Bradycardia risk stratification with implantable loop recorder after unexplained syncope

BACKGROUND

An implantable loop recorder is an effective tool for diagnosing unexplained syncope. However, after a first episode in non-high-risk patients, the usefulness of implantable loop recorder implantation remains unclear.

AIMS

To analyse relevant risk factors for significant bradycardia in order to identify patients who do or do not benefit from implantable loop recorder implantation. Also, to study whether implantable loop recorder implantation with remote monitoring is associated with less recurrence of traumatic syncope.

METHODS

This was a retrospective monocentric study including patients with implantable loop recorder implantation after unexplained syncope, using remote monitoring and iterative consultations.

RESULTS

Two hundred and thirty-seven patients were implanted for unexplained syncope. Significant bradycardia occurred in 53 patients (22.4%): 23 (43.4%) caused by paroxysmal atrioventricular block and 30 (56.6%) caused by sinus node dysfunction, leading to permanent pacemaker implantation in 48 patients. Compared with younger patients, there was a 3.46-fold increase (95% confidence interval 1.92-6.23; P<0.0001) in the risk of significant bradycardia in patients aged≥60 years. Based on multivariable analysis, only "typical syncope" was associated with significant bradycardia occurrence (hazard ratio 3.14, 95% confidence interval 1.75-5.65; P=0.0001). There was no recurrence of significant bradycardia with traumatic complications among patients implanted for traumatic syncope.

CONCLUSIONS

This study shows that: (1) implantable loop recorders identify more significant bradycardia in patients aged≥60 presenting with a first non-high-risk typical syncope, suggesting that an implantable loop recorder should be implanted after a first episode of unexplained syncope in such conditions; and (2) after traumatic syncope, implantable loop recorder implantation is safe, and is associated with little or no recurrence of traumatic syncope.

Asystole on loop recorder in patients with unexplained syncope and negative tilt testing: age distribution and clinical predictors

BACKGROUND

Approximately 50% of patients with unexplained syncope and negative head-up tilt test (HUTT) who have an electrocardiogram (ECG) documentation of spontaneous syncope during implantable loop recorder (ILR) show an asystolic pause at the time of the event.

OBJECTIVE

The aim of the study was to evaluate the age distribution and clinical predictors of asystolic syncope detected by ILR in patients with unexplained syncope and negative HUTT.

METHODS

This research employed a retrospective, single-center study of consecutive patients. The ILR-documented spontaneous syncope was classified according to the International Study on Syncope of Uncertain Etiology (ISSUE) classification.

RESULTS

Among 113 patients (54.0 ± 19.6 years; 46% male), 49 had an ECG-documented recurrence of syncope during the observation period and 28 of these later (24.8%, corresponding to 57.1% of the patients with a diagnostic event) had a diagnosis of asystolic syncope at ILR: type 1A was present in 24 (85.7%), type 1B in 1 (3.6%), and type 1C in 3 (10.7%) patients. The age distribution of asystolic syncope was bimodal, with a peak at age < 19 years and a second peak at the age of 60-79 years. At Cox multivariable analysis, syncope without prodromes (OR 3.7; p = 0.0008) and use of beta blockers (OR 3.2; p = 0.002) were independently associated to ILR-detected asystole.

CONCLUSIONS

In patients with unexplained syncope and negative HUTT, the age distribution of asystolic syncope detected by ILR is bimodal, suggesting a different mechanism responsible for asystole in both younger and older patients. The absence of prodromes and the use of beta blockers are independent predictors of ILR-detected asystole.

A Study of Spectrum of Cardiac Rhythm Disturbance after Acute Ischemic Stroke Using 24 Hours Holter Monitoring

Studies have reported that acute stroke leads to imbalance of central autonomic control; stroke can cause over activity of sympathetic or parasympathetic control, myocardial injury, ECG abnormalities, cardiac arrhythmias and even sudden death. Studies support the notion that patients with acute cerebrovascular events are susceptible to cardiac arrhythmias.

