Cardiac blood vessels and irreversible electroporation: findings from pulsed field ablation

The clinical use of irreversible electroporation in invasive cardiac laboratories, termed pulsed field ablation (PFA), is gaining early enthusiasm among electrophysiologists for the management of both atrial and ventricular arrhythmogenic substrates. Though electroporation is regularly employed in other branches of science and medicine, concerns regarding the acute and permanent vascular effects of PFA remain. This comprehensive review aims to summarize the preclinical and adult clinical data published to date on PFA's effects on pulmonary veins and coronary arteries. These data will be contrasted with the incidences of iatrogenic pulmonary vein stenosis and coronary artery injury secondary to thermal cardiac ablation modalities, namely radiofrequency energy, laser energy, and liquid nitrogen-based cryoablation.

Characterization of septal coronary venous tributaries with computed tomography: What's in a name?

An important subset of focal ventricular arrhythmias (VA) originate from intramural sites. These areas present substantial challenges to contemporary mapping and ablation strategies, since traditional endocardial and epicardial sites may be relatively remote from the site of origin. This article is protected by copyright. All rights reserved.

Non-Concordance between Patient and Clinician Estimates of Prognosis in Advanced Heart Failure

IMPORTANCE

Despite efforts to enhance serious illness communication, patients with advanced heart failure (HF) lack prognostic understanding.

OBJECTIVES

To determine rate of concordance between HF patients' estimation of their prognosis and their physician's estimate of the patient's prognosis, and to compare patient characteristics associated with concordance.

DESIGN

Cross-sectional analysis of a cluster randomized controlled trial with 24-month follow-up and analysis completed on 09/01/2020. Patients were enrolled in inpatient and outpatient settings between September 2011 to February 2016 and data collection continued until the last quarter of 2017.

SETTING

Six teaching hospitals in the U.S.

PARTICIPANTS

Patients with advanced HF and implantable cardioverter defibrillators (ICDs) at high risk of death. Of 537 patients in the parent study, 407 had complete data for this analysis.

INTERVENTION

A multi-component communication intervention on conversations between HF clinicians and their patients regarding ICD deactivation and advance care planning.

MAIN OUTCOME(S) AND MEASURE(S)

Patient self-report of prognosis and physician response to the "surprise question" of 12-month prognosis. Patient-physician prognostic concordance (PPPC) measured in percentage agreement and kappa. Bivariate analyses of characteristics of patients with and without PPPC.

RESULTS

Among 407 patients (mean age 62.1 years, 29.5% female, 42.4% non-white), 300 (73.7%) dyads had non-PPPC; of which 252 (84.0%) reported a prognosis >1 year when their physician estimated <1 year. Only 107 (26.3%) had PPPC with prognosis of ≤ 1 year (n=20 patients) or > 1 year (n=87 patients); (Κ = -0.20, p = 1.0). Of those with physician estimated prognosis of < 1 year, non-PPPC was more likely among patients with lower symptom burden- number and severity (both p ≤.001), without completed advance directive (p=.001). Among those with physician prognosis estimate > 1 year, no patient characteristic was associated with PPPC or non-PPPC.

CONCLUSIONS AND RELEVANCE

Non-PPPC between HF patients and their physicians is high. HF patients are more optimistic than clinicians in estimating life expectancy. These data demonstrate there are opportunities to improve the quality of prognosis disclosure between patients with advanced HF and their physicians. Interventions to improve PPPC might include serious illness communication training.

Outcomes in patients implanted with a Watchman device in relation to choice of anticoagulation and indication for implant

BACKGROUND

Patients with atrial fibrillation are increasingly prescribed a direct oral anticoagulant (DOAC) over warfarin and seek to avoid anticoagulation even without a history of major bleeding. This study explores the outcomes of patients implanted with a Watchman device in relation to anticoagulation choice (warfarin versus DOAC) in the post-procedure period and a history of bleeding.

METHODS

Patients implanted with a Watchman device at a single center were retrospectively analyzed. Characteristics including anticoagulation in the first 45 days and history of major bleed were assessed and efficacy (thromboembolism) and safety (bleeding) outcomes compared by Kaplan-Meier analysis.

RESULTS

Two hundred nine patients were implanted (57% male, age 74.6 ± 7.8 years) and followed for 23.5 ± 7.1 months. In the first half of patients, 98% were prescribed warfarin, which dropped to 51% in the second half (p < 0.0001). A history of major bleed was present in 80.8% of the first half of patients and decreased to 60% in the second half (p = 0.001). There were 16 safety and 4 efficacy events. There was no difference in safety outcomes according to history of major bleeding or anticoagulant choice in the first 45 days. There was no difference in efficacy outcomes over the duration of follow-up according to anticoagulation choice in the first 45 days.

CONCLUSIONS

Patients implanted with a Watchman device were increasingly over time prescribed a DOAC and implanted without a history of major bleeding. Bleeding and thromboembolic events were infrequent and related neither to choice of anticoagulant nor to prior major bleeding.

