Upgrading pacemaker to cardiac resynchronization therapy: an option for patients with chronic right ventricular pacing and heart failure.
BACKGROUND
Long-term pacing from the right ventricle (RV) has been shown to induce a deleterious effect on left ventricular function. Cardiac resynchronization therapy (CRT) is an established treatment for heart failure (HF) patients. The purpose of this study was to assess the benefit from upgrading to CRT in chronically RV-paced patients with a low left ventricular ejection fraction (LVEF<35%).


METHODS
Thirty-seven HF patients (age 71.4 ± 7.7, 26 male), who fulfilled CRT indications, were included. Study subjects had undergone VVI or DDD pacemaker implantation 6.1 ± 5.7 years earlier and were referred to our centre because of worsened clinical condition or a depleted battery. Patients were assessed at baseline and six months after CRT. Evaluation included NYHA classification, functional capacity assessed by six-minute walk test (6 MWT), hospitalization rate and echocardiographic assessment.


RESULTS
Biventricular pacing was possible in 34 of the 37 cases (91.7%) who had their device upgraded to CRT-P (n=8) or to CRT-D (n=26). After the implementation of CRT the patients showed a noteworthy clinical improvement. Average NYHA class changed from 3.3 ± 0.6 to 2.5 ± 0.9 (p<0.001), 6 MWT performance increased from 246 ± 105 m to 321 ± 101 m (p<0.001), while six-month hospitalization rate dropped from 1.4 ± 1 to 0.7 ± 0.8 admissions (p<0.001). LVEF increased from 26.3 ± 5.4% to 31.4 ± 6.7% (p<0.001) and left ventricular end-systolic volume changed from 134.3 ± 46 mL to 111.9 ± 41.1 mL (p<0.001). A reduction in QRS duration by 28 ms (p<0.001) was also noted.


CONCLUSIONS
RV-paced patients should be closely monitored, and upgrade to CRT should be considered promptly if they develop moderate or severe HF.
Cardiology Department, Hippokration Hospital, Athens, Greece.
Skevos
S
Sideris
Emmanouil
E
Poulidakis
Constantina
C
Aggeli
Kostas
K
Gatzoulis
Ioannis
I
Vlaseros
Polychronis
P
Dilaveris
Ilias
I
Sotiropoulos
Dimitris
D
Papoutis
Stratos
S
Xristakopoulos
Konstantinos
K
Manakos
Konstadinos
K
Trachanas
Odysseas
O
Kaitozis
Iosif
I
Koutagiar
Ioannis
I
Felekos
Christodoulos
C
Stefanadis
Ioannis
I
Kallikazaros
D000368:Aged; D058406:Cardiac Resynchronization Therapy; D005260:Female; D006333:Heart Failure / Q000628:therapy*; D006352:Heart Ventricles; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial; D011446:Prospective Studies