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A simplified method for determination of the optimal atrioventricular delay in cardiac resynchronization therapy
International Journal of Cardiology 176 (2014) 1239–1241
Contents lists available at ScienceDirect
International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard
Letter to the Editor
A simplified method for determination of the optimal atrioventricular delay in cardiac resynchronization therapy☆ Han Wang, Xiaoqi Deng, Jin Li, Lin Tong, Hanxiong Liu ⁎, Lin Cai ⁎ Cardiovascular Disease Research Institute, The Third People's Hospital of Chengdu, The Second Affiliated Chengdu Clinical College of Chongqing Medical University, Chengdu, 82 Qinlong St. Chengdu, Sichuan 610031, PR China
a r t i c l e
i n f o
Article history: Received 25 June 2014 Accepted 27 July 2014 Available online 8 August 2014 Keywords: Optimization Atrioventricular delay Cardiac resynchronization therapy
Dear Editor, We read with great interest the paper of Raphael et al. [1] regarding the evaluation of the iterative method of optimal atrioventricular (AV) delay for cardiac resynchronization therapy (CRT). The paper addressed an important issue that iterative AV optimization is not executed reliably by experts. Such optimization is essentially important in CRT, which could reduce morbidity and mortality in patients with severe heart failure if the value is settled appropriately [2]. However, despite the fact that several methods have been proposed, AV delay is often programmed via an empirical method or left to a predefined value. [3,4] Here, a simplified method for determination of optimal AV delay was developed in patients with CRT, and its relationship with the method of aortic velocity time intergral/intracardiac electrogram (AVTI/IEGM) was assessed. The study was conducted in 21 patients with CRT in sinus rhythm. Informed consent was obtained from each patient and the study was approved by the local ethics committee. All patients (1) exhibited the left bundle branch bloke of QRS duration ≥ 120 ms, (2) had a left ventricular ejection fraction b35% and were in the New York Heart Association heart failure functional class III/IV, and (3) had a left ventricular end-diastolic diameter (LVEDD) N 55 mm. In the present study, three methods were carried out to optimize AV delay for each patient:
☆ Conflict of interest: None declared. ⁎ Corresponding authors. Tel.: +86 28 61318681. E-mail address: [email protected] (L. Cai).
http://dx.doi.org/10.1016/j.ijcard.2014.07.207 0167-5273/© 2014 Published by Elsevier Ireland Ltd.
AVTI, IEGM, and the simplified one. Measurements of optimal AV delay and AVTI were recorded and details of each method are described as follows: • Simplified method: According to Ritter' method [5], the AVD was considered as optimal if the termination of the A wave of transmitral filling coincided with the onset of isovolumic left ventricular contraction. Optimal AV delay was calculated as “(AVlong − (QAshort − QAlong)”, hence optimal AV delay = “(AVlong + QAlong) − QAshort”. In fact, the sum of AVlong and QAlong, named AA, was regarded as the interval from the beginning of atrial electrical activity to the end of atrial contraction, which equaled to the total time for atrial electromechanical coupling and atrial contraction (Fig. 1). In addition, QAshort, named QAreflow, actually represented the interval from the onset of ventricular electrical activity to the beginning of isovolumic ventricular contraction (heralded by systolic mitral regurgitation), meaning the time of ventricular electromechanical coupling. Therefore, the optimal AV delay was simply calculated as “AA − QAreflow” in the simplified method. • AVTI method [6]: Doppler echocardiography was performed within 24 h after CRT implantation. Care was taken to maintain the same transducer position and sample volume location during the entire series of AV programming. Measurements of continuous-wave aortic Doppler flow velocities were done in the apical five-chamber view at 15 AV intervals with pacing above sinus rate (AV: 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, and 250 ms). After 20 cardiac cycles at each AV delay, measurements were made on the final three cardiac cycles. The optimal AV delay was determined as the AV delay that resulted in the greatest increase in AVTI. • IEGM method [7]: All patients had been previously implanted with a St. Jude Medical CRT. They were tested with IEGM method using the automated programmer optimization algorithm (QuickOptTM). Optimal AV delay was calculated as the sum of paced AV delay and pacing latency (50 ms). AVTI measurements were also recorded by the IEGM method. A total of 21 patients were included in the analysis. Table 1 demonstrates clinical features and optimal AV delay/AVTI in the sample. There were no significant differences among the three methods regarding optimal AV delay (simplified method: 169.05 ± 36.18 ms vs AVTI method: 172.86 ± 41.97 ms vs IEGM method: 166.19 ± 24 ms; all p value N 0.05) and AVTI value (simplified method: 20.74 ± 3.45 cm vs AVTI method: 22.32 ± 3.42 cm vs IEGM method: 19.24 ± 3.01 cm; all p value N 0.05). The AVTI predicted by the simplified
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H. Wang et al. / International Journal of Cardiology 176 (2014) 1239–1241
Ventricular contraction
AA A
QAreflow = from ventricular electrical activity to the onset of ventricular contraction = QAshort AA=from atrial electrical activity to the end of atrial contraction =AVlong+QAlong
AVlong
oAVD =(AVlong+QAlong)-QAshort =AA- QA reflow
QAlong
Fig. 1. Schematic presentation of pulsed Doppler and electrocardiogram recording of oAVD.
