The deleterious effects of long-term right ventricular pacing necessitated the search for alternative pacing sites which could prevent or alleviate pacinginduced cardiomyopathy.Until recently,biventricular pacing(BiVP...The deleterious effects of long-term right ventricular pacing necessitated the search for alternative pacing sites which could prevent or alleviate pacinginduced cardiomyopathy.Until recently,biventricular pacing(BiVP)was the only modality which could mitigate or prevent pacing induced dysfunction.Further,BiVP could resynchronize the baseline electromechanical dssynchrony in heart failure and improve outcomes.However,the high non-response rate of around 20%-30%remains a major limitation.This non-response has been largely attributable to the direct non-physiological stimulation of the left ventricular myocardium bypassing the conduction system.To overcome this limitation,the concept of conduction system pacing(CSP)came up.Despite initial success of the first CSP via His bundle pacing(HBP),certain drawbacks including lead instability and dislodgements,steep learning curve and rapid battery depletion on many occasions prevented its widespread use for cardiac resynchronization therapy(CRT).Subsequently,CSP via left bundle branch-area pacing(LBBP)was developed in 2018,which over the last few years has shown efficacy comparable to BiVP-CRT in small observational studies.Further,its safety has also been well established and is largely free of the pitfalls of the HBP-CRT.In the recent metanalysis by Yasmin et al,comprising of 6 studies with 389 participants,LBBPCRT was superior to BiVP-CRT in terms of QRS duration,left ventricular ejection fraction,cardiac chamber dimensions,lead thresholds,and functional status amongst heart failure patients with left bundle branch block.However,there are important limitations of the study including the small overall numbers,inclusion of only a single small randomized controlled trial(RCT)and a small follow-up duration.Further,the entire study population analyzed was from China which makes generalizability a concern.Despite the concerns,the meta-analysis adds to the growing body of evidence demonstrating the efficacy of LBBP-CRT.At this stage,one must acknowledge that the fact that still our opinions on this technique are largely based on observational data and there is a dire need for larger RCTs to ascertain the position of LBBPCRT in management of heart failure patients with left bundle branch block.展开更多
A 54-year-old female patient with congenital heart disease had a persistent complete left bundle branch block three months after closure by an Amplatzer ventricular septal defect occluder. Nine months later, the patie...A 54-year-old female patient with congenital heart disease had a persistent complete left bundle branch block three months after closure by an Amplatzer ventricular septal defect occluder. Nine months later, the patient suffered from chest distress, palpitation, and sweating at daily activities, and her 6-min walk distance decreased significantly （155 m）. Her echocardiography showed increased left ventricular end-diastolic diameter with left ventricular ejection fraction of 37%. Her symptoms reduced significantly one week after received cardiac resynchronization therapy. She had no symptoms at daily activities, and her echo showed left ventricular ejection fraction of 46%and 53%. Moreover, left ventricular end-diastolic diameter decreased 6 and 10 months after cardiac resynchronization therapy, and 6-min walk dis-tance remarkably increased. This case demonstrated that persistent complete left bundle branch block for nine months after transcatheter closure with ventricular septal defect Amplatzer occluder could lead to left ventricular enlargement and a significant decrease in left ventricular systolic function. Cardiac resynchronization therapy decreased left ventricular end-diastolic diameter and increased left ventricular ejection fraction, thereby improving the patient’s heart functions.展开更多
Background Using tissue Doppler imaging and conventional echocardiographic technique, we examined the cardiac function and synchronicity in individuals with isolated right bundle branch block （RBBB） or left bundle b...Background Using tissue Doppler imaging and conventional echocardiographic technique, we examined the cardiac function and synchronicity in individuals with isolated right bundle branch block （RBBB） or left bundle branch block （LBBB） and assessed the relationship between QRS duration and synchronicity.展开更多
