Premature ventricular contractions in patients with an implantable cardioverter defibrillator cardiac resynchronization therapy device: Results from the UMBRELLA registry

Contemporary Advances in Cardiac Remote Monitoring: A Comprehensive, Updated Mini-Review

Over the past decade, remote monitoring (RM) has become an increasingly popular way to improve healthcare and health outcomes. Modern cardiac implantable electronic devices (CIEDs) are capable of recording an increasing amount of data related to CIED function, arrhythmias, physiological status and hemodynamic parameters, providing in-depth and updated information on patient cardiovascular function. The extensive use of RM for patients with CIED allows for early diagnosis and rapid assessment of relevant issues, both clinical and technical, as well as replacing outpatient follow-up improving overall management without compromise safety. This approach is recommended by current guidelines for all eligible patients affected by different chronic cardiac conditions including either brady- and tachy-arrhythmias and heart failure. Beyond to clinical advantages, RM has demonstrated cost-effectiveness and is associated with elevated levels of patient satisfaction. Future perspectives include improving security, interoperability and diagnostic power as well as to engage patients with digital health technology. This review aims to update existing data concerning clinical outcomes in patients managed with RM in the wide spectrum of cardiac arrhythmias and Hear Failure (HF), disclosing also about safety, effectiveness, patient satisfaction and cost-saving.

Impact of ventricular arrhythmia management on suboptimal biventricular pacing in cardiac resynchronization therapy

BACKGROUND

Reduced biventricular pacing (BiVP) is a common phenomenon in cardiac resynchronization therapy (CRT) with impact on CRT-response and patients' prognosis. Data on treatment strategies for patients with ventricular arrhythmia and BiVP reduction is sparse. We sought to assess the effects of ventricular arrhythmia treatment on BiVP.

METHODS

In this retrospective analysis, the data of CRT patients with a reduced BiVP ≤ 97% due to ventricular arrhythmia were analyzed. Catheter ablation or intensified medical therapy was performed to optimize BiVP.

RESULTS

We included 64 consecutive patients (73 ± 10 years, 89% male, LVEF 30 ± 7%). Of those, 22/64 patients (34%) underwent ablation of premature ventricular contractions (PVC) and 15/64 patients (23%) underwent ventricular tachycardia (VT) ablation while 27/64 patients (42%) received intensified medical treatment. Baseline BiVP was 88.1% ± 10.9%. An overall increase in BiVP percentage points of 8.8% (range - 5 to + 47.6%) at 6-month follow-up was achieved. No changes in left ventricular function were observed but improvement in BiVP led to an improvement in NYHA class in 24/64 patients (38%). PVC ablation led to a significantly better improvement in BiVP [9.9% (range 4 to 22%) vs. 3.2% (range - 5 to + 10.7%); p =  < 0.001] and NYHA class (12/22 patients vs. 4/27 patients; p = 0.003) than intensified medical therapy. All patients with VT and reduced BiVP underwent VT ablation with an increase of BiVP of 16.3 ± 13.4%.

CONCLUSION

In this evaluation of ventricular arrhythmia treatment aiming for CRT optimization, both medical therapy and catheter ablation were shown to be effective. Compared to medical therapy, a higher increase in BiVP was observed after PVC ablation, and more patients improved in NYHA class.

CLINICAL TRIAL REGISTRATION

The study was registered at clinical trials.org in August 2019: NCT04065893.

Acute echocardiographic and electrocardiographic effects of triggered left ventricular pacing

Cardiac resynchronization therapy (CRT) is an essential pillar in the therapy of heart failure patients with reduced ejection fraction (HFrEF) presenting with broad left bundle branch block (LBBB) or pacemaker dependency. To achieve beneficial effects, CRT requires high bi-ventricular (BiV) pacing rates. Therefore, device-manufacturers designed pacing algorithms which maintain high BiV pacing rates by a left ventricular (LV) pacing stimulus immediately following a right ventricular sensed beat. However, data on clinical impact of these algorithms are sparse. We studied 17 patients implanted with a CRT device providing triggered left ventricular pacing (tLVp) in case of atrioventricular nodal conduction. Assessment of LV dyssynchrony was performed using echocardiographic and electrocardiographic examination while CRT-devices were set to three different settings: 1. Optimized bi-ventricular-stimulation (BiV); 2. Physiological AV nodal conduction (tLVp-off); 3. Physiological AV nodal conduction and tLVp-algorithm turned on (tLVp-on). QRS duration increased when the CRT-device was set to tLVp-off compared to BiV-Stim, while QRS duration was comparable to BiV-Stim with the tLVp-on setting. Echocardiographic analysis revealed higher dyssynchrony during tLVp-off compared to BiV-Stim. TLVp-on did not improve LV dyssynchrony compared to tLVp-off. QRS duration significantly decreased using tLVp-algorithms compared to physiological AV nodal conduction. However, echocardiographic examination could not show functional benefit from tLVp-algorithms, suggesting that these algorithms are inferior to regular biventricular pacing regarding cardiac resynchronization. Therefore, medical treatment and ablation procedures should be preferred, when biventricular pacing rates have to be increased. TLVp-algorithms can be used in addition to these treatment options.

