Limits...
Cardiac resynchronization therapy during rest and exercise: comparison of two optimization methods.

Valzania C, Eriksson MJ, Boriani G, Gadler F - Europace (2008)

Bottom Line: Rest-to-exercise variations in optimal VV delay were observed in 58% of patients.Substantial agreement of AV and VV delays was observed between both the optimization methods.Exercise optimization of VV delay by either method improved intraventricular dyssynchrony and increased aortic velocity time integral compared with the resting setting (P < 0.001).

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, Division of Cardiology, Karolinska Institutet, Stockholm, Sweden. cinzia.valzania2@studio.unibo.it

ABSTRACT

Aims: Optimal exercise programming of cardiac resynchronization therapy (CRT) devices is unknown. We aimed to: (i) investigate variations in optimal atrioventricular (AV) and interventricular (VV) delays from rest to exercise, assessed by both echocardiography and an automated intracardiac electrogram (IEGM) method; (ii) evaluate the acute haemodynamic impact of CRT optimization performed during exercise.

Methods and results: Twenty-four heart failure patients, previously implanted with a CRT defibrillator, underwent AV and VV delay optimization, by echocardiography and IEGM methods, both at rest and during supine bicycle exercise. Rest-to-exercise variations in optimal VV delay were observed in 58% of patients. Conversely, optimal AV delay did not change during exercise compared with rest. Substantial agreement of AV and VV delays was observed between both the optimization methods. Exercise optimization of VV delay by either method improved intraventricular dyssynchrony and increased aortic velocity time integral compared with the resting setting (P < 0.001).

Conclusion: In patients implanted with a CRT device, optimal VV delay varied considerably from rest to exercise, while AV delay did not change. Re-assessment of the optimal pacing configuration during supine exercise, by echocardiography as well as IEGM methods, yielded an additional haemodynamic benefit to that provided by resting optimization.

Show MeSH

Related in: MedlinePlus

Boxplot (25th–75th percentile), median values (□) showing distributions in LVOT VTI during intrinsic rhythm (without biventricular stimulation) and during cardiac resynchronization therapy with IEGM and echo-optimized atrioventricular and interventricular delays, both at rest and during exercise. IEGM, intracardiac electrogram; ECHO, echocardiogram; LVOT, left ventricular outflow tract; VTI, velocity time integral; biv, biventricular pacing.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2552406&req=5

EUN216F3: Boxplot (25th–75th percentile), median values (□) showing distributions in LVOT VTI during intrinsic rhythm (without biventricular stimulation) and during cardiac resynchronization therapy with IEGM and echo-optimized atrioventricular and interventricular delays, both at rest and during exercise. IEGM, intracardiac electrogram; ECHO, echocardiogram; LVOT, left ventricular outflow tract; VTI, velocity time integral; biv, biventricular pacing.

Mentions: Figure 3 shows values of LVOT VTI among all patients during spontaneous rhythm (without biventricular stimulation), and during CRT with IEGM and echo-optimized AV and VV delays. At rest, median (range) VTI during spontaneous rhythm was 13.65 cm (11.53–17.92 cm) and increased during CRT with both the IEGM and the echocardiogram-based setting (P < 0.0001 vs. spontaneous rhythm for both). A small, albeit significant, difference in LVOT VTI between the two methods was observed at rest (15.18 cm, range 13.03–19.82 cm, with IEGM vs. 15.53 cm, range 13.32–20.78 cm, with echocardiography, P = 0.003), but not during exercise.


Cardiac resynchronization therapy during rest and exercise: comparison of two optimization methods.

Valzania C, Eriksson MJ, Boriani G, Gadler F - Europace (2008)

Boxplot (25th–75th percentile), median values (□) showing distributions in LVOT VTI during intrinsic rhythm (without biventricular stimulation) and during cardiac resynchronization therapy with IEGM and echo-optimized atrioventricular and interventricular delays, both at rest and during exercise. IEGM, intracardiac electrogram; ECHO, echocardiogram; LVOT, left ventricular outflow tract; VTI, velocity time integral; biv, biventricular pacing.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2552406&req=5

EUN216F3: Boxplot (25th–75th percentile), median values (□) showing distributions in LVOT VTI during intrinsic rhythm (without biventricular stimulation) and during cardiac resynchronization therapy with IEGM and echo-optimized atrioventricular and interventricular delays, both at rest and during exercise. IEGM, intracardiac electrogram; ECHO, echocardiogram; LVOT, left ventricular outflow tract; VTI, velocity time integral; biv, biventricular pacing.
Mentions: Figure 3 shows values of LVOT VTI among all patients during spontaneous rhythm (without biventricular stimulation), and during CRT with IEGM and echo-optimized AV and VV delays. At rest, median (range) VTI during spontaneous rhythm was 13.65 cm (11.53–17.92 cm) and increased during CRT with both the IEGM and the echocardiogram-based setting (P < 0.0001 vs. spontaneous rhythm for both). A small, albeit significant, difference in LVOT VTI between the two methods was observed at rest (15.18 cm, range 13.03–19.82 cm, with IEGM vs. 15.53 cm, range 13.32–20.78 cm, with echocardiography, P = 0.003), but not during exercise.

Bottom Line: Rest-to-exercise variations in optimal VV delay were observed in 58% of patients.Substantial agreement of AV and VV delays was observed between both the optimization methods.Exercise optimization of VV delay by either method improved intraventricular dyssynchrony and increased aortic velocity time integral compared with the resting setting (P < 0.001).

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, Division of Cardiology, Karolinska Institutet, Stockholm, Sweden. cinzia.valzania2@studio.unibo.it

ABSTRACT

Aims: Optimal exercise programming of cardiac resynchronization therapy (CRT) devices is unknown. We aimed to: (i) investigate variations in optimal atrioventricular (AV) and interventricular (VV) delays from rest to exercise, assessed by both echocardiography and an automated intracardiac electrogram (IEGM) method; (ii) evaluate the acute haemodynamic impact of CRT optimization performed during exercise.

Methods and results: Twenty-four heart failure patients, previously implanted with a CRT defibrillator, underwent AV and VV delay optimization, by echocardiography and IEGM methods, both at rest and during supine bicycle exercise. Rest-to-exercise variations in optimal VV delay were observed in 58% of patients. Conversely, optimal AV delay did not change during exercise compared with rest. Substantial agreement of AV and VV delays was observed between both the optimization methods. Exercise optimization of VV delay by either method improved intraventricular dyssynchrony and increased aortic velocity time integral compared with the resting setting (P < 0.001).

Conclusion: In patients implanted with a CRT device, optimal VV delay varied considerably from rest to exercise, while AV delay did not change. Re-assessment of the optimal pacing configuration during supine exercise, by echocardiography as well as IEGM methods, yielded an additional haemodynamic benefit to that provided by resting optimization.

Show MeSH
Related in: MedlinePlus