Surface ECG and Fluoroscopy are Not Predictive of Right Ventricular Septal Lead Position Compared to Cardiac CT

Paced QRS morphology mimicking complete left bundle branch block induced by right ventricular pacing is associated with pacing-induced cardiomyopathy

INTRODUCTION

Right ventricular (RV) pacing sometimes causes left ventricular (LV) systolic dysfunction, also known as pacing-induced cardiomyopathy (PICM). However, the association between specifically paced QRS morphology and PICM development has not been elucidated. This study aimed to investigate the association between paced QRS mimicking a complete left bundle branch block (CLBBB) and PICM development.

METHODS

We retrospectively screened 2009 patients who underwent pacemaker implantation from 2010 to 2020 in seven institutions. Patients who received pacemakers for an advanced atrioventricular block or bradycardia with atrial fibrillation, baseline LV ejection fraction (LVEF) ≥ 50%, and echocardiogram recorded at least 6 months postimplantation were included. The paced QRS recorded immediately after implantation was analyzed. A CLBBB-like paced QRS was defined as meeting the CLBBB criteria of the American Heart Association/American College of Cardiology Foundation/Heart Rhythm Society in 2009. PICM was defined as a ≥10% LVEF decrease, resulting in an LVEF of <50%.

RESULTS

Among the 270 patients analyzed, PICM was observed in 38. Baseline LVEF was lower in patients with PICM, and CLBBB-like paced QRS was frequently observed in PICM. Multivariate analysis revealed that low baseline LVEF (odds ratio [OR]: 0.93 per 1% increase, 95% confidence interval [CI]: 0.89-0.98, p = 0.006) and CLBBB-like paced QRS (OR: 2.69, 95% CI: 1.25-5.76, p = 0.011) were significantly associated with PICM development.

CONCLUSION

CLBBB-like paced QRS may be a novel risk factor for PICM. RV pacing, which causes CLBBB-like QRS morphology, may need to be avoided, and patients with CLBBB-like paced QRS should be followed-up carefully.

Novel non-invasive ECG imaging method based on the 12-lead ECG for reconstruction of ventricular activation: A proof-of-concept study

Aim

Current non-invasive electrocardiographic imaging (ECGi) methods are often based on complex body surface potential mapping, limiting the clinical applicability. The aim of this pilot study was to evaluate the ability of a novel non-invasive ECGi method, based on the standard 12-lead ECG, to localize initial site of ventricular activation in right ventricular (RV) paced patients. Validation of the method was performed by comparing the ECGi reconstructed earliest site of activation against the true RV pacing site determined from cardiac computed tomography (CT).

Methods

This was a retrospective study using data from 34 patients, previously implanted with a dual chamber pacemaker due to advanced atrioventricular block. True RV lead position was determined from analysis of a post-implant cardiac CT scan. The ECGi method was based on an inverse-ECG algorithm applying electrophysiological rules. The algorithm integrated information from an RV paced 12-lead ECG together with a CT-derived patient-specific heart-thorax geometric model to reconstruct a 3D electrical ventricular activation map.

Results

The mean geodesic localization error (LE) between the ECGi reconstructed initial site of activation and the RV lead insertion site determined from CT was 13.9 ± 5.6 mm. The mean RV endocardial surface area was 146.0 ± 30.0 cm² and the mean circular LE area was 7.0 ± 5.2 cm² resulting in a relative LE of 5.0 ± 4.0%.

Conclusion

We demonstrated a novel non-invasive ECGi method, based on the 12-lead ECG, that accurately localized the RV pacing site in relation to the ventricular anatomy.

Computed tomography validated right ventricular mid-septal lead implantation using right ventricular angiography

BACKGROUND

Right ventricular (RV) mid-septal pacing has been proposed as an alternative to RV apical pacing. Fluoroscopic and electrocardiogram criteria are unreliable for predicting the RV mid-septal lead position. This study aimed to define the optimal RV mid-septal pacing site using RV angiography.

METHODS

We randomized patients undergoing pacemaker implantation (PPM) to the RV angiography-guided group (Group A) or conventional fluoroscopy-guided group (Group F). In Group A, we performed an angiogram in right anterior oblique (RAO 30°), left anterior oblique (LAO 40°), and left lateral (LL) views. We made a 5-segment grid in RAO 30° and LL views and a 3-segment grid in LAO 40° on the angiographic silhouette to define the lead position. Computed tomography (CT) was used to validate the lead tip position in both groups.

RESULTS

We enrolled 53 patients (Group A: 26, Group F: 27) with a mean age of 55.9 ± 12.2 years. CT images validated the lead position in the mid-septum (Group A, 23 [88.5%]; Group F, 11 [40.7%], P = .0003) and anteroseptal (Group A, 3 [11.5%]; Group F, 5 [18.5%], P = .24). In Group F, the lead was in the anterior wall in 9 patients (33.3%) and the right ventricular outflow tract in 2 (7.4%) patients and none in these two positions in Group A. The lead tip in segment one on the angiographic 5-segment grid in RAO 30° and LL views indicated a mid-septal lead position on CT.