Sustained Suppression of Premature Ventricular Contractions by a Three-Month Pacing Adjustment

Premature ventricular contractions (PVCs) that comprise more than 15% of total heartbeats can induce cardiomyopathy in patients with systolic dysfunction, and cardiac ablation is frequently used to reduce PVCs in this patient group. However, cardiac ablation is not entirely without hazards. We report a noninvasive method that dramatically reduced PVCs in a cardiac pacemaker patient from 31% to 3% in seven days by increasing the lower limit pacing rate from 50 beats per minute (bpm) to 60 bpm. Not only were our patient's PVCs reduced by the initial pacing elevation, but PVC levels were maintained below 5% even after the pacemaker's lower limit was returned to its original value of 50 bpm. This irreversible suppression of PVC activity following a three-month pacing elevation is a novel result that might be caused by ventricular remodeling of the original ectopic focus.

Clinical characteristics and outcomes of patients with ventricular arrhythmias after continous-flow left ventricular assist device implant

Background

Ventricular arrhythmias (VAs) are observed in 25%–50% of continuous‐flow left ventricular assist device (CF‐LVAD) recipients, but their role on mortality is debated.

Methods

Sixty‐nine consecutive patients with a CF‐LVAD were retrospectively analyzed. Study endpoints were death and occurrence of first episode of VAs post CF‐LVAD implantation. Early VAs were defined as VAs in the first month after CF‐LVAD implantation.

Results

During a median follow‐up of 29.0 months, 19 patients (27.5%) died and 18 patients (26.1%) experienced VAs. Three patients experienced early VAs, and one of them died. Patients with cardiac resynchronization therapy (CRT‐D) showed a trend toward more VAs (p = 0.076), compared to patients without CRT‐D; no significant difference in mortality was found between patients with and without CRT‐D (p = 0.63). Patients with biventricular (BiV) pacing ≥98% experienced more frequently VAs (p = 0.046), with no difference in mortality (p = 0.56), compared to patients experiencing BiV pacing <98%. There was no difference in mortality among patients with or without VAs after CF‐LVAD [5 patients (27.8%) vs. 14 patients (27.5%), p = 0.18)], and patients with or without previous history of VAs (p = 0.95). Also, there was no difference in mortality among patients with a different timing of implant of implantable cardioverter‐defibrillator (ICD), before and after CF‐LVAD (p = 0.11).

Conclusions

VAs in CF‐LVAD are a common clinical problem, but they do not impact mortality. Timing of ICD implantation does not have a significant impact on patients' survival. Patients with BiV pacing ≥98% experienced more frequently VAs.

[Management of premature ventricular ectopy in cardiac resynchronization therapy : Treatment strategies for an optimized cardiac resynchronization]

Cardiac resynchronization therapy (CRT) is an integral part in the treatment of chronic heart failure. However, a high degree of biventricular pacing is essential for the effectiveness of this therapy. In addition to atrial fibrillation, premature ventricular contractions (PVC) are a common cause of reduced biventricular stimulation in CRT. In addition to the prognostically unfavorable reduction of biventricular pacing, PVC are generally associated with reduced outcome in the presence of structural heart disease. Options to increase biventricular stimulation percentage by reprogramming the CRT devices are limited in the majority of cases. Due to the mutual relationship between cardiomyopathy and ventricular arrhythmias, adequate heart failure therapy is essential for the reduction of ventricular ectopy. In addition to beta-blocker therapy, specific antiarrhythmic medication is mostly limited to class III antiarrhythmic drugs due to the structural heart disease usually present in CRT patients. Catheter ablation is superior to pharmacological therapy especially in the field of idiopathic PVC, but promising data are also available for catheter ablation of PVC in structural heart disease and CRT nonresponders.