Electrocardiographic changes after implantation of a left ventricular assist device - Potential implications for subcutaneous defibrillator therapy.

BACKGROUND: Implantation of a left ventricular assist device (LVAD) leads to a diverse spectrum of changes on the twelve-lead surface electrocardiogram (ECG). We aimed to elucidate the changes of the surface ECG in patients after LVAD implantation potentially impacting ECG based screening tests of subcutaneous implantable cardioverter-defibrillators (S-ICD).

METHODS: Patients from 2005 until 2017 with a documented twelve-lead ECG before and after LVAD implantation were included. Baseline parameters were obtained through hospital records. The twelve-lead ECGs registered before and after LVAD implantation were analyzed.

RESULTS: From 415 patients undergoing an LVAD implantation, complete datasets were available for 253 patients. 216 patients (85%) were male. Mean age at time of LVAD implantation was 54.7 ± 12.4 years. The underlying etiology was ischemic cardiomyopathy in 119 (47%), dilated cardiomyopathy in 112 (44%), myocarditis in 8 (3%) and other in 14 (6%). We observed a reduction in the amplitude of the R wave in lead I (p < 0.0001), lead II (p < 0.0001), lead III (p < 0.004), lead aVL (p < 0.001) and lead aVF (p < 0.0001) as well as of the S wave in lead III (p < 0.001) and lead aVR (p < 0.0001) after LVAD implantation. We also noticed a reduction of the R:T ratio in lead I (p < 0.0001) as well as in lead II (p = 0.100) and lead aVF (p = 0.292) although statistically non-significant.

CONCLUSION: LVAD implantation leads to significant alterations of the surface ECG, especially the R:T ratio in leads I, II and aVF. These leads correlate with the vectors of the ECG based S-ICD screening test. Thus, these ECG changes may impact the continuous eligibility for subcutaneous ICD therapy in patients after LVAD implantation.