Achieving bi-directional conduction block during catheter ablation is not enough to prevent recurrence of cavo-tricuspid isthmus dependant atrial flutter: Role of subclinical conduction.

BACKGROUND: Achieving bi-directional conduction block, as assessed by differential pacing and change in activation along tricuspid annulus (TA), across the cavo-tricuspid isthmus (CTI), is considered a satisfactory end point during catheter ablation of atrial flutter (AFL). AIM: To assess role of subclinical conduction by observing polarity reversal of local bipolar signals from RS to QR pattern lateral to the line of ablation, in predicting recurrence of CTI dependant AFL after ablation in patients with bidirectional conduction block. METHOD AND RESULTS: Of 683 patients undergoing ablation of CTI dependent AFL, 73 (10.6%) patients underwent redo flutter ablation and were evaluated further. The mean age was 60.8 years and 51% were males. Evidence of bidirectional block by differential pacing and change is activation along multipolar catheter and reversal of local bipolar signals from RS to QR pattern lateral to the line of ablation, during the 1st and subsequent procedure, were studied. 60% patients had confirmed bidirectional block of which 71% had lack of voltage reversal, at the end of 1st procedure. All patients with bidirectional block with lack of reversal of bipolar signals, after the first procedure had recurrence of AFL whereas only 3/11 (27%) people with bidirectional block and with absence of subclinical conduction had recurrence of AFL. CONCLUSION: Achieving bidirectional conduction block is not sufficient to prevent recurrence of AFL after CTI ablation. Reversal of local bipolar signals, from RS to QR pattern along with achieving bidirectional conduction delay would reduce recurrence of AFL, post ablation.

Time trends in sudden cardiac death risk in heart failure patients with cardiac resynchronization therapy: a systematic review.

AIMS: While data from randomized trials suggest a declining incidence of sudden cardiac death (SCD) among heart failure patients, the extent to which such a trend is present among patients with cardiac resynchronization therapy (CRT) has not been evaluated. We therefore assessed changes in SCD incidence, and associated factors, in CRT recipients over the last 20 years. METHODS AND RESULTS: Literature search from inception to 30 April 2018 for observational and randomized studies involving CRT patients, with or without defibrillator, providing specific cause-of-death data. Sudden cardiac death was the primary endpoint. For each study, rate of SCD per 1000 patient-years of follow-up was calculated. Trend line graphs were subsequently constructed to assess change in SCD rates over time, which were further analysed by device type, patient characteristics, and medical therapy. Fifty-three studies, comprising 22 351 patients with 60 879 patient-years of follow-up and a total of 585 SCD, were included. There was a gradual decrease in SCD rates since the early 2000s in both randomized and observational studies, with rates falling more than four-fold. The rate of decline in SCD was steeper than that of all-cause mortality, and accordingly, the proportion of deaths which were due to SCD declined over the years. The magnitude of absolute decline in SCD was more prominent among CRT-pacemaker (CRT-P) patients compared to those receiving CRT-defibrillator (CRT-D), with the difference in SCD rates between CRT-P and CRT-D decreasing considerably over time. There was a progressive increase in age, use of beta-blockers, and left ventricular ejection fraction, and conversely, a decrease in QRS duration and antiarrhythmic drug use. CONCLUSION: Sudden cardiac death rates have progressively declined in the CRT heart failure population over time, with the difference between CRT-D vs. CRT-P recipients narrowing considerably.

Very long-term survival and late sudden cardiac death in cardiac resynchronization therapy patients.

