Atrial detection and timing for atrioventricular synchronous pacing

Dual chamber pacing can be employed to restore atrioventricular synchrony in patients with heart block; and chronotropic incompetence and sinus bradycardia in those with sinus node dysfunction (SND). The focus of this thesis is the feasibility and consequences of proper atrial sensing and pacing to atrioventricular (AV) synchrony in dual chamber pacing. With isolated AV block showed that single lead VDD pacing (single pass ventricular lead with a dual chamber electrode system) can be an alternative to standard dual chamber pacing systems. Adequate sinus-driven atrial rate and no history of paroxysmal atrial fibrillation or cardiac enlargement predict reasonably good long-term maintenance of the VDD pacing mode in elderly patients treated for heart block. Retrograde atrial waves can be discriminated from sinus waves in many patients by using a high sampling rate and algorithms for digital signal processing with data collected by a pacemaker (PM). This approach could enhance the capability of future devices to adapt their stimulation to the spontaneous heart rhythm and improve the collection of diagnostic information on arrhythmias. Atrial tachyarrhythmia (AT) sensing algorithms incorporated in a state-of-the art DDDR (dual lead atrioventricular pacing) pacemaker can accurately identify patients who develop ATs. However transient undersensing of continuous atrial fibrillation (AF) and failure to detect very short episodes ATs can occur frequently, despite the use of refined detection algorithms. With a fixed long AV delay in DDDR pacing as in this study, temporal disruption of AV synchrony and inappropriate mode switch (MS) due to repetitive non-reentrant ventriculo-atrial synchronous rhythm (RNRVAS) is relatively common with SND patients (in 25%) in the presence of retrograde VA conduction. An advanced atrio ventricular search hysteresis (AVSH) algorithm reduced incidence of unnecessary ventricular pacing in the majority of SND patients with both intact and impaired AV conduction and in patients with intermittent AV block, regardless of the lead positions in the right atrium and the ventricle. The avoidance of possible harmful right ventricular (RV) pacing with used state of art AVSH algorithm was not associated with unphysiological over-long AV delays. In conclusion, proper atrial detection and timing for atrioventricular pacing is also feasible in the long-term with contemporary clinical pacing. With appropriate programming, these devices may contribute to the avoidance of possible adverse consequences like congestive heart failure, atrial fibrillation and unwanted harmful symptoms. In future devices with digital signal processing the detection of atrial signals can be further improved.Eteistunnistus ja ajoitus tahdistuksen eteis-kammiosynkroniassa Sydämen hidaslyöntisyyden tahdistinhoidon tavoite on korjata sydämen johtoradan vaurioitumisen aiheuttaman puutteellisen syketaajuuden haitta. Eteis-kammiokatkoksessa palautetaan eteis-kammiosynkronia ja sinussolmukkeen viassa korjataan hidaslyöntisyys ja puutteellinen sykenousu. Parhaiten tämä toteutetaan pysyvällä eteis-kammiotahdistuksella. Asianmukaisen eteis-kammiotahdistuksen perusedellytykset ovat hyvä luontaisen sykkeen ja rytmihäiriöiden tunnistus, sopivat sydämen sisäiset tahdistuspaikat ja potilaskohtainen tahdistuksen ja tunnistuksen ohjelmointi. Väitöskirjassa selvitettiin, mikä on eteissignaalien tunnistuksen ja eteistahdistuksen merkitys asianmukaisen eteis-kammiotahdistuksen toteutumisessa. Tutkimukset käsittivät yhteensä 406 Meilahden sairaalan tahdistinpotilaan ja 389 kansainvälisen monikeskustutkimuksen potilasaineistot. ---------- Väitöstutkimus osoitti, että yhden johdon VDD-tyyppinen tahdistin voi olla vaihtoehto DDD-tahdistimelle sydänkatkoksessa, kun potilaalla on asianmukainen sinussolmukkeen toiminto, anamnestisesti ei ole eteisvärinäkohtauksia eikä sydänlaajentuman löydöksiä. Lisäksi osoitettiin, että tahdistimen digitaalisen signaalikäsittelyn muotoparametrioiden avulla pystytään erottelemaan tavanomainen sinusrytmin aikainen eteissignaali retrogradisesti aktivoituvasta eteissignaalista. Osoitettiin myös, että eteisvärinän tunnistuksen tahdistinalgoritmit pystyvät tunnistamaan luotettavasti kaikki ne potilaat, joilla on eteisvärinää. Hetkellistä eteisvärinä alitunnistusta ja hyvin lyhytkestoisten eteistakykardiakohtausten alitunnistusta kuitenkin tapahtuu. Lisäksi virheellistä eteisvärinän tunnistusta aiheuttaa takaisin johtuminen (VA-johtuminen) jopa neljänneksellä sinussolmukesairauspotilaista. Näytettiin, että riippumatta sydämen sisäisistä tahdistuspaikoista eteiskammiojohtumista suosiva tahdistinalgoritmi sallii luontaisen eteis-kammiojohtumisen potilailla, joilla on tavanomainen tai heikentynyt eteis-kammiojohtuminen. Tällaisen algoritmin käytöllä pystytään välttämään tarpeetonta kammiotahdistusta ilman, että tämä liittyisi epäfysiologisen pitkien eteis-kammiovälien käyttöön