MATERIAL

This cross Sectional Study was conducted in over a period of One and half year duration and included subjects of acute ischemic stroke confirmed by brain imaging. After performing a 12 lead ECG in emergency ward, all eligible stroke patients were subjected to 24 hour Holter monitoring.

OBSERVATION

Out of 92 stroke patients, 35.28% had abnormal ECG. Changes included LVH in 10.87%, T wave inversion in 9.78%, ST segment depression in4.35%% followed by QTc prolongation 3.26% .24 hours Holter monitoring revealed that common cardiac rhythm disturbances were ventricular ectopics (44.57%) supraventricular ectopics (30.43%), supraventricular tachycardia (11.96%), atrial fibrillation (7.60%). Amongst brady-arrhythmias sinus pause was detected in 1.09%.

CONCLUSION

ECG changes occur commonly in case of acute ischemic stroke, even in those having no history of coronary heart disease as suggested clinically. Identification of paroxysmal Atrial Fibrilation episodes is important due to its relevance for planning of long-term treatment.

Scanning of paroxysmal atrial fibrillation as an etiological risk factor in patients with acute ischemic stroke: prospective study

BACKGROUND

Prevention of recurrence of stroke depends on recognition of the underlying mechanism of ischemia.

OBJECTIVE

To screen patients who were hospitalized with diagnosis of acute ischemic stroke in terms of atrial fibrillation (AF) with repeated Holter electrocardiography recordings.

DESIGN AND SETTING

Prospective study conducted at Konya Education and Research Hospital, Turkey.

METHODS

Patients with a diagnosis of acute ischemic stroke, without atrial fibrillation on electrocardiography (ECG), were evaluated. Their age, gender, histories of previous ischemic attack, occurrences of paroxysmal atrial fibrillation (PAF) and other risks were assessed during the first week after acute ischemic stroke and one month thereafter. ECG recordings were obtained from 130 patients through 24-hour ambulatory Holter. Patients without PAF attack during the first Holter were re-evaluated.

RESULTS

PAF was detected through the first Holter in 33 (25.4%) out of 130 acute ischemic stroke patients. A second Holter was planned for 97 patients: 53 (54.6%) of them could not attend due to COVID-19 pandemic; while 44 (45.3%) patients had the second Holter and, among these, 4 (9.1%) had PAF. The only parameter associated with PAF was older age. Four (10.8%) of the 37 patients with PAF had also symptomatic carotid stenosis.

CONCLUSIONS

Detecting the presence of PAF by screening patients with no AF in the ECG through Holter ECG examinations is valuable in terms of changing the course of the treatment. It should be kept in mind that the possibility of accompanying PAF cannot be ruled out in the presence of other factors that pose a risk of stroke.

Palpitations: Evaluation and management by primary care practitioners

Palpitations are a common, non-specific presenting complaint in primary healthcare and emergency departments. Palpitations are mostly a symptom of benign underlying disease but a sign of life-threatening conditions. Importantly, palpitations are a symptom and not a diagnosis, and cardiac causes are the most concerning aetiology. Clinicians should seek to identify the underlying cause. History and physical examination are important in the assessment of patients with palpitations, and the use of a 12-lead electrographic (ECG) monitor on presentation is the gold standard of diagnosis. If the aetiology cannot be determined, an ambulatory Holter 24–48-h monitor can be used. Treatment and follow-up of patients presenting with palpitations as the main complaint will depend on the aetiology and investigation findings. Patients with palpitations accompanied by dizziness, excessive fatigue, or chest pains should receive adequate acute care aiming to stabilise their condition before referring to a higher level of care.

Effect of Implantable vs Prolonged External Electrocardiographic Monitoring on Atrial Fibrillation Detection in Patients With Ischemic Stroke: The PER DIEM Randomized Clinical Trial

IMPORTANCE

The relative rates of detection of atrial fibrillation (AF) or atrial flutter from evaluating patients with prolonged electrocardiographic monitoring with an external loop recorder or implantable loop recorder after an ischemic stroke are unknown.

