Role of dofetilide in patients with ventricular arrhythmias.

BACKGROUND OR PURPOSE: To assess effectiveness of dofetilide in reducing the burden of ventricular arrhythmias (VAs). BACKGROUND: Prior small sample studies show that dofetilide has benefit in reducing VA. However, large sample investigations with long-term follow-up are lacking. METHODS: Two hundred seventeen consecutive patients admitted between January 2015 and December 2021 for dofetilide initiation for control of VA were assessed. Dofetilide was successfully started in 176 patients (81%) and had to be discontinued in the remaining 41 patients (19%). Dofetilide was initiated for control of ventricular tachycardia (VT) in 136 patients (77%), whereas 40 (23%) patients were initiated on dofetilide for reducing the burden of premature ventricular complexes (PVCs). RESULTS: The mean follow-up was 24 ± 7 months. In total, among the 136 VT patients, 33 (24%) died, 11 (8%) received a left ventricular assist device (LVAD), and 3 (2%) received a heart transplant during follow-up. Dofetilide was discontinued in 117 (86%) patients due to lack of sustained effectiveness during follow-up. Dofetilide use was associated with similar odds of the composite outcome of all-cause mortality/LVAD/heart transplant (OR: 0.97, 0.55-4.23) in patients with ischemic cardiomyopathy (ICM) compared to those with non-ischemic cardiomyopathy (NICM). Dofetilide did not reduce PVC burden during follow-up in the 40 patients with PVCs (mean baseline PVC burden: 15%, at 1-year follow-up: 14%). CONCLUSIONS: Dofetilide use was less effective in reducing VA burden in our cohort of patients. Randomized controlled studies are needed to confirm our findings.

Catheter ablation using pulmonary vein isolation with versus without left atrial posterior wall isolation for persistent atrial fibrillation: an updated systematic review and meta-analysis.

BACKGROUND: Pulmonary vein isolation (PVI) is the cornerstone of catheter ablation of atrial fibrillation (AF); however, the results are suboptimal for persistent AF. The left atrial posterior wall (LAPW) is thought to be a major additional area in initiation and perpetuation of persistent AF. Therefore, adjunctive ablation of the posterior wall may reduce AF recurrence in patients with persistent AF. OBJECTIVE: The objective of this study was to compare outcomes of catheter ablation in patients with persistent AF using PVI alone versus a combination of PVI and LAPW isolation. METHODS: Literature search was conducted in PubMed, PubMed Central, Scopus, and Embase since inception to February 2023. Screening of studies was done via Covidence software. Risk of bias assessment was done using appropriate tools. Data extraction and a narrative synthesis were carried out accordingly. RESULTS: Ten studies were included, of which five were randomized controlled trials. PVI with LAPW ablation group had significantly lower recurrence of overall atrial tachyarrhythmia (OR 0.47, CI 0.32-0.70) and AF (OR 0.39, CI 0.23-0.69). In sensitivity analysis, freedom from atrial arrhythmias was noted to be significantly higher in the PVI with LAPW ablation group (OR 2.22, CI 1.36-3.64). However, there was no significant difference in occurrence of atrial flutter (OR 1.36, CI 0.86-2.14) or with periprocedural adverse events (OR 1.10, CI 0.60-1.99). CONCLUSION: LAPW ablation, in addition to PVI, significantly improves the rates of arrhythmia freedom and reduces the recurrence of overall atrial tachyarrhythmia. There was no significant difference in atrial flutter or periprocedural adverse events.

A comparative study of the two leadless pacemakers in clinical practice.

