Assessing the diagnostic value of left ventricular synchrony indices derived from phase analysis by D-SPECT in identifying obstructive coronary artery disease.

This study aimed to assess the diagnostic efficacy of left ventricular synchrony (LVS) for detecting coronary artery disease (CAD). We explored whether the LVS index derived from phase analysis of D-SPECT provides superior diagnostic value compared to conventional perfusion analysis in identifying obstructive CAD. Patients with suspected or confirmed CAD underwent drug-stress/rest gated D-SPECT myocardial perfusion imaging (MPI) and coronary angiography (CAG). A 50% stenosis was set as the threshold for obstructive CAD. 110 participants were enrolled in this analysis. There were significant differences in phase standard deviation (PSD), phase histogram bandwidth (PHB) and entropy among the four groups. Patients without cardiac disease and those with mild-moderate stenosis exhibited no noticeable contraction asynchrony. However, LVS indices demonstrated a gradual increase with the progression of coronary stenosis when compared to NC (P < 0.001). Obstructive CAD was identified in 43 out of 110 participants (39%). Optimal cutoff values for diagnosing obstructive CAD during stress were determined as 7.6° for PSD, 24° for PHB, and 37% for entropy, respectively. Notably, PSD, PHB, and entropy indices exhibited higher sensitivity compared to MPI. The integration of the stress-induced LVS indices into routine MPI analysis resulted in a significantly greater area under the curve (AUC), leading to improved diagnostic performance and enhanced differential capacity. Stress-induced LVS indices increase with the severity of coronary artery stenosis by D-SPECT phase analysis. Further, the indices-derived phase analysis exhibits superior sensitivity and discriminatory ability compared to MPI in detecting obstructive CAD.

Outcomes with Physiologic His Bundle Pacing in Patients with Narrow QRS Complex.

BACKGROUND: In patients with narrow QRS complex, both ventricular and biventricular pacing is associated with increased cardiac morbidity and mortality. This risk is not decreased by ventricular pacing avoidance algorithms which cause non-physiologic atrioventricular delays. OBJECTIVE: To report outcomes in patients with narrow QRS complex, when paced complex is in normal range and physiologic atrioventricular delays are programmed. METHODS: In 196 patients with QRS duration of 92 ± 10 msec, permanent pacing was done at site of His bundle electrogram. The pacemakers were then programmed to maintain physiologic AV delays and increase heart rates in response to exercise. Patients received usual care and were followed for 3-years. RESULTS: The paced complex exhibited a delta wave and the ventricular activation time, QRS axis and lead-I voltage remained in normal range. Physiologic programming resulted in His bundle pacing burden of 92%. In patients with decreased ejection fraction, there was significant improvement in left ventricular function, left ventricular dilatation and mitral regurgitation (p <0.003). In patients with normal ejection fraction, left ventricular function remained normal without new valvular abnormalities. The 3-year all-cause mortality was 10%, and there was no increase in heart failure admissions. CONCLUSION: In patients with narrow QRS complex, when paced QRS morphology is maintained in normal range and atrio-ventricular dyssynchrony is avoided, His bundle pacing is associated with a low all-cause mortality and improvement in abnormal echocardiographic parameters. The paced QRS morphology and physiologic atrioventricular delays may be important factors to evaluate in future trials of conduction system pacing.

Response predictors to cardiac resynchronization therapy in chronic heart failure: a 10-year-cardiovascular center experience / Predictores de respuesta a la terapia de resincronización cardíaca en insuficiencia cardíaca crónica: 10 años de experiencia en un centro cardiovascular

Abstract Background: Cardiac resynchronization therapy (CRT) has been established as an effective therapy for heart failure with reduced ejection fraction. Randomized clinical trials have shown its impact on mortality and HF hospitalizations, as well as improvement of symptoms and quality of life. Objectives: Finding clinical, electrocardiographic, and echocardiographic variables that may predict the response to cardiac resynchronization therapy (CRT). Methods: We performed a single-center, observational, analytic, and retrospective study that included 102 patients with heart failure (HF) diagnosis who underwent CRT according to guideline-directed therapy from January 2010 to April 2020 in a third-level center. CRT response was defined as an improvement of New York Heart Association functional class in at least 1 category associated with a recovery of ≥ 5% in the left ventricular ejection fraction (LVEF). Results: Our study population was 102 patients of which 61 (59.8%) were men. The mean age at HF diagnosis was 54 ± 18.7 years. Ischemic heart disease was the etiology in 37 (36.3%) cases. Fifty-one (50%) patients were classified as responders. Responders had wider QRS, and lower LVEF and right ventricular fractional area change at baseline. After CRT, responders had a greater reduction of QRS duration, and improvement in LVEF, global longitudinal strain, and echocardiographic dyssynchrony parameters. Multivariate regression analysis showed that left bundle branch block (LBBB), left ventricular end-diastolic volume (LVEDV), tricuspid annular plane systolic excursion (TAPSE), and baseline difference of pre-ejection periods were predictors of a positive response to CRT in this population. Conclusions: LBBB, TAPSE, LVEDV, and pre-ejection time difference are independent variables that can predict adequate response to CRT.

