients; mean left ventricle ejection fraction (LVEF) was 26.5 +/- 6.5 %, 48% presented with idiopathic dilated cardiomyopathy and 49% with ischemic heart disease. Cox multiple variable regression analysis was performed in search of predictors of death. RESULTS: The clinical characteristics of the 117 CRT-PM and 116 CRT-D recipients were similar, except for LVEF (28.2 +/- 6.2% vs 25.0 +/- 6.5%, respectively; P < 0.001), and ischemic versus nonischemic etiology of heart failure (41% vs 56%, respectively P = 0.02). Over a mean follow-up of 58 +/- 15 months, no significance difference in overall mortality rate was observed between the two study groups. Male sex, NYHA functional class IV, and atrial fibrillation at implant were significant predictors of death. CONCLUSIONS: There was no difference in long-term survival rate among patients with CRT-D versus CRT-PM, although CRT-D more effectively lowered the sudden death rate. Male sex, NYHA functional class IV, and atrial fibrillation predicted the worst prognosis.

Effect of right ventricular apical pacing in survivors of myocardial infarction.

BACKGROUND: Much information is available regarding the possible negative effects of long-term right ventricular (RV) apical pacing, which may cause worsening of heart failure. However, very limited data are available regarding the effects of RV pacing in patients with a previous myocardial infarction (MI). METHODS AND RESULTS: We screened 115 consecutive post-MI patients and matched a group of 29 pacemaker (PM) recipients with a group of 49 unpaced patients, for age, left ventricular (LV) ejection fraction, and site of MI. During a median follow-up of 54 months, echocardiograms showed a decrease in LV ejection fraction in the paced group, from 51 +/- 10 to 39 +/- 11 (P < 0.01), and a minimal change in the unpaced group, from 57 +/- 8 to 56 +/- 7 (P = 0.98). Similar change was observed in systolic and diastolic diameters and volumes. CONCLUSIONS: The study showed that, in post-MI patients, RV apical pacing was associated with a worsening of LV function, suggesting that, among MI survivors, the need for a PM is a marker of worse outcome.

Efficacy of ultrasound-guided axillary/subclavian venous approaches for pacemaker and defibrillator lead implantation: a randomized study.

PURPOSE: Subclavian access is a reliable technique for lead insertion in pacemaker and defibrillator (ICD) implantation, but it is often accompanied by complications. The aim of this study was to compare the efficacy of the ultrasound-guided axillary approach to the subclavian method. METHODS: This randomized comparative study was performed on 174 patients: as a first attempt, 116 patients underwent the ultrasound-guided axillary access and 58 patients underwent the subclavian approach. A total of 364 leads were placed. Operators were trained in ultrasound-guided vein access technique. RESULTS: Axillary access was successful in 69% of patients (32/46), in the training phase and, as a first attempt, in 91.4% of patients (106/116), in the randomized phase. When axillary approach failed, we performed the following: subclavian access in 5.2% of patients (6/116), cephalic approach in 2.6% of patients (3/116), surgical method in 0.9% of patients (1/116). The subclavian technique was effective, as a first attempt, in 55 patients (94.8%). When the subclavian access failed, the ultrasound axillary approach successfully performed in all three cases. During a mean follow-up of 18 ± 6 months, the number of lead complications was similar in the subclavian group compared to the axillary group (p = 0.664). CONCLUSIONS: As first attempt, ultrasound-guided axillary method showed similarly high-success rate than subclavian approach and well performed when the first attempt in subclavian group failed. Axillary access can be considered a safe and effective alternative technique to the conventional subclavian method for device implantation.

Highly complicated lead extraction procedure in patient with previous early orthotopic heart transplantation: A first case report.

We report a first case of a highly complicated lead extraction in a young man who previously underwent orthotopic heart transplantation (OHT).Lead extraction in transplanted patients may be a feasible and safe procedure in order to maintain a low infective risk and to preserve alternative vascular access sites.

Effect of dual-chamber minimal ventricular pacing on paroxysmal atrial fibrillation incidence in myotonic dystrophy type 1 patients: A prospective, randomized, single-blind, crossover study.

BACKGROUND: Atrial fibrillation (AF) is a common finding in the myotonic dystrophy type 1 (DM1) population. Pacemakers (PMs) may facilitate the diagnosis and management of frequent subclinical asymptomatic AF episodes. OBJECTIVE: The purpose of this study was to evaluate the effect of minimal ventricular pacing on paroxysmal AF incidence in DM1 patients during a 24-month follow-up period. METHODS: We enrolled 70 DM1 patients (age 43.4 ± 13.8 years; 39 women) who underwent dual-chamber PM implantation. Patients were randomized to minimizing ventricular pacing features (ON) or not (OFF). Patients crossed over to the opposite pacing programming 12 months later. We counted the number of DM1 patients with at least 1 episode of AF, the AF total duration, and the burden recorded by PM diagnostics during the MVP ON and OFF phases. RESULTS: Twenty-five DM1 patients (41.7%) showed at least 1 AF episode. Seven patients (11.7%) demonstrated AF episodes during MVP ON phase and 25 patients (41.7%) during MVP OFF phase (P <.001). Thirty-five patients had no AF during MVP ON or OFF phase, 3 patients had AF episodes only during MVP ON phase, 21 patients had AF episodes only during MVP OFF phase, and 4 patients had AF episodes during MVP ON and OFF phases. Activation of the MVP algorithm was associated with a 44% reduction in relative risk of developing AF. Furthermore, during the MVP ON phases, the study population showed a shorter total AF duration and a lower AF burden. CONCLUSION: MVP is an efficacy strategy for reducing the risk of AF in DM1 patients who have undergone PM implantation.