AIMS: The very long-term outcome of patients who survive the first few years after receiving cardiac resynchronization therapy (CRT) has not been well described thus far. We aimed to provide long-term outcomes, especially with regard to the occurrence of sudden cardiac death (SCD), in CRT patients without (CRT-P) and with defibrillator (CRT-D). METHODS AND RESULTS: A total of 1775 patients, with ischaemic or non-ischaemic dilated cardiomyopathy, who were alive 5 years after CRT implantation, were enrolled in this multicentre European observational cohort study. Overall long-term mortality rates and specific causes of death were assessed, with a focus on late SCD. Over a mean follow-up of 30 months (interquartile range 10-42 months) beyond the first 5 years, we observed 473 deaths. The annual age-standardized mortality rates of CRT-D and CRT-P patients were 40.4 [95% confidence interval (CI) 35.3-45.5] and 97.2 (95% CI 85.5-109.9) per 1000 patient-years, respectively. The adjusted hazard ratio (HR) for all-cause mortality was 0.99 (95% CI 0.79-1.22). Twenty-nine patients in total died of late SCD (14 with CRT-P, 15 with CRT-D), corresponding to 6.1% of all causes of death in both device groups. Specific annual SCD rates were 8.5 and 5.8 per 1000 patient-years in CRT-P and CRT-D patients, respectively, with no significant difference between groups (adjusted HR 1.0, 95% CI 0.45-2.44). Death due to progressive heart failure represented the principal cause of death (42.8% in CRT-P patients and 52.6% among CRT-D recipients), whereas approximately one-third of deaths in both device groups were due to non-cardiovascular death. CONCLUSION: In this first description of very long-term outcomes among CRT recipients, progressive heart failure death still represented the most frequent cause of death in patients surviving the first 5 years after CRT implant. In contrast, SCD represents a very low proportion of late mortality irrespective of the presence of a defibrillator.

Detecting IoT Devices and How They Put Large Heterogeneous Networks at Security Risk.

The introduction of the Internet of Things (IoT), i.e., the interconnection of embedded devices over the Internet, has changed the world we live in from the way we measure, make calls, print information and even the way we get energy in our offices or homes. The convenience of IoT products, like closed circuit television (CCTV) cameras, internet protocol (IP) phones, and oscilloscopes, is overwhelming for end users. In parallel, however, security issues have emerged and it is essential for infrastructure providers to assess the associated security risks. In this paper, we propose a novel method to detect IoT devices and identify the manufacturer, device model, and the firmware version currently running on the device using the page source from the web user interface. We performed automatic scans of the large-scale network at the European Organization for Nuclear Research (CERN) to evaluate our approach. Our tools identified 233 IoT devices that fell into eleven distinct device categories and included 49 device models manufactured by 26 vendors from across the world.

Do women benefit equally as men from the primary prevention implantable cardioverter-defibrillator?

Women traditionally have been and are still underrepresented in research in many important areas of cardiology, and guideline recommendations which also encompass women are mostly based on research conducted predominantly in men. However, there is plausible cause to believe that sex may have a potential influence on the benefit derived from the implantable cardioverter-defibrillators (ICD), alone or in association with cardiac resynchronization therapy. We assessed the possible relationship between sex and outcome with ICD implantation in the setting of primary prevention, by pooling the results of MUSTT, MADIT-II, DEFINITE, COMPANION, SCD-HeFT and DANISH trials in a meta-analysis. We pooled results for female and male patients separately. The results suggest that women as a group do not seem to obtain a significant survival benefit from the primary prevention ICD, contrary to men. This in turn may also have contributed to a relative underestimation of the ICD benefit among males when looking at the results in total. It is time for the medical and research communities to actively question the presumed overarching benefit of ICDs irrespective of sex and engage in systematic scientific efforts to definitively evaluate the value of this intervention in women.

Cause-of-death analysis in patients with cardiac resynchronization therapy with or without a defibrillator: a systematic review and proportional meta-analysis.

