Fig 1 -

Electrogram (EGM) and electrocardiogram (ECG) of the three different settings: 1. optimized bi-ventricular-stimulation (BiV); 2. Physiological AV nodal conduction without triggered left ventricular pacing (tLVp-off); 3. TLVp algorithm turned on (tLVp-on) with physiological AV nodal conduction (a), and after premature ventricular contraction (PVC; b). (ECG–electrocardiogram, IEGM–internal electrogram, PVC—premature ventricular contraction, tLVp—triggered left ventricular pacing).</p

QRS width (ecg) in the different CRT modes.

(BiV–biventricular pacing, LV—left ventricle, tLVp—triggered left ventricular pacing).</p

Electrocardiographic and echocardiographic markers depending on the amount of QRS shortening by tLVp with regard to intrinsic QRS complex.

Electrocardiographic and echocardiographic markers depending on the amount of QRS shortening by tLVp with regard to intrinsic QRS complex.</p

Fig 5 -

(A) QRS width; (B) Max. LV delay depending on the amount of QRS shortening by tLVp with regard to intrinsic QRS complex (BiV–biventricular pacing, LV—left ventricle, tLVp—triggered left ventricular pacing); n = 9 for ≤20ms, n = 8 for >20ms.</p

Echocardiographic (echo) markers in the different CRT modes.

(A) 3D LVEF (echo); (B) Systolic dyssynchrony index (SDI; echo). (3D - 3-dimensional, BiV–biventricular pacing, LV—left ventricle, LVEF–left ventricular ejection fraction, tLVp—triggered left ventricular pacing).</p

Patient characteristics (n = 17).

Patient characteristics (n = 17).</p

LV delay, measured by 2D strain (echo) in the different CRT modes.

Max. (BiV–biventricular pacing, LV—left ventricle, LVEF–left ventricular ejection fraction, tLVp—triggered left ventricular pacing).</p

Fig 2 -

Sankey plot showing the number of eligible vectors before and after LVAD implantation using the ECG-based (A) and the device-based (B) S-ICD screening test. LVAD = left ventricular assist device.</p

Baseline patient characteristics (n = 22).

BackgroundThe number of left ventricular assist devices (LVADs) implanted in patients with end-stage heart failure is increasing. In this patient cohort, subcutaneous implantable cardioverter defibrillators (S-ICDs) could be a promising alternative to transvenous ICDs due to lower infection rates and avoidance of venous access. However, eligibility for the S-ICD depends on ECG features that may be influenced by an LVAD. The aim of the present study was a prospective evaluation of S-ICD eligibility before and after LVAD implantation.MethodsThe study recruited all patients presenting at Hannover Medical School for LVAD implantation between 2016 and 2020. S-ICD eligibility was evaluated using the ECG-based and the device-based S-ICD screening test before and after LVAD implantation.ResultsTwenty-two patients (57.3 ± 8.7 years of age, 95.5% male) were included in the analysis. The most common underlying diseases were dilated cardiomyopathy (n = 16, 72.7%) and ischemic cardiomyopathy (n = 5, 22.7%). Before LVAD implantation 16 patients were found eligible for the S-ICD according to both screening tests (72.7%), but only 7 patients were eligible after LVAD, 31.8%; p = 0.05). Oversensing due to electromagnetic interference was observed in 6 patients (66.6%) found ineligible for S-ICD after LVAD implantation. A lower S wave amplitude in leads I (p = 0.009), II (p = 0.006) and aVF (p = 0.006) before LVAD implantation was associated with higher rate of S-ICD ineligibility after LVAD implantation.ConclusionLVAD implantation can impair S-ICD eligibility. Patients with lower S wave amplitude in leads I, II and aVF were more likely to be ineligible for S-ICD implantation after LVAD implantation. Thus, S-ICD therapy should be carefully considered in patients who are candidates for LVAD therapy.</div

Comparison of recorded parameters between patients eligible and ineligible for S-ICD implantation after implantation of left ventricular assist device.

Comparison of recorded parameters between patients eligible and ineligible for S-ICD implantation after implantation of left ventricular assist device.</p