Arrhythmic Risk Profile and Outcomes of Patients Undergoing Cardiac Sympathetic Denervation for Recurrent Monomorphic Ventricular Tachycardia After Ablation.

Background Cardiac sympathetic denervation (CSD) has been used as a bailout strategy for refractory ventricular tachycardia (VT). Risk of VT recurrence in patients with scar-related monomorphic VT referred for CSD and the extent to which CSD can modify this risk is unknown. We aimed to quantify arrhythmia recurrence risk and impact of CSD in this population. Methods and Results Adjusted competing risk time to event models were developed to adjust for risk of VT recurrence and sustained VT/implantable cardioverter-defibrillator shocks after VT ablation based on patient comorbidities at the time of VT ablation. Adjusted VT and implantable cardioverter-defibrillator shock recurrence rates were estimated for the subgroup who subsequently required CSD after ablation. The expected adjusted recurrence rates were then compared with the observed rates after CSD. Data from 381 patients with scar-mediated monomorphic VT who underwent VT ablation were analyzed, excluding patients with polymorphic VT. Sixty eight patients underwent CSD for recurrent VT. CSD reduced the expected adjusted VT recurrence rate by 36% (expected rate of 5.61 versus observed rate of 3.58 per 100 person-months, P=0.01) and the sustained VT/implantable cardioverter-defibrillator shock rates by 34% (expected rate of 4.34 versus observed 2.85 per 100 person-months, P=0.03). The median number of sustained VT/implantable cardioverter-defibrillator shocks in the year before versus the year after CSD was reduced by 90% (10 versus 1, P<0.0001). Conclusions Patients referred for CSD for refractory scar-mediated monomorphic VT are at a higher risk of VT recurrence after ablation as compared with those not requiring CSD, mostly because of their cardiac comorbidities. CSD significantly reduced both the expected risk of recurrences and VT burden.

Non-invasive stereotactic body radiation therapy for refractory ventricular arrhythmias: an institutional experience.

BACKGROUND: Initial studies have reported excellent safety and efficacy for stereotactic body radiation therapy (SBRT) in patients with refractory ventricular tachycardia (VT). METHODS: This is a single-center retrospective analysis of eight consecutive patients who underwent SBRT for refractory, scar-related VT. The anatomic target for radioablation was defined based on surface 12-lead ECG VT morphology, cardiac magnetic resonance imaging, and electroanatomic mapping data when available. The target volume treated and the prescribed radiation dose (15-25 Gy) was based on the combined clinical assessment of the cardiac electrophysiologist and radiation oncologist. Ventricular arrhythmias, radiation-related outcomes, and adverse events were monitored at follow-up. RESULTS: Eight patients underwent nine SBRT sessions. All patients were male with an average age of 75 ± 7.3 years and mean ejection fraction of 21 ± 7%. SBRT was performed with delivery of an average of 22.2 ± 3.6 Gy in a single session with a procedure time of 18.2 ± 6.0 min. All but one session was performed on an inpatient basis. No acute complications occurred. During a median follow-up of 7.8 months (IQR 4.8, 9.9), ICD therapies decreased from median 69.5 (43.5, 115.8) pre-SBRT to 13.3 (IQR 7.7, 35.8) post-SBRT (p = 0.036). There were three patient deaths in the follow-up period, unrelated to SBRT. Apparent clinical benefit occurred 33% of the time after SBRT. CONCLUSIONS: The patients experienced overall reduction in VT burden following SBRT, though not with the immediate effect seen in other patient series. Further studies (basic, translational, and clinical) are essential to determine the benefit of SBRT and if so, the optimal protocols and patient selection.

Recurrent ventricular tachycardia after cardiac sympathetic denervation: Prolonged cycle length with improved hemodynamic tolerance and ablation outcomes.

