The role of biventricular pacing in the prevention and therapy of pacemaker-induced cardiomyopathy

Pacing-Induced Cardiomyopathy in Leadless and Traditional Pacemakers: A Single-Center Retrospective Analysis

BACKGROUND

 Pacing-induced cardiomyopathy (PICM) is a clinical syndrome that is characterized by a drop in the left ventricular ejection fraction (LVEF) due to chronic high-burden right ventricular (RV) pacing. It has been postulated that leadless pacemakers (LPs) cause decreased risk of PICM compared to transvenous pacemakers (TVPs), but the exact risk reduction is unknown.

METHODS

We performed a single-center retrospective analysis of adults who received an LP or TVP between January 1, 2014, and April 1, 2022, and had echocardiograms before and after the pacemaker implant. This study's outcomes were the RV pacing percentage, change in EF, the need for cardiac resynchronization therapy (CRT) upgrade, and follow-up duration. A Wilcoxon rank-sum test calculated the change in EF. RV time, defined as the duration from pacemaker placement to the follow-up echocardiogram in months multiplied by the RV pacing percentage, served as a surrogate for how long the RV was paced.

RESULTS

A total of 614 patients were screened, and 198 patients were included in the study, where 72 received LP and 126 received TVP. The median follow-up was 480 days. The average of the reported RV percentage pacing was 63.43% for LP and 71.30% for TVP (p=0.14). The incidence of PICM and CRT upgrade was 44% and 9.7% in the LP group and 37% and 9.5% in the TVP group (p=0.3 and p>0.9), respectively. After accounting for age, sex, LP versus TVP, atrioventricular nodal ablation, RV pacing percentage, and follow-up duration, univariate analysis showed that RV time was significantly different between the two types of pacemakers (13.54 ± 14.21 months (LP) versus 9.26 ± 13.95 months (TVP), p=0.009). The difference in RV time between patients who underwent CRT upgrade and those who did not was statistically insignificant (12.11 ± 14.47 months (no CRT) versus 9.19 ± 12.00 months (CRT), p=0.5).

CONCLUSIONS

This analysis demonstrated that the incidence of PICM was high in both groups (44% (LP) versus 37% (TVP)), despite significantly more RV time in patients with LP. There was no difference in CRT upgrade between LP and TVP.

A Case Report of Pacemaker-Induced Cardiomyopathy in a Patient With Post-atrioventricular Node Ablation for Atrial Fibrillation

Pacemaker-induced cardiomyopathy (PICM) is a rare but well-recognised phenomenon in patients requiring right ventricular (RV) pacing. It can be caused by single-chamber or dual-chamber pacemakers. We present a case of a 64-year-old female patient presenting to the pacemaker clinic with worsening shortness of breath and legs swelling. She was found to have atrial fibrillation and underwent atrioventricular node ablation followed by a dual chamber permanent pacemaker (PPM) implantation as part of a 'pace and ablate' strategy to treat refractory symptomatic atrial tachycardia, and the patient was entirely dependent on RV pacing. In the immediate two months following PPM implantation, the patient was seen in the clinic and reported shortness of breath that was attributed to interstitial lung disease. However, a month later her symptoms worsened, stimulating a referral for echocardiography, which demonstrated a fall in her left ventricular ejection fraction (LVEF) from 60% to 30% in just four months after the device implantation. The patient was diagnosed with PICM. The patient's prognostic heart failure treatment was optimised and her device was upgraded to a cardiac resynchronisation (CRT) device with pacing functionality in an attempt to improve biventricular synchrony. The patient's symptoms have improved significantly since and a repeat echocardiogram 2 months later showed significant improvement in LVEF to 45-50%.

Premature ventricular contraction increases the risk of heart failure and ventricular tachyarrhythmia

Premature ventricular contraction (PVC), a common arrhythmia affecting 1–2% of the general population, has been considered to have a benign clinical course. However, people with PVC often develop heart failure and ventricular arrhythmias such as ventricular tachycardia. We aimed to clarify the risk of heart failure and lethal ventricular arrhythmias in people with PVC. The Korean National Health Insurance Service database was used for this study. People who underwent nationwide health check-ups in 2009 were enrolled in this study and clinical follow-up data until December 2018 were analyzed. Newly diagnosed PVC in 2009 (≥ 1 inpatient or outpatient claim) were identified and cumulative incidence of heart failure (≥ 1 inpatient claim) and ventricular arrhythmias (≥ 1 inpatient or outpatient claim) were compared. A total of 4515 people were first diagnosed with PVC in 2009 among 9,743,582 people without prior history of PVC, heart failure, or ventricular arrhythmias. People with newly diagnosed PVC in 2009 had a significantly higher incidence of heart failure compared to those without PVC [adjusted hazard ratio (HR)  1.371; 95% confidence interval (CI)  1.177–1.598; p  < 0.001]. Significant interaction was observed between age and PVC with young age people at greater risk of developing heart failure for having PVC. The incidence of ventricular arrhythmia was also significantly increased in people with PVC (HR  5.588; 95% CI  4.553–6.859; p  < 0.001). Age and chronic kidney disease had significant interactions with PVC. In conclusion, the incidence of heart failure and ventricular arrhythmia was significantly increased in people with PVC. Outpatient follow-up of people with PVC can be helpful to detect early signs of heart failure or advanced forms of ventricular arrhythmia.