INTRODUCTION: AVEIR-VR leadless pacemaker (LP) was recently approved for clinical use. Although trial data were promising, post-approval real world data with regard to its effectiveness and safety is lacking. To report our early experience with AVEIR-VR LP with regard to its effectiveness and safety and compare it with MICRA-VR. METHODS: The first 25 patients to undergo AVEIR-VR implant at our institution between June and November 2022, were compared to 25 age- and sex-matched patients who received MICRA-VR implants. RESULTS: In both groups, mean age was 73 years and 48% were women. LP implant was successful in 100% of patients in both groups. Single attempt deployment was achieved in 80% of AVEIR-VR and 60% of MICRA-VR recipients (p = 0.07). Fluoroscopy, implant, and procedure times were numerically longer in the AVEIR-VR group compared to MICRA-VR group (p > 0.05). No significant periprocedural complications were noted in both groups. Incidence of ventricular arrhythmias were higher in the AVEIR-VR group (20%) compared to the MICRA-VR group (0%) (p = 0.043). At 2 and 8 weeks follow-up, device parameters remained stable in both groups with no device dislodgements. The estimated battery life at 8 weeks was significantly longer in the AVEIR-VR group (15 years) compared to the MICRA-VR group (8 years) (p = 0.047). With 3-4 AVEIR-VR implants, the learning curve for successful implantation reached a steady state. CONCLUSION: Our initial experience with AVEIR-VR show that it has comparable effectiveness and safety to MICRA-VR. Larger sample studies are needed to confirm our findings.

Anatomical location of leadless pacemaker and the risk of pacing-induced cardiomyopathy.

BACKGROUND: It is unclear if the location of implantation of the leadless pacemaker (LP) makes a difference in the incidence of pacing-induced cardiomyopathy (PICM). AIM: The aim of this study was to compare the incidence of PICM based on the location of implantation of LP. METHODS: A total of 358 consecutive patients [women: 171 (48%), mean age: 73 ± 15 years] with left ventricular ejection fraction (EF) > 50%, who received an LP (Micra) between January 2017 and June 2022, formed the study cohort. Micra-AV and Micra-VR were implanted in 122 (34%) and 236 (66%) patients, respectively. Fluoroscopically, the location of implantation of LP in the interventricular septum (IS) was divided into two equal halves (apex/apical septum [AS] and mid/high septum [HS]). During follow-up, PICM was defined as an EF drop of ≥10%. RESULTS: LP was implanted in 109 (34%) and 249 (66%) patients at AS and HS locations, respectively. During a mean 18 ± 8 months follow-up, 28 patients (7.8%) developed PICM. Among the 249 patients with HS placement of LP, 10 (4%) developed PICM, whereas among the 109 patients with AS placement of LP, 18 (16.5%) developed PICM (p = .002). AS location was associated with a higher risk of PICM compared to HS locations (adjusted hazard ratio: 4.42, p < .001). CONCLUSION: AS location of LP was associated with a higher risk of PICM compared to HS placement. Larger randomized studies are needed to confirm our findings.

Outcome of In-Hospital Cardiac Arrest among Patients with COVID-19: A Systematic Review and Meta-Analysis.

BACKGROUND: Outcomes following in-hospital cardiac arrest (IHCA) in patients with COVID-19 have been reported by several small single-institutional studies; however, there are no large studies contrasting COVID-19 IHCA with non-COVID-19 IHCA. The objective of this study was to compare the outcomes following IHCA between COVID-19 and non-COVID-19 patients. METHODS: We searched databases using predefined search terms and appropriate Boolean operators. All the relevant articles published till August 2022 were included in the analyses. The systematic review and meta-analysis were conducted as per Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. An odds ratio with a 95% confidence interval (CI) was used to measure effects. RESULTS: Among 855 studies screened, 6 studies with 27,453 IHCA patients (63.84% male) with COVID-19 and 20,766 (59.7% male) without COVID-19 were included in the analysis. IHCA among patients with COVID-19 has lower odds of achieving return of spontaneous circulation (ROSC) (OR: 0.66, 95% CI: 0.62-0.70). Similarly, patients with COVID-19 have higher odds of 30-day mortality following IHCA (OR: 2.26, 95% CI: 2.08-2.45) and have 45% lower odds of cardiac arrest because of a shockable rhythm (OR: 0.55, 95% CI: 0.50-0.60) (9.59% vs. 16.39%). COVID-19 patients less commonly underwent targeted temperature management (TTM) or coronary angiography; however, they were more commonly intubated and on vasopressor therapy as compared to patients who did not have a COVID-19 infection. CONCLUSIONS: This meta-analysis showed that IHCA with COVID-19 has a higher mortality and lower rates of ROSC compared with non-COVID-19 IHCA. COVID-19 is an independent risk factor for poor outcomes in IHCA patients.