Progression of infarct-mediated arrhythmogenesis in a rodent model of heart failure

Heart failure (HF) post-myocardial infarction (MI) presents with increased vulnerability to monomorphic ventricular tachycardia (mmVT). To appropriately evaluate new therapies for infarct-mediated reentrant arrhythmia in the preclinical setting, chronologic characterization of the preclinical animal model pathophysiology is critical. This study aimed to evaluate the rigor and reproducibility of mmVT incidence in a rodent model of HF. We hypothesize a progressive increase in the incidence of mmVT as the duration of HF increases. Adult male Sprague-Dawley rats underwent permanent left coronary artery ligation or SHAM surgery and were maintained for either 6 or 10 wk. At end point, SHAM and HF rats underwent echocardiographic and invasive hemodynamic evaluation. Finally, rats underwent electrophysiologic (EP) assessment to assess susceptibility to mmVT and define ventricular effective refractory period (ERP). In 6-wk HF rats (n = 20), left ventricular (LV) ejection fraction (EF) decreased (P < 0.05) and LV end-diastolic pressure (EDP) increased (P < 0.05) compared with SHAM (n = 10). Ten-week HF (n = 12) revealed maintenance of LVEF and LVEDP (P > 0.05), (P > 0.05). Electrophysiology studies revealed an increase in incidence of mmVT between SHAM and 6-wk HF (P = 0.0016) and ERP prolongation (P = 0.0186). The incidence of mmVT and ventricular ERP did not differ between 6- and 10-wk HF (P = 1.0000), (P = 0.9831). Findings from this rodent model of HF suggest that once the ischemia-mediated infarct stabilizes, proarrhythmic deterioration ceases. Within the 6- and 10-wk period post-MI, no echocardiographic, invasive hemodynamic, or electrophysiologic changes were observed, suggesting stable HF. This is the necessary context for the evaluation of experimental therapies in rodent HF.NEW & NOTEWORTHY Rodent model of ischemic cardiomyopathy exhibits a plateau of inducible monomorphic ventricular tachycardia incidence between 6 and 10 wk postinfarction.

Prognostic Awareness and Goals of Care Discussions Among Patients With Advanced Heart Failure

BACKGROUND

Prognostic awareness (PA)-the understanding of limited life expectancy-is critical for effective goals of care discussions (GOCD) in which patients discuss their goals and values in the context of their illness. Yet little is known about PA and GOCD in patients with advanced heart failure (HF). This study aims to determine the prevalence of PA among patients with advanced HF and patient characteristics associated with PA and GOCD.

METHODS

We assessed the prevalence of self-reported PA and GOCD using data from a multisite communication intervention trial among patients with advanced HF with an implantable cardiac defibrillator at high risk of death.

RESULTS

Of 377 patients (mean age 62 years, 30% female, 42% nonwhite), 78% had PA. Increasing age was a negative predictor of PA (odds ratio, 0.95 [95% CI, 0.92-0.97]; P<0.01). No other patient characteristics were associated with PA. Of those with PA, 26% had a GOCD. Higher comorbidities and prior advance directives were associated with GOCD but were of only borderline statistical significance in a fully adjusted model. Symptom severity (odds ratio, 1.77 [95% CI, 1.19-2.64]; P=0.005) remained a robust and statistically significant positive predictor of having a GOCD in the fully adjusted model.

CONCLUSIONS

In a sample of patients with advanced HF, the frequency of PA was high, but fewer patients with PA discussed their end-of-life care preferences with their physician. Improved efforts are needed to ensure all patients with advanced HF have an opportunity to have GOCD with their doctors. Clinicians may need to target older patients with HF and continue to focus on those with signs of worsening illness (higher symptoms). Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01459744.

Evaluation of a Novel Educational Intervention to Improve Conversations About Implantable Cardioverter-Defibrillators Management in Patients with Advanced Heart Failure

Background: Implantable cardioverter-defibrillators (ICDs) reduce the incidence of sudden cardiac death for high-risk patients with heart failure (HF), but shocks from these devices can also cause pain and anxiety at the end of life. Although professional society recommendations encourage proactive discussions about ICD deactivation, clinicians lack training in conducting these conversations, and they occur infrequently. Methods: As part of a six-center randomized controlled trial, we evaluated the educational component of a multicomponent intervention shown to increase conversations about ICD deactivation by clinicians who care for a subset of patients with advanced HF. This consisted of a 90-minute training workshop designed to improve the quality and frequency of conversations about ICD management. To characterize its utility as an isolated intervention, we compared HF clinicians' pre- and postworkshop scores (on a 5-point Likert scale) assessing self-reported confidence and skills in specific practices of advance care planning, ICD deactivation discussions, and empathic communication. Results: Forty intervention-group HF clinicians completed both pre- and postworkshop surveys. Preworkshop scores showed high baseline levels of confidence (4.36, standard deviation [SD] = 0.70) and skill (4.08, SD = 0.72), whereas comparisons of pre- and postworkshop scores showed nonsignificant decreases in confidence (-1.16, p = 0.252) and skill (-0.20, p = 0.843) after the training session. Conclusions: Our findings showed no significant changes in self-assessment ratings immediately after the educational intervention. However, our data did demonstrate that HF clinicians had high baseline self-perceptions of their skills in advance care planning conversations and appear to be well-primed for further professional development to improve communication in the setting of advanced HF.

Improving Communication in Heart Failure Patient Care

BACKGROUND

Although implantable cardioverter-defibrillators (ICDs) reduce sudden death, these patients die of heart failure (HF) or other diseases. To prevent shocks at the end of life, clinicians should discuss deactivating the defibrillation function.

OBJECTIVES

The purpose of this study was to determine if a clinician-centered teaching intervention and automatic reminders increased ICD deactivation discussions and increased device deactivation.

METHODS

In this 6-center, single-blinded, cluster-randomized, controlled trial, primary outcomes were proportion of patients: 1) having ICD deactivation discussions; and 2) having the shocking function deactivated. Secondary outcomes included goals of care conversations and advance directive completion.