Adverse Consequences of Right Ventricular Apical Pacing and Novel Strategies to Optimize Left Ventricular Systolic and Diastolic Function

Several studies have focused on the deleterious consequences of Right Ventricular Apical (RVA) pacing on Left Ventricular (LV) function, mediated by pacing-induced ventricular dyssyn-chrony. Therapeutic strategies to reduce the detrimental consequences of RVA pacing have been pro-posed, that includes upgrading of RVA pacing to Cardiac Resynchronization Therapy (CRT), alterna-tive Right Ventricular (RV) pacing sites, minimal ventricular pacing strategies, as well as atrial-based pacing. In developing countries, single chamber RV pacing still constitutes a majority of cases of permanent pacing, and assessment of the optimal RV pacing site is of paramount importance. In chronically-paced patients, it is crucial to maintain as close and normal LV physiological function as possible, by minimizing ventricular dyssynchrony, reducing the chances for heart failure and other complications to develop. This review provides an analysis of the deleterious immediate and long-term consequences of RVA pacing, and the most recent available evidence regarding improvements in pacing options and strategies to optimize LV diastolic and systolic function. Furthermore, the place of advanced echocardiography in the identification of patients with pacing-induced LV dysfunction, the potential role of a new predictor of LV dysfunction in RV-paced subjects, and the long- term out-comes of patients with RV septal pacing will be explored

Comorbidity and long-term outcome in patients with congenital heart block and their siblings exposed to Ro/SSA autoantibodies in utero

Objective

Congenital heart block (CHB) may develop in fetuses of Ro/SSA autoantibody-positive women. Given the rarity of CHB, information on comorbidity and complications later in life is difficult to systematically collect for large groups of patients. We therefore used nation-wide healthcare registers to investigate comorbidity and outcomes in patients with CHB and their siblings.

Methods

Data from patients with CHB (n= 119) and their siblings (n= 128), all born to anti-Ro/SSA-positive mothers, and from matched healthy controls (n= 1,190) and their siblings (n= 1,071), were retrieved from the Swedish National Patient Register. Analyses were performed by Cox proportional hazard modelling.

Results

Individuals with CHB had a significantly increased risk of cardiovascular comorbidity, with cardiomyopathy and/or heart failure observed in 20 (16.8%) patients versus 3 (0.3%) controls, yielding a HR of 70.0 (95% CI 20.8 to 235.4), and with a HR for cerebral infarction of 39.9 (95% CI 4.5 to 357.3). Patients with CHB also had a higher risk of infections. Pacemaker treatment was associated with a decreased risk of cerebral infarction but increased risks of cardiomyopathy/heart failure and infection. The risk of systemic connective tissue disorder was also increased in patients with CHB (HR 11.8, 95% CI 4.0 to 11.8), and both patients with CHB and their siblings had an increased risk to develop any of 15 common autoimmune conditions (HR 5.7, 95% CI 2.83 to 11.69 and 3.6, 95% CI 1.7 to 8.0, respectively).

Conclusions

The data indicate an increased risk of several cardiovascular, infectious and autoimmune diseases in patients with CHB, with the latter risk shared by their siblings.

Clinical features, predictors, and long-term prognosis of pacing-induced cardiomyopathy

AIMS

We investigated the clinical features, predictors, and long-term prognosis of pacing-induced cardiomyopathy (PiCM).

METHODS AND RESULTS

From a retrospective analysis of 1418 consecutive pacemaker patients, 618 were found to have a preserved baseline left ventricular ejection fraction (LVEF), follow-up echocardiographic data, and no history of heart failure (HF). PiCM was defined as a reduction in LVEF (< 50%) along with either (i) a ≥ 10% decrease in LVEF, or (ii) new-onset regional wall motion abnormality unrelated to coronary artery disease. PiCM occurred in 87 of 618 patients (14.1%), with a decrease in mean LVEF from 60.5% to 40.1%. The median time to PiCM was 4.7 years. Baseline left bundle branch block, wider paced QRS duration (≥ 155 ms), and higher ventricular pacing percentage (≥ 86%) were identified as independent predictors of PiCM in multivariate logistic regression analysis. The risk of PiCM increased gradually with the number of identified predictors, becoming more significant in the presence of two or more predictors (P < 0.001). During the entire follow-up (median 7.2 years), the risk of all-cause death or HF admission was significantly higher in patients with PiCM compared to those without PiCM (38.3% vs. 54.0%, adjusted hazard ratio 2.93; 95% confidence interval 1.82-4.72; P < 0.001).

CONCLUSION

Pacing-induced cardiomyopathy patients showed a worse long-term prognosis than those without PiCM. Therefore, patients with multiple risk factors of PiCM should be monitored carefully even if their left ventricular systolic function is preserved initially. A timely upgrade to a biventricular or His-bundle pacing device needs to be considered in patients with PiCM.

Pacing-Induced Cardiomyopathy

Pacing-induced cardiomyopathy (PICM) is a well described phenomenon that occurs in a minority of patients exposed to high-burden right ventricular (RV) pacing. Although several risk factors may identify patients at increased risk of PICM, many individuals tolerate high-burden RV pacing for many years without obviously deleterious effects, and the ability to identify those at highest risk remains insufficient. Treatment of PICM has primarily involved upgrade to cardiac resynchronization therapy once signs of cardiomyopathy manifest. The emergence of His bundle pacing may offer an opportunity to prevent PICM before it occurs.