Background Left bundle branch block （LBBB） results in an altered pattern of left ventricular （LV） activation and subsequent contraction. Cardiac synchrony and cardiac function are deteriorated by LBBB. However, th...Background Left bundle branch block （LBBB） results in an altered pattern of left ventricular （LV） activation and subsequent contraction. Cardiac synchrony and cardiac function are deteriorated by LBBB. However, the effect of LBBB history on progressive heart dysfunction and clinical efficacy of cardiac resynchronization therapy （CRT） in such patients are not clear. In this study we explore the clinical efficacy and predictor of cardiac resynchronization therapy in LBBB heart dysfunction. Methods Twenty-seven LBBB patients with severe heart failure were treated with CRT. Twenty-six LBBB patients without CRT served as control. During 6 months follow-up, ECG, plasma NT-proBNP and echocardiogram indexes were measured. Results Compared with baseline, NYHA functional class of 23 patients （85.2%） was improved in CRT group. Compared with baseline and control, QRS duration （QRSd） was significantly more narrow （P = 0.023, P = 0.019）, NT-proBNP was significantly lower （P = 0.011,P = 0.009）, ventricular septal to left ventricular posterior wall delay time and left ventricular dyssynchrony index （Ts-SD） were significantly worse （P 〈 0.05）; left ventricular ejection fraction, left ventricular end-systolic volume, mitral regurgitation area were significantly improved in CRT group （P 〈 0.05）. when the LBBB history was I〉 2 years and QRSd I〉 155 ms, the sensitivity and specificity of CRT super-response were 53.4% and 85.6% respectively. Conclusions CRT can improve the synchronization and hemodynamic of LBBB patients with heart dysfunction, the LBBB history I〉 2 years and QRSd I〉 155 ms are one of the CRT super-response predictors.展开更多
Background:Left bundle branch block(LBBB)-induced cardiomyopathy has been proposed,but the association between LBBB and cardiac resynchronization therapy(CRT)response remains unclear and practical criteria for selecti...Background:Left bundle branch block(LBBB)-induced cardiomyopathy has been proposed,but the association between LBBB and cardiac resynchronization therapy(CRT)response remains unclear and practical criteria for selecting CRT candidates are needed.Methods:One hundred and seventeen consecutive heart failure patients were reviewed,24 of whom received CRT.Only two patients had a clear temporal relation between cardiomyopathy and LBBB.Results:Compared with the patient with“cardiomyopathy-induced LBBB,”the patient with“LBBB-induced cardiomyopathy”had higher left ventricular(LV)wall thickness,higher LV wall thickening rate,higher peak circumferential strain,and longer peak circumferential strain delay.The LV deformation patterns in the two patients were obviously distinct on cardiovascular magnetic resonance tissue tracking.During follow-up,the patient with LBBB-induced cardiomyopathy had a good response to CRT(LV ejection fraction 23 before CRT vs.30%at 6 months vs.29 at 12 months vs.32%at 18 months;LV end-diastolic diameter 77 mm before CRT vs.66 mm at 6 months vs.62 mm at 12 months vs.63 mm at 18 months),and the other patient had no response to CRT(LV ejection fraction 29 before CRT vs.29%at 6 months vs.26 at 12 months vs.22%at 24 months;LV end-diastolic diameter 85 mm before CRT vs.88 mm at 6 months vs.85 mm at 12 months vs.84 mm at 24 months).Conclusion:The temporal relation between cardiomyopathy and LBBB could be a determinant for CRT response.Cardiovascular magnetic resonance tissue tracking may be a useful tool to identify the chronological order and a principal consideration for selecting candidates for CRT.Larger prospective clinical trials are needed to study the prevalence of,time course of,and risk factors for LBBB-induced cardiomyopathy.展开更多
Cardiac resynchronization therapy(CRT) effected via biventricular pacing has been established as prime therapy for heart failure patients of New York Heart Association functional class Ⅱ, Ⅲ and ambulatory Ⅳ, reduce...Cardiac resynchronization therapy(CRT) effected via biventricular pacing has been established as prime therapy for heart failure patients of New York Heart Association functional class Ⅱ, Ⅲ and ambulatory Ⅳ, reduced left ventricular(LV) function, and a widened QRS complex. CRT has been shown to improve symptoms, LV function, hospitalization rates, and survival. In order to maximize the benefit from CRT and reduce the number of non-responders, consideration should be given to target the optimal site for LV lead implantation away from myocardial scar and close to the latest LV site activation; and also to appropriately program the device paying particular attention to optimal atrioventricular and interventricular intervals. We herein review current data related to both optimal LV lead placement and device programming and their effects on CRT clinical outcomes.展开更多