RESULTS

A total of 525 subjects were included with advanced HF who had an ICD: 301 intervention and 224 control. At baseline, 52% (n = 272) were not candidates for advanced therapies (i.e., cardiac transplant or mechanical circulatory support). There were no differences in discussions (41 [14%] vs. 26 [12%]) or deactivation (33 [11%] vs. 26 [12%]). In pre-specified subgroup analyses of patients who were not candidates for advanced therapies, the intervention increased deactivation discussions (32 [25%] vs. 16 [11%]; odds ratio: 2.90; p = 0.003). Overall, 99 patients died; there were no differences in conversations or deactivations among decedents.

SECONDARY OUTCOMES

Among all participants, there was an increase in goals of care conversations (47% intervention vs. 38% control; odds ratio: 1.53; p = 0.04). There were no differences in completion of advance directives.

CONCLUSIONS

The intervention increased conversations about ICD deactivation and goals of care. HF clinicians were able to apply new communication techniques based on patients' severity of illness. (An Intervention to Improve Implantable Cardioverter-Defibrillator Deactivation Conversations [WISDOM]; NCT01459744).

aVR ST Segment Elevation: Acute STEMI or Not? Incidence of an Acute Coronary Occlusion

BACKGROUND

Identification of ST elevation myocardial infarction (STEMI) is critical because early reperfusion can save myocardium and increase survival. ST elevation (STE) in lead augmented vector right (aVR), coexistent with multilead ST depression, was endorsed as a sign of acute occlusion of the left main or proximal left anterior descending coronary artery in the 2013 STEMI guidelines. We investigated the incidence of an acutely occluded coronary in patients presenting with STE-aVR with multilead ST depression.

METHODS

STEMI activations between January 2014 and April 2018 at the University of Arizona Medical Center were identified. All electrocardiograms (ECGs) and coronary angiograms were blindly analyzed by experienced cardiologists. Among 847 STEMI activations, 99 patients (12%) were identified with STE-aVR with multilead ST depression.

RESULTS

Emergent angiography was performed in 80% (79/99) of patients. Thirty-six patients (36%) presented with cardiac arrest, and 78% (28/36) underwent emergent angiography. Coronary occlusion, thought to be culprit, was identified in only 8 patients (10%), and none of those lesions were left main or left anterior descending occlusions. A total of 47 patients (59%) were found to have severe coronary disease, but most had intact distal flow. Thirty-two patients (40%) had mild to moderate or no significant disease. However, STE-aVR with multilead ST depression was associated with 31% in-hospital mortality compared with only 6.2% in a subgroup of 190 patients with STEMI without STE-aVR (p<0.00001).

CONCLUSIONS

STE-aVR with multilead ST depression was associated with acutely thrombotic coronary occlusion in only 10% of patients. Routine STEMI activation in STE-aVR for emergent revascularization is not warranted, although urgent, rather than emergent, catheterization appears to be important.

Electrophysiologic Considerations After Sudden Cardiac Arrest

Background:

Sudden Cardiac Death (SCD) remains a major public health concern, accounting for more than 50% of cardiac deaths. The majority of these deaths are related to ischemic heart disease, however increasingly recognized are non-ischemic causes such as cardiac channelopathies. Bradyarrhythmias and pulseless electrical activity comprise a larger proportion of out-of-hospital arrests than previously realized, particularly in patients with more advanced heart failure or noncardiac triggers such as pulmonary embolism. Patients surviving Sudden Cardiac Arrest (SCA) have a substantial risk of recurrence, particularly within 18 months post event. The timing of tachyarrhythmias complicating acute infarction has important implications regarding the likelihood of recurrence, with those occurring within 48 hours having a more favorable long-term outcome. In the absence of a clear reversible cause, implantable cardioverter defibrillators remain the mainstay in the secondary prevention of SCD. Post defibrillation electromechanical dissociation is common in patients with cardiomyopathy and can lead to SCD despite successful defibrillation of the primary tachyarrhythmia. Antiarrhythmic agents are highly effective in preventing recurrent arrhythmias in specific diseases such as the congenital long QT syndrome.

Conclusion:

Catheter ablation is used most commonly to prevent recurrent ICD therapies in patients with structural heart disease-related ventricular arrhythmias, however recent publications have shown substantial benefit in other entities such as idiopathic ventricular fibrillation.

Importance of the Interventricular Septum as Part of the Ventricular Tachycardia Substrate in Nonischemic Cardiomyopathy

OBJECTIVES

This study sought to characterize septal substrate in patients with nonischemic left ventricular cardiomyopathy (NILVCM) undergoing ventricular tachycardia (VT) ablation.

BACKGROUND

The interventricular septum is an important site of VT substrate in NILVCM.

METHODS

The authors studied 95 patients with NILVCM and VT. Electroanatomic mapping using standard bipolar (<1.5 mV) and unipolar (<8.3 mV) low-voltage criteria identified septal scar location and size. Analysis of unipolar voltage was performed and scars quantified using graded unipolar cutoffs from 4 to 8.3 mV were correlated with delayed gadolinium-enhanced cardiac magnetic resonance (DE-CMR), performed in 57 patients.

RESULTS

Detailed LV endocardial mapping (mean 262 ± 138 points) showed septal bipolar and unipolar voltage abnormalities (VAs) in 44 (46%) and 79 (83%) patients, most commonly with basal anteroseptal involvement. Of the 59 patients in whom the septum was targeted, bipolar and unipolar septal VAs were seen in 36 (61%) and 54 (92%). Of the 35 with CMR-defined septal scar, bipolar and unipolar septal VAs were seen in 18 (51%) and 31 (89%). In 12 patients without CMR septal scar, 6 (50%) had isolated unipolar septal VAs on electroanatomic mapping, a subset of whom the septum was targeted for ablation (44%). In the graded unipolar analysis, the optimal cutoff associated with magnetic resonance imaging septal scar was 4.8 mV (sensitivity 75%, specificity 70%; area under the curve: 0.75; 95% confidence interval: 0.60 to 0.90).