Sextio år av pacemakerbehandling - medicin och ingenjörskonst

English summary. Kardiologi

Enhanced detection of atrial tachyarrhythmias with pacing devices by using more accurate atrial sensing

Publisher Copyright: © 2021, The Author(s).Purpose: Cardiac pacing devices can detect and monitor atrial tachyarrhythmias (ATA) which increase the risk of thromboembolic complications. The aim of this study was to compare (1) two different atrial leads and (2) standard and optimized settings to detect ATA and reject far-field R-wave signal (FFRW). Methods: This was a prospective, randomized multi-center trial comparing St. Jude Medical OptiSense lead (tip-to-ring spacing 1.1 mm) and Tendril lead (tip-to-ring spacing 10.0 mm), having programmed atrial sensitivity at 0.2 mV and post-ventricular atrial blanking at 60 ms. We measured intra-atrial amplitudes of FFRW, intrinsic atrial signals, the amount of FFRW oversensing, and other inappropriate mode switching. Results: One hundred and ten patients were enrolled. The mean amplitude of sensed and paced FFRW bipolar signal was 0.13 mV vs. 0.21 mV (p < 0.001) and 0.13 mV vs. 0.26 mV (p < 0.001) with OptiSense and Tendril lead, respectively. The mean amplitude of the atrial bipolar signal was 2.84 mV with OptiSense and 3.48 mV with Tendril lead, p = 0.014. With the optimized settings with OptiSense lead, one patient out of 20 (5%) had FFRW oversensing, none had undersensing of ATAs due to 2:1-blanking of atrial depolarizations, and the concordance of the ATAs by Holter and pacemaker memory was high (Spearman’s rank correlation coefficient = 0.90). In the Tendril group, 12 out of 25 patients (48%) had oversensing and 4 had atrial undersensing (p < 0.001). Conclusions: The technique with an atrial lead with short tip-to-ring spacing combined with optimized pacemaker programming resulted in reliable and accurate atrial arrhythmia detection. Trial registration: ClinicalTrials.gov number NCT01074749.Peer reviewe

Vasemman eteiskorvakkeen sulku

Teema : eteisvärinä. English summaryPeer reviewe

Cardiac Magnetic Resonance Imaging-Based Screening for Cardiac Sarcoidosis in Patients With Atrioventricular Block Requiring Temporary Pacing

Background Some myocardial diseases, such as cardiac sarcoidosis, predispose to complete atrioventricular block. The European Society of Cardiology Guidelines on cardiac pacing in 2021 recommend myocardial disease screening in patients with conduction disorder requiring pacemaker with multimodality imaging, including cardiac magnetic resonance (CMR) imaging. The ability of CMR imaging to detect myocardial disease in patients with a temporary pacing wire is not well documented. Methods and Results Our myocardial disease screening protocol is based on using an active fixation pacing lead connected to a reusable extracorporeal pacing generator (temporary permanent pacemaker) as a bridge to a permanent pacemaker. From 2011 to 2019, we identified 17 patients from our CMR database who underwent CMR imaging with a temporary permanent pacemaker for atrioventricular block. We analyzed their clinical presentations, CMR data, and pacemaker therapy. All CMRs were performed without adverse events. Pacing leads induced minor artifacts to the septal myocardial segments. The extent of late gadolinium enhancement in CMR imaging was used to screen patients for the presence of myocardial disease. Patients with evidence of late gadolinium enhancement underwent endomyocardial biopsy. If considered clinically indicated, also 18-F-fluorodeoxyglucose positron emission tomography and extracardiac tissue biopsy were performed if sarcoidosis was suspected. Eventually, 8 of 17 patients (47.1%) were diagnosed with histologically confirmed granulomatous inflammatory cardiac disease. Importantly, only 1 had a previously diagnosed extracardiac sarcoidosis at the time of presentation with high-degree atrioventricular block. Conclusions CMR imaging with temporary permanent pacemaker protocol is an effective and safe early screening tool for myocardial disease in patients presenting with atrioventricular block requiring immediate, continuous pacing for bradycardia.Peer reviewe