Aims: The additional benefit of a defibrillator in cardiac resynchronization therapy (CRT) patients is a matter of debate. Cause-of-death analysis in a CRT population has been recently proposed as a useful approach to gain insight into this problem. We performed a systematic review and meta-analysis looking at cause of death in studies involving CRT subjects with (CRT-D) or without (CRT-P) a defibrillator. Methods and results: Literature search performed from inception to 31 March 2016 for relevant studies. Proportional and conventional meta-analyses were performed to obtain and compare causes of death in CRT-D vs. CRT-P patients, including sudden cardiac death (SCD), all-cause mortality, heart failure, cardiovascular, and non-cardiovascular mortalities. The systematic review included a total of 44 studies and 18 874 patients (13 248 receiving CRT-D and 5626 receiving CRT-P), representing 48 504 patient-years of follow-up. CRT-D recipients were younger, more often male, had lower NYHA class, less atrial fibrillation, more ischaemic heart disease and were more often on beta-blockers than those receiving CRT-P. There were an additional 42 deaths per 1000 patient-years in the CRT-P group compared with CRT-D (97 ± 9, 95% CI 79-115 vs. 55 ± 5, 95% CI 44-65, respectively), of which 35.7% were due to SCD (20 ± 2, 95% CI 15-24 vs. 5 ± 1, 95% CI 3-6) and the remaining 64.3% due to non-SCD. Of all deaths reported in CRT-D and CRT-P patients, 9.1% and 20.6% were due to SCD, respectively. The extent of SCD in CRT-P patients significantly increased in studies with higher percentage of males, ischaemic cardiomyopathy and NYHA class 3. Conclusion: Overall, compared with CRT-D patients, unadjusted mortality rate was almost two-fold higher in CRT-P recipients, with SCD representing one third of the excess mortality. Rate of SCD was significantly higher in certain subgroups (males, ischaemic cardiomyopathy, NYHA class 3), where a CRT-D may be of more pronounced benefit. This deserves further focused investigation.

Improved outcome and cost effectiveness in ablation of persistent atrial fibrillation under general anaesthetic.

Aims: Outcome of persistent atrial fibrillation (AF) ablation remains suboptimal. Techniques employed to reduce arrhythmia recurrence rate are more likely to be embraced if cost-effectiveness can be demonstrated. A single-centre observational study assessed whether use of general anaesthesia (GA) in persistent AF ablation improved outcome and was cost-effective. Methods and results: Two hundred and ninety two patients undergoing first ablation procedures for persistent AF under conscious sedation or GA were followed. End points were freedom from listing for repeat ablation at 18 months and freedom from recurrence of atrial arrhythmia at 1 year. Freedom from atrial arrhythmia was higher in patients who underwent ablation under GA rather than sedation (63.9% vs. 42.3%, hazard ratio (HR) 1.87, 95% confidence interval (CI): 1.23-2.86, P = 0.002). Significantly fewer GA patients were listed for repeat procedures (29.2% vs. 42.7%, HR 1.62, 95% CI: 1.01-2.60, P = 0.044). Despite GA procedures costing slightly more, a saving of £177 can be made per patient in our centre for a maximum of two procedures if all persistent AF ablations are performed under GA. Conclusions: In patients with persistent AF, it is both clinical and economically more effective to perform ablation under GA rather than sedation.

Patients upgraded to cardiac resynchronization therapy due to pacing-induced cardiomyopathy are at low risk of life-threatening ventricular arrhythmias: a long-term cause-of-death analysis.

Aims: Upgrade to cardiac resynchronization therapy (CRT) should be offered to patients who have developed pacing-induced cardiomyopathy with conventional right ventricular pacing. The extent to which these patients would also benefit from defibrillator back-up at the time of CRT upgrade is, however, unknown. Methods and results: Retrospective observational cohort study of 199 patients with pacing-induced cardiomyopathy and no history of sustained ventricular arrhythmia, including 104 upgraded to CRT-Pacemaker (CRT-P) and 95 upgraded to CRT-Defibrillator (CRT-D). The incidence of ventricular arrhythmias and the risk of sudden arrhythmic death obtained through a cause-of-death analysis based on clinical data and necropsy results were assessed and compared between the two groups. During a mean follow-up of 66 ± 24 months, 40 (38.5%) CRT-P patients died: three from primary arrhythmic death, while the remaining died of different causes (especially progressive heart failure), giving an incidence of 6.2 sudden arrhythmic deaths per 1000 patient-years. No episode of sustained VT was observed in the study group. There were no sudden arrhythmic deaths in the CRT-D group during a shorter follow-up, but the small and non-significant difference in all-cause mortality between CRT-Pacemaker (CRT-P) and CRT-D groups was mostly accounted for by an increase in non-sudden death. Women upgraded to CRT were at particularly low risk of all-cause mortality compared with men (HR 0.232, P = 0.048). Conclusion: Our findings suggest that patients who develop pacing-induced cardiomyopathy and are upgraded to CRT may not derive any significant benefit from the addition of the defibrillator in the absence of a history of ventricular arrhythmias.

Safety and long-term effectiveness of paroxysmal atrial fibrillation ablation with a contact force-sensing catheter: real-world experience from a prospective, multicentre observational cohort registry.