CONCLUSIONS

Septal substrate by unipolar or bipolar voltage mapping in patients with NILVCM and VT is common. A unipolar voltage cutoff of 4.8 mV provides the best correlation with DE-CMR. A subset of patients with septal VT had normal DE-CMR or endocardial bipolar voltage with abnormal unipolar voltage.

Contemporary Tools and Techniques for Substrate Ablation of Ventricular Tachycardia in Structural Heart Disease

As we have witnessed in other arenas of catheter-based therapeutics, ventricular tachycardia (VT) ablation has become increasingly anatomical in its execution. Multi-modality imaging provides anatomical detail in substrate characterization, which is often complex in nonischemic cardiomyopathy patients. Patients with intramural, intraseptal, and epicardial substrates provide challenges in delivering effective ablation to the critical arrhythmia substrate due to the depth of origin or the presence of adjacent critical structures. Novel ablation techniques such as simultaneous unipolar or bipolar ablation can be useful to achieve greater lesion depth, though at the expense of increasing collateral damage. Disruptive technologies like stereotactic radioablation may provide a tailored approach to these complex patients while minimizing procedural risk. Substrate ablation is a cornerstone of the contemporary VT ablation procedure, and recent data suggest that it is as effective and more efficient that conventional activation guided ablation. A number of specific targets and techniques for substrate ablation have been described, and all have shown a fairly high success in achieving their acute procedural endpoint. Substrate ablation also provides a novel and reproducible procedural endpoint, which may add predictive value for VT recurrence beyond conventional programmed stimulation. Extrapolation of outcome data to nonischemic phenotypes requires caution given both the variability in substrate nonischemic distribution and the underrepresentation of these patients in previous trials.

Long-Term Outcomes of Catheter Ablation of Ventricular Tachycardia in Patients With Cardiac Sarcoidosis

BACKGROUND

Catheter ablation (CA) of ventricular tachycardia (VT) in patients with cardiac sarcoidosis can be challenging because of the complex underlying substrate. We sought to determine the long-term outcome of CA of VT in patients with cardiac sarcoidosis.

METHODS AND RESULTS

We enrolled 31 patients (age, 55±10 years) with diagnosis of cardiac sarcoidosis based on Heart Rhythm Society criteria and VT who underwent CA. In 23 (74%) patients, preprocedure cardiac magnetic resonance imaging and positron emission tomographic (PET) evaluation were performed. Preprocedure magnetic resonance imaging was positive for late gadolinium enhancement in 21 of 23 (91%) patients, whereas abnormal 18-fluorodeoxyglucose uptake was found in 15 of 23 (65%) cases. In 14 of 15 patients with positive PET at baseline, PET was repeated after 6.1±3.7-month follow-up. After a median follow-up of 2.5 (range, 0-10.5) years, 1 (3%) patient died and 4 (13%) underwent heart transplant. Overall VT-free survival was 55% at 2-year follow-up. Among the 16 (52%) patients with VT recurrences, CA resulted in a significant reduction of VT burden, with 8 (50%) having only isolated (1-3) VT episodes and only 1 patient with recurrent VT storm. The presence of late gadolinium enhancement at magnetic resonance imaging, a positive PET at baseline, and lack of PET improvement over follow-up were associated with increased risk of recurrent VT.

CONCLUSIONS

In patients with cardiac sarcoidosis and VT, CA is effective in achieving long-term freedom from VT or improvement in VT burden in the majority of patients. The presence of late gadolinium enhancement at magnetic resonance imaging, a positive PET scan at baseline, or lack of improvement at repeat PET over follow-up predict worse arrhythmia-free survival.

Pulmonary Vein Antral Isolation and Nonpulmonary Vein Trigger Ablation Are Sufficient to Achieve Favorable Long-Term Outcomes Including Transformation to Paroxysmal Arrhythmias in Patients With Persistent and Long-Standing Persistent Atrial Fibrillation

BACKGROUND

Transformation from persistent to paroxysmal atrial fibrillation (AF) after ablation suggests modification of the underlying substrate. We examined the nature of initial arrhythmia recurrence in patients with nonparoxysmal AF undergoing antral pulmonary vein isolation and nonpulmonary vein trigger ablation and correlated recurrence type with long-term ablation efficacy after the last procedure.

METHODS AND RESULTS

Three hundred and seventeen consecutive patients with persistent (n=200) and long-standing persistent (n=117) AF undergoing first ablation were included. AF recurrence was defined as early (≤6 weeks) or late (>6 weeks after ablation) and paroxysmal (either spontaneous conversion or treated with cardioversion ≤7 days) or persistent (lasting >7 days). During median follow-up of 29.8 (interquartile range: 14.8-49.9) months, 221 patients had ≥1 recurrence. Initial recurrence was paroxysmal in 169 patients (76%) and persistent in 52 patients (24%). Patients experiencing paroxysmal (versus persistent) initial recurrence were more likely to achieve long-term freedom off antiarrhythmic drugs (hazard ratio, 2.2; 95% confidence interval, 1.5-3.2; P<0.0001), freedom on/off antiarrhythmic drugs (hazard ratio, 2.5; 95% confidence interval, 1.6-3.8; P<0.0001), and arrhythmia control (hazard ratio, 5.2; 95% confidence interval, 2.9-9.2; P<0.0001) after last ablation.

