Optimizing Patient Selection for Physiological Pacing in Bradyarrhythmia: Factors Associated With High Ventricular Pacing Burden

Background

Right ventricular (RV) pacing is established as the most common ventricular pacing (VP) strategy for patients with symptomatic bradyarrhythmia. Some patients with high VP burden suffer deterioration of left ventricular (LV) function, termed pacing-induced cardiomyopathy (PICM). Patients who pace > 20% of the time from the RV apex are at increased risk of PICM, but independent predictors of increased RV pacing burden have not been elucidated in those who have a permanent pacemaker (PPM) inserted for bradyarrhythmia.

Methods

We aimed to identify factors that are associated with increased VP burden > 20%, hence determining those at risk for resultant PICM. In this retrospective cohort study, we identified the most recent 300 consecutive cardiac implantable electronic device (CIED) implants in our center and collected past medical history, electrocardiogram (ECG), echo, medication and pacemaker check data.

Results

A total of 236 individuals met inclusion criteria. Of the patients, 35% had RV pacing burden < 20%, while 65% had VP burden ≥ 20%; 96.2% of patients with complete heart block (CHB) paced > 20% (P = 0.002). Utilization of DDD or VVI (75.2% and 89.2% of patients, respectively) without mode switch algorithms was associated with VP > 20% (P < 0.001). Male or previous coronary artery bypass grafting (CABG) patients also statistically paced > 20%. Other factors trending towards significance included prolonged PR interval, atrial fibrillation or more advanced age.

Conclusion

High-grade atrioventricular (AV) block was associated with an RV pacing burden > 20% over 3 years but this was not consistent in patients with only transient episodes of high-grade AV block. We found a significant association between high VP% and male sex, previous CABG and the absence of mode switching algorithms.

Left bundle branch area pacing as a first line pacing strategy, which patients should we consider?

Background

A higher right ventricular (RV) pacing burden in those with permanent pacemakers results in accelerated pacing induced cardiomyopathy, in addition to increased incidence of heart failure and mortality [1–3]. This process may necessitate upgrade to a biventricular system in time, as the cardiomyopathy progresses. Physiological conduction system pacing targets such as His-bundle pacing (HBP) or Left Bundle Branch Area Pacing (LBBAP) have been shown to generate comparatively narrower QRS complexes and thus mitigate this cardiomyopathy development [4,5].

The 2021 ESC guidelines have a class 2b indication for consideration of HBP as an alternative to RV pacing in those with AV block and left ventricular ejection fraction &gt;40%, who are anticipated to have &gt;20% ventricular pacing burden [6].

Purpose

To retrospectively identify ECG, echocardiographic, permanent pacemaker (PPM) setting and patient factors associated with high RV pacing burden that may aid selection of those who may benefit from conduction system pacing (CSP).

Methods

We retrospectively identified 300 consecutive patients who underwent cardiac implantable electronic device insertion in our Electrophysiology Lab from the years 2017–2018. We excluded patients who underwent generator replacements, in addition to those who had biventricular devices or implantable cardioverter defibrillators inserted. We collated ECG, echo, past medical history and pacing data for each patient over a three-year follow up period.

Data were analysed using SPSS v.26.

Results

160 patients met inclusion criteria. Those with an RV pacing burden &gt;20% were categorised group one (n=85) and those with &lt;20% in group two (n=75). Baseline characteristics of these two groups are compared in Table 1 and Table 2.

Our analysis showed that significant differences between these groups included a lower mean HR (Table 1) (55.1±17.8 vs 57.63±17.4) with a more prolonged PR interval (225.7ms ± 8.34 vs. 188.6ms ± 6.62) or atrial fibrillation/flutter (AF/AFL) on admission ECG. There were more males with a greater mean age (High Ventricular Paced (VP) = 76.6 years ± 8.4 vs Low VP = 71.23 years ± 12.3) in the higher VP group, and they demonstrated more incidence of dilated RA/RV on echo (Enlarged RA = 30.5%; Enlarged RV = 23.6% vs 10% and 8.4% respectively).

There were significant differences in PPM indications and setting between groups (Table 2), with the higher VP groups having PPM inserted for persistent high-grade AV block (CHB = 31.5% vs 4.9% and Mobitz 2 = 9.6% vs 0%) and had less MVP mode activated (Mode switch algorithm = 13.3% vs 71%).

Conclusion

Our data suggests that those with persistent high grade AV block such as Mobitz 2 or CHB should be considered for CSP. Other considerations include older age, male sex, dilated RV/RA, prolonged PR, lower intrinsic HR or AF/AFL on admission ECG. PPM mode switching settings to reduce RV pacing burden should be utilised where possible.

Funding Acknowledgement

Type of funding sources: None.