Clinical experience of magnetic resonance imaging in patients with cardiac pacing devices : unrestricted patient population

Background Magnetic resonance imaging (MRI) in patients with cardiac pacing devices has become available despite previously being considered absolutely contraindicated. However, most institutional safety protocols have included several limitations on patient selection, leaving MRI unavailable for many patients. Purpose To evaluate the first 1000 MRI examinations conducted on patients with cardiac pacing devices at Helsinki University Hospital for any potential safety hazards and also to evaluate the long-term functionality of the safety protocol in "real-life" clinical practice. Material and Methods A total of 1000 clinically indicated MRI scans were performed with a 1.5-T MRI scanner according to the safety protocol. The following information was collected from the electronic medical record (EMR): patients' date of birth; sex; pacing device generator model; date of MRI scan; date of the latest pacing device generator implantation; and the body region scanned. The EMR of these patients was checked and especially searched for any pacing device related safety hazards or adverse outcomes during or after the MRI scan. Results Only one potentially dangerous adverse event was noted in our study group. In addition, patients with abandoned leads, temporary pacing devices, and newly implanted pacing device generators were scanned successfully and safely. Conclusion MRI scans can be performed safely in patients with cardiac pacing devices if the dedicated safety protocol is followed.Peer reviewe

Eteisvärinäpotilaan aivoinfarkti ja varfariinihoidon toteutuminen

English summaryPeer reviewe

Tahdistinpotilaan turvallinen magneettikuvaus on mahdollista

Teema : Magneettikuvau

Cardiac manifestations in Finnish gelsolin amyloidosis patients

Introduction Finnish gelsolin amyloidosis (AGel amyloidosis) is an inherited systemic amyloidosis with well-known ophthalmological, neurological and cutaneous symptoms. Additionally, cardiomyopathies, conduction disorders and need of cardiac pacemakers occur in some patients. This study focuses on electrocardiographic (ECG) findings in AGel amyloidosis and their relation to cardiac magnetic resonance (CMR) changes. We also assessed whether ECG abnormalities were associated with pacemaker implantation and mortality. Materials and methods In this cohort study, 51 genetically verified AGel amyloidosis patients (mean age 66 years) without cardiac pacemakers underwent 12-lead ECG and CMR imaging with contrast agent in 2017. Patients were followed-up for 3 years. Results Conduction disturbances were found in 22 patients (43%). Nine (18%) presented with first-degree atrioventricular block, six (12%) with left anterior hemiblock, seven (14%) with left or right bundle branch block and two (4%) with non-specific intraventricular conduction delay. Low QRS voltage was present in two (4%) patients. Late gadolinium enhancement (LGE) concentrating on the interventricular septum and inferior parts of the heart was present in 19 (86%) patients with conduction abnormalities. During the follow-up, only one patient received a pacemaker, and one patient died. Discussion Conduction disorders and septal LGE are common in AGel amyloidosis, whereas other ECG and CMR findings typically observed in most common cardiac amyloidosis types were rare. Septal pathology seen in CMR may interfere with the cardiac conduction system in AGel amyloidosis, explaining conduction disorders, although pacemaker therapy is rarely required.Peer reviewe

Arkivaikuttavuuden arviointi yhdellä mittarilla

Terveystaloustiede.Suomessa kehitetty 15D on jo levinnyt laajaan käyttöön. Kokemukset Husista ja Taysista osoittavat sen käyttökelpoiseksi yleisen elämänlaadun mittariksi arkivaikuttavuuden arviointiin