Immediate pharmacotherapy intensification after cardiac resynchronization therapy: incidence, characteristics, and impact.

AIMS: Cardiac resynchronization therapy (CRT) is an established treatment for drug-refractory heart failure (HF) in patients with left bundle branch block (LBBB). Acute haemodynamic improvement after CRT implantation may enable the intensification of HF medication soon thereafter. Immediate pharmacotherapy intensification (IPI) after CRT implantation achieves a synergetic effect, possibly leading to a better prognosis. This study aimed to explore the incidence, characteristics, and impact of IPI on real-world outcomes among CRT recipients with a history of hospitalization for acute HF. METHODS AND RESULTS: This multicentre retrospective study enrolled CRT recipients with LBBB morphology, a QRS width ≥120 ms, a left ventricular ejection fraction ≤35%, and New York Heart Association II-IV HF symptoms. All patients had previous HF hospitalizations within the previous year and received guideline-directed medical therapy before CRT implantation. Patient baseline characteristics, including HF medication, were collected. IPI was defined as the intensification of beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and mineralocorticoid receptor antagonists within 30 days of CRT implantation. The primary endpoint was all-cause death or first hospitalization for HF; the secondary endpoint was all-cause death. We enrolled 194 patients (75% male; mean age, 65 ± 13 years; 78% with non-ischaemic cardiomyopathy). One hundred five (54%) patients received IPI. Patients who received IPI exhibited a significantly shorter QRS duration (159 ± 26 vs. 171 ± 32 ms; P = 0.004), higher estimated glomerular filtration rate (55.2 ± 20.0 vs. 47.8 ± 24.7 mL/min/1.73 m2 ; P = 0.022), and more dilated cardiomyopathy. During a median follow-up period of 29 months, 70 (36%) patients reached the primary endpoint and 42 (22%) patients died. Patients with IPI showed significantly better outcomes for the primary and secondary endpoints than patients without IPI. The volumetric responder ratio at 6 months after implantation was not significantly different between patients with and without IPI; however, patients who received IPI had reduced mortality even at 6 months after implantation. In the multivariate analysis, IPI was an independent predictor of the primary endpoint (hazard ratio, 0.51; 95% confidence interval, 0.27-0.97; P = 0.043). CONCLUSIONS: Immediate intensification of HF medication was achieved in 54% of CRT recipients and was significantly higher in patients without excessive QRS prolongation, preserved renal function, and dilated cardiomyopathy than others. In patients with LBBB morphology and QRS ≥ 120 ms, IPI was associated with a significantly better prognosis and fewer HF hospitalizations after CRT implantation than others.

Impact of adaptive cardiac resynchronization therapy in patients with systolic heart failure: Beyond QRS duration and morphology.

BACKGROUND: Mechanical and electrical restoration by cardiac resynchronization therapy (CRT) with adaptive pacing algorithm (aCRT) in heart failure patients with a moderately wide (120-149 ms) QRS has not been fully evaluated. The purpose of this study was to investigate the therapeutic effect of aCRT compared with conventional biventricular CRT (BiV-CRT) regardless of QRS morphology. METHODS: Seventeen consecutive patients with a QRS ≥120 ms, regardless of morphology, underwent CRT device implantation with an aCRT pacing algorithm. Propensity score matched analysis was performed to evaluate the impact of aCRT on the improvement in mechanical and electrical parameters after CRT device implantation using historical controls (HC) from the clinical registry of BiV-CRT (START trial). RESULTS: Left ventricular (LV) volume significantly decreased after CRT in all patients in both the aCRT and HC groups. The difference in relative reduction of LV end-systolic volume (LVESV) was not significantly different between the 2 arms. QRS shortening after CRT was significantly greater in the aCRT group than in the BiV-CRT group, and the difference was prominent in patients with a moderately wide QRS (120-149 ms). In patients with a moderately wide QRS, the relative reduction in LVESV [39 (29-47)% vs. 2 (-6-20)%, p = 0.04] and proportion of LV volume responders (90% vs. 38%, p = 0.04) were significantly greater in the aCRT group than in the HC group. The proportion of volume responders was not significantly different in patients with a wide QRS (≥150 ms). CONCLUSIONS: The aCRT algorithm improved electrical and mechanical parameters in patients with a moderately wide QRS, regardless of QRS morphology.