Interatrial block to predict atrial fibrillation in myotonic dystrophy type 1.

Paroxysmal atrial fibrillation frequently occurs in Myotonic dystrophy type 1 (DM1) patients. Interatrial block is recognized as predictor of atrial arrhythmias, particularly atrial fibrillation (AF). The aim of this study was to evaluate the role of interatrial block in predicting the onset of atrial fibrillation during 2-year follow-up in DM1 patients who underwent pacemaker implantation for conduction system disorders. The study prospectively enrolled 70 DM1 patients (aged 36-69; 31 M) who underwent pacemaker implantation for cardiac rhythm abnormalities in accordance with the current guidelines. All DM1 patients underwent 12-lead surface ECG, 2D color Doppler echocardiogram and device interrogation at implantation, one month after and every six months thereafter for a minimum of 2-year follow-up. 12-lead surface ECGs were analyzed to diagnose interatrial block (IAB), defined as a P-wave duration ≥120 ms without (partial IAB) or with (advanced IAB) biphasic morphology (±) in the inferior leads. Device interrogation was performed to evaluate the development of new onset atrial high rate electrograms compatible with paroxysmal atrial fibrillation episodes. Interatrial block was detected in 22 patients (31.4%): 18 partial (25.7%) and 4 advanced (5.7%). During follow-up, AF episodes were detected in 18 DM1 patients (25.7%). The study population was divided into 2 groups according to the presence of AF (AF+ Group vs AF- Group). The AF+ Group was older and showed higher prevalence of IAB than the AF- Group. IAB was found to be independent predictor of AF in DM1 population (P < 0.001). A cut-off value of 121 ms for IAB had a sensitivity of 83.3% and specificity of 90.3% in identifying DM1 patients at high risk of developing AF. Interatrial block represents an independent predictor of AF occurrence in our DM1 population with conduction disturbances who had previously undergone pacemaker implantation.

Optimal left ventricular lead placement for cardiac resynchronization therapy in postmyocardial infarction patients.

AIM: To evaluate at a 12-month follow-up, the clinical and echocardiographic outcomes in postmyocardial infarction (MI) heart failure patients who underwent cardiac resynchronization therapy (CRT) device implantation. MATERIALS & METHODS: A total of 100 patients received a CRT device, and the study population was divided into three groups, according to the site of MI and left ventricular (LV) lead placed downstream of the ischemic area, as evaluated by echocardiography. RESULTS: At the end of the 12-month follow-up, we reported a general improvement of LV ejection fraction from 28 ± 7% to 35 ± 9% (p < 0.001) and a significant reverse remodeling: LV end-systolic volume changed from 147 ± 54 to 125 ± 63 (p = 0.001) with a 53% of echocardiographic responders. We also observed 67% of CRT responders in the group with optimal LV lead placement compared with 38% in the remaining population (p = 0.01). CONCLUSION: The optimal positioning of LV lead is a feasible method to improve the percentage of CRT responders in post-MI heart failure patients.

The role of the atrial electromechanical delay in predicting atrial fibrillation in beta-thalassemia major patients.

BACKGROUND: Paroxysmal atrial tachyarrhythmias frequently occur in beta-thalassemia major (ß-TM) patients. The aim of the current study was to evaluate the atrial electromechanical delay (AEMD) in a large ß-TM population with normal cardiac function and its relationship to atrial fibrillation (AF) onset. METHODS: Eighty ß-TM patients (44 men, 36 women), with a mean age of 36.2 ± 11.1 years, and 80 healthy subjects used as controls, matched for age and gender, were studied for the occurrence of AF during a 5-year follow-up, through 30-day external loop recorder (ELR) monitoring performed every 6 months. Intra-AEMD and inter-AEMD of both atria were measured through tissue Doppler echocardiography. P-wave dispersion (PD) was carefully measured using 12-lead electrocardiogram (ECG). RESULTS: Compared to the healthy control group, the ß-TM patients showed a statistically significant increase in inter-AEMD, intra-left AEMD, maximum P-wave duration, and PD. Dividing the ß-TM group into two subgroups (patients with or without AF), the inter-AEMD, intra-left AEMD, maximum P-wave duration, and PD were significantly higher in the subgroup with AF compared to the subgroup without AF. There were significant good correlations of intra-left AEMD and inter-AEMD with PD. A cut-off value of 40.1 ms for intra-left AEMD had a sensitivity of 76.2% and a specificity of 97.5% in identifying ß-TM patients with AF risk. A cut-off value of 44.8 ms for inter-AEMD had a sensitivity of 81.2% and a specificity of 98.7% in identifying this category of patients. CONCLUSIONS: Our results showed that the echocardiographic atrial electromechanical delay indices (intra-left and inter-AEMD) and the PD were significantly increased in ß-TM subjects with normal cardiac function. PD and AEMD represent non-invasive, inexpensive, useful, and simple parameters to assess the AF risk in ß-TM patients.

Voltage-directed cavo-tricuspid isthmus ablation using a novel ablation catheter mapping technology in a myotonic dystrophy type I patient.

A successful case of maximum voltage-directed cavo-tricuspid isthmus (CTI) ablation using a novel ablation catheter mapping technology in a myotonic dystrophy type I (DM1) patient is reported. The patient complained recurrent episodes of atrial flutter, revealed by the atrio-ventricular electrograms analysis during the routine pacemaker controls.