Resumen Antecedentes: La terapia de resincronización cardíaca (TRC) se ha establecido como una terapia efectiva para la insuficiencia cardíaca con fracción de eyección reducida. Ensayos clínicos aleatorizados han demostrado su impacto en la mortalidad y hospitalizaciones por insuficiencia cardíaca, así como la mejora de los síntomas y la calidad de vida. Objetivos: Determinar las variables clínicas, electrocardiográficas y ecocardiográficas que puedan predecir la respuesta a la terapia de resincronización cardíaca (TRC). Método: Estudio unicéntrico, observacional, analítico, retrospectivo, que incluyó 102 pacientes con diagnóstico de IC sometidos a TRC y terapia dirigida por guías, de enero de 2010 a abril de 2020, en un centro de tercer nivel. La respuesta a TRC fue definida como mejoría de la clase funcional de la New York Heart Association en al menos 1 categoría, asociado con una recuperación ≥ 5% en la fracción de expulsión del ventrículo izquierdo (FEVI). Resultados: Incluimos a 102 pacientes, 61 (59.8%) fueron hombres. El promedio de edad al diagnóstico de IC fue 54 ± 18.7 años. La cardiopatía isquémica fue la etiología en 37 (36.3%) pacientes. 51 (50%) pacientes, fueron clasificados como respondedores. Los respondedores presentaron QRS amplio, menor FEVI y menor fracción de acortamiento del ventrículo derecho al inicio del estudio. Después de la TRC, los respondedores tuvieron una mayor reducción en la duración del QRS, mejoría en la FEVI, strain longitudinal global y parámetros de disincronía ecocardiográfica. El análisis de regresión multivariado mostró que el bloqueo de rama izquierdo (BRI), el volumen telediastólico del ventrículo izquierdo (VTDVI) la excursión sistólica del plano anular tricuspídeo (TAPSE) y la diferencia basal del período expulsivo fueron predictores de respuesta positiva a TRC. Conclusiones: BRI, TAPSE, VTDVI y la diferencia basal de períodos preexpulsivos son variables independientes que predicen respuesta adecuada a TRC.

Response predictors to cardiac resynchronization therapy in chronic heart failure: a 10-year-cardiovascular center experience.

BACKGROUND: Cardiac resynchronization therapy (CRT) has been established as an effective therapy for heart failure with reduced ejection fraction. Randomized clinical trials have shown its impact on mortality and HF hospitalizations, as well as improvement of symptoms and quality of life. OBJECTIVES: Finding clinical, electrocardiographic, and echocardiographic variables that may predict the response to cardiac resynchronization therapy (CRT). METHODS: We performed a single-center, observational, analytic, and retrospective study that included 102 patients with heart failure (HF) diagnosis who underwent CRT according to guideline-directed therapy from January 2010 to April 2020 in a third-level center. CRT response was defined as an improvement of New York Heart Association functional class in at least 1 category associated with a recovery of ≥ 5% in the left ventricular ejection fraction (LVEF). RESULTS: Our study population was 102 patients of which 61 (59.8%) were men. The mean age at HF diagnosis was 54 ± 18.7 years. Ischemic heart disease was the etiology in 37 (36.3%) cases. Fifty-one (50%) patients were classified as responders. Responders had wider QRS, and lower LVEF and right ventricular fractional area change at baseline. After CRT, responders had a greater reduction of QRS duration, and improvement in LVEF, global longitudinal strain, and echocardiographic dyssynchrony parameters. Multivariate regression analysis showed that left bundle branch block (LBBB), left ventricular end-diastolic volume (LVEDV), tricuspid annular plane systolic excursion (TAPSE), and baseline difference of pre-ejection periods were predictors of a positive response to CRT in this population. CONCLUSIONS: LBBB, TAPSE, LVEDV, and pre-ejection time difference are independent variables that can predict adequate response to CRT.