method corrected very closely with the AVTI values determined by the AVTI method (concordance correlation coefficient = 0.94, 95% CI 0.87–0.98). In addition, our method determined optimal AV delay was reasonably close to the AVTI prediction (concordance correlation coefficient = 0.88, 95% CI 0.74–0.95). So far, a reliable optimization method is not yet available [3]. Obviously, echocardiographic iterative method was very time-consuming and unpopular, so Raphael et al. [1] suggested that it should be retracting any recommendation in current guidelines. Several methods of AV delay optimization have been proposed in the past 15 years [5,8–10]. In 2002, Ismer proposed a method of optimal AV delay in CRT as follows: time of the atrial electromechanical coupling minus left ventricular electromechanical coupling. But the method is difficult to apply in clinical practice because it needs a bipolar esophageal
Table 1 Clinical parameters and optimal AV delay/AVTI in patients with CRT. Parameters
n = 21
Male gender, n(%) Age, years sinus rhythm, n(%) QRS duration, ms LVEDD, mm NYHA class Class III, n(%) Class IV, n(%) LV ejection fraction, % Drugs administration Beta-block, n (%) ACE inhibitor or ARB, n (%) Spironolactone, n (%) Diuretics, n (%) Digoxin, n (%) Simplified method oAVD, ms AVTI, cm AVTI method oAVD, ms AVTI, cm IEGM method oAVD, ms AVTI, cm
13 (61.9) 66 ± 10 21 (100) 160.71 ± 19.58 62.67 ± 5.24 15 (71.4) 6 (28.6) 26.43 ± 4.81 20 (95.2) 19 (90.4) 16 (76.2) 20 (95.2) 13 (61.9) 169.05 ± 36.18 20.74 ± 3.45 172.86 ± 41.97 22.32 ± 3.42 166.19 ± 24 19.24 ± 3.01
CRT, cardiac resynchronization therapy; LVEDD, left ventricle end-diastolic dimension; LV, left ventricle; oAVD, optimal atrioventricular delay; AVTI, aortic velocity time intergral; IEGM, intracardiac electrogram.
electrogram. In 1999, Ishikawa et al. [9] modified the Ritter's method, and proposed a new formula. However, it requires at least different echocardiographic views with two measurements. In Meluzin's method [10], optimal AV delay is calculated as AVlong minus t1 (the time interval from the end of A wave to the onset of systolic mitral regurgitation), which is similar to our method. However, Meluzin et al. [10] only included patients who had at least minimum functional mitral regurgitation. In practice, a few patients with CRT implantation had normal closure of mitral valve. Additionally, our approach needs the recording of simultaneous echocardiography and electrocardiogram. However, it had an important clinical significance for illegible beginning of ventricular contraction in patients with heart failure. For example, it is difficult to distinguish mitral valve closure/mitral regurgitation from echocardiographic signals in some cases. According to the simplified method, the testing AV delay can be of sufficient length to obtain the measurements of AA, then a short enough AV delay can be established to ensure the mitral valve closure for the measurements of QAreflow. Our prospective study also demonstrated a close correlation between AVTI at optimal AV delay predicted by the simplified method and AVTI determined by AVTI/IEGM method. In addition, our method determined optimal AV delay was reasonably close to the AVTI/IEGMbased prediction. These results strongly suggest that the simplified method can be used in clinical practice.
Acknowledgment The authors would like to thank the Project supported by The National Natural Science Foundation of China (Grant No. 81300243) for their support.