INTRODUCTION: Cardiac sympathetic denervation (CSD) is utilized for the management of ventricular tachycardia (VT) in structural heart disease when refractory to radiofrequency ablation (RFA) or when patient/VT characteristics are not conducive to RFA. METHODS: We studied consecutive patients who underwent CSD at our institution from 2009 to 2018 with VT requiring repeat RFA post-CSD. Patient demographics, VT/procedural characteristics, and outcomes were assessed. RESULTS: Ninety-six patients had CSD, 16 patients underwent RFA for VT post-CSD. There were 15 male and 1 female patients with mean age of 54.2 ± 13.2 years. Fourteen patients had nonischemic cardiomyopathy. A mean of 2.0 ± 0.8 RFAs for VT was unsuccessful before the patient undergoing CSD. The median time between CSD and RFA was 104 days (interquartile range [IQR] = 15-241). The clinical VT cycle length was significantly increased after CSD both spontaneously on ECG and/or ICD interrogation (355 ± 73 ms pre-CSD vs. 422 ± 94 ms post-CSD, p = .001) and intraprocedurally (406 ± 86 ms pre-CSD vs. 457 ± 88 ms post-CSD, p = .03). Two patients had polymorphic and 14 had monomorphic VT (MMVT) pre-CSD, and all patients had MMVT post-CSD. The proportion of mappable, hemodynamically stable VTs increased from 35% during pre-CSD RFA to 58% during post-CSD RFA (p = .038). At median follow-up of 413 days (IQR = 43-1840) after RFA, eight patients had no further VT. CONCLUSION: RFA for recurrent MMVT post-CSD is a reasonable treatment option with intermediate-term clinical success in 50% of patients. Clinical VT cycle length was significantly increased after CSD with associated improvement in mappable, hemodynamically tolerated VT during RFA.

Renal denervation as adjunctive therapy to cardiac sympathetic denervation for ablation refractory ventricular tachycardia.

BACKGROUND: Autonomic modulation is finding an increasing role in the treatment of ventricular arrhythmias. Renal denervation (RDN) has been described as a treatment modality for refractory ventricular tachycardia (VT) in case series. OBJECTIVE: The purpose of this study was to evaluate RDN as an adjunctive therapy to cardiac sympathetic denervation (CSD) for ablation refractory VT. METHODS: Patients who underwent RDN after radiofrequency ablation and CSD procedures at our center from 2012 to 2019 were evaluated. RESULTS: Ten patients underwent RDN after CSD (9 bilateral and 1 left-sided only) with a median follow-up of 23 months. The mean age was 59.9 ± 10.4 years, and 9/10 (90%) were men. All had cardiomyopathy with a mean ejection fraction of 33% ± 11% (20% ischemic). Four (40%) underwent CSD during the same hospitalization as that for RDN. Patients who underwent RDN as adjunctive therapy to CSD had a decrease in all implantable cardioverter-defibrillator therapies (shocks + antitachycardia pacing [ATP]) from 29.5 ± 25.2 to 7.1 ± 10.1 comparing 6 months pre-RDN to 6 months post-RDN (P = .028). Implantable cardioverter-defibrillator shocks were significantly decreased from 7.0 ± 6.1 to 1.7 ± 2.5 comparing 6 months pre-RDN to 6 months post-RDN (P = .026). This benefit was driven by a decrease in therapies for 6 patients who had a staged procedure, not performed during the same hospitalization (28.5 ± 24.3 to 1.0 ± 1.2; P = .043). CONCLUSION: RDN demonstrates the potential benefit when VT recurs after radiofrequency ablation and CSD. The benefit is seen in patients who undergo a staged procedure. The need for acute RDN after CSD portends a poor prognosis.

Repeated misclassifications of tachycardia by an implantable cardiac defibrillator.

This case describes repeated misclassifications of SVT due to AV node reentry as VT by an ICD. This case illustrates the limitations of SVT-VT discrimination algorithm. Careful analysis of the stored tracings is of critical importance to reach the correct diagnosis.

Relationship between sinus rhythm late activation zones and critical sites for scar-related ventricular tachycardia: systematic analysis of isochronal late activation mapping.

BACKGROUND: It is not known whether the most delayed late potentials are functionally most specific for scar-related ventricular tachycardia (VT) circuits. METHODS AND RESULTS: Isochronal late activation maps were constructed to display ventricular activation during sinus rhythm over 8 isochrones. Analysis was performed at successful VT termination sites and prospectively tested. Thirty-three patients with 47 scar-related VTs where a critical site was demonstrated by termination of VT during ablation were retrospectively analyzed. In those who underwent mapping of multiple surfaces, 90% of critical sites were on the surface that contained the latest late potential. However, only 11% of critical sites were localized to the latest isochrone (87.5%-100%) of ventricular activation. The median percentage of latest activation at critical sites was 78% at a distance from the latest isochrone of 18 mm. Sites critical to reentry were harbored in regions with slow conduction velocity, where 3 isochrones were present within a 1-cm radius. Ten consecutive patients underwent ablation prospectively guided by isochronal late activation maps, targeting concentric isochrones outside of the latest isochrone. Elimination of the targeted VT was achieved in 90%. Termination of VT was achieved in 6 patients at a mean ventricular activation percentage of 78%, with only 1 requiring ablation in the latest isochrone. CONCLUSIONS: Late potentials identified in the latest isochrone of activation during sinus rhythm are infrequently correlated with successful ablation sites for VT. The targeting of slow conduction regions propagating into the latest zone of activation may be a novel and promising strategy for substrate modification.