Background The effects of trimetazidine on patients with dilated cardiomyopathy（DCM） and left bundle branch block（LBBB） are not clear. Methods Sixty consecutive patients with DCM, LBBB and heart dysfunction（35% ...Background The effects of trimetazidine on patients with dilated cardiomyopathy（DCM） and left bundle branch block（LBBB） are not clear. Methods Sixty consecutive patients with DCM, LBBB and heart dysfunction（35% ≤ LVEF ≤ 45%） were randomly allocated to heart failure therapy plus trimetazidine group（20 mg three times a day; 30 patients） or heart failure therapy alone group（30 patients）. During follow-up of 6months, QRS morphology, plasma NT-proBNP, 6-minute walk test（6MWT） and echocardiographic indexes were measured. Results At the 6th month, a significant functional improvement was noted in patients receiving trimetazidine added to heart failure treatment. In patients from the trimetazidine group, an increase of left ventricular ejection fraction（LVEF） was noted（from 38 ± 5.5% to 47 ± 7.1%, P = 0.020）. The increase of LVEF in the trimetazidine group was associated with a more significant reduction of the left ventricular endsystolic diameter（LVESD） compared with the control group at 6-month follow-up. The NT-pro BNP levels decreased significantly in the trimetazidine group（3.11 ± 0.47 at baseline and 2.77 ± 0.45 at 6-month followup, P 〈 0.01） and the 6MWT increased significantly in the trimetazidine group（325 ± 44 m at baseline and419 ± 56 m at 6-month follow-up, P 〈 0.01）. The differences in NT-pro BNP levels（2.77 ± 0.45 vs 2.96 ±0.46, P = 0.036） and 6MWT（419 ± 56 m vs 366 ± 54 m, P = 0.032） between the two groups were significant at 6-month follow-up. Conclusions Trimetazidine can improve LV function caused by DCM and LBBB. The positive effects of trimetazidine on LV function are especially evident in patients with optimization of drug therapy for heart failure, which strongly suggests an additive effect of these therapy modalities.展开更多
文摘The deleterious effects of long-term right ventricular pacing necessitated the search for alternative pacing sites which could prevent or alleviate pacinginduced cardiomyopathy.Until recently,biventricular pacing(BiVP)was the only modality which could mitigate or prevent pacing induced dysfunction.Further,BiVP could resynchronize the baseline electromechanical dssynchrony in heart failure and improve outcomes.However,the high non-response rate of around 20%-30%remains a major limitation.This non-response has been largely attributable to the direct non-physiological stimulation of the left ventricular myocardium bypassing the conduction system.To overcome this limitation,the concept of conduction system pacing(CSP)came up.Despite initial success of the first CSP via His bundle pacing(HBP),certain drawbacks including lead instability and dislodgements,steep learning curve and rapid battery depletion on many occasions prevented its widespread use for cardiac resynchronization therapy(CRT).Subsequently,CSP via left bundle branch-area pacing(LBBP)was developed in 2018,which over the last few years has shown efficacy comparable to BiVP-CRT in small observational studies.Further,its safety has also been well established and is largely free of the pitfalls of the HBP-CRT.In the recent metanalysis by Yasmin et al,comprising of 6 studies with 389 participants,LBBPCRT was superior to BiVP-CRT in terms of QRS duration,left ventricular ejection fraction,cardiac chamber dimensions,lead thresholds,and functional status amongst heart failure patients with left bundle branch block.However,there are important limitations of the study including the small overall numbers,inclusion of only a single small randomized controlled trial(RCT)and a small follow-up duration.Further,the entire study population analyzed was from China which makes generalizability a concern.Despite the concerns,the meta-analysis adds to the growing body of evidence demonstrating the efficacy of LBBP-CRT.At this stage,one must acknowledge that the fact that still our opinions on this technique are largely based on observational data and there is a dire need for larger RCTs to ascertain the position of LBBPCRT in management of heart failure patients with left bundle branch block.