CONCLUSIONS

RV angiography is safe and may be used to confirm the mid-septal lead position during PPM.

Localization of right ventricular non-apical lead position: comparison of three-dimensional echocardiography, computed tomography, and fluoroscopic imaging

OBJECTIVE

Right ventricular (RV) septal pacing is considered a better pacing procedure compared with traditional apical pacing. This study aimed to investigate agreement among computed tomography (CT), three-dimensional echocardiography (3D-echo), and fluoroscopy for evaluating the tip of the RV pacing lead in the non-apical position in patients with permanent pacemaker implantation.

METHODS

Fifty-four patients were prospectively enrolled. Data on patients' characteristics and imaging findings were analyzed. The agreement rate in distinguishing the RV septal lead position among the three imaging modalities was determined.

RESULTS

Thirty-three (61%) patients were men and the median age was 76 years. Overall, the agreement rate among the three imaging modalities was 87% (47/54; Kappa ratio: 0.734). The agreement of 3D-echo compared with thoracic CT (Kappa ratio: 0.893) was better than that for thoracic CT and fluoroscopy (Kappa ratio: 0.658). Agreement between fluoroscopy and 3D-echo was lowest (Kappa ratio: 0.632).

CONCLUSIONS

Agreement in evaluating the position of the septal lead between thoracic CT and 3D-echo is better than that between other imaging modalities. Our findings indicate that 3D-echo imaging might be the best imaging tool for defining the tip of the RV non-apical lead position and be useful for guiding positioning of the RV lead.

Can QRS morphology be used to differentiate between true septal vs. apparently septal lead placement? An analysis of ECG of real mid-septal, apparent mid-septal, and apical pacing

The location of the pacemaker lead is based on the shape of the lead on fluoroscopy only, typically in the left and right anterior oblique positions. However, these fluoroscopy criteria are insufficient and many leads apparently considered to be in septum are in fact anchored in anterior wall. Periprocedural ECG could determine the correct lead location. The aim of the current analysis is to characterize ECG criteria associated with a correct position of the right ventricular (RV) lead in the mid-septum. Patients with indications for a pacemaker had the RV lead implanted in the apex (Group A) or mid-septum using the standard fluoroscopic criteria. The exact position of the RV lead was verified using computed tomography. Based on the findings, the mid-septal group was divided into two subgroups: (i) true septum, i.e. lead was found in the mid-septum, and (ii) false septum, i.e. lead was in the adjacent areas (anterior wall, anteroseptal groove). Paced ECGs were acquired from all patients and multiple criteria were analysed. Paced ECGs from 106 patients were analysed (27 in A, 36 in true septum, and 43 in false septum group). Group A had a significantly wider QRS, more left-deviated axis and later transition zone compared with the true septum and false septum groups. There were no differences in presence of q in lead I, or notching in inferior or lateral leads between the three groups. QRS patterns of true septum and false septum groups were similar with only one exception of the transition zone. In the multivariate model, the only ECG parameters associated with correct lead placement in the septum was an earlier transition zone (odds ratio (OR) 2.53, P = 0.001). ECGs can be easily used to differentiate apical pacing from septal or septum-close pacing. The only ECG characteristic that could help to identify true septum lead position was the transition zone in the precordial leads. ClinicalTrials.gov identifier: NCT02412176.

Correlation of pacing site in right ventricle with paced QRS complex duration

Background

Pacing from RV mid septum and outflow tract septum has been proposed as a more physiological site of pacing and narrower paced QRS complex duration. The paced QRS morphology and duration in different RV pacing sites is under continued discussion. Hence, this study was designed to address the correlation of pacing sites in right ventricle with paced QRS complex duration.

Methods

Two hundred fifty-two consecutive patients who underwent pacemaker implantation were enrolled. Baseline clinical characteristics were recorded for each patient. All patient underwent fluoroscopy, electrocardiogram and echocardiography post pacemaker implantation. Paced QRS duration was calculated from the leads with maximum QRS duration.

Results

Mean paced QRS (pQRS) duration was significantly higher in apical septum group with a mean of 148.9 ± 14.8 m s compared to mid septum (139.6 ± 19.9 m s; p-value 0.003) and RVOT septum (139.6 ± 14.8 m s; p-value 0.002) groups, respectively. There was no significant difference between mid-septal and RVOT septal pQRS duration. On multivariate analysis, female gender, baseline QRS duration and RVOT septal pacing were the only predictors for narrow pQRS duration (<150 msec).

Conclusion

RV mid-septal and RVOT septal pacing were associated with significantly lower pQRS duration as compared with apical pacing. Based on multivariate analysis RVOT septal pacing appears to be preferred and more physiological pacing site.