References [1] Raphael CE, Kyriacou A, Jones S, et al. Multinational evaluation of the interpretability of the iterative method of optimisation of AV delay for CRT. Int J Cardiol 2013;168: 407–13. [2] Abraham WT, Fisher WG, Smith AL, et al. Cardiac resynchronisation in chronic heart failure. N Engl J Med 2002;346:1845–53. [3] Antonini L, Auriti A, Pasceri V, et al. Optimization of the atrioventricular delay in sequential and biventricular pacing: physiological bases, critical review, and new purposes. Europace 2012;14:929–38. [4] Sohaib SM, Whinnett ZI, Ellenbogen KA, et al. Cardiac resynchronisation therapy optimisation strategies: systematic classification, detailed analysis, minimum standards and a roadmap for development and testing. Int J Cardiol 2013;170:118–31.
H. Wang et al. / International Journal of Cardiology 176 (2014) 1239–1241 [5] Ritter P, Padeletti L, Gillio-Meina L, Gaggini G. Determination of the optimal atrioventricular delay in DDD pacing. Comparison between echo and peak endocardial acceleration measurements. Europace 1999;1:126–30. [6] Sawhney NS, Waggoner AD, Garhwal S, Chawla MK, Osborn J, Faddis MN. Randomized prospective trial of atrioventricular delay programming for cardiac resynchronization therapy. Heart Rhythm 2004;1:562–7. [7] Baker JH, McKenzie III J, Beau S, et al. Acute evaluation of programmer-guided AV/PV and VV delay optimisation comparing an IEGM method and echocardiogram for cardiac resynchronisation therapy in heart failure patients and dual chamber ICD implants. J Cardiovasc Electrophysiol 2007;18:185–91.
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[8] Ismer B, Von Knorre GH, Voss W, et al. Definition of the optimal atrioventricular delay by simultaneous measurement of electrocardiographic and Doppler echocardiographic parameters. Prog Biomed Res 2002;7:116–20. [9] Ishikawa T, Sumita S, Kimura K, et al. Prediction of optimal atrioventricular delay in patients with implanted DDD pacemakers. Pacing Clin Electrophysiol 1999;22: 1365–71. [10] Meluzin J, Novak M, Mullerova J, et al. A fast and simple echocardiographic method of determination of the optimal atrioventricular delay in patients after biventricular stimulation. Pacing Clin Electrophysiol 2004;27:58–64.
Contents lists available at ScienceDirect
International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard
Letter to the Editor
A simplified method for determination of the optimal atrioventricular delay in cardiac resynchronization therapy☆ Han Wang, Xiaoqi Deng, Jin Li, Lin Tong, Hanxiong Liu ⁎, Lin Cai ⁎ Cardiovascular Disease Research Institute, The Third People's Hospital of Chengdu, The Second Affiliated Chengdu Clinical College of Chongqing Medical University, Chengdu, 82 Qinlong St. Chengdu, Sichuan 610031, PR China
a r t i c l e
i n f o
Article history: Received 25 June 2014 Accepted 27 July 2014 Available online 8 August 2014 Keywords: Optimization Atrioventricular delay Cardiac resynchronization therapy
Dear Editor, We read with great interest the paper of Raphael et al. [1] regarding the evaluation of the iterative method of optimal atrioventricular (AV) delay for cardiac resynchronization therapy (CRT). The paper addressed an important issue that iterative AV optimization is not executed reliably by experts. Such optimization is essentially important in CRT, which could reduce morbidity and mortality in patients with severe heart failure if the value is settled appropriately [2]. However, despite the fact that several methods have been proposed, AV delay is often programmed via an empirical method or left to a predefined value. [3,4] Here, a simplified method for determination of optimal AV delay was developed in patients with CRT, and its relationship with the method of aortic velocity time intergral/intracardiac electrogram (AVTI/IEGM) was assessed. The study was conducted in 21 patients with CRT in sinus rhythm. Informed consent was obtained from each patient and the study was approved by the local ethics committee. All patients (1) exhibited the left bundle branch bloke of QRS duration ≥ 120 ms, (2) had a left ventricular ejection fraction b35% and were in the New York Heart Association heart failure functional class III/IV, and (3) had a left ventricular end-diastolic diameter (LVEDD) N 55 mm. In the present study, three methods were carried out to optimize AV delay for each patient:
☆ Conflict of interest: None declared. ⁎ Corresponding authors. Tel.: +86 28 61318681. E-mail address: [email protected] (L. Cai).
http://dx.doi.org/10.1016/j.ijcard.2014.07.207 0167-5273/© 2014 Published by Elsevier Ireland Ltd.