Aims: Real-time contact force (CF)-sensing radiofrequency ablation catheter for treatment of paroxysmal atrial fibrillation (PAF) allows optimization of electrode-tissue contact, which correlates with long-term success. This prospective, multicentre observational registry assessed the real-world clinical effectiveness of a CF-sensing catheter for ablation of drug-refractory PAF. Methods and results: Patients were followed-up at 3, 6, and 12 months after ablation. Outcome measures included isolation of targeted pulmonary veins (PVs) confirmed by entrance block (acute success), patient-reported freedom from symptomatic atrial fibrillation (AF) at 12 months (long-term effectiveness), Atrial Fibrillation Effect on Quality-of-life scores at 6 and 12 months, and incidence of predefined procedural complications. The registry enrolled 261 PAF patients (mean age 58.8 ± 11.3 years; 70.7% men; 91.7% Caucasian). Acute PV isolation was reported in 98.8% of patients [95% confidence interval (CI): 96.4-99.7%], and 12-month success for freedom from symptomatic AF was 75.7% (95% CI: 69.7-80.7%). Average CF for the evaluable cohort was 16.4 ± 3.9 g. There was a significant correlation between long-term effectiveness and stability of CF use [percentage of time CF was within investigator-selected working range; odds ratio (95% Wald CI), 1.0 (1.00-1.1); P = 0.030]. Average CF did not correlate with 12-month success. Clinically meaningful quality of life (QoL) improvements were observed at 6 and 12 months. Primary adverse events occurred in 2.7% patients. Conclusion: This observational registry showed that PAF ablation with a CF-sensing catheter had high acute success rates, favourable 12-month outcomes, and a good safety profile. Patients' QoL improved significantly. Long-term effectiveness significantly correlated with stable CF with adequate catheter-tissue contact (NCT01677052).

Ripple mapping: Initial multicenter experience of an intuitive approach to overcoming the limitations of 3D activation mapping.

BACKGROUND: Ripple mapping (RM) displays electrograms as moving bars over a three-dimensional surface displaying bipolar voltage, and has shown in a single-center series to be effective for atrial tachycardia (AT) mapping without annotation of local activation time or window-of-interest assignment. We tested the reproducibility of these findings in operators naïve to RM, using it for the first time in postablation AT. METHODS: Maps were collected with multielectrode catheters and CARTO ConfiDENSE. A diagnosis of the tachycardia mechanism was made using RM and an assessment of operator confidence was made according to a three-grade scale (1 highest-3 lowest). RESULTS: The first 20 patients (64 ± 9 years, median two previous ablations) undergoing RM-guided AT ablation across five sites were studied. High-density maps (2,935 ± 1,328 points) in AT (CL = 296 ± 95 milliseconds) were collected. Macroreentrant ATs bordered by scar or anatomical obstacles were identified in n = 12 (60%), small reentrant ATs around scar in n = 3 (15%), and focal ATs from scar in n = 5 (25%). Diagnostic confidence with RM was grade 1 in n = 13 (65%), where operators felt confident to proceed to ablation without entrainment. Ablation offered the correct diagnosis n = 18 (90%). Retrospective review of the accompanying LAT maps demonstrated potential sources for error related to the window of interest selection, interpolation, and differentiating regions of scar during tachycardia on the voltage map. CONCLUSION: RM was easy to adopt by operators using it for the first time, and identified the correct target for ablation with high diagnostic confidence in most cases of complex AT.

Prophylactic implantable cardioverter defibrillator in heart failure: the growing evidence for all or Primum non nocere for some?

Heart failure (HF) is a common health problem and has reached epidemic in many western countries. Despite the current era of HF treatment, the risk of sudden cardiac death (SCD) in HF remains significant. Implantable cardioverter defibrillator (ICD) support has been shown to reduce the risk of SCD in patients with HF and impaired left ventricular function. Prophylactic ICD implantation in HF patients seems a logical step to reduce mortality through a reduction in SCD. However, ICD implantation is an invasive procedure, and both short- and long-term complications can occur. This needs to be carefully considered when evaluating the risk-benefit ratio of ICD implantation for individual patients. As the severity of HF increases, the proportion of SCD compared with HF-related deaths decreases. The challenge lies in identifying patients with HF who are at significant risk of SCD and who would most benefit from an ICD in addition to other anti-arrhythmic strategies. This review offers insight on the applicability and practicability of ICD for this growing population.