ANTECEDENTES: La terapia de resincronización cardíaca (TRC) se ha establecido como una terapia efectiva para la insuficiencia cardíaca con fracción de eyección reducida. Ensayos clínicos aleatorizados han demostrado su impacto en la mortalidad y hospitalizaciones por insuficiencia cardíaca, así como la mejora de los síntomas y la calidad de vida. OBJETIVOS: Determinar las variables clínicas, electrocardiográficas y ecocardiográficas que puedan predecir la respuesta a la terapia de resincronización cardíaca (TRC). MÉTODO: Estudio unicéntrico, observacional, analítico, retrospectivo, que incluyó 102 pacientes con diagnóstico de IC sometidos a TRC y terapia dirigida por guías, de enero de 2010 a abril de 2020, en un centro de tercer nivel. La respuesta a TRC fue definida como mejoría de la clase funcional de la New York Heart Association en al menos 1 categoría, asociado con una recuperación ≥ 5% en la fracción de expulsión del ventrículo izquierdo (FEVI). RESULTADOS: Incluimos a 102 pacientes, 61 (59.8%) fueron hombres. El promedio de edad al diagnóstico de IC fue 54 ± 18.7 años. La cardiopatía isquémica fue la etiología en 37 (36.3%) pacientes. 51 (50%) pacientes, fueron clasificados como respondedores. Los respondedores presentaron QRS amplio, menor FEVI y menor fracción de acortamiento del ventrículo derecho al inicio del estudio. Después de la TRC, los respondedores tuvieron una mayor reducción en la duración del QRS, mejoría en la FEVI, strain longitudinal global y parámetros de disincronía ecocardiográfica. El análisis de regresión multivariado mostró que el bloqueo de rama izquierdo (BRI), el volumen telediastólico del ventrículo izquierdo (VTDVI) la excursión sistólica del plano anular tricuspídeo (TAPSE) y la diferencia basal del período expulsivo fueron predictores de respuesta positiva a TRC. CONCLUSIONES: BRI, TAPSE, VTDVI y la diferencia basal de períodos preexpulsivos son variables independientes que predicen respuesta adecuada a TRC.

Early effects of left bundle branch area pacing on ventricular activation by speckle tracking echocardiography.

BACKGROUND: Left bundle branch area pacing (LBBAP) is an emerging cardiac pacing modality that preserves fast electrical activation of the ventricles and provides very good electrical measures. Little is known on mechanical ventricular activation during this pacing modality. METHODS: We prospectively enrolled patients receiving LBBAP. Electrocardiographic and electrical parameters were evaluated at implantation, < 24 h and 3 months. Transthoracic echocardiography with strain analysis was performed at baseline and after 3 months, when ventricular mechanical activation and synchrony were analyzed by time-to-peak standard deviation (TPSD) of strain curves for both ventricles. Intraventricular left ventricular (LV) dyssynchrony was investigated by LV TPSD and interventricular dyssynchrony by left ventricle-right ventricle TPSD (LV-RV TPSD). RESULTS: We screened 58 patients with permanent pacing indication who attempted LBBAP. Procedural success was obtained in 56 patients (97%). Strain data were available in 50 patients. QRS duration was 124.1 ± 30.7 ms at baseline, while paced QRS duration was 107.7 ± 13.6 ms (p < 0.001). At 3 months after LBBAP, left ventricular ejection fraction (LVEF) increased from 52.9 ± 10.6% at baseline to 56.9 ± 8.4% (p = 0.004) and both intraventricular LV dyssynchrony and interventricular dyssynchrony significantly improved (LV TPSD reduction from 38.2 (13.6-53.9) to 15.1 (8.3-31.5), p < 0.001; LV-RV TPSD from 27.9 (10.2-41.5) to 13.9 (4.3-28.7), p = 0.001). Ameliorations with LBBAP were consistent in all subgroups, irrespective of baseline QRS duration, types of intraventricular conduction abnormalities, and LVEF. CONCLUSIONS: Echocardiographic strain analysis shows that LBBAP determines a fast and synchronous biventricular contraction with a stereotype mechanical activation, regardless of baseline QRS duration, pattern, and LV function.

Left atrial strain is a good predictor of atrio-ventricular synchrony in leadless pacemaker pacing.

INTRODUCTION: The importance of atrio-ventricular synchrony pacing in sinus rhythm patients is known. To identify patients in whom leadless pacemakers are able to guarantee this atrio-ventricular synchrony, we explored correlations among echocardiographic measures of left atrial (LA) size and function (doppler parameter and strain) with A4 amplitude in patients implanted with new generation Micra-AV device. METHODS: After implantation with Micra-AV system, patients underwent device interrogation to evaluate AV synchrony based on the sensing of atrial mechanics and echocardiographic exam to assess LA morphology and LA function. RESULTS: In the 21 studied patients (14 males, 72 ± 13 years), the A4 wave amplitude values inversely correlated with LA antero-posterior diameter, LA volume, LA contraction strain and LA conduit strain, while they were positively related with LA reservoir strain. DISCUSSION: Our results indicate a statistically significant relationship between morphological echocardiographic LA parameters and atrial contraction signal (A4), detected by leadless pacemakers and used to synchronize ventricular pacing with the atrium. Instantaneous LA function assessment obtained with LA strain provides incremental information over morphological parameters. LA strain evaluates atrial myocardial deformation during the whole cardiac cycle. We found higher value of A4 in patients that have grater absolute value of LAsr, LAscd and LAsct, that are simple and measurable parameters of LA functional capacity. CONCLUSION: Preimplant echocardiographic evaluation of the atrial contractility may be useful in predicting adequate A4 sensing and consequently a good atrio-ventricular synchrony pacing. Echocardiography LA strain study seems promising in Micra-AV patient selection.