Comparative assessment of safety with leadless pacemakers compared to transvenous pacemakers: a systemic review and meta-analysis.

BACKGROUND: Leadless pacemakers (LP) and transvenous pacemakers (TVP) are two stable pacing platforms currently available in clinical practice. Observational data show mixed results with regards to their comparative safety. This meta-analysis was aimed to evaluate the comparative safety of LP over TVP. METHODS: The study protocol was registered in PROSPERO registry (CRD42022325376). Six databases were searched for published literature from inception to April 12, 2022. RevMan 5.4.1 was used for statistical analysis. Odds ratio (OR) and mean difference were used to estimate the outcome with a 95% confidence interval (CI). RESULTS: A total of 879 studies were imported from the databases. Among these, 41 papers were screened for full text and 17 meet the inclusion criteria. Among them, pooled results showed 42% lower odds of occurrence of complications in the LP group (OR 0.58, CI 0.42-0.80) compared to TVP group. Notably, 70% lower odds of device dislodgment (OR 0.30, CI 0.21-0.43), 46% lower odds of re-intervention (OR 0.54, CI 0.45-0.64), 87% lower odds of pneumothorax (OR 0.13, CI 0.03-0.57), albeit, 2.65 times higher odds of pericardial effusion (OR 2.65, CI 1.49-4.70) were observed in the LP group. CONCLUSIONS: This meta-analysis showed LP to be a significantly safer modality compared to TVP, in terms of re-intervention, device dislodgment, pneumothoraxes, and overall complications. However, there were higher rates of pericardial effusion in the LP group. There was a diverse number of patients included, and all studies were observational. Randomized trials are needed to validate our findings.

Ambulatory atrioventricular synchronous pacing over time using a leadless ventricular pacemaker: Primary results from the AccelAV study.

BACKGROUND: Previous studies demonstrated that accelerometer-based, mechanically timed atrioventricular synchrony (AVS) is feasible using a leadless ventricular pacemaker. OBJECTIVE: The purpose of this study was to determine the performance of a leadless ventricular pacemaker with accelerometer-based algorithms that provide AVS pacing. METHODS: AccelAV was a prospective, single-arm study to characterize AVS in patients implanted with a Micra AV, which uses the device accelerometer to mechanically detect atrial contractions and promote VDD pacing. The primary objective was to characterize resting AVS at 1 month in patients with complete atrioventricular block (AVB) and normal sinus function. RESULTS: A total of 152 patients (age 77 ± 11 years; 48% female) from 20 centers were enrolled and implanted with a leadless pacemaker. Among patients with normal sinus function and complete AVB (n = 54), mean resting AVS was 85.4% at 1 month, and ambulatory AVS was 74.8%. In the subset of patients (n = 20) with programming optimization, mean ambulatory AVS was 82.6%, representing a 10.5% improvement (P <.001). Quality of life as measured by the EQ-5D-3L (EuroQol Five-Dimensions Three-Level questionnaire) improved significantly from preimplant to 3 months (P = .031). In 37 patients with AVB at both 1 and 3 months, mean AVS during rest did not differ (86.1% vs 84.1%; P = .43). There were no upgrades to dual-chamber devices or cardiac resynchronization therapy through 3 months. CONCLUSION: Accelerometer-based mechanical atrial sensing provided by a leadless pacemaker implanted in the right ventricle significantly improves quality of life in a select cohort of patients with AV block and normal sinus function. AVS remained stable through 3 months, and there were no system upgrades to dual-chamber pacemakers.

AngioVac Debulking in Endocarditis Patients with Large, Device-related Vegetations.