Dual-site right ventricular pacing in patients undergoing cardiac resynchronization therapy: Results of a multicenter propensity-matched analysis.

BACKGROUND: Dual-site right ventricular pacing (Dual RV) has been proposed as an alternative for patients with heart failure undergoing cardiac resynchronization therapy (CRT) with a failure to deliver a coronary sinus (CS) lead. Only short-term hemodynamic and echocardiographic results of Dual RV are available. We aimed to assess the long-term results of Dual RV and its impact on survival. METHODS: Multicenter retrospective assessment of all CRT implants during a 12-year period. Patients with failed CS lead implantation, treated with Dual RV, were followed and assessed for the primary endpoint of all-cause mortality and/or heart transplant. A control group was obtained from contemporary patients using propensity matching for all available baseline variables. RESULTS: Ninety-three patients were implanted with Dual RV devices and compared with 93 matched controls. During a median of 1,273 days (interquartile range 557-2,218), intention-to-treat analysis showed that all-cause mortality and/or heart transplant was higher in the Dual RV group (adjusted hazard ratio [HR] = 1.66, 95% confidence interval [CI] 1.12-2.47, P = 0.012). As-treated analysis yielded similar results (HR = 1.97, 95% CI 1.31-2.96, P = 0.001). Cardiac device-related infections occurred seven times more frequently in the Dual RV site group (HR = 7.60, 95% CI 1.51-38.33, P = 0.014). Among Dual RV nonresponders, four had their apical leads switched off, five required an epicardial LV lead insertion, a transseptal LV lead was implanted in two, and in nine patients, after reviewing the CS venogram, a new CS lead insertion was successfully attempted. CONCLUSION: Dual RV pacing is associated with worse clinical outcomes and higher complication rates than conventional CRT.

Applicability of a risk score for prediction of the long-term benefit of the implantable cardioverter defibrillator in patients receiving cardiac resynchronization therapy.

AIMS: The Goldenberg risk score, comprising five clinical risk factors (New York Heart Association class >2, atrial fibrillation, QRS duration >120 ms, age >70 years, and urea >26 mg/dL), may help identify patients in whom the survival benefit of the defibrillator may be limited. We aim at assessing whether this score can accurately predict the long-term all-cause mortality risk of patients receiving cardiac resynchronization therapy (CRT) and identify those who are more likely to benefit from the defibrillator. METHODS AND RESULTS: In this retrospective observational cohort study, 638 patients with ischaemic or non-ischaemic dilated cardiomyopathy who had CRT-defibrillator (CRT-D) (n = 224) vs. CRT-pacemaker (CRT-P) (n = 414) implantation were prospectively followed up for survival outcomes. The long-term outcome of patients with CRT-D vs. CRT-P was compared within risk score categories and in patients with severe renal dysfunction. Mean follow-up in surviving and deceased patients was 62.7 and 32.5 months, respectively. This score showed higher discriminative performance in all-cause mortality prediction in CRT-D vs. CRT-P patients (area under the curve 0.718 ± 0.041 vs. 0.650 ± 0.032, respectively, P = 0.001). In those with scores 0-2, a CRT-D device decreased mortality rates in the first 4 years of follow-up compared with CRT-P (11.3 vs. 24.7%, P = 0.041), but this effect attenuated with longer follow-up duration (21.2 vs. 32.7%, P = 0.078). In this group, the benefit of CRT-D during the follow-up was seen after adjusting for traditional mortality predictors (hazard ratio 0.339, P = 0.001). No significant differences in mortality rates were seen in patients with score ≥3 (57.9% with CRT-D vs. 56.9%, P = 0.8) and those with severe renal dysfunction (92.9% in CRT-D vs. 76.2%, P = 0.17). Similar results were seen following propensity score matching. CONCLUSION: A simple risk stratification score comprising five clinical risk factors may help identify CRT patients who are more likely to benefit from the presence of the defibrillator.

Implantable cardioverter-defibrillators in the elderly: rationale and specific age-related considerations.