OBJECTIVE

To determine, in patients with a recent ischemic stroke, whether 12 months of implantable loop recorder monitoring detects more occurrences of AF compared with conventional external loop recorder monitoring for 30 days.

DESIGN, SETTING, AND PARTICIPANTS

Investigator-initiated, open-label, randomized clinical trial conducted at 2 university hospitals and 1 community hospital in Alberta, Canada, including 300 patients within 6 months of ischemic stroke and without known AF from May 2015 through November 2017; final follow-up was in December 2018.

INTERVENTIONS

Participants were randomly assigned 1:1 to prolonged electrocardiographic monitoring with either an implantable loop recorder (n = 150) or an external loop recorder (n = 150) with follow-up visits at 30 days, 6 months, and 12 months.

MAIN OUTCOMES AND MEASURES

The primary outcome was the development of definite AF or highly probable AF (adjudicated new AF lasting ≥2 minutes within 12 months of randomization). There were 8 prespecified secondary outcomes including time to event analysis of new AF, recurrent ischemic stroke, intracerebral hemorrhage, death, and device-related serious adverse events within 12 months.

RESULTS

Among the 300 patients who were randomized (median age, 64.1 years [interquartile range, 56.1 to 73.7 years]; 121 were women [40.3%]; and 66.3% had a stroke of undetermined etiology with a median CHA2DS2-VASc [congestive heart failure, hypertension, age ≥75 years, diabetes, stroke or transient ischemic attack, vascular disease, age 65 to 74 years, sex category] score of 4 [interquartile range, 3 to 5]), 273 (91.0%) completed cardiac monitoring lasting 24 hours or longer and 259 (86.3%) completed both the assigned monitoring and 12-month follow-up visit. The primary outcome was observed in 15.3% (23/150) of patients in the implantable loop recorder group and 4.7% (7/150) of patients in the external loop recorder group (between-group difference, 10.7% [95% CI, 4.0% to 17.3%]; risk ratio, 3.29 [95% CI, 1.45 to 7.42]; P = .003). Of the 8 specified secondary outcomes, 6 were not significantly different. There were 5 patients (3.3%) in the implantable loop recorder group who had recurrent ischemic stroke vs 8 patients (5.3%) in the external loop recorder group (between-group difference, -2.0% [95% CI, -6.6% to 2.6%]), 1 (0.7%) vs 1 (0.7%), respectively, who had intracerebral hemorrhage (between-group difference, 0% [95% CI, -1.8% to 1.8%]), 3 (2.0%) vs 3 (2.0%) who died (between-group difference, 0% [95% CI, -3.2% to 3.2%]), and 1 (0.7%) vs 0 (0%) who had device-related serious adverse events.

CONCLUSIONS AND RELEVANCE

Among patients with ischemic stroke and no prior evidence of AF, implantable electrocardiographic monitoring for 12 months, compared with prolonged external monitoring for 30 days, resulted in a significantly greater proportion of patients with AF detected over 12 months. Further research is needed to compare clinical outcomes associated with these monitoring strategies and relative cost-effectiveness.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02428140.

Effect of Long-term Continuous Cardiac Monitoring vs Usual Care on Detection of Atrial Fibrillation in Patients With Stroke Attributed to Large- or Small-Vessel Disease: The STROKE-AF Randomized Clinical Trial

IMPORTANCE

Patients with ischemic stroke attributed to large- or small-vessel disease are not considered at high risk for atrial fibrillation (AF), and the AF incidence rate in this population is unknown.

OBJECTIVES

To determine whether long-term cardiac monitoring is more effective than usual care for AF detection in patients with stroke attributed to large- or small-vessel disease through 12 months of follow-up.

DESIGN, SETTING, AND PARTICIPANTS

The STROKE-AF trial was a randomized (1:1), multicenter (33 sites in the US) clinical trial that enrolled 496 patients between April 2016 and July 2019, with primary end point follow-up through August 2020. Eligible patients were aged 60 years or older or aged 50 to 59 years with at least 1 additional stroke risk factor and had an index stroke attributed to large- or small-vessel disease within 10 days prior to insertable cardiac monitor (ICM) insertion.

