Effect of biventricular pacing on symptoms and cardiac remodelling in patients with end-stage hypertrophic cardiomyopathy.
BACKGROUND
Biventricular (BiV) pacing is an established therapy for heart failure in ischaemic and dilated cardiomyopathy. Its effects in end-stage hypertrophic cardiomyopathy (HCM) are unknown.


OBJECTIVE
To assess the potential benefits of BiV pacing in patients with symptomatic end-stage HCM.


METHODS
Twenty patients with non-obstructive HCM (12 male, mean age 57+/-13 years), left bundle branch block and symptoms of heart failure refractory to medical therapy underwent implantation of a BiV device. NYHA class, echocardiographic parameters and exercise capacity were assessed before and after implantation.


RESULTS
At a mean follow-up of 13+/-6 months, an improvement of at least one NYHA class was reported in 8 (40%) patients. A clinical response was associated with an increase in ejection fraction (from 41+/-14% to 50+/-12%, p=0.009), and reductions in left ventricular end-diastolic diameter (from 57+/-6 mm to 52+/-7 mm, p=0.031) and left atrial diameter (from 65+/-8 mm to 57+/-6 mm, p=0.005). Percentage predicted peak oxygen consumption was unchanged in responders but significantly declined in non-responders (p=0.029).


CONCLUSIONS
BiV pacing improved heart failure symptoms in a significant proportion of patients with end-stage HCM. Symptomatic improvement was associated with reverse remodelling of the left atrium and ventricle.
Rogers
Dominic P S
DP
The Heart Hospital, University College London, UK. minirogers@googlemail.com
Marazia
Stefania
S
Chow
Anthony W
AW
Lambiase
Pier D
PD
Lowe
Martin D
MD
Frenneaux
Michael
M
McKenna
William J
WJ
Elliott
Perry M
PM
D000328:Adult; D000368:Aged; D002037:Bundle-Branch Block / Q000628:therapy; D002304:Cardiac Pacing, Artificial; D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D014463:Ultrasonography; D020257:Ventricular Remodeling / Q000502:physiology*