文摘A 54-year-old female patient with congenital heart disease had a persistent complete left bundle branch block three months after closure by an Amplatzer ventricular septal defect occluder. Nine months later, the patient suffered from chest distress, palpitation, and sweating at daily activities, and her 6-min walk distance decreased significantly （155 m）. Her echocardiography showed increased left ventricular end-diastolic diameter with left ventricular ejection fraction of 37%. Her symptoms reduced significantly one week after received cardiac resynchronization therapy. She had no symptoms at daily activities, and her echo showed left ventricular ejection fraction of 46%and 53%. Moreover, left ventricular end-diastolic diameter decreased 6 and 10 months after cardiac resynchronization therapy, and 6-min walk dis-tance remarkably increased. This case demonstrated that persistent complete left bundle branch block for nine months after transcatheter closure with ventricular septal defect Amplatzer occluder could lead to left ventricular enlargement and a significant decrease in left ventricular systolic function. Cardiac resynchronization therapy decreased left ventricular end-diastolic diameter and increased left ventricular ejection fraction, thereby improving the patient’s heart functions.
文摘Background Using tissue Doppler imaging and conventional echocardiographic technique, we examined the cardiac function and synchronicity in individuals with isolated right bundle branch block （RBBB） or left bundle branch block （LBBB） and assessed the relationship between QRS duration and synchronicity.
基金supported by Science and Technology Key Foundation of Guangdong Province(No.2010B031600166)the Science and Technology Foundation of Guangdong Province(No.2011B061300072)the Natural Science Foundation of Guangdong Province(No.7001020)
文摘Background Left bundle branch block （LBBB） results in an altered pattern of left ventricular （LV） activation and subsequent contraction. Cardiac synchrony and cardiac function are deteriorated by LBBB. However, the effect of LBBB history on progressive heart dysfunction and clinical efficacy of cardiac resynchronization therapy （CRT） in such patients are not clear. In this study we explore the clinical efficacy and predictor of cardiac resynchronization therapy in LBBB heart dysfunction. Methods Twenty-seven LBBB patients with severe heart failure were treated with CRT. Twenty-six LBBB patients without CRT served as control. During 6 months follow-up, ECG, plasma NT-proBNP and echocardiogram indexes were measured. Results Compared with baseline, NYHA functional class of 23 patients （85.2%） was improved in CRT group. Compared with baseline and control, QRS duration （QRSd） was significantly more narrow （P = 0.023, P = 0.019）, NT-proBNP was significantly lower （P = 0.011,P = 0.009）, ventricular septal to left ventricular posterior wall delay time and left ventricular dyssynchrony index （Ts-SD） were significantly worse （P 〈 0.05）; left ventricular ejection fraction, left ventricular end-systolic volume, mitral regurgitation area were significantly improved in CRT group （P 〈 0.05）. when the LBBB history was I〉 2 years and QRSd I〉 155 ms, the sensitivity and specificity of CRT super-response were 53.4% and 85.6% respectively. Conclusions CRT can improve the synchronization and hemodynamic of LBBB patients with heart dysfunction, the LBBB history I〉 2 years and QRSd I〉 155 ms are one of the CRT super-response predictors.
基金the Ministry of Science and Technology of the People’s Republic of China(grants 2016YFC1301000 and 2016YFC0900900).