Integración de los parámetros de remodelado, sincronía y velocidad máxima de vaciado para evaluar la función sistólica del ventrículo izquierdo / Integration of ventricular remodeling, synchrony and filling rate parameters to improve the assessment of left ventricular systolic function

Objetivos El objetivo es estudiar la relación entre los parámetros estructurales, de remodelado, de sincronía y de función sistólica del ventrículo izquierdo (VI) mediante gSPECT. Obtener los valores de corte del VI para el índice de la forma telediastólica (iFTD), el índice de la forma telesistólica (iFTS), el índice de excentricidad (iEX) y la velocidad máxima de vaciado (VMV). Desarrollar un nuevo índice para evaluar diferentes patrones de función sistólica del VI. Material y métodos Analizamos prospectivamente 238 pacientes (edad: 63,4±13 años) estudiados mediante gSPECT de esfuerzo-reposo (grupo-control, n=148; pacientes con infarto de miocardio [IM] previo, n=90). Estudio aprobado por el Comité de Ética del Hospital (PR[AG]168.2010). Resultados En el grupo-control, el índice del volumen telediastólico (iVTD) y el iEX influyeron en el iFTD (r2: 0,52, p<0,001). El iVTD, la VMV, ser varones y el iEX (r2: 0,44; p<0,001) influyeron en el iFTS. El iFTD, iFTS, la fracción de eyección VI (FEVI) y el volumen de eyección sistólica (r2: 0,62; p<0,001) influyeron en el iEX. La FEVI, la frecuencia cardíaca, el ancho de banda (AB) y la desviación estándar influyeron (r2: 0,76; p<0,001) en la VMV. Los valores de corte para iFTD, iFTS, iEX y VMV fueron 0,59, 0,42, 0,87 y −3,3 respectivamente. La VMV, el iFTS y el AB fueron los parámetros mejor relacionados con los pacientes con IM previo (AUC: 0,89), y sumados a la FEVI permitieron obtener distintos patrones de función sistólica (índice PERRS). Conclusiones Los parámetros de remodelado, sincronía y función sistólica del VI deben interpretarse simultáneamente, ya que esto permite obtener distintos patrones de función sistólica del VI (AU)

Introduction and objectives The aim of this study is to assess the relationship between structural, remodeling, synchrony, and systolic left ventricular (LV) function parameters using gated-SPECT myocardial-perfusion-images (gSPECT-MPI). In addition, obtaining the cut-off values for end-diastolic LV-shape-index (EDLVsi), end-systolic LV-shape-index (ESLVsi), ECC (eccentricity-index) and PER, and developing a new index to evaluate different patterns of the LV systolic function. Methods The study was approved by the Hospital's Ethical-Committee (PR[AG]168.2010), and all patients gave their informed consent. We analyzed prospectively 238 patients (age 63.4±13 years) who underwent stress-rest gSPECT-MPI (control-group, n=148; patients with previous myocardial infarction [MI], n=90). Results In the control group, with regard to remodeling parameters: the end-diastolic-volume-index (EDV) and the ECC were the parameters that influenced the EDLVsi (r2: 0.52, P<.001). EDV, PER, men, and the ECC were the parameters (r2: 0.44; P<.001) which influenced the ESLVsi. EDLVsi, ESLVsi, LVEF and the stroke-volume were the parameters (r2: 0.62; P<.001) which influenced the ECC. With regards to PER: LVEF, heart-rate, bandwidth, and the standard-deviation were the influencing parameters (r2: 0.76; P<.001). The cut-off values for EDLVsi, ESLVsi, ECC, and PER were 0.59, 0.42, 0.87, and 3.3, respectively. The PER, the ESLVsi and the bandwidth were the parameters related to patients with previous MI (AUC: 0.89); and they allow the assessment of different patterns of systolic function (PERRS-index: Peak-Emptying-Rate, left ventricular-Remodeling and Synchrony). Conclusions The remodeling, synchrony and the systolic function parameters of the LV should be interpreted together (PERRS-index). In this way, we obtain different patterns of LV systolic function (AU)

Integration of ventricular remodeling, synchrony and filling rate parameters to improve the assessment of left ventricular systolic function.

INTRODUCTION AND OBJECTIVES: The aim of this study is to assess the relationship between structural, remodeling, synchrony, and systolic left ventricular (LV) function parameters using gated-SPECT myocardial-perfusion-images (gSPECT-MPI). In addition, obtaining the cut-off values for end-diastolic LV-shape-index (EDLVsi), end-systolic LV-shape-index (ESLVsi), ECC (eccentricity-index) and PER, and developing a new index to evaluate different patterns of the LV systolic function. METHODS: The study was approved by the Hospital's Ethical-Committee (PR[AG]168.2010), and all patients gave their informed consent. We analyzed prospectively 238 patients (age 63.4 ±â€¯13 years) who underwent stress-rest gSPECT-MPI (control-group, n = 148; patients with previous myocardial infarction [MI], n = 90). RESULTS: In the control group, with regard to remodeling parameters: the end-diastolic-volume-index (EDV) and the ECC were the parameters that influenced the EDLVsi (r2: 0.52, p < 0.001). EDV, PER, men, and the ECC were the parameters (r2: 0.44; p < 0.001) which influenced the ESLVsi. EDLVsi, ESLVsi, LVEF and the stroke-volume were the parameters (r2: 0.62; p < 0.001) which influenced the ECC. With regards to PER: LVEF, heart-rate, bandwidth, and the standard-deviation were the influencing parameters (r2: 0.76; p < 0.001). The cut-off values for EDLVsi, ESLVsi, ECC, and PER were 0.59, 0.42, 0.87, and 3.3, respectively. The PER, the ESLVsi and the bandwidth were the parameters related to patients with previous MI (AUC: 0.89); and they allow the assessment of different patterns of systolic function (PERRS-index: peak-emptying-rate, left ventricular-remodeling and synchrony). CONCLUSIONS: The remodeling, synchrony and the systolic function parameters of the LV should be interpreted together (PERRS-index). In this way, we obtain different patterns of LV systolic function.

