Cardiac output response to changes of the atrioventricular delay in different body positions and during exercise in patients receiving cardiac resynchronization therapy

TY - JOUR

T1 - Cardiac output response to changes of the atrioventricular delay in different body positions and during exercise in patients receiving cardiac resynchronization therapy

AU - Ståhlberg, Marcus

AU - Damgaard, Morten

AU - Norsk, Peter

AU - Gabrielsen, Anders

AU - Sahlén, Anders

AU - Linde, Cecilia

AU - Braunschweig, Frieder

N1 - Keywords: Aged; Atrioventricular Node; Cardiac Output; Cardiac Pacing, Artificial; Female; Heart Failure; Heart Rate; Humans; Male; Physical Exertion; Posture

PY - 2009

Y1 - 2009

N2 - AIMS: The aim of this study was to study the haemodynamic effect of atrioventricular delay (AVD) modifications within a narrow range in different body positions and during exercise in patients receiving cardiac resynchronization therapy (CRT). METHODS: The previously optimized AVD was shortened and prolonged by 40 ms in 27 CRT patients and 9 controls without heart failure. Cardiac output (CO) was measured by inert gas rebreathing (Innocor) as the average over different body positions (left-lateral, supine, sitting, standing, and exercise). In eight CRT patients with an implantable haemodynamic monitor, the estimated pulmonary artery diastolic pressure (ePAD) was analysed. RESULTS: The magnitude of CO response to AVD changes was greater in CRT patients than in controls (0.25 vs. 0.20 L/min, P<0.05), varied substantially between individuals (range: 0.12-0.56 L/min), and correlated with left atrial size (r=0.61, P<0.001). On average, AVD shortening decreased CO slightly (0.07+/-0.17 L/min) and increased ePAD (1.1+/-0.8 mmHg, both P<0.05), whereas prolongation had no significant effect. CONCLUSION: The haemodynamic response to AVD modifications within a narrow range is larger in CRT patients than in normal controls and varies substantially between individuals. These findings suggest that optimal AVD tuning is clinically important in selected patients.

AB - AIMS: The aim of this study was to study the haemodynamic effect of atrioventricular delay (AVD) modifications within a narrow range in different body positions and during exercise in patients receiving cardiac resynchronization therapy (CRT). METHODS: The previously optimized AVD was shortened and prolonged by 40 ms in 27 CRT patients and 9 controls without heart failure. Cardiac output (CO) was measured by inert gas rebreathing (Innocor) as the average over different body positions (left-lateral, supine, sitting, standing, and exercise). In eight CRT patients with an implantable haemodynamic monitor, the estimated pulmonary artery diastolic pressure (ePAD) was analysed. RESULTS: The magnitude of CO response to AVD changes was greater in CRT patients than in controls (0.25 vs. 0.20 L/min, P<0.05), varied substantially between individuals (range: 0.12-0.56 L/min), and correlated with left atrial size (r=0.61, P<0.001). On average, AVD shortening decreased CO slightly (0.07+/-0.17 L/min) and increased ePAD (1.1+/-0.8 mmHg, both P<0.05), whereas prolongation had no significant effect. CONCLUSION: The haemodynamic response to AVD modifications within a narrow range is larger in CRT patients than in normal controls and varies substantially between individuals. These findings suggest that optimal AVD tuning is clinically important in selected patients.

U2 - 10.1093/europace/eup173

DO - 10.1093/europace/eup173

M3 - Journal article

C2 - 19578177

SN - 1099-5129

VL - 11

SP - 1160

EP - 1167

JO - Europace

JF - Europace

IS - 9

ER -