As the number and complexity of cardiovascular implantable electronic devices has increased, so too has the incidence of device-related infections. Such a rise requires that the focus be directed toward developing universal standards for infected lead removal. To date, no consensus currently exists regarding the optimal management of patients with large vegetations (diameter > 2 cm). In these individuals, medical therapy is universally ineffective and they are often too ill for surgical extraction; furthermore, transvenous lead extraction (TLE) carries with it a risk of large septic pulmonary emboli. We present a series of five cases in which the AngioVac thrombectomy system (AngioDynamics Inc., Latham, NY, USA) was used as an adjunct to TLE. Debridement of infected leads prior to percutaneous lead extraction was accomplished as either a bridge to or as concomitant therapy with laser lead removal at our institution. This study included three males and two females with an average age of 52 years. The sizes of vegetations removed from leads ranged from 1.5 cm to 3.9 cm in the largest dimension and the average diameter was 2.65 cm ± 1.1 cm. The vegetations were successfully debulked in all five patients. This suggests that TLE performed with assistance from the AngioVac system (AngioDynamics Inc., Latham, NY, USA) is a safe and effective alternative to open surgical lead removal in patients with large lead vegetations.

Characterization of Ribozymes Targeting a Congenital Night Blindness Mutation in Rhodopsin Mutation.

The G90D mutation in the rhodopsin gene leads to autosomal dominant congenital stationary night blindness (CSNB) in patients. This occurs because the G90D mutant protein cannot efficiently bind chromophore and is constitutively active. To combat this mutation, we designed and characterized two different hammerhead ribozymes to cleave G90D transcript. In vitro testing showed that the G90D1 ribozyme efficiently and specifically cleaved the mutant transcript while G90D2 cleaved both WT and mutant transcript. AAV-mediated delivery of G90D1 under the control of the mouse opsin promoter (MOP500) to G90D transgenic eyes showed that the ribozyme partially retarded the functional degeneration (as measured by electroretinography [ERG]) associated with this mutation. These results suggest that with additional optimization, ribozymes may be a useful part of the gene therapy knockdown strategy for dominant retinal disease.

Short alleles, bigger smiles? The effect of 5-HTTLPR on positive emotional expressions.

The present research examined the effect of the 5-HTTLPR polymorphism in the serotonin transporter gene on objectively coded positive emotional expressions (i.e., laughing and smiling behavior objectively coded using the Facial Action Coding System). Three studies with independent samples of participants were conducted. Study 1 examined young adults watching still cartoons. Study 2 examined young, middle-aged, and older adults watching a thematically ambiguous yet subtly amusing film clip. Study 3 examined middle-aged and older spouses discussing an area of marital conflict (that typically produces both positive and negative emotion). Aggregating data across studies, results showed that the short allele of 5-HTTLPR predicted heightened positive emotional expressions. Results remained stable when controlling for age, gender, ethnicity, and depressive symptoms. These findings are consistent with the notion that the short allele of 5-HTTLPR functions as an emotion amplifier, which may confer heightened susceptibility to environmental conditions.

Behaviour, physiology and experience of pathological laughing and crying in amyotrophic lateral sclerosis.

Pathological laughing and crying is a disorder of emotional expression seen in a number of neurological diseases. The aetiology is poorly understood, but clinical descriptions suggest a disorder of emotion regulation. The goals of this study were: (i) to characterize the subjective, behavioural and physiological emotional reactions that occur during episodes of pathological laughing and crying; (ii) to compare responses during these episodes to those that occur when emotions are elicited under standard conditions (watching sad and amusing emotional films, being startled); and (iii) to examine the ability of patients with this disorder to regulate their emotions under standardized conditions. Twenty-one patients with pathological laughing and crying due to amyotrophic lateral sclerosis and 14 with amyotrophic lateral sclerosis but no pathological laughing and crying were studied. Emotional measures included self-reported emotional experience, video recordings of facial reactivity and peripheral physiological responses (skin conductance, heart rate and somatic activity). Nineteen of the 21 patients with histories of pathological laughing and crying had at least one episode in the laboratory that they agreed constituted pathological laughing or crying (a total of 56 episodes were documented). Compared with viewing sad and amusing films, the episodes were associated with greater facial and physiological activation. Contrary to many clinical descriptions, episodes were often induced by contextually appropriate stimuli and associated with strong experiences of emotion that were consistent with the display. When instructed to regulate their facial responses to emotion-eliciting films, patients with pathological laughing and crying showed impairments compared with patients who did not have a history of this disorder. These findings support the idea that pathological laughing and crying represents activation of all channels of emotional responding (i.e. behavioural, physiological and subjective). Furthermore, they support previously advanced theories that, rather than being associated with general emotional hyperreactivity, this disorder may be due to dysfunction in frontal neural systems that support voluntary regulation of emotion.