Left bundle branch area pacing results in more physiological ventricular activation than biventricular pacing in patients with left bundle branch block heart failure.

Biventricular pacing (Biv) and left bundle branch area pacing (LBBAP) are methods of cardiac resynchronization therapy (CRT). Currently, little is known about how they differ in terms of ventricular activation. This study compared ventricular activation patterns in left bundle branch block (LBBB) heart failure patients using an ultra-high-frequency electrocardiography (UHF-ECG). This was a retrospective analysis including 80 CRT patients from two centres. UHF-ECG data were obtained during LBBB, LBBAP, and Biv. Left bundle branch area pacing patients were divided into non-selective left bundle branch pacing (NSLBBP) or left ventricular septal pacing (LVSP) and into groups with V6 R-wave peak times (V6RWPT) < 90 ms and ≥ 90 ms. Calculated parameters were: e-DYS (time difference between the first and last activation in V1-V8 leads) and Vdmean (average of V1-V8 local depolarization durations). In LBBB patients (n = 80) indicated for CRT, spontaneous rhythms were compared with Biv (39) and LBBAP rhythms (64). Although both Biv and LBBAP significantly reduced QRS duration (QRSd) compared with LBBB (from 172 to 148 and 152 ms, respectively, both P < 0.001), the difference between them was not significant (P = 0.2). Left bundle branch area pacing led to shorter e-DYS (24 ms) than Biv (33 ms; P = 0.008) and shorter Vdmean (53 vs. 59 ms; P = 0.003). No differences in QRSd, e-DYS, or Vdmean were found between NSLBBP, LVSP, and LBBAP with paced V6RWPTs < 90 and ≥ 90 ms. Both Biv CRT and LBBAP significantly reduce ventricular dyssynchrony in CRT patients with LBBB. Left bundle branch area pacing is associated with more physiological ventricular activation.

Echocardiographic Evaluation of His Bundle Pacing in Patients with Prolonged PR Intervals.

Background: Patients with PR intervals >240ms have atrio-ventricular (AV) dyssynchrony, which can increase risk of atrial fibrillation and all-cause mortality. When requiring pacing, long AV delays (AVDs) have been programmed to avoid ventricular dyssychrony. His bundle pacing (HBP) may provide improved AV synchrony in patients with prolonged PR. Methods: 10 patients with sinus node dysfunction and prolonged PR who received HBP were studied. Real-time echocardiographic was performed with 3 pacemaker modes (RV septal, non-selective HBP, and selective HBP) using the following pacemaker settings: control (no ventricular pacing), pacing with AVD of 180ms, 150ms, 120ms, 100ms, and 70ms. Echocardiographic Doppler measurements: EA/RR, >40% = AV synchrony; E/e', <8 = normal left atrial pressure; pulmonic-to-aortic pre-ejection time difference, <40ms = interventricular synchrony; septal-to-lateral wall activation time difference, <56ms = intraventricular synchrony; and LVOT VTI. Unpaired T test was used to evaluate for significance. Exclusion criteria: persistent atrial fibrillation, second-degree AV block. Results: Compared to control programming, HBP showed a 31.5% increase in EA/RR time, a decrease in E/e' of 26.9%, and an increase in the LVOT VTI of 21.3%. Compared to RV septal pacing, there was a similar increase in LVOT VTI. These findings met statistical significance and were considered optimal based on Doppler echocardiography findings primarily at AVDs of 150ms and 120ms. Comparisons between selective and non-selective pacing were not significantly different. Conclusion: Compared to controls and RV septal pacing, physiologic His bundle pacing was shown to increase markers of AV synchrony and LV stroke volume while maintaining ventricular synchrony.

Echocardiography- versus intracardiac electrocardiogram-based optimization of cardiac resynchronization therapy: A systematic review.