Stellate Ganglion Phototherapy Using Low-Level Laser: A Novel Rescue Therapy for Patients With Refractory Ventricular Arrhythmias.

OBJECTIVES: This study investigates the effect of stellate ganglion (SG) phototherapy in healthy participants and assesses its efficacy in suppressing electrical storm (ES) refractory to antiarrhythmic drugs and catheter ablation. BACKGROUND: Modulation of the autonomic nervous system has been shown to be an effective adjunctive therapy for ES. METHODS: Ten-minute SG phototherapy was performed twice weekly for 4 weeks in 20 healthy volunteers. To evaluate the acute and chronic effects of SG phototherapy, heart rate variability and serum concentrations of adrenaline, noradrenaline, and dopamine were obtained before phototherapy, immediately after the first phototherapy session, after 8 sessions of phototherapy, and 3 months after the first phototherapy session. In addition, the efficacy of SG phototherapy was evaluated in 11 patients with ES refractory to medication, sedation, and catheter ablation. RESULTS: In healthy participants, serum adrenaline concentration significantly decreased after phototherapy, whereas low-frequency power/high-frequency power significantly decreased during phototherapy. Moreover, the effect on heart rate variability did not last beyond 3 months. In the clinical pilot study, 7 patients had a suppression of ES after SG phototherapy; however, without maintenance therapy, 2 patients had a recurrence of ventricular arrhythmias. Furthermore, it did not control ES in 4 patients. CONCLUSIONS: SG phototherapy reduced sympathetic activity and may be a safe and effective adjunctive therapy to control ES in some patients, but its long-term efficacy remains unknown. Chronic phototherapy might help reduce ES recurrence.

The Usefulness and Limitations of Impedance Cardiography for Cardiac Resynchronization Therapy Device Optimization.

Identifying the optimal atrioventricular (AV) or interventricular (VV) delay is beneficial for patients using cardiac resynchronization therapy (CRT) devices. Ultrasonic echocardiography (UCG) has been the most commonly used method; however, it requires high technical knowledge. Impedance cardiography (ICG) can calculate stroke volume by measuring changes in transthoracic electric impedance. This study sought to assess the clinical utility of ICG in comparison with that of UCG for the optimization of CRT devices.Patients who underwent CRT device implantation were retrospectively analyzed. One week after implantation, optimization of AV delay (AVD) was performed in every patient with ICG (AVD-ICG) and UCG (AVD-UCG). VV delay (VVD) was then determined according to the optimal AVD using these two methods.Forty-two patients were enrolled. Average AVD-ICG was significantly shorter than AVD-UCG (128 ± 49 versus 146 ± 41 milliseconds, P = 0.018). Five patients (12%) had the same optimized AVD with two methods, and the difference between AVD-ICG and AVD-UCG was ≤ 20 milliseconds in 19 patients (45%). In the multivariate analysis, the presence of postoperative mitral regurgitation (MR) was an independent predictor of AVD-ICG/AVD-UCG mismatch, defined as a difference over 20 milliseconds (odds ratio = 10.71; 95% confidence interval = 1.72 to 66.72; P = 0.018). The results of optimized VVD were similar using both methods.ICG might be a promising tool for the rapid optimization of CRT devices. However, in patients with moderate-to-severe MR, ICG may not be able to optimize AVD.

Mechanistic implication of decreased plasma atrial natriuretic peptide level for transient rise in the atrial capture threshold early after ICD or CRT-D implantation.