Greater sadness reactivity in late life.

Although previous research suggests that overall emotional reactivity does not change with normal aging, it is possible that different emotions follow different developmental courses. We examined emotional reactivity to films selected to elicit sadness, disgust, and a neutral state in young, middle-aged and older adults (total N = 222). Physiology and expressive behavior were measured continuously and reports of subjective emotional experience were obtained following each film. Results indicated that older adults reported greater sadness in response to all films and greater physiological responses to the sadness film than did the younger age groups. There were no age differences found in self-reported disgust or in behavioral expressions of sadness or disgust in response to any film. The age differences that were found were maintained even after controlling for pre-film self-reported sadness and for personal experiences of loss. These findings support the notion that sadness reactivity is heightened with age.

Motivational interviewing versus prescriptive advice for smokers who are not ready to quit.

OBJECTIVE: Smokers who are not ready to quit are a very difficult group to treat. Physicians, nurses, and nurse practitioners are in a unique position to encourage patients to quit smoking. However, the best approach to do so is not clear. METHODS: A two-group randomized controlled trial with 218 pack-a-day precontemplative and contemplative smokers recruited from the community. The laboratory-based study was designed to simulate outpatient visits to general practitioners. Participants were randomized to a 15-min intervention to compare the effectiveness of brief motivational or prescriptive counseling by a health professional. Thirteen outcome variables included intentions to quit and verbal reports at 1 and 6 months with biological verification. A composite outcome measure was constructed to provide greater power to detect study differences. RESULTS: Approximately 33% of the sample reported at least one 24-h quit period during the 6 months they were followed after the trial. Results suggest that while neither treatment was superior, there were subgroup differences. Participants in the motivational condition were also more likely to respond to follow-up calls. CONCLUSIONS AND PRACTICE IMPLICATIONS: Motivational interviewing and prescriptive advice were equally effective for precontemplative and contemplative smokers. Practitioners should use the method that appeals to them.

Stretch-activated receptors mediate cardiac memory.

BACKGROUND: Cardiac memory refers to long-lasting T-wave changes that follow an episode of altered ventricular activation sequence. Memory-induced alterations in repolarizing ion channel activity have been characterized. However, the mechanism by which changes in activation sequence produce these effects is unknown. We hypothesized that cardiac memory is mediated by the response of stretch-activated receptors (SARs) to a change in mechanical activation sequence. METHODS: In anesthetized, closed-chest dogs, coronary sinus leads were used to pace the posterolateral left ventricle (LV) continuously for 1 hour at a rate of 120 bpm. The surface vectorcardiogram was used to quantify cardiac memory by measuring T-wave displacement after pacing. Streptomycin, which has been shown to block SARs, was given at a dose of 4 g intramuscularly 1 hour before experimental LV pacing sessions. T-wave displacement after control sessions of LV pacing in the absence of drug (n = 12) was compared to that produced by pacing after streptomycin administration (n = 10 sessions). RESULTS: There was a distinct and consistent cardiac memory seen after 1 hour of LV pacing under control conditions, with T-wave displacement of 1.28 +/- 0.43 mV (P < 0.001 vs baseline). Pretreatment with streptomycin had no direct effect on the electrocardiogram or hemodynamics, but decreased pacing-induced T-wave displacement to 0.50 +/- 0.28 mV (P < 0.001 vs control sessions). CONCLUSIONS: Streptomycin, a SAR blocker, dramatically attenuated the development of cardiac memory following epicardial pacing. These data suggest that SARs are a critical link between mechanical sequence of activation and regional modulation of action potential duration that is responsible for cardiac memory.