Despite the increasingly high rate of implantation of cardioverter-defibrillators (ICD) in elderly patients, data supporting their clinical and cost-effectiveness in this age stratum are ambiguous and contradictory. We comprehensively reviewed the state-of-the-art data regarding the applicability, safety, clinical- and cost-effectiveness of the ICD in elderly patients, and analysed which patients in this age stratum are more likely to get a survival benefit from this therapy. Although peri-procedural risk may be slightly higher in the elderly, this procedure is still relatively safe in this age group. In terms of correcting potentially life-threatening arrhythmias, the effectiveness of ICD therapy is comparable in older and younger individuals. However, the assumption of persistent ICD benefit in the elderly population is questionable, as any advantage of the device on arrhythmic death may be largely attenuated by a higher total non-arrhythmic mortality. While septuagenarians and octogenarians have higher annual all-cause mortality rates, ICD therapy may remain effective in highly selected patients at high risk of arrhythmic death and with minimum comorbidities despite advanced age. ICD intervention among the elderly, as a group, may not be cost-effective, but the procedure may reach cost-effectiveness in those expected to live >5-7 years after implantation. Biological age rather than chronological age per se should be the decisive factor in making a decision on ICD selection for survival benefit.

Cardioverter-defibrillator implantation and generator replacement in the octogenarian.

AIMS: Increase in life expectancy has led to increased rate of implantable cardioverter-defibrillator (ICD) implantation in patients in their 80s, but there are no current formal recommendations to guide physicians when elderly patients with ICDs require elective unit replacement (EUR). This study aims at assessing survival and rates of ICD therapies in patients who have had ICD implantation or EUR above the age of 80, focusing on the latter. METHODS AND RESULTS: Retrospective analysis of a prospectively kept database of all ICD-related procedures carried out in a single tertiary centre. Patients 80 years of age or older submitted to ICD implantation (n = 42) or EUR (n = 34) between November 1991 and May 2012 were included. Using collected baseline and outcome data from this cohort, we assessed survival of these patients and the rates of ICD therapies. Median additional years of life after ICD implantation and ICD EUR in patients who died before data retrieval was 2.5 and 1.2, respectively, and while 65% of deceased patients after ICD implantation died in the first 3 years after the procedure, 50% of deceased post-ICD EUR patients died within the first year. Mortality rates at 1 and 2 years post-EUR were 23.1 and 38.1%, respectively. Furthermore, ventricular tachycardia occurred in a small minority of patients after EUR (16.7%) and no ventricular fibrillation-triggered ICD therapies were reported in both groups. CONCLUSION: In octogenarians who are due for an ICD EUR, careful thought should be given to the current clinical status, comorbidities, and general frailty prior to considering them for the procedure. A survival benefit from ICD EUR in this age stratum is not likely.

Ventricular arrhythmia storm in the era of implantable cardioverter-defibrillator.

In the era of widespread use of implantable cardioverter-defibrillators (ICDs) for both primary and secondary prevention of sudden cardiac death, a significant proportion of patients experience episodes of multiple ventricular tachycardia/fibrillation over a short period of time requiring device interventions. The episodes are termed ventricular arrhythmia (VA) or electrical storms. VA storm is a tragic experience for patients, with many psychological consequences. Current management for VA storms remains complex. Acutely, administration of ß-blockers, amiodarone and sedation or intubation is generally required to suppress sympathetic tone. Interventional treatment includes catheter ablation and sympathetic blockade by left cardiac sympathetic denervation. Strategies to modify autonomic tone to suppress VAs are the rationale of various novel interventions that have been published in recent studies. All patients with VA storm should be considered for transfer to an experienced high-volume tertiary centre for evaluation and treatment to prevent further recurrence of VA storm.

Post-acute management of the acquired long QT syndrome.