OP0274-PARE EVALUATION OF PATIENT SATISFACTION FOR TELEHEALTH (PHONE AND VIDEO) IN RHEUMATOLOGY OUTPATIENTS DURING COVID-19 PANDEMIC

Background:

Telehealth via phone (TPhone) or video conference (TVideo) in rheumatology has been a topic of interest for many years. Its use was rapidly expanded due to the international public health emergency of coronavirus disease-19 (COVID-19) outbreak in 2020. Australian Medicare Benefits Schedule (MBS) swiftly enabled temporary MBS telehealth items on 13 March 2020, currently extended until 31 March 20211. In the early phase of the COVID-19 pandemic, Antony et al. conducted a single-centre public survey to assess patient perception of rheumatology telehealth. Their results showed that 98.4% of patients consider telehealth acceptable during the pandemic2. It is unclear, however, whether this positive perception persists after patients experience a telehealth. In addition, a survey data in 2019 suggested more than half of Australian rheumatologists work in private practice3. Therefore, inclusion of private patients will better represent patient perception of telehealth.

Objectives:

The aim of this study was to evaluate patient satisfaction with telehealth during the COVID-19 pandemic. This would determine its feasibility to be integrated in future rheumatology outpatient model.

Methods:

A questionnaire containing 30 questions was sent to rheumatology patients who attended telehealth appointments at a level 2 public hospital and a local private clinic between April and May 2020. The questionnaires aimed to obtain information on baseline demographics (sex, age, public or private patient, employment status, visual or auditory impairment), appointment details (TPhone or TVideo, usual arrangement for face-to-face (F2F) appointment, cost effectiveness) and appointment satisfaction using a 5-point Likert scale. Descriptive statistical analysis was conducted.

Results:

The questionnaire was sent to 1452 patients, of which 494 patients responded (34%). Female predominance (77.1%) and a higher proportion of TPhone (79.1%) was seen in the respondents. A majority of patients were existing patients known to the services (90.9%). More than 70% of responses indicated overall satisfaction in specialist care via telehealth, and 88.7% perceived this suitable during a pandemic. Of all respondents, 21.7% were prescribed new medication, and the majority of these patients were confident in taking the new medication after the telehealth appointment. Future acceptability for TPhone was significantly lower in private patients compared to public patients (p= 0.01). Subgroup analysis revealed that higher telehealth satisfaction was associated with needing to take time off work to attend face-to-face appointment (p= 0.02), perception of cost effectiveness (p<0.001) and TVideo (p=0.03).

Conclusion:

This is the first study which included both public and private rheumatology patients to evaluate patient satisfaction for telehealth during the COVID-19 pandemic. Overall high level of satisfaction was seen in telehealth most notably associated with its cost effectiveness. A higher percentage of patients who had TVideo compared to TPhone were receptive to future telehealth via TVideo, supportive of the importance of visual cues. This in turn will have significant administrative and technological burdens to coordinate in comparison to a F2F or TPhone review. This qualitative study provides valuable insight of patient perception of telehealth, which has the potential to compliment the traditional rheumatology outpatient model of care following the pandemic.

References:

[1]COVID-19 Temporary MBS Telehealth Services 2020 [Available from: http://www.mbsonline.gov.au/internet/mbsonline/publishing.nsf/Content/Factsheet-TempBB.

[2]Antony A, Connelly K, De Silva T, Eades L, Tillett W, Ayoub S, et al. Perspectives of Patients With Rheumatic Diseases in the Early Phase of COVID-19. Arthritis Care & Research. 2020;72(9):1189-95.

[3]Association AR. Workforce Survey Exective Summary 2019 2019 [Available from: https://rheumatology.org.au/members/documents/WorkforceSurveyExecutiveSummary-websiteMay2019.pdf.

Acknowledgements:

University of Queensland

Nursing staff at Redcliffe Hospital and Administration officers at Redcliffe & Northside Rheumatology

Disclosure of Interests:

None declared

The association of middle ear effusion with trigeminal nerve mass lesions in dogs

The trigeminal nerve is involved in the opening of the pharyngeal orifice of the Eustachian tube by operating the tensor veli palatini muscle. The hypothesis was investigated that middle ear effusion occurs in a more severe disease phenotype of canine trigeminal nerve mass lesions compared with dogs without middle ear effusion. Three observers reviewed canine MRIs with an MRI-diagnosis of trigeminal nerve mass lesion from three institutions. Various parameters describing the musculature innervated by the trigeminal nerve were scored and compared between dogs with and without middle ear effusion. Nineteen dogs met the inclusion criteria. Ipsilateral middle ear effusion was observed in 63 per cent (95% CI 48.4 per cent to 77.6 per cent) of the dogs. The size of the trigeminal nerve mass lesions was positively correlated with the severity of masticatory muscle mass loss (Spearman r=0.5, P=0.03). Dogs with middle ear effusion had a significantly increased generalised masticatory muscle mass loss (P=0.02) or tensor veli palatini muscle loss score (P=0.03) compared with those without. Larger trigeminal nerve mass lesions were associated with a greater degree of masticatory muscle mass loss. Masticatory muscle mass and, importantly, tensor veli palatini muscle mass was more severely affected in dogs with middle ear effusion suggesting an associated Eustachian tube dysfunction.