OBJECTIVE: This systematic review aimed to evaluate the performance of echocardiography-based programming in comparison with the intracardiac electrocardiogram (IEGM)-based method for the optimization of cardiac resynchronization therapy (CRT). METHODS: A literature review was conducted using digital databases to systematically identify the studies reporting CRT optimization through echocardiography compared with IEGM. Detailed patient-level study characteristics including the type of study, sample size, therapy, the New York Heart Classification (NYHA) status, lead placement, and other parameters were abstracted. Finally, postprogramming outcomes were extracted for each article. RESULTS: In a total of 11 studies, 919 patients were recruited for the final analysis. Overall, 692 (75.29%) were males. The mean duration of the QRS complex in our study population ranged from 145.2 ± 21.8 ms to 183 ± 19.9 ms. There was an equal improvement in the NYHA class between the two methods while the left ventricular ejection fraction (LVEF) demonstrated an improvement by IEGM. Many studies supported IEGM to increase the 6-minute walk test and left ventricular outflow tract velocity time interval (LVOT VTI) when compared to echocardiography. The mean time for echocardiography-based optimization was 60.15 min while that of IEGM-based optimization was 6.65 min. CONCLUSION: IEGM is an alternative method for CRT optimization in improving the NYHA class, LVEF, and LVOT VTI, and is less time-consuming when compared to the echocardiography-based methods.

Comparison of ventricular synchrony in children with left bundle branch area pacing and right ventricular septal pacing.

OBJECTIVE: This study aimed to determine the ideal pacing site in children by comparing the postoperative ventricular synchrony in children with left bundle branch area pacing and those with right ventricular septal pacing. METHODS: This retrospective study included children with complete atrioventricular block who underwent permanent pacemaker implantation from March 2019 to August 2021. Patients were grouped according to their ventricular pacing site, the left bundle branch area pacing group and the right ventricular septal pacing group. Two-dimensional speckle tracking echocardiography was used to evaluate the ventricular synchrony. RESULTS: Forty-eight children (median age, 2.7 years; interquartile range, 1.7-4.6 years) were included. The paced QRS duration in the left bundle branch area pacing group was significantly narrower than that in the right ventricular septal pacing group (100.2 ± 9.3 versus 115.4 ± 15.1 ms, p = 0.001). The median follow-up duration was 1.5 years (interquartile range, 1-2 years). At the last follow-up, the average capture threshold of the ventricular electrode in the left bundle branch area pacing group was lower than that in the right ventricular septal pacing group (0.79 ± 0.18 versus 1.20 ± 0.56 V, p = 0.008). The left ventricular intraventricular synchrony parameters in the left bundle branch area pacing group were better than those in the right ventricular septal pacing group (e.g. standard deviation of the time to peak longitudinal strain, 37.4 ± 4.3 versus 46.6 ± 8.2 ms, p = 0.000). The average interventricular mechanical delay time in the left bundle branch area pacing group was significantly shorter than that in the right ventricular septal pacing group (36.4 ± 14.2 versus 52.5 ± 22.7 ms, p = 0.016). CONCLUSION: Compared with right ventricular septal pacing, left bundle branch area pacing in children produces a narrower QRS duration and better pacing and ventricular synchrony parameters postoperatively.

Left bundle branch area pacing in patients with baseline narrow, left, or right bundle branch block QRS patterns: insights into electrocardiographic and echocardiographic features.

AIMS: Left bundle branch area pacing (LBBAP) is a recent technique aiming at preservation of physiological ventricular electrical activation. Our goal was to assess mechanical synchrony parameters in relation to electrocardiographic features during LBBAP performed in routine practice. METHODS AND RESULTS: From June 2020 to August 2021, all patients of our institution with permanent pacemaker implantation indication were eligible for LBBAP. A 'qR' pattern in V1 and a delay from pacing spike to the peak of the R-wave in V6 < 80 ms defined a successful LBBAP. Electrocardiogram and echocardiography were performed during spontaneous rhythm and LBBAP: left ventricular mechanical synchrony (LVMS) parameters using 2D Speckle tracking and interventricular mechanical delay (IVMD) were collected. LBBAP was attempted with success in 134/163 patients (82.2%). During LBBAP, the mean QRS width was 104 ± 12 ms. In patients with left bundle branch block (n = 47), LBBAP provided a significant decrease of QRS width from 139 ± 16 to 105 ± 12 ms (P < 0.001) with reduction of LVMS (53 ± 21 vs. 90 ± 46 ms, P = 0.009), and IVMD (14 ± 13 vs. 49 ± 18 ms, P < 0.001). In patients with right bundle branch block (n = 38), LBBAP led to a significant decrease of QRS width from 134 ± 14 to 106 ± 13 ms (P < 0.001) with no effect on LVMS and a reduction of IVMD (17 ± 14 vs. 50 ± 16 ms, P < 0.001). CONCLUSION: LBBAP in routine practice preserved intra-ventricular mechanical synchrony in patients with narrow and RBBB QRS and improved asynchrony parameters in patients with LBBB.

Comparison of cardiac function before and after Micra implantation using pool scintigraphy and myocardial work: A case report.