INTERVENTIONS

Patients randomized to the intervention group (n = 242) received ICM insertion within 10 days of the index stroke; patients in the control group (n = 250) received site-specific usual care consisting of external cardiac monitoring, such as 12-lead electrocardiograms, Holter monitoring, telemetry, or event recorders.

MAIN OUTCOMES AND MEASURES

Incident AF lasting more than 30 seconds through 12 months.

RESULTS

Among 492 patients who were randomized (mean [SD] age, 67.1 [9.4] years; 185 [37.6%] women), 417 (84.8%) completed 12 months of follow-up. The median (interquartile range) CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, stroke or transient ischemic attack, vascular disease, age 65 to 74 years, sex category) score was 5 (4-6). AF detection at 12 months was significantly higher in the ICM group vs the control group (27 patients [12.1%] vs 4 patients [1.8%]; hazard ratio, 7.4 [95% CI, 2.6-21.3]; P < .001). Among the 221 patients in the ICM group who received an ICM, 4 (1.8%) had ICM procedure-related adverse events (1 site infection, 2 incision site hemorrhages, and 1 implant site pain).

CONCLUSIONS AND RELEVANCE

Among patients with stroke attributed to large- or small-vessel disease, monitoring with an ICM compared with usual care detected significantly more AF over 12 months. However, further research is needed to understand whether identifying AF in these patients is of clinical importance.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02700945.

Frequent Premature Atrial Contractions as a Poor Prognostic Factor in Cryptogenic Stroke Patients with Concomitant Non-Sustained Atrial Tachycardia

In cryptogenic stroke patients, early detection of new-onset atrial fibrillation (AF) and recurrent stroke is required to prevent poor clinical outcomes. Therefore, we investigated the predictors of new-onset AF and recurrent stroke in cryptogenic stroke patients without previously diagnosed AF. In total, 390 patients who were diagnosed with stroke and non-sustained atrial tachycardia (NSAT) on 24-hour Holter monitoring were followed up to assess new-onset AF and recurrent stroke. The 5-year event-free survival as well as the predictors of recurrent stroke or new-onset AF were investigated. Based on receiver operating characteristic analysis, frequent premature atrial contractions (PACs) were defined as PACs >44 beats/day. The median follow-up period was 35 months. The composite event rate was 11.5%. In Kaplan-Meier analysis, the 5-year cumulative incidence of composite events was higher in cryptogenic stroke patients with frequent PACs than in those without frequent PACs. Multivariate analysis revealed that current smoking, increased left atrial volume index, and frequent PACs were poor prognostic predictors of composite event, and frequent PACs were an independent poor prognostic factor of new-onset AF in cryptogenic stroke patients. Therefore, frequent PACs might be associated with poor clinical outcomes (new-onset AF and recurrent stroke) in cryptogenic stroke patients with concomitant NSAT.

The implantable loop recorder in children

OBJECTIVE

To evaluate use of the implantable loop recorder in children.

SETTING

Royal Hospital for Sick Children, Glasgow, UK.

METHOD

Retrospective study of children who had an implantable loop recorder between September 1998 and October 2005.

RESULTS

38 devices were implanted in 34 children. Median age at implantation 11.3 years (range 1.8-17.6); median follow-up period 15 months (range 2-58). The main presenting complaint was syncope in 26 (76.5%), seizures in 6 (17.6%) and palpitations in 2 (5.9%). After implantation, 19 (55.9%) patients had symptom recurrence. Of these, 11 were shown to have sinus rhythm during symptoms and 8 had an abnormal ECG. Four patients had asystole >3 seconds and were diagnosed with reflex asystolic syncope; 2 had polymorphic ventricular tachycardia. One patient who already had a diagnosis of long QT syndrome was shown to have ventricular ectopy during symptoms and beta-blockers were increased. One patient had transient complete heart block during symptoms but refused a pacemaker. In almost half the patients (44.1%), symptoms resolved after implantation. Complications requiring removal of the device occurred in 6 (15.8%) implants.