CONCLUSIONS

In patients with persistent and long-standing persistent AF, limited ablation targeting pulmonary veins and documented nonpulmonary vein triggers improves the maintenance of sinus rhythm and reverses disease progression. Transformation to paroxysmal AF after initial ablation may be a step toward long-term freedom from recurrent arrhythmia.

Long-Term Outcome After Catheter Ablation of Ventricular Tachycardia in Patients With Nonischemic Dilated Cardiomyopathy

BACKGROUND

Catheter ablation (CA) of ventricular tachycardia (VT) in patients with nonischemic dilated cardiomyopathy can be challenging because of the complexity of underlying substrates. We sought to determine the long-term outcomes of endocardial and adjuvant epicardial CA in nonischemic dilated cardiomyopathy.

METHODS AND RESULTS

We examined 282 consecutive patients (aged 59±15 years, 80% males) with nonischemic dilated cardiomyopathy who underwent CA. Ablation was guided by activation/entrainment mapping for tolerated VT and pacemapping/targeting of abnormal electrograms for unmappable VT. Adjuvant epicardial ablation was performed for recurrent VT or persistent inducibility after endocardial-only ablation. Epicardial ablation was performed in 90 (32%) patients. Before ablation, patients failed a median of 2 antiarrhythmic drugs), including amiodarone, in 166 (59%) patients. The median follow-up after the last procedure was 48 (19-67) months. Overall, VT-free survival was 69% at 60-month follow-up. Transplant-free survival was 76% and 68% at 60- and 120-month follow-up, respectively. Among the 58 (21%) patients with VT recurrence, CA still resulted in a significant reduction of VT burden, with 31 (53%) patients having only isolated (1-3) VT episodes in 12 (4-35) months after the procedure. At the last follow-up, 128 (45%) patients were only on β-blockers or no treatment, 41 (15%) were on sotalol or class I antiarrhythmic drugs, and 62 (22%) were on amiodarone.

CONCLUSIONS

In patients with nonischemic dilated cardiomyopathy and VT, endocardial and adjuvant epicardial CA is effective in achieving long-term VT freedom in 69% of cases, with a substantial improvement in VT burden in many of the remaining patients.

Right Atrial Approach for Ablation of Ventricular Arrhythmias Arising From the Left Posterior–Superior Process of the Left Ventricle

Background—

The posterior–superior process of the left ventricle (PSP-LV) is the most inferior and posterior aspect of the basal LV that extends posteriorly to the plane of the tricuspid valve. The PSP-LV is anatomically adjacent to the inferior and medial aspect of the right atrium (RA). We report a series of patients with ventricular arrhythmias (VAs) arising from the PSP-LV and describe a mapping and ablation approach from the RA guided by intracardiac echocardiography.

Methods and Results—

Mapping and ablation of the PSP-LV with an RA approach under intracardiac echocardiography guidance were performed in 5 patients with VAs (aged 44±14 years, 2 males) who had failed ablation attempts from multiple endocardial and epicardial (1 patient) sites. Mapping of the PSP-LV from the adjacent inferomedial RA was performed at sites anatomically opposite to the earliest endocardial site of activation under direct intracardiac echocardiography visualization. From the RA side of the PSP-LV, a small atrial signal and a larger ventricular signal were recorded in each case, with an activation time of 32±7 ms pre-QRS (versus 16±5 ms pre-QRS in the LV endocardium; P =0.068). We were able to capture the LV from these sites. Cryoablation was performed in 2 patients, and radiofrequency was used in the remaining 3 cases. In all patients, ablation from the RA eliminated the arrhythmia. All patients remained free of recurrent VAs after a mean follow-up of 12 (7–16) months. There were no immediate or long-term complications.

Conclusions—

The PSP-LV can be a site of origin of VAs, which can be successfully eliminated from the adjacent RA under direct intracardiac echocardiographic visualization.

Early recurrence of atrial arrhythmias following pulmonary vein antral isolation: Timing and frequency of early recurrences predicts long-term ablation success

BACKGROUND

Early recurrence of atrial arrhythmia (ERAA) is common after atrial fibrillation (AF) ablation and is associated with long-term recurrence. However, the association between timing or frequency of ERAA and long-term ablation success remains unclear.

OBJECTIVE

We aimed to examine whether timing or frequency of ERAA after pulmonary vein antral isolation (PVAI) affects long-term ablation success.

METHODS

Three hundred AF patients (100 paroxysmal, 100 persistent, 100 long-standing persistent; mean age 59.5 ± 9.6 years, 79% male) undergoing PVAI were included. All patients underwent 30-day monitoring with mobile continuous outpatient telemetry after PVAI and were followed for >1 year. ERAA was defined as AF or organized atrial tachycardia (OAT) in the first 6 weeks, and was categorized as early (weeks 1-2), intermediate (weeks 3-4), or late (weeks 5-6). Long-term ablation success was defined as the absence of AF/OAT lasting >30 seconds off antiarrhythmic drugs 1 year after a single ablation (excluding first 6 weeks).

RESULTS

ERAA occurred in 169 patients (53%); of those, 79 (46.7%) had single ERAA and 90 (53.3%) had multiple ERAAs. ERAA occurred less commonly with paroxysmal versus persistent or long-standing persistent AF (46% vs 57% and 66%; P = .017). ERAA was associated with worse ablation success at 1 year (38.1% vs 79.5% [no ERAA]; P < .001). Multiple (vs single) ERAA more strongly predicted long-term ablation failure (OR: 4.5; 95% CI [2.3-8.8]).