AVTI, IEGM, and the simplified one. Measurements of optimal AV delay and AVTI were recorded and details of each method are described as follows: • Simplified method: According to Ritter' method [5], the AVD was considered as optimal if the termination of the A wave of transmitral filling coincided with the onset of isovolumic left ventricular contraction. Optimal AV delay was calculated as “(AVlong − (QAshort − QAlong)”, hence optimal AV delay = “(AVlong + QAlong) − QAshort”. In fact, the sum of AVlong and QAlong, named AA, was regarded as the interval from the beginning of atrial electrical activity to the end of atrial contraction, which equaled to the total time for atrial electromechanical coupling and atrial contraction (Fig. 1). In addition, QAshort, named QAreflow, actually represented the interval from the onset of ventricular electrical activity to the beginning of isovolumic ventricular contraction (heralded by systolic mitral regurgitation), meaning the time of ventricular electromechanical coupling. Therefore, the optimal AV delay was simply calculated as “AA − QAreflow” in the simplified method. • AVTI method [6]: Doppler echocardiography was performed within 24 h after CRT implantation. Care was taken to maintain the same transducer position and sample volume location during the entire series of AV programming. Measurements of continuous-wave aortic Doppler flow velocities were done in the apical five-chamber view at 15 AV intervals with pacing above sinus rate (AV: 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, and 250 ms). After 20 cardiac cycles at each AV delay, measurements were made on the final three cardiac cycles. The optimal AV delay was determined as the AV delay that resulted in the greatest increase in AVTI. • IEGM method [7]: All patients had been previously implanted with a St. Jude Medical CRT. They were tested with IEGM method using the automated programmer optimization algorithm (QuickOptTM). Optimal AV delay was calculated as the sum of paced AV delay and pacing latency (50 ms). AVTI measurements were also recorded by the IEGM method. A total of 21 patients were included in the analysis. Table 1 demonstrates clinical features and optimal AV delay/AVTI in the sample. There were no significant differences among the three methods regarding optimal AV delay (simplified method: 169.05 ± 36.18 ms vs AVTI method: 172.86 ± 41.97 ms vs IEGM method: 166.19 ± 24 ms; all p value N 0.05) and AVTI value (simplified method: 20.74 ± 3.45 cm vs AVTI method: 22.32 ± 3.42 cm vs IEGM method: 19.24 ± 3.01 cm; all p value N 0.05). The AVTI predicted by the simplified
1240
H. Wang et al. / International Journal of Cardiology 176 (2014) 1239–1241
Ventricular contraction
AA A
QAreflow = from ventricular electrical activity to the onset of ventricular contraction = QAshort AA=from atrial electrical activity to the end of atrial contraction =AVlong+QAlong
AVlong
oAVD =(AVlong+QAlong)-QAshort =AA- QA reflow
QAlong
Fig. 1. Schematic presentation of pulsed Doppler and electrocardiogram recording of oAVD.
method corrected very closely with the AVTI values determined by the AVTI method (concordance correlation coefficient = 0.94, 95% CI 0.87–0.98). In addition, our method determined optimal AV delay was reasonably close to the AVTI prediction (concordance correlation coefficient = 0.88, 95% CI 0.74–0.95). So far, a reliable optimization method is not yet available [3]. Obviously, echocardiographic iterative method was very time-consuming and unpopular, so Raphael et al. [1] suggested that it should be retracting any recommendation in current guidelines. Several methods of AV delay optimization have been proposed in the past 15 years [5,8–10]. In 2002, Ismer proposed a method of optimal AV delay in CRT as follows: time of the atrial electromechanical coupling minus left ventricular electromechanical coupling. But the method is difficult to apply in clinical practice because it needs a bipolar esophageal
Table 1 Clinical parameters and optimal AV delay/AVTI in patients with CRT. Parameters
n = 21
Male gender, n(%) Age, years sinus rhythm, n(%) QRS duration, ms LVEDD, mm NYHA class Class III, n(%) Class IV, n(%) LV ejection fraction, % Drugs administration Beta-block, n (%) ACE inhibitor or ARB, n (%) Spironolactone, n (%) Diuretics, n (%) Digoxin, n (%) Simplified method oAVD, ms AVTI, cm AVTI method oAVD, ms AVTI, cm IEGM method oAVD, ms AVTI, cm
13 (61.9) 66 ± 10 21 (100) 160.71 ± 19.58 62.67 ± 5.24 15 (71.4) 6 (28.6) 26.43 ± 4.81 20 (95.2) 19 (90.4) 16 (76.2) 20 (95.2) 13 (61.9) 169.05 ± 36.18 20.74 ± 3.45 172.86 ± 41.97 22.32 ± 3.42 166.19 ± 24 19.24 ± 3.01
CRT, cardiac resynchronization therapy; LVEDD, left ventricle end-diastolic dimension; LV, left ventricle; oAVD, optimal atrioventricular delay; AVTI, aortic velocity time intergral; IEGM, intracardiac electrogram.