CONCLUSIONS

In children with syncope and palpitations, the implantable loop recorder appears to be an excellent method of effecting a "cure" in almost 50% of subjects. For those who remain symptomatic, it is successful in determining cardiac rhythm during symptoms, but the complication rate in children may be higher than that of adults.

Implantable hemodynamic monitoring (the Chronicle IHM system): remote telemonitoring for patients with heart failure

(1) Remote monitoring for ambulatory heart failure patients uses an implantable device to record hemodynamic data and transmit it to a central server for continuous assessment. (2) Preliminary evidence from observational studies suggests a potential for reducing hospitalizations with the use of right ventricle implantable hemodynamic monitoring (IHM). However, although a multicentre, randomized controlled trial (COMPASS-HF) showed a reduction in hospitalizations in the IHM group the results were not statistically significant and the US Food and Drug Administration panel concluded the trial failed to meet its primary efficacy endpoint. (3) In the COMPASS-HF study the most common device-related complication was lead dislodgement. (4) Large randomized controlled trials are needed to demonstrate the clinical utility of IHM, particularly in terms of its impact on reducing hospitalization and improving patient outcomes.

Efficacy of implantable loop recorders in establishing symptom-rhythm correlation in young patients with syncope and palpitations

OBJECTIVE

To evaluate efficacy of the recently introduced implantable loop recorder (ILR) in establishing symptom-rhythm correlation in young patients with syncope, near syncope, palpitations, and acute life-threatening events (ALTEs).

METHODS

A retrospective study was conducted with patients with ILR from 3 pediatric centers. Inclusion criteria were age <or=25 years and a minimum follow-up of 1 month. All ILR-stored events were analyzed regularly for the presence or absence of an arrhythmia at the time of the symptomatic event.

RESULTS

Twenty-one patients (12 male, 9 female) with an average age of 12.3 +/- 5.3 years (range: 0.8-22 years) were included in the study. Five (24%) patients had structural heart disease, 2 (10%) had a family history of sudden cardiac death, 3 (14%) had QT prolongation on electrocardiogram, and 11 had no cardiovascular disease. Indications for ILR were recurrent syncope and near syncope (n = 15), palpitations (n = 2), and ALTE (n = 2). Fourteen (67%) patients continued to have symptoms, and 7 (33%) had no symptoms after ILR over a follow-up period of 8.4 +/- 4.7 months (range: 1.9-16 months). Symptom-rhythm correlation was possible in all 14 patients who continued to have symptoms (supraventricular tachycardia in 4, ventricular tachycardia in 2, torsades de points in 1, asystole in 1, junctional bradycardia in 1, and sinus rhythm in 5).

CONCLUSIONS

ILR is useful in determining the presence or absence of an arrhythmia during symptoms of syncope, near syncope, and palpitations as well as ALTEs in patients with and without structural heart disease when conventional diagnostic testing, such as electrocardiogram, Holter monitoring, and/or external loop recording, is inconclusive.

Contact dermatitis from electrocardiograph-monitoring electrodes: role of p-tert-butylphenol-formaldehyde resin

Three cases of allergic contact dermatitis localized to the sites of electrocardiograph-monitoring electrodes are reported. All patients had positive patch tests to both the gel and the adhesive part of the Red Dot 2239 3M monitoring electrode used and to the p-tert-butylphenol-formaldehyde resin (PTBP-F-R) of the standard series. Two patients had a history of possible exposition to the resin previously but there was no explanation for the third. No information about the presence of PTBP-F-R in the electrodes could be obtained from the manufacturers. Chemical analysis of samples of the electrode, using a gas chromatography-mass spectrometry (GC-MS) and high pressure liquid chromatography (HPLC) analytical system, demonstrated the presence of several PTBP-F-R derivatives in both the gel and the adhesive part.