CONCLUSIONS

ERAA after PVAI is associated with decreased long-term ablation success. Patients experiencing multiple ERAA events are at greatest risk for long-term arrhythmia recurrence and represent a subgroup in whom early reablation may be considered.

Predictors of Finding Occult Atrial Fibrillation After Cryptogenic Stroke

Background and Purpose—

Occult paroxysmal atrial fibrillation (AF) is found in a substantial minority of patients with cryptogenic stroke. Identifying reliable predictors of paroxysmal AF after cryptogenic stroke would allow clinicians to more effectively use outpatient cardiac monitoring and ultimately reduce secondary stroke burden.

Methods—

We analyzed a retrospective cohort of consecutive patients who underwent 28-day mobile cardiac outpatient telemetry after cryptogenic stroke or transient ischemic stroke. Univariate and multivariable analyses were performed to identify clinical, echocardiographic, and radiographic features associated with the detection of paroxysmal AF.

Results—

Of 227 patients with cryptogenic stroke (179) or transient ischemic stroke (48), 14% (95% confidence interval, 9%–18%) had AF detected on mobile cardiac outpatient telemetry, 58% of which was ≥30 seconds in duration. Age >60 years (odds ratio, 3.7; 95% confidence interval, 1.3–11) and prior cortical or cerebellar infarction seen on neuroimaging (odds ratio, 3.0; 95% confidence interval, 1.2–7.6) were independent predictors of AF. AF was detected in 33% of patients with both factors, but only 4% of patients with neither. No other clinical features (including demographics, CHA 2 DS 2 -VASc [combined stroke risk score: congestive heart failure, hypertension, age, diabetes, prior stroke/transient ischemic attack, vascular disease, sex] score, or stroke symptoms), echocardiographic findings (including left atrial size or ejection fraction), or radiographic characteristics of the acute infarction (including location, topology, or number) were associated with AF detection.

Conclusions—

Mobile cardiac outpatient telemetry detects AF in a substantial proportion of cryptogenic stroke patients. Age >60 years and radiographic evidence of prior cortical or cerebellar infarction are robust indicators of occult AF. Patients with neither had a low prevalence of AF.

Electrophysiologic findings and long-term outcomes in patients undergoing third or more catheter ablation procedures for atrial fibrillation

INTRODUCTION

Pulmonary vein (PV) status, arrhythmia sources, and outcomes with ≥3 ablation procedures have not been characterized.

METHODS AND RESULTS

All patients with ≥3 procedures were included and underwent antral reisolation of reconnected PVs and ablation of non-PV triggers. Of 2,886 patients who underwent PVI, 181 (6%) had more than 2 ablation procedures (3 procedures in 146 and ≥4 procedures in 35). In 12 patients, the clinical arrhythmia was other than AF. Of the remaining 169 patients, 69 (41%) had 4 reconnected PVs, 27 (16%) had 3, 31 (18%) had 2, and 29 (17%) had 1. Only 13 (8%) had all PVs still isolated. Provocative techniques in 127 patients initiated PV triggers in 92 patients, including AF or PV atrial tachycardia in 64 (50%), and reproducible PV APDs in 28 (22%). Thirty-six (20%) had a new non-PV trigger targeted. At a mean of 36 months (12-119 months) after last procedure, 63 patients (47%) had no AF off antiarrhythmic drugs (AAD); 28 (21%) had no AF with AAD; and 18 (13%) had rare AF with good symptom control; 26 patients (19%) had recurrent AF.

CONCLUSIONS

At time of third or greater AF ablation, PV reconnection is the rule (92%) and PV triggers initiating AF can be demonstrated. Following repeat PVI and targeting non-PV triggers, 81% of patients had clinical AF control. Our findings suggest that PV reisolation and attempts to identify and eliminate non-PV triggers are effective and support the role of multiple repeat procedures for AF recurrence.

Acute hemodynamic decompensation during catheter ablation of scar-related ventricular tachycardia: incidence, predictors, and impact on mortality

BACKGROUND

The occurrence of periprocedural acute hemodynamic decompensation (AHD) in patients undergoing radiofrequency catheter ablation of scar-related ventricular tachycardia (VT) has not been previously investigated.

METHODS AND RESULTS

We identified univariate predictors of periprocedural AHD in 193 consecutive patients undergoing radiofrequency catheter ablation of scar-related VT. AHD was defined as persistent hypotension despite vasopressors and requiring mechanical support or procedure discontinuation. AHD occurred in 22 (11%) patients. Compared with the rest of the population, patients with AHD were older (68.5±10.7 versus 61.6±15.0 years; P=0.037); had a higher prevalence of diabetes mellitus (36% versus 18%; P=0.045), ischemic cardiomyopathy (86% versus 52%; P=0.002), chronic obstructive pulmonary disease (41% versus 13%; P=0.001), and VT storm (77% versus 43%; P=0.002); had more severe heart failure (New York Heart Association class III/IV: 55% versus 15%, P<0.001; left ventricular ejection fraction: 26±10% versus 36±16%, P=0.003); and more often received periprocedural general anesthesia (59% versus 29%; P=0.004). At 21±7 months follow-up, the mortality rate was higher in the AHD group compared with the rest of the population (50% versus 11%, log-rank P<0.001).

CONCLUSIONS

AHD occurs in 11% of patients undergoing radiofrequency catheter ablation of scar-related VT and is associated with increased risk of mortality over follow-up. AHD may be predicted by clinical factors, including advanced age, ischemic cardiomyopathy, more severe heart failure status (New York Heart Association class III/IV, lower ejection fraction), associated comorbidities (diabetes mellitus and chronic obstructive pulmonary disease), presentation with VT storm, and use of general anesthesia.