Urinary, faecal and sexual dysfunction in patients with multiple sclerosis

The prevalence and nature of bladder and bowel dysfunction were examined in a population-based study of 221 patients with multiple sclerosis who returned postal questionnaires. This preliminary investigation was supplemented by personal review which also provided information on sexual dysfunction in 174 and laboratory and urodynamic tests in 152 participants. Thirty of 221 (14%) currently used an indwelling catheter, and 84 of the remaining 190 (44%) reported symptoms of urinary dysfunction, of which the most common were urgency and frequency. Thirteen of 144 (9%) patients had biochemical evidence of renal dysfunction, and 40 of 132 (30%) had infected urine samples. Eleven of 54 patients in whom investigation of upper urinary tract was thought to be appropriate demonstrated abnormalities. Sixty-four of 221 (29%) patients had experienced faecal incontinence, and 120 of 221 (54%) were constipated. Fifty-six of 68 (82%) men and 55 of 106 (52%) women reported a deterioration in sexual activity, the commonest symptoms being erectile failure in men and fatigue in women.

Dose-dependent decrements in adult male rat sexual behavior after neonatal clorimipramine treatment

Previous studies found that months after clorimipramine (CLI) treatment of male neonatal rats, the mature animals developed behavioral deficits and REM sleep abnormalities that modeled human endogenous depression. In the initial studies neonatal rats received CLI 30 mg/kg/IP daily from age 8 through 21 days. Diminished sexual activity of the adult rats treated neonatally in this manner was a behavioral deficit that supported the depression model. However, in subsequent studies in our laboratory, the same neonatal treatment occasionally failed to produce adult sexual deficiencies found in the initial studies. The inconsistency raised the possibility that neonatal CLI treatment was not a reliable method to produce an animal model of depression. An alternative hypothesis was that the CLI dose was too low. The present study tested this hypothesis. Placebo or one of four CLI doses was administered daily to male neonatal rats (n = 12/treatment group) from age 8 days through 21 days: 30 (the original dose), 40, 50, and 60 mg/kg/IP. Six components of adult sexual behavior were measured at age 5 months. Deficiency of each sexual behavior was found to be dose-dependent (r = 0.5, p < 0.001). The 30 mg/kg/day dose caused deficiencies in some, but not all, sexual behavior measures. Higher doses caused deficiencies in all measures of sexual behavior. The results support the hypothesis that neonatal CLI treatment at doses higher than the original 30 mg/kg/day caused reliable impairments in adult male rat sexual behavior, and therby support the reliability of neonatal CLI treatment to produce an animal model of endogenous depression.

Diminished sexual activity in a new animal model of endogenous depression

Our laboratory has proposed a new animal model of endogenous depression. The proposal is that in rats neonatal clomipramine (CLI) produces adult animals that model endogenous depression. Diminished sexual activity is a salient behavioral abnormality found in endogenous depression. This suggests that an animal model of endogenous depression should show diminished sexual activity. We report here a test of the prediction that after neonatal treatment with CLI, adult male rats show decreased sexual activity. We found that after neonatal CLI, adult male Long-Evans rats had a pervasive diminution of sexual activities including decreased mounts, intromissions, ejaculations, and increased mount latencies and postejaculatory pause. Sprague-Dawley and Wistar strains also tended to show decreased intromissions and ejaculations, but their baseline sexual activity was too low to give interpretable data. The results with the sexually active Long-Evans strain are consistent with the hypothesis that neonatal CLI produces adult rats that model human endogenous depression.

Drug effects on REM sleep and on endogenous depression

In earlier work REM sleep deprivation (RSD) by arousals improved endogenous depression. This suggested that drugs producing a similar RSD would have antidepressant activity. The arousal RSD was large, persisted for weeks, and was followed by a REM rebound. We call RSD with these properties arousal-type RSD. The present study reviewed literature from 1962 to 1989 on drug REM sleep effects to examine the hypothesis that drugs producing arousal-type RSD improve endogenous depression. The literature reviewed concerned the REM sleep effects of amine precursors, antidepressants, antihistamines, antipsychotics, barbiturates, benzodiazepines, other hypnotics, drugs affecting cholinergic and noradrenergic neurotransmission, ethanol, lithium and narcotics. Four hundred and sixty-eight relevant papers were read and 215 contributed information that could be used in the review. The findings indicated that all drugs producing arousal-type RSD improved endogenous depression. Four drugs that improved endogenous depression did not produce arousal-type RSD.