Table 1.
Clinical characteristics between patients with low and high burdens of ventricular pacing.
Fig 1.
Patient distribution through the study at 12 months.
Algorithm showing total number of cases considered for recruitment and the reasons for exclusion, leading to selection of the final 55 patients.
Table 2.
Differences in LVEF and GLS values between patients with and without pacing-induced LV dysfunction.
Table 3.
Differences in LVEF and GLS in patients with a decline in LVEF (PICMP and PIVD) compared to cases without a decline in LVEF.
Fig 2.
Examples of normal and abnormal polar plot strain maps.
(A) Normal polar plot map (GLS -20%). (B) Abnormal polar plot map from a patient who developed PICMP by 12 months. GLS and TPS-SD measure -12% and 75ms respectively, indicating reduced global longitudinal strain and LV dyssynchrony.
Fig 3.
(A) Global longitudinal strain for cases of all cases of PIVD (PICMP included). Global longitudinal strain was significantly lower in patients with a decline in LVEF ≥ 5% compared to cases without (one month GLS -12.6 ± 0.9 vs. -16.4 ±0.6 respectively; p = 0.022). One and 12 month GLS were reduced compared to baseline for cases of with a decline in LVEF at 12 months (PIVD and PICMP), but not for cases without a decline in LVEF (PIVD and PICMP: baseline GLS, -16.3 ±0.5 vs. -12.6 ±0.9 and -11.9 ±2.5; p = 0.012. No decline in LVEF: baseline GLS -17.5 ±0.6 vs. -16.4 ±0.6 and -15.8 ±3.9; p = 0.311). (B) Global longitudinal strain for cases with PIVD (PICMP excluded). One and 12 month GLS were significantly reduced for cases of PIVD compared to baseline (Baseline GLS -16.4 ±0.7 vs -13.3 ±.2 and -12.8 ±2.6 respectively; p = 0.024).
Fig 4.
Global longitudinal strain analysis.
(A) pre pacemaker implant, (B) one-month after the initiation of pacing in a patient who developed PIVD and (C) 12 months after pacing in a patient who went on to develop PICMP.