A study to improve communication between clinicians and patients with advanced heart failure: methods and challenges behind the working to improve discussions about defibrillator management trial

We report the challenges of the Working to Improve Discussions About Defibrillator Management trial, our novel, multicenter trial aimed at improving communication between cardiology clinicians and their patients with advanced heart failure (HF) who have implantable cardioverter defibrillators (ICDs). The study objectives are (1) to increase ICD deactivation conversations, (2) to increase the number of ICDs deactivated, and (3) to improve psychological outcomes in bereaved caregivers. The unit of randomization is the hospital, the intervention is aimed at HF clinicians, and the patient and caregiver are the units of analysis. Three hospitals were randomized to usual care and three to intervention. The intervention consists of an interactive educational session, clinician reminders, and individualized feedback. We enroll patients with advanced HF and their caregivers, and then we regularly survey them to evaluate whether the intervention has improved communication between them and their HF providers. We encountered three implementation barriers. First, there were institutional review board concerns at two sites because of the palliative nature of the study. Second, we had difficulty in creating entry criteria that accurately identified an HF population at high risk of dying. Third, we had to adapt our entry criteria to the changing landscape of ventricular assist devices and cardiac transplant eligibility. Here we present our novel solutions to the difficulties we encountered. Our work has the ability to enhance conduct of future studies focusing on improving care for patients with advanced illness.

Ventricular Tachycardia Ablation - The Right Approach for the Right Patient

Scar-related reentry is the most common mechanism of monomorphic ventricular tachycardia (VT) in patients with structural heart disease. Catheter ablation has assumed an increasingly important role in the management of VT in this setting, and has been shown to reduce VT recurrence and implantable cardioverter defibrillator (ICD) shocks. The approach to mapping and ablation will depend on the underlying heart disease etiology, VT inducibility and haemodynamic stability. This review explores pre-procedural planning, approach to ablation of both mappable and unmappable VT, and post-procedural testing. Future developments in techniques and technology that may improve outcomes are discussed.

Idiopathic ventricular arrhythmias originating from the moderator band: Electrocardiographic characteristics and treatment by catheter ablation

BACKGROUND

The moderator band (MB) can be a source of premature ventricular contractions (PVCs), monomorphic ventricular tachycardia (VT), and idiopathic ventricular fibrillation (IVF).

OBJECTIVE

The purpose of this study was to define the electrocardiographic (ECG) characteristics and procedural techniques to successfully identify and ablate MB PVCs/VT.

METHODS

In 10 patients with left bundle branch block morphology PVCs/VT, electroanatomic mapping in conjunction with intracardiac echocardiography (ICE) localized the site of origin of the PVCs to the MB. Clinical characteristics of the patients, ECG features, and procedural data were collected and analyzed.

RESULTS

Seven patients presented with IVF and 3 presented with monomorphic VT. In all patients, the ventricular arrhythmias (VAs) had a left bundle branch block QRS with a late precordial transition (>V4), a rapid downstroke of the QRS in the precordial leads, and a left superior frontal plane axis. Mean QRS duration was 152.7 ± 15.2 ms. Six patients required a repeat procedure. After mean follow-up of 21.5 ± 11.6 months, all patients were free of sustained VAs, with only 1 patient requiring antiarrhythmic drug therapy and 1 patient having isolated PVCs no longer inducing VF. There were no procedural complications.

CONCLUSION

VAs originating from the MB have a distinctive morphology and often are associated with PVC-induced ventricular fibrillation. Catheter ablation can be safely performed and is facilitated by ICE imaging.

Characterization of Trans-septal Activation During Septal Pacing

Background—

Identification of intramural basal-septal ventricular tachycardia (VT) substrate is challenging in nonischemic cardiomyopathy. We sought to (1) characterize normal/abnormal trans-septal right ventricular (RV) to left ventricular activation; (2) assess the effect of opposite RV pacing on left ventricular septal bipolar electrograms (EGMs); and (3) establish criteria for the identification of intramural septal VT substrate.

Methods and Results—

Endocardial activation mapping and local EGM assessment of the left interventricular septum was performed during RV basal septal pacing in 40 patients undergoing VT ablation with no evidence of septal scar (group 1, n=14) and with septal scar (group 2, n=26) defined by low septal unipolar voltage (<8.3 mV) and delayed enhancement on cardiac MRI with/without abnormal bipolar voltage (<1.5 mV) in sinus rhythm. Left ventricular trans-septal activation time was prolonged in Group 2 compared with Group 1 (55.3±33.0 versus 25.7±8.8 ms; P =0.003). In 6 group 2 patients, left ventricular septal breakthrough was displaced to the scar border. During RV pacing, group 2 had fractionated (8.8%), late (2.8%), and split (5.7%) EGMs not seen in group 1. Trans-septal activation >40 ms (sensitivity 60%, specificity 100%; P <0.001) and EGM duration >95 ms during pacing (sensitivity 22%, specificity 91%; P <0.001) identified septal scar (13/26 pts).

Conclusions—

In patients with nonischemic cardiomyopathy, VT and septal scar, delayed transmural conduction time (>40 ms) and fractionated, late, split, and wide (>95 ms) bipolar EGMs during RV basal pacing identify intramural VT substrate. In select cases, the basal septum appears compartmentalized as the stimulated wavefront is rerouted to the scar border.