The mechanisms underlying drug induced QT prolongation and the immediate treatment of torsade de pointes have been extensively studied but the post-acute management of the Acquired Long QT Syndrome (ALQTS) remains to be addressed. We aimed to review the state of the art data regarding risk stratification, arrhythmic prevention and treatment of patients with ALQTS. A comprehensive review of the scientific data collectable from MEDLINE, EMBASE and COCHRANE (from inception to April 2013) was performed, and descriptive and qualitative information was extracted from the most relevant manuscripts. QT prolonging drugs are widely used in hospital clinical practice, and several studies have shown a high prevalence of QT interval prolongation in patients admitted to hospital and a high rate of prescription of QT interval prolonging drugs to patients presenting with QT interval prolongation. Therefore, the acute and post-acute management of ALQTS is of the utmost importance. Avoidance of offending triggers, electrocardiographic screening, pacing at a relatively fast lower rate limit and using pause prevention programming (preferably with concomitant ß blocker treatment), implantable defibrillators in the highest risk patients, genetic testing and counselling in selected cases, and family screening are among the potentially applicable strategies. The latter is justifiable by the fact that some studies unveiled a surprisingly similar positive mutation rate in drug induced LQTS compared with congenital LQTS, supporting the hypothesis that the former can be regarded as a latent form of the latter. Drug challenge with D,L-sotalol in suspected LQTS and treatment with a carvedilol analogue, verapamil or an Ikr activating drug are still in need of further investigation. The post-acute management of patients with ALQTS has received scarce attention in the past, probably due to the fact that it is considered a reversible phenomenon in most cases. Considering the relatively high risk of arrhythmic recurrence in the highest risk ALQTS patients, effective preventive and treatment strategies are warranted, and further research is needed.

UltraSOUND-based characterization of ventricular tachycardia SCAR and arrhythmogenic substrate: The SOUNDSCAR study.

BACKGROUND: Intracardiac echocardiography (ICE) represents a valuable image integration technique, with the unique advantage of dynamic real-time scar characterization. OBJECTIVES: The goals of this study were to assess the correlation between ICE-defined and electroanatomic mapping (EAM)-defined scar in patients with ischemic cardiomyopathy and to define the outcomes of ICE-guided ventricular tachycardia (VT) ablation. METHODS: Thirty-eight patients with ischemic cardiomyopathy (SOUNDSCAR cohort) underwent full left ventricular (LV) ICE imaging and EAM. ICE-defined scar parameters (end-diastolic and end-systolic wall diameter [EDWD and ESWD], end-systolic wall thickening [percentage difference between EDWD and ESWD with respect to EDWD], slope [end-diastole to end-systole wall thickening], and American Heart Association wall motion scoring) were correlated with EAM-defined scar (voltage <1.5 mV). In a separate cohort (n = 21), outcomes of an ICE-guided VT ablation approach (EAM focused to ICE-defined scar regions) were compared with those of conventional ablation (full left ventricular mapping with EAM only; n = 21). RESULTS: In the 38 SOUNDSCAR patients (mean age 67 ± 11 years; 35 male [92%]; left ventricular ejection fraction 31% ± 10%; 2474 ICE segments; 524 ICE sectors), all ICE-defined parameters strongly predicted EAM-defined scar (area under the curve: American Heart Association score 0.873; ESWD 0.880; EDWD 0.827; slope 0.855; percentage difference between EDWD and ESWD with respect to EDWD, 0.851). All ICE-defined parameters had large effect sizes for predicting EAM-defined scar (logistic regression, P < .001). A detailed topographical comparison of ICE-defined (slope) and EAM-defined scar was possible in 25 patients and demonstrated 88% ± 10% overlap. Compared with conventional VT ablation, ICE-guided ablation was associated with shorter procedure times and comparable VT-free survival (ICE-guided vs conventional: procedure time 240 ± 20 minutes vs 298 ± 39 minutes; P < .001; VT recurrence 3 [14%] vs 7 [31%]; P = .19). CONCLUSION: ICE-defined scar demonstrates a strong correlation with EAM-defined scar. ICE-guided VT ablation is associated with enhanced procedural efficiency.

Importance of superior vena cava isolation in successful ablation of persistent atrial fibrillation in patient with partial anomalous pulmonary vein.

Ectopic foci arising from pulmonary veins (PVs) are the predominant sources for the initiation and maintenance of atrial fibrillation (AF) in a vast majority of cases. However, ectopic foci also exist in the non-PV areas like superior vena cava (SVC) in 10-20% of the cases. We report the significance of SVC isolation in a patient with persistent AF and anomalous pulmonary venous connection of the right superior pulmonary vein into the SVC.