PURPOSE: Despite the use of steroid-eluting leads, a transient but not persistent rise in the atrial/ventricular capture threshold (TRACT/TRVCT) can occur early after pacemaker implantation in patients with sick sinus syndrome. This study aimed to assess the prevalence, predictors, and mechanisms of TRACT/TRVCT in patients with heart failure undergoing implantable cardioverter defibrillator (ICD) or cardiac resynchronization therapy (CRT) implantation. METHOD: One hundred twenty consecutive patients underwent ICD (N = 70) or CRT (N = 50) implantation. Capture threshold was measured at implantation, 7-day, 1-month, and 6-month post-implantation. TRACT/TRVCT was defined as a threshold rise at 7 days by more than twice the height of the threshold at implantation, with full recovery during follow-up. Atrial and brain natriuretic peptide (ANP and BNP) levels were measured before implantation. RESULTS: TRACT and TRVCT were observed in 13 (11%) and 10 (8%) patients, respectively. Patients with TRACT had lower ANP level (median 72 [42-105] vs. 99 [49-198] pg/mL, P = 0.06), lower ANP/BNP ratio (0.29 [0.20-0.36] vs. 0.50 [0.33-0.70], P < 0.01), lower atrial sensing amplitude (2.0 ± 0.8 vs. 2.7 ± 1.3 mV, P = 0.02), and lower left ventricular ejection fraction (32 ± 12 vs. 40 ± 14%, P = 0.04) than those without TRACT. TRACT recovered within 1 month, whereas TRVCT recovered within 6 months. In multivariable analysis, ANP/BNP ratio was the only independent predictor of TRACT (OR, 0.018; 95% CI, 0.001-0.734; P = 0.034). CONCLUSIONS: Atrial degenerative change characterized by lower ANP/BNP ratio was associated with the occurrence of TRACT in patients with heart failure. TRVCT could also occur, but it required a longer recovery time than TRACT.

Difficulty and potential risks of single-lead atrioventricular synchronous pacing leads in transvenous lead extraction.

OBJECTIVES: The purpose of this study was to examine the factors affecting the outcome of successful lead extraction with an excimer laser sheath, which have not been clearly elucidated. METHODS: Between January 2011 and December 2016 in our institution, 372 leads were intravenously extracted from 176 patients (mean age, 67 ± 15 years; 83% male) with the use of an excimer laser sheath. The mean time since lead implantation was 7.1 ± 6.7 years. Indications for this procedure were infection (76.1%), non-functional lead (11.3%), functional lead (9.7%) and others (2.9%). RESULTS: The clinically successful removal rate was 96%. The procedural failure group had a longer time from implantation (P = 0.01), longer fluoroscopy time (P < 0.01) and greater use of a single-lead atrioventricular synchronous (VDD) pacing lead (P < 0.01) compared to the clinical success group. The significant factors of clinical failure were the use of a VDD-pacing lead (odds ratio 30.9, 95% confidence interval 5.8-165; P < 0.01) and the time from first implantation (odds ratio 1.1, 95% confidence interval 1.0-1.3; P = 0.02). In addition, there was no significant difference between the use of a VDD-pacing lead and the time from first implantation (P = 0.28). CONCLUSIONS: A VDD-pacing lead is an unsuccessful factor of lead extraction. When performing VDD-pacing lead extraction, an operator should pay special attention to the procedure.

Underrecognized entity of the transient rise in the atrial capture threshold early after dual-chamber pacemaker implantation.

BACKGROUND: Steroid-eluting pacemaker leads suppress acute rises in pacing threshold by preventing inflammatory processes. However, we occasionally encounter not persistent but transient rise in the atrial capture threshold (TRACT) early after pacemaker implantation. We believe that this phenomenon is underrecognized in clinical practice and may potentially lead to unnecessary reintervention. We aimed to clarify the prevalence, predictors, and possible mechanisms of TRACT. METHODS AND RESULTS: We reviewed clinical records from 239 consecutive patients who underwent dual-chamber pacemaker implantation for sick sinus syndrome (SSS) (N = 102) or atrioventricular block (AVB) (N = 137). Atrial capture threshold was measured at implantation and 7 days, 2 months, and 8 months postimplantation. TRACT was defined as a rise in the threshold at day 7 to ≥twice that at implantation, with an absolute value ≥1.0 V/0.4 ms, and full recovery by 8 months into follow-up. TRACT was observed in 15 patients (6%), of whom13 (87%) suffered from SSS but not AVB. Patients with TRACT had greater body mass index (BMI) (25 ± 5 kg/m2 vs 23 ± 4 kg/m2 , P = 0.01), larger left atrium (42 ± 5 mm vs 38 ± 7 mm, P = 0.03), and were more likely to suffer from paroxysmal atrial fibrillation (60% vs 31%, P = 0.02) than those without TRACT. In multivariable logistic regression analysis, BMI and SSS were the independent predictors of TRACT (odds ratio [OR], 1.172; 95% confidence interval [CI], 1.019-1.349; P = 0.03 and OR, 11.53; 95% CI, 2.010-66.21; P = 0.006, respectively). CONCLUSIONS: The distinct phenomenon of TRACT was not rare in clinical practice early after dual-chamber pacemaker implantation, and its occurrence was strongly associated with SSS.