New unipolar electrogram criteria to identify irreversibility of nonischemic left ventricular cardiomyopathy

OBJECTIVES

This study sought to assess the value of left ventricular (LV) endocardial unipolar electroanatomical mapping (EAM) in identifying irreversibility of LV systolic dysfunction in patients with left ventricular nonischemic cardiomyopathy (LVCM).

BACKGROUND

Identifying irreversibility of LVCM would be helpful but cannot be reliably accomplished by bipolar EAM or cardiac magnetic resonance identification of macroscopic scar.

METHODS

Detailed endocardial LV EAM was performed in 3 groups: 1) 24 patients with irreversible LVCM (I-LVCM) but with no or minimal macroscopic scar (<15% LV surface) evidenced on bipolar voltage EAM and/or cardiac magnetic resonance; 2) 14 patients with reversible ventricular premature depolarization-mediated LVCM (R-LVCM); and 3) 17 patients with structurally normal hearts. LV endocardial unipolar electrogram amplitude and area of unipolar amplitude abnormality were defined after excluding macroscopic scar.

RESULTS

Unipolar amplitude differed in the 3 groups: median of 7.6 (interquartile range [IQR]: 5.5 to 9.7) mV in I-LVCM group, 13.2 (IQR: 10.4 to 16.2) mV in R-LVCM group, and 16.3 (IQR: 13.6 to 19.8) mV in structurally normal hearts group (p < 0.001). Areas of unipolar abnormality represented a large proportion of total LV surface in I-LVCM, 64.7% (IQR: 47.5% to 75.9%) compared with R-LVCM, 5.2% (IQR: 0.0% to 19.1%) and structurally normal hearts, 0.1% (IQR: 0.0% to 0.9%), groups (p < 0.001). A unipolar abnormality area cutoff of 32% of total LV surface was 96% sensitive and 100% specific in identifying irreversible cardiomyopathy among patients with LV dysfunction (I-LVCM and R-LVCM), p < 0.001.

CONCLUSIONS

Detailed unipolar voltage mapping can identify irreversible myocardial dysfunction consistent with fibrosis, even in the absence of bipolar EAM or cardiac magnetic resonance abnormalities, and may serve as valuable prognostic tool in patients presenting with LVCM to facilitate clinical decision making.

ECG criteria for accurate localization of left anterolateral and posterolateral accessory pathways

BACKGround : Left lateral accessory pathway (AP) location along the mitral annulus (MA) can influence ablation strategy, including choice of a transseptal or retrograde aortic approach and the use of deflectable sheaths and/or bidirectional catheters. We aimed to develop electrocardiographic (ECG) criteria to accurately localize a left lateral AP, hypothesizing that the relationship of QRS amplitudes in limb leads II and III could be used to differentiate left anterolateral (LAL) from left posterolateral (LPL) AP locations.

METHODS

The ECGs from patients who underwent ablation of a left-sided AP between 2001 and 2008 were evaluated for the relationship of QRS amplitudes in limb leads II and III. A LAL-AP was defined by successful ablation between 12 and 3 o'clock on the MA, as seen in left anterior oblique (LAO) fluoroscopic projection. A LPL-AP was defined by successful ablation between 3 and 6 o'clock in the LAO projection.

RESULTS

In 249 consecutive patients undergoing AP ablation, 23 met the prespecified inclusion criteria: manifest preexcitation due to single AP, ablated successfully in a LAL or LPL location. The ratio of dominant QRS amplitude in lead II to lead III was ≥ 1 in 10/11 patients with LAL-AP, compared with 3/12 patients with a LPL-AP (P = 0.002). Using these criteria, two blinded reviewers predicted a LAL or LPL location with 87% accuracy and 100% interobserver agreement.

CONCLUSIONS

We report new ECG criteria that can be used to accurately predict the anterior and posterior location of a left lateral AP. Such localization may facilitate procedural planning.

Noninvasive programmed ventricular stimulation early after ventricular tachycardia ablation to predict risk of late recurrence

OBJECTIVES

The goal of this study was to evaluate the ability of noninvasive programmed stimulation (NIPS) after ventricular tachycardia (VT) ablation to identify patients at high risk of recurrence.

BACKGROUND

Optimal endpoints for VT ablation are not well defined.

METHODS

Of 200 consecutive patients with VT and structural heart disease undergoing ablation, 11 had clinical VT inducible at the end of ablation and 11 recurred spontaneously. Of the remaining 178 patients, 132 underwent NIPS through their implantable cardioverter-defibrillator 3.1 ± 2.1 days after ablation. At 2 drive cycle lengths, single, double, and triple right ventricular extrastimuli were delivered to refractoriness. Clinical VT was defined by comparison with 12-lead electrocardiograms and stored implantable cardioverter-defibrillator electrograms from spontaneous VT episodes. Patients were followed for 1 year.

RESULTS

Fifty-nine patients (44.7%) had no VT inducible at NIPS; 49 (37.1%) had inducible nonclinical VT only; and 24 (18.2%) had inducible clinical VT. Patients with inducible clinical VT at NIPS had markedly decreased 1-year VT-free survival compared to those in whom no VT was inducible (<30% vs. >80%; p = 0.001), including 33% recurring with VT storm. Patients with inducible nonclinical VT only, had intermediate 1-year VT-free survival (65%).

CONCLUSIONS

When patients with VT and structural heart disease have no VT or nonclinical VT only inducible at the end of ablation or their condition is too unstable to undergo final programmed stimulation, NIPS should be considered in the following days to further define risk of recurrence. If clinical VT is inducible at NIPS, repeat ablation may be considered because recurrence over the following year is high.