Leadless pacemakers, specifically Micra (Medtronic), have recently become a preferred alternative to transvenous pacemakers for use in bradyarrhythmia. Problems with conventional transvenous pacemakers include wound infection, lead disconnection, and tricuspid valve dysfunction. While Micra has the advantage of not being associated with the aforementioned complications, there have been reports of cardiac injury during Micra implantation, which have raised safety concerns. Many reports have evaluated Micra safety, but its effect on cardiac function remains unclear. In an 85-year-old man with bradycardic atrial fibrillation, a heart rate of approximately 35 bpm, and symptoms of dizziness, we analyzed ventricular workload, ejection fraction of the left and right ventricles, and inter/intraventricular synchrony using cardiac blood pool scintigraphy and myocardial work. Micra was successfully implanted into the right ventricular septum via the left femoral vein. A follow-up, 2 days later, showed no major complications associated with Micra pacing threshold and impedance. At this time, there was no apparent worsening of heart failure. Micra implantation for bradycardic atrial fibrillation has the potential to improve left ventricular work efficiency without the loss of ventricular synchrony.

Hemodynamic Effects of Permanent His Bundle Pacing Compared to Right Ventricular Pacing Assessed by Two-Dimensional Speckle-Tracking Echocardiography.

We compared the effects of right ventricular (RVP; n = 26) and His bundle (HBP; n = 24) pacing in patients with atrioventricular conduction disorders and preserved LVEF. Postoperatively (1D), and after six months (6M), the patients underwent global longitudinal strain (GLS) and peak systolic dispersion (PSD) evaluation with 2D speckle-tracking echocardiography, assessment of left atrial volume index (LAVI) and QRS duration (QRSd), and sensing/pacing parameter testing. The RVP threshold was lower than the HBP threshold at 1D (0.65 ± 0.13 vs. 1.05 ± 0.20 V, p < 0.001), and then it remained stable, while the HBP threshold increased at 6M (1.05 ± 0.20 vs. 1.31 ± 0.30 V, p < 0.001). The RVP R-wave was higher than the HBP R-wave at 1D (11.52 ± 2.99 vs. 4.82 ± 1.41 mV, p < 0.001). The RVP R-wave also remained stable, while the HBP R-wave decreased at 6M (4.82 ± 1.41 vs. 4.50 ± 1.09 mV, p < 0.02). RVP QRSd was longer than HBP QRSd at 6M (145.0 ± 11.1 vs. 112.3 ± 9.3 ms, p < 0.001). The absolute value of RVP GLS decreased at 6M (16.32 ± 2.57 vs. 14.03 ± 3.78%, p < 0.001), and HBP GLS remained stable. Simultaneously, RVP PSD increased (72.53 ± 24.15 vs. 88.33 ± 30.51 ms, p < 0.001) and HBP PSD decreased (96.28 ± 33.99 vs. 84.95 ± 28.98 ms, p < 0.001) after 6 months. RVP LAVI increased (26.73 ± 5.7 vs. 28.40 ± 6.4 mL/m2, p < 0.05), while HBP LAVI decreased at 6M (30.03 ± 7.8 vs. 28.73 ± 8.7 mL/m2, p < 0.01). These results confirm that HBP does not disrupt ventricular synchrony and provides advantages over RVP.

An electrographic AV optimization for the maximum integrative atrioventricular and ventricular resynchronization in CRT.

BACKGROUND: Atrioventricular (AV) delay could affect AV and ventricular synchrony in cardiac resynchronization therapy (CRT). Strategies to optimize AV delay according to optimal AV synchrony (AVopt-AV) or ventricular synchrony (AVopt-V) would potentially be discordant. This study aimed to explore a new AV delay optimization algorithm guided by electrograms to obtain the maximum integrative effects of AV and ventricular resynchronization (opt-AV). METHODS: Forty-nine patients with CRT were enrolled. AVopt-AV was measured through the Ritter method. AVopt-V was obtained by yielding the narrowest QRS. The opt-AV was considered to be AVopt-AV or AVopt-V when their difference was < 20 ms, and to be the AV delay with the maximal aortic velocity-time integral between AVopt-AV and AVopt-V when their difference was > 20 ms. RESULTS: The results showed that sensing/pacing AVopt-AV (SAVopt-AV/PAVopt-AV) were correlated with atrial activation time (Pend-As/Pend-Ap) (P < 0.05). Sensing/pacing AVopt-V (SAVopt-V/PAVopt-V) was correlated with the intrinsic AV conduction time (As-Vs/Ap-Vs) (P < 0.01). The percentages of patients with more than 20 ms differences between SAVopt-AV/PAVopt-AV and SAVopt-V/PAVopt-V were 62.9% and 57.1%, respectively. Among them, opt-AV was linearly correlated with SAVopt-AV/PAVopt-AV and SAVopt-V/PAVopt-V. The sensing opt-AV (opt-SAV) = 0.1 × SAVopt-AV + 0.4 × SAVopt-V + 70 ms (R2 = 0.665, P < 0.01) and the pacing opt-AV (opt-PAV) = 0.25 × PAVopt-AV + 0.5 × PAVopt-V + 30 ms (R2 = 0.560, P < 0.01). CONCLUSION: The SAVopt-AV/PAVopt-AV and SAVopt-V/PAVopt-V were correlated with the atrial activation time and the intrinsic AV conduction interval respectively. Almost half of the patients had a > 20 ms difference between SAVopt-AV/PAVopt-AV and SAVopt-V/PAVopt-V. The opt-AV could be estimated based on electrogram parameters.