文摘Background:Left bundle branch block(LBBB)-induced cardiomyopathy has been proposed,but the association between LBBB and cardiac resynchronization therapy(CRT)response remains unclear and practical criteria for selecting CRT candidates are needed.Methods:One hundred and seventeen consecutive heart failure patients were reviewed,24 of whom received CRT.Only two patients had a clear temporal relation between cardiomyopathy and LBBB.Results:Compared with the patient with“cardiomyopathy-induced LBBB,”the patient with“LBBB-induced cardiomyopathy”had higher left ventricular(LV)wall thickness,higher LV wall thickening rate,higher peak circumferential strain,and longer peak circumferential strain delay.The LV deformation patterns in the two patients were obviously distinct on cardiovascular magnetic resonance tissue tracking.During follow-up,the patient with LBBB-induced cardiomyopathy had a good response to CRT(LV ejection fraction 23 before CRT vs.30%at 6 months vs.29 at 12 months vs.32%at 18 months;LV end-diastolic diameter 77 mm before CRT vs.66 mm at 6 months vs.62 mm at 12 months vs.63 mm at 18 months),and the other patient had no response to CRT(LV ejection fraction 29 before CRT vs.29%at 6 months vs.26 at 12 months vs.22%at 24 months;LV end-diastolic diameter 85 mm before CRT vs.88 mm at 6 months vs.85 mm at 12 months vs.84 mm at 24 months).Conclusion:The temporal relation between cardiomyopathy and LBBB could be a determinant for CRT response.Cardiovascular magnetic resonance tissue tracking may be a useful tool to identify the chronological order and a principal consideration for selecting candidates for CRT.Larger prospective clinical trials are needed to study the prevalence of,time course of,and risk factors for LBBB-induced cardiomyopathy.
文摘Cardiac resynchronization therapy(CRT) effected via biventricular pacing has been established as prime therapy for heart failure patients of New York Heart Association functional class Ⅱ, Ⅲ and ambulatory Ⅳ, reduced left ventricular(LV) function, and a widened QRS complex. CRT has been shown to improve symptoms, LV function, hospitalization rates, and survival. In order to maximize the benefit from CRT and reduce the number of non-responders, consideration should be given to target the optimal site for LV lead implantation away from myocardial scar and close to the latest LV site activation; and also to appropriately program the device paying particular attention to optimal atrioventricular and interventricular intervals. We herein review current data related to both optimal LV lead placement and device programming and their effects on CRT clinical outcomes.
基金supported by Science and Technology Key Foundation of Guangdong Province(No.2010B031600166)the Science and Technology Foundation of Guangdong Province(No.2011B061300072)the Natural Science Foundation of Guangdong Province(No.7001020)
文摘Background The effects of trimetazidine on patients with dilated cardiomyopathy（DCM） and left bundle branch block（LBBB） are not clear. Methods Sixty consecutive patients with DCM, LBBB and heart dysfunction（35% ≤ LVEF ≤ 45%） were randomly allocated to heart failure therapy plus trimetazidine group（20 mg three times a day; 30 patients） or heart failure therapy alone group（30 patients）. During follow-up of 6months, QRS morphology, plasma NT-proBNP, 6-minute walk test（6MWT） and echocardiographic indexes were measured. Results At the 6th month, a significant functional improvement was noted in patients receiving trimetazidine added to heart failure treatment. In patients from the trimetazidine group, an increase of left ventricular ejection fraction（LVEF） was noted（from 38 ± 5.5% to 47 ± 7.1%, P = 0.020）. The increase of LVEF in the trimetazidine group was associated with a more significant reduction of the left ventricular endsystolic diameter（LVESD） compared with the control group at 6-month follow-up. The NT-pro BNP levels decreased significantly in the trimetazidine group（3.11 ± 0.47 at baseline and 2.77 ± 0.45 at 6-month followup, P 〈 0.01） and the 6MWT increased significantly in the trimetazidine group（325 ± 44 m at baseline and419 ± 56 m at 6-month follow-up, P 〈 0.01）. The differences in NT-pro BNP levels（2.77 ± 0.45 vs 2.96 ±0.46, P = 0.036） and 6MWT（419 ± 56 m vs 366 ± 54 m, P = 0.032） between the two groups were significant at 6-month follow-up. Conclusions Trimetazidine can improve LV function caused by DCM and LBBB. The positive effects of trimetazidine on LV function are especially evident in patients with optimization of drug therapy for heart failure, which strongly suggests an additive effect of these therapy modalities.