electrogram. In 1999, Ishikawa et al. [9] modified the Ritter's method, and proposed a new formula. However, it requires at least different echocardiographic views with two measurements. In Meluzin's method [10], optimal AV delay is calculated as AVlong minus t1 (the time interval from the end of A wave to the onset of systolic mitral regurgitation), which is similar to our method. However, Meluzin et al. [10] only included patients who had at least minimum functional mitral regurgitation. In practice, a few patients with CRT implantation had normal closure of mitral valve. Additionally, our approach needs the recording of simultaneous echocardiography and electrocardiogram. However, it had an important clinical significance for illegible beginning of ventricular contraction in patients with heart failure. For example, it is difficult to distinguish mitral valve closure/mitral regurgitation from echocardiographic signals in some cases. According to the simplified method, the testing AV delay can be of sufficient length to obtain the measurements of AA, then a short enough AV delay can be established to ensure the mitral valve closure for the measurements of QAreflow. Our prospective study also demonstrated a close correlation between AVTI at optimal AV delay predicted by the simplified method and AVTI determined by AVTI/IEGM method. In addition, our method determined optimal AV delay was reasonably close to the AVTI/IEGMbased prediction. These results strongly suggest that the simplified method can be used in clinical practice.
Acknowledgment The authors would like to thank the Project supported by The National Natural Science Foundation of China (Grant No. 81300243) for their support.
References [1] Raphael CE, Kyriacou A, Jones S, et al. Multinational evaluation of the interpretability of the iterative method of optimisation of AV delay for CRT. Int J Cardiol 2013;168: 407–13. [2] Abraham WT, Fisher WG, Smith AL, et al. Cardiac resynchronisation in chronic heart failure. N Engl J Med 2002;346:1845–53. [3] Antonini L, Auriti A, Pasceri V, et al. Optimization of the atrioventricular delay in sequential and biventricular pacing: physiological bases, critical review, and new purposes. Europace 2012;14:929–38. [4] Sohaib SM, Whinnett ZI, Ellenbogen KA, et al. Cardiac resynchronisation therapy optimisation strategies: systematic classification, detailed analysis, minimum standards and a roadmap for development and testing. Int J Cardiol 2013;170:118–31.
H. Wang et al. / International Journal of Cardiology 176 (2014) 1239–1241 [5] Ritter P, Padeletti L, Gillio-Meina L, Gaggini G. Determination of the optimal atrioventricular delay in DDD pacing. Comparison between echo and peak endocardial acceleration measurements. Europace 1999;1:126–30. [6] Sawhney NS, Waggoner AD, Garhwal S, Chawla MK, Osborn J, Faddis MN. Randomized prospective trial of atrioventricular delay programming for cardiac resynchronization therapy. Heart Rhythm 2004;1:562–7. [7] Baker JH, McKenzie III J, Beau S, et al. Acute evaluation of programmer-guided AV/PV and VV delay optimisation comparing an IEGM method and echocardiogram for cardiac resynchronisation therapy in heart failure patients and dual chamber ICD implants. J Cardiovasc Electrophysiol 2007;18:185–91.
1241
[8] Ismer B, Von Knorre GH, Voss W, et al. Definition of the optimal atrioventricular delay by simultaneous measurement of electrocardiographic and Doppler echocardiographic parameters. Prog Biomed Res 2002;7:116–20. [9] Ishikawa T, Sumita S, Kimura K, et al. Prediction of optimal atrioventricular delay in patients with implanted DDD pacemakers. Pacing Clin Electrophysiol 1999;22: 1365–71. [10] Meluzin J, Novak M, Mullerova J, et al. A fast and simple echocardiographic method of determination of the optimal atrioventricular delay in patients after biventricular stimulation. Pacing Clin Electrophysiol 2004;27:58–64.