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Chi-square analysis was used, considering RVSP and PASP as categorical variable. Single and multiple variable analysis
was performed, using Student’s t-test categorical variables to compare the changes in RVSP and PASP before and after implantation of RV lead in patients with high and low RV pacing. All tests were two We used SPSS for Windows version 14.0 (SPSS Inc., Chicago, IL, USA).
RESULTS
A total of 206 patients were enrolled in this study. Demographic, pacing and echocardiographic characteristics of the studied patients are depicted in Table 1. The mean age of the patients was 74 ±14 years, and the follow-up duration was 29 ±19 months.
RV pacing was associated with a non- increase in the LVESD (37 ±10 vs. 38 ±14; P=0.02). RV pacing was associated with a worsening of LVEF (55 ±19 vs. 50 ±12; P= 0.002). The frequency of RV pacing had a great impact on LVEF. While there was no difference in patients with low frequency of RV pacing (55 ±16 vs. 54 ±17; P=0.87), there high frequency of RV (55 ±16 vs. 44 ±18; P=0.001). Figure 1 shows the impact of
RV pacing on LV Function.
RV pacing was associated with a worsening in both RVSP (44 ±13 vs. 47 ±14; P=0.02) and PASP (52 ±16 vs. 56 ±17; P=0.02). The frequency of RV pacing had a major impact on the degree of RVSP
and PASP worsening (Figure 2). While the worsening was more pronounced in patients with high frequency of RV [RVSP
TABLE 1. Baseline Demographic, Pacing and Echocardiographic Data
Baseline Characteristics
All Patients (N= 206)
Age (years) 74±14 Sex 56% 44%
Follow-up period (months) 29±19 Patients with Atrial Fibrillation 35% Type of RV Pacing 120
86 Indication of Pacemaker/ 18%
Male
Female
PPM
ICD
Sick Sinus Syndrome
ICD
33% 9% 4%
35%
AV Block
Profound Unexplained Syncope
Uncontrolled A Fib with AV Ablation and DDD
Primary Prevention (ICD)
Single vs. Dual Chamber 25%
75%
Frequency of RV Pacing 35% (patients number) 65%
Average Percentage of 97% RV Pacing 16%
Single RV Lead
Dual Chamber Leads
High frequency of RV Pacing
Low frequency of RV Pacing
High frequency of RV Pacing
Low frequency of RV Pacing
Echocardiographic Parameters Before Pacemaker Implantation
TR Grade Before Implantation
Absent or Trace Mild
Moderate Severe
MR Grade Before Implantation
Absent or Trace Mild
Moderate Severe
LV Function Before Implants
Average LVEF
Average LVEDD (mm)
Average LVESD (mm)
Right Ventricle and Pulmonary Artery Pressures RVSP (mmHg)
PASP (mmHg)
(42 ±14 vs. 48 ±15; P=0.01) and PASP (50 ±17 vs. 56 ±18; P=0.005)], the difference pacing [RVSP (43 ±12 vs. 46 ±13; P=0.06) and PASP (51 ±15 vs. 54 ±16; P=0.11)].
DISCUSSION
This study showed that there are considerable effects of high frequency of RV pacing on LV dysfunction and pulmonary hypertension.
34.5% 45.1% 16% 4.4%
44.5% 33% 15% 7.5%
55±19 % 49±13 37±10
44±13 52±16
More data on the adverse effect of RV apical pacing have just become available via studies assessing the prevalence of LV dysfunction in patients with RV pacing.3-5 There are studies even showing the development of pacing-induced cardiomyopathy in patients with normal LVEF after long term right ventricular pacing.6 In the present study, the effect of transvenous leads implantation and the frequency of RV pacing on pulmonary artery pressure was studied.
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Del Med J | August 2015 | Vol. 87 | No. 8