Tissue voltage discordance during tachycardia versus sinus rhythm: implications for catheter ablation.

BACKGROUND: Electroanatomic mapping systems are an important tool to identify cardiac chamber voltage and assess channels of slow conduction. OBJECTIVE: To assess the correlation between electroanatomic mapping voltage maps obtained during macroreentrant tachycardia compared to sinus rhythm (SR) with a contact mapping system. METHODS: We retrospectively evaluated patients with atrial flutter (AFL) referred for radiofrequency ablation with electroanatomic voltage maps obtained during AFL and SR. The atrium was divided into predetermined segments. Overall atrial and segmental peak-to-peak bipolar voltages in AFL and SR were assessed. To directly compare a region within the same patient, tissue voltage differences during AFL and SR were assessed on the basis of mean voltage difference. RESULTS: Sixteen patients (87% men) had available voltage maps. Eighty-one percent had typical cavotricuspid isthmus-dependent right AFL. A mean of 441.7±153.9 vs 398.1±125.4 total points (P = .22) were sampled during AFL and SR, with a mean of 99.5±58.9 vs 91.2±60.4 points (P = .45) sampled per region. Overall right atrial mean voltage was significantly higher during AFL than SR (0.554±0.092mV vs 0.473±0.079mV; P≤.001), with the lateral wall (0.707±0.120mV vs 0.573±0.097mV; P = .0004) and the cavotricuspid isthmus (0.559±0.100mV vs 0.356±0.066mV; P<.0001) also showing higher mean voltage during AFL. When compared within an individual patient, 19% (14 of 75) of the patient regions had a>0.5mV mean voltage difference and 40% (30 of 75) had a>0.25mV mean voltage difference. CONCLUSIONS: These data suggest that voltage maps performed during macroreentrant atrial arrhythmias often vary significantly from maps obtained during SR.

Epicardial ablation of ventricular tachycardia: an institutional experience of safety and efficacy.

BACKGROUND: Epicardial ablation has been shown to be a useful adjunct for treatment of ventricular tachycardia (VT). OBJECTIVE: To report the trends, safety, and efficacy of epicardial mapping and ablation at a single center over an 8-year period. METHODS: Patients referred for VT ablation (June 2004 to July 2011) were divided into 3 groups: ischemic cardiomyopathy (ICM), nonischemic cardiomyopathy (NICM), and idiopathic ventricular arrhythmias (VA). Patients with scar-mediated VT who underwent combined epicardial and endocardial (epi-endo) mapping and ablation were compared with those who underwent endocardial-only (endo-only) ablation with regard to patient characteristics, acute procedural success, 6- and 12-month clinical outcomes. RESULTS: Among 144 patients referred for VT ablation, 95 patients underwent 109 epicardial procedures (94% access rate). Major complications were seen in 8 patients (8.8%) with pericardial bleeding (>80 cm(3)) in 6 cases (6.7%), although no tamponade, surgical intervention, or procedural mortality was seen. Patients with ICM who underwent a combined epi-endo ablation had improved freedom from VT compared with those who underwent endo-only ablation at 12 months (85% vs 56%; P = .03). In patients with NICM, no differences were seen between those who underwent epi-endo ablation and those who underwent endo-only ablation at 12 months (36% vs 33%; P = 1.0). In idiopathic VA, only 2 of 17 patients were successfully ablated from the epicardium. CONCLUSIONS: In this large tertiary single-center experience, complication rates are acceptably low and improved clinical outcomes were associated with epi-endo ablation in patients with ICM. Patients with NICM represent a growing referred population, although clinical recurrence remains high despite epicardial ablation. Epicardial ablation has a low yield in idiopathic VA.