Noninvasive Localization of Accessory Pathways in Wolff-Parkinson-White Syndrome by Three-Dimensional Speckle Tracking Echocardiography.

BACKGROUND: We have developed a noninvasive isochrone activation imaging (AI) system with 3-dimensional (3D) speckle tracking echocardiography (STE), which allows visualization of the wavefront image of mechanical propagation of the accessory pathway (ACP) in Wolff-Parkinson-White syndrome. METHODS AND RESULTS: Patients with manifest Wolff-Parkinson-White syndrome were imaged in 3D-STE AI mode, which quantified the time from QRS onset to regional endocardial deformation. In 2 patients with left- and right-side ACP, we confirmed that intraoperative contact endocardial electric mapping and the 3D-STE AI system showed comparable images pre- and postablation. In normal heart assessment by 3D-echo AI, the earliest activation sites were found at the attachment of the papillary muscles in the left ventricle and midseptum in the right ventricle, and none showed earliest activation at the peri-atrioventricular valve annuli. An analyzer who was unaware of the clinical information assessed 39 ACP locations in 38 Wolff-Parkinson-White syndrome patients using 3D-STE. All showed abnormal perimitral or tricuspid annular activations, and the location of 34 ACP (87%) showed agreement with the successful ablation sites within a 2-o'clock range. Especially for left free wall ACP, 17/18 (94%) showed consistency with the ablation site within a 2 o'clock range. Among 15 ACP at the ventricular septum, 9 (60%) showed early local activation in both right and left sides of the septum. CONCLUSIONS: Isochrone AI with 3D-STE may be a promising noninvasive imaging tool to assess cardiac synchronized activation in normal hearts and detect abnormal breakthrough of mechanical activation from both atrioventricular annuli in Wolff-Parkinson-White syndrome.

The QRS morphology pattern in V5R is a novel and simple parameter for differentiating the origin of idiopathic outflow tract ventricular arrhythmias.

AIMS: There are many reports on the ECG characteristics of idiopathic outflow tract ventricular arrhythmias (OT-VAs) to predict their origin. However, differentiating near regions using 12-lead ECGs is still complicated. The synthesized 18-lead ECG derived from the 12-lead ECG can provide virtual waveforms of the right-sided chest leads (V3R, V4R, and V5R) and back leads (V7, V8, and V9). The aim of this study was to develop a simple and useful parameter for differentiating OT-VA origins using the 18-lead ECG. METHODS AND RESULTS: We studied 28 and 73 patients with idiopathic VAs in a pacemapping study and validation cohort, respectively. In the pacemapping study, several sites out of five different sites were paced in each patient: the anterior and posterior right ventricular OT (RVOT-ant and RVOT-post), right and left coronary cusps (RCC and LCC), and junction of both cusps (RLJ). The 18-lead ECGs during pacemapping among the five sites were compared for establishing a simple parameter to predict VA origins. A novel parameter using 18-lead ECGs was tested prospectively in 73 patients. In the pacemapping study, the dominant QRS morphology pattern in the synthesized V5R significantly differed among those sites (RVOT-ant:Rs, RVOT-post:rS, RCC:QS, RLJ:qR, and LCC:R). The patients in the validation cohort were divided into five groups depending on those QRS morphology patterns during VAs in the synthesized V5R. Each V5R QRS morphology pattern could predict a precise origin of the OT-VAs with an overall accuracy of 75%. CONCLUSION: The QRS morphology pattern in V5R was a simple and useful parameter for differentiating detailed OT-VA origins.