Síndrome de marcapasos: cuál es el mecanismo? / Pacemaker syndrome: what is the mechanism?

Resumen Presentamos un caso de síndrome de marcapasos asociado a la ausencia de sincronía aurículo-ventricular, debido a la colocación invertida e inadvertida de los electrodos, en una paciente portadora de bloqueo aurículo-ventricular completo; para su diagnóstico, es fundamental un cuidadoso análisis del electrocardiograma, las imágenes con rayos X y los electrogramas intracavitarios.

Abstract Pacemaker syndrome: what is the mechanism? We present the case of pacemaker syndrome related to the absence of atrioventricular synchrony, due to inverted and inadvertent placement of the electrodes, in a patient with complete atrioventricular block. A careful analysis of the electrocardiogram, X-ray images and intracavitary electrograms are essential for its diagnosis.

Changes in QRS Duration Are Associated with a Therapeutic Response to Sacubitril-valsartan in Heart Failure with Reduced Ejection Fraction.

BACKGROUND: Recent studies have demonstrated that angiotensin receptor neprilysin inhibitors (ARNIs) can reverse the cardiac remodeling effects that occur in heart failure with reduced ejection fraction (HFrEF). These studies have also suggested that ARNIs have favorable effects on ventricular dyssynchrony. We assessed the changes in QRS duration associated with ARNIs in patients with HFrEF. METHODS: We retrospectively investigated patients with HFrEF (defined by a left ventricular ejection fraction [LVEF] ≤ 35%) who were treated with ARNIs for at least six months. We divided the patients into QRS shortening and non-QRS shortening groups according to their electrocardiogram (ECG) findings. We also compared changes in echocardiographic parameters between the groups. RESULTS: A total of 68 patients with HFrEF were included (mean age: 62.5 years, 74.6% male). Twenty-one patients had significant ischemic heart disease (IHD). Thirty-five patients exhibited QRS-duration shortening on follow-up ECGs (mean change: -7.8 msec), and 33 patients showed no changes or increased QRS duration (mean change: 5.1 msec). The QRS shortening group exhibited significant improvement in LVEF (12.5 ± 15.3% vs. 1.7 ± 9.5%; p < 0.001) when compared with the non-QRS shortening group. The QRS shortening group also had significantly lower LV end-diastolic dimension (LVEDD), LV end-systolic dimension (LVESD) and LV mass index (LVMI) than did the non-QRS shortening group. The change in QRS duration was significantly correlated with the change in LVEF (r = -0.329, p = 0.011) and LVESD (r = 0.298, p = 0.022). CONCLUSIONS: Among patients with HFrEF treated with ARNIs, the QRS shortening group showed favorable LV systolic function recovery, and reversal of cardiac remodeling compared to those of the non-QRS shortening group. Change in the QRS duration, which reflects LV synchrony, may be associated with response to ARNIs in patients with HFrEF.

Cardiac resynchronization therapy by left bundle branch area pacing in patients with heart failure and left bundle branch block.

BACKGROUND: Cardiac resynchronization therapy (CRT) via biventricular pacing has demonstrated clinical benefits in patients with heart failure (HF) and ventricular dyssynchrony. Other approaches of CRT is little known. OBJECTIVE: The purpose of this study was to assess the feasibility, safety, and efficacy of left bundle branch area pacing (LBBAP) in patients with HF and left bundle branch block (LBBB). METHODS: Eleven consecutive patients with HF, reduced left ventricular ejection fraction and LBBB and indicated for CRT were recruited. LBBAP was achieved via transventricular septal approach and characterized by narrower QRS duration, shortened peak left ventricular activation time, and right bundle branch conduction delay on the electrocardiogram. Electrocardiogram, echocardiogram, and cardiac function were evaluated at baseline and follow-up. Interventricular mechanical delay and 3-dimensional tissue synchronization imaging during LBBAP and intrinsic LBBB status were measured by echocardiography at follow-up. RESULTS: LBBAP significantly shortened QRS duration (from baseline 180.00 ± 15.86 ms to 129.09 ± 15.94 ms; P < .01) and left ventricular activation time (from baseline 108.18 ± 15.54 ms to 80.91 ± 9.95 ms; P < .01). Interventricular mechanical delay and the standard deviation of tissue synchronization imaging of 12 left ventricular (LV) segments were significantly shorter during LBBAP than in intrinsic LBBB status (both with P < .01). At a mean follow-up period of 6.7 months, New York Heart Association functional class, plasma level of B-type natriuretic peptide, LV end-systolic diameter, and left ventricular ejection fraction were significantly improved (all with P < .05 vs baseline). CONCLUSION: The study demonstrates that LBBAP is clinically feasible in patients with systolic HF and LBBB. LBBAP can be a new CRT technique to correct LBBB, provide ventricular synchrony, and improve clinical symptoms with LV reverse remodeling.