Noh voice quality.

In Noh, a traditional performing art of Japan, extremely expressive voice quality is used to convey an emotional message. A periodicity of voice appears responsible for these special effects. Acoustic signals were recorded for selected portions of dramatic singing in order to study the acoustic effects of delicate voice control by a master of the Konparu school. Using a signal analysis-synthesis algorithm, TANDEM-STRAIGHT, to represent multiple candidates for pitch perception, signals deviating from the harmonic structure have been successfully displayed, corresponding to auditory impressions of pitch movements, even when narrow-band spectrograms failed to show the perceived events. Strong interaction between vocal tract resonance and vocal fold vibration seems to play a major role in producing these expressive voice qualities.

Device extraction in adults with congenital heart disease.

BACKGROUND: Device extraction is a critical component in the treatment of patients with device-related infections. Due to complex anatomic considerations, device extraction in adults with congenital heart disease presents unique challenges to the electrophysiologist. METHODS: Here, we present a series of device-extraction cases performed in patients with transposition of the great arteries status post either Mustard or Senning surgical procedures that subsequently had permanent pacemakers placed and ultimately developed device-related infections. RESULTS: All of these patients eventually underwent successful laser extractions of their infected devices resulting in complete removal of all hardware and resolution of their infections. CONCLUSIONS: These cases illustrate that endovascular device extraction has been safely and effectively performed in adult patients with congenital heart disease, though further studies are needed to determine the procedural risks and success rates of this procedure in this patient population.

Left ventricular apical wall motion abnormality is associated with lack of response to cardiac resynchronization therapy in patients with ischemic cardiomyopathy.

BACKGROUND: Many patients with appropriate indications fail to respond to cardiac resynchronization therapy (CRT). OBJECTIVE: The purpose of our study was to determine the relationship between CRT response and preimplantation apical wall motion abnormality. METHODS: We analyzed data from 83 patients with ischemic cardiomyopathy who underwent CRT. All patients had New York Heart Association class III or IV symptoms despite maximal medical therapy, left ventricular ejection fraction (LVEF) < or =35%, and QRS duration > or =130 ms or <130 ms with left ventricular dyssynchrony. CRT responders at 6 months were defined as surviving patients with: (1) no hospitalization for heart failure, and (2) improvement of New York Heart Association classification. Patients underwent echocardiography before and 6 months after implantation to assess changes in regional wall motion and LVEF. RESULTS: At baseline, CRT responders (n = 39) and nonresponders (n = 44) had similar LVEF (22.9% +/- 6.9% vs 23.1% +/- 8.3%), QRS duration (159 +/- 43 ms vs 159 +/- 36 ms), and medical treatment. CRT nonresponders had a higher prevalence of preimplantation apical wall motion abnormality (68% vs 33%, P = .003). Patients with baseline apical wall motion abnormalities (n = 43) were less likely than others (n = 40) to show improvement in wall motion at 6 months (30% vs 81%, P < .001) or clinical response to CRT (31% vs 64%, P = .003). CONCLUSION: The presence of a preimplantation apical wall motion abnormality was associated with a lower rate of CRT response in patients with ischemic cardiomyopathy.

Asymmetric Ring-Closing Metathesis Catalyzed by Chiral Molybdenum Alkylidene Complexes.

Kinetic resolution was observed in ring-closing metathesis of racemic dienes catalyzed by the newly developed chiral molybdenum alkylidene complexes (R,R)-Mo(CHCMe(2)Ph)(NAr)(TBEC) 1 (Ar = 2,6-i-Pr(2)C(6)H(3), TBEC = 2',2',2",2"-tetrakis(trifluoromethyl)-1,2-bis(2'-hydroxyethyl)cyclopentane) and (R,R)-Mo(CHCMe(2)Ph)(NAr)(TBEH) 2 (Ar = 2,6-i-Pr(2)C(6)H(3), TBEH = 2',2',2",2"-tetrakis(trifluoromethyl)-1,2-bis(2'-hydroxyethyl)cyclohexane). In the case of a prochiral symmetric triene substrate, optically active cyclized product was formed by catalytic ring-closing metathesis with 1, which opens the possibility of a new version of two-directional synthesis. Although the observed enantiomeric excesses were modest to low, this data demonstrates the feasibility of asymmetric induction by chiral alkylidene catalysts in ring-closing metathesis.