Segmental Wall Motion Abnormality Analyzed by Equilibrium Radionuclide Angiography and Improvement in Ventricular Function by Cardiac Resynchronization Therapy

Introduction: The purpose of this study was to determine the impact of the left ventricular (LV) segmental wall motion abnormalities detected by equilibrium radionuclide angiography (ERNA) on the improvement in LV and right ventricular (RV) function during biventricular (BIV) stimulation .
Results: We studied 28 patients in NYHA functional classes III or IV and QRS duration >150 ms on resting electrocardiogram. ERNA was performed before and during BIV stimulation at a 6-month follow-up. A significant shortening of QRS duration was observed during BIV stimulation (165 ± 5 ms before vs 133 ± 6 ms during, P < 0.01). Wall motion abnormalities (WMA) were observed in 16 patients (10 with nonischemic cardiomyopathies). In this group, LV and RV ejection fractions (EF) did not increase during BIV stimulation (LVEF = 22 ± 2% vs 20 ± 1.6%, ns; RVEF = 34 ± 3% vs 37 ± 3.8%, ns). Significant increases in RVEF (23 ± 3.2 %→ 38 ± 2.9%, P = 0.001) and LVEF (20 ± 2.5 %→ 30 ± 3%, P = 0.01) were observed in the group of patients without segmental WMA and with global hypokinesia (GH). In this group, a significant decrease in the dispersion in the phase of RV contraction was observed (SD = 39 ± 5 vs 26 ± 2 ms; P < 0.01). WMA predicted an increase in LVEF, in contrast to a baseline 6-minute-walk test, maximal oxygen consumption and LVEF, or amount of QRS shortening.
Conclusions: BIV stimulation increased in LV and RV EF in patients with ventricular dyssynchrony in absence of segmental WMA. ERNA was reliable in the selection of candidates for CRT.     

Cardiac Resynchronization Therapy in Patients with Right Ventricular Pacing-Induced Cardiomyopathy

Background: It is not known whether patients with normal baseline left ventricular (LV) function who develop right ventricular (RV) pacing-induced cardiomyopathy as a result of dual-chamber pacing can benefit from cardiac resynchronization therapy (CRT). We retrospectively assessed the effect of a CRT upgrade on RV pacing-induced cardiomyopathy.
Methods and Results: We reviewed the charts of patients who received a CRT device for RV pacing-induced cardiomyopathy. We assessed the effects of CRT on LV function, recovery, and other response parameters. From September 2005 through February 2009, 21 patients (13 men; aged 63 ± 9 years) underwent a treatment upgrade to a CRT system. Before the dual-chamber pacemaker was implanted, the LV ejection fraction (LVEF) was 53 ± 2.3%. After pacing, the LVEF was 31.2 ± 3.8%, the LV end-diastolic dimension (LVEDD) was 5.8 ± 0.5 cm, and B-type natriuretic peptide (BNP) levels were 426 ± 149 pg/mL. The duration of pacing before documentation of pacing-induced cardiomyopathy was 3.8 ± 1.5 months. All the patients had been on a stable medical regimen for at least 2 months. After the upgrade to CRT, the follow-up time was 4.9 ± 0.9 months. Sixteen patients (76%) reported a significant improvement in their symptoms. After the CRT upgrade, the LVEF increased to 37.4 ± 9.0% (P < 0.01 vs pre-CRT). The LVEDD decreased to 5.0 ± 1.0 cm (P = 0.03 vs pre-CRT), and BNP levels decreased to 139 ± 92 pg/mL (P = 0.08 vs pre-CRT).
Conclusion: A CRT upgrade is an effective treatment for RV pacing-induced cardiomyopathy and should be implemented as soon as the diagnosis is established. Unfortunately, about 24% of our patients did not respond to the upgrade. (PACE 2010; 37–40)     

Serial Changes in Right Ventricular Apical Pacing Lead Impedance Predict Changes in Left Ventricular Ejection Fraction and Functional Class in Heart Failure Patients

Pacing impedance has been proposed to monitor the clinical status of patients with congestive heart failure (CHF). This study examined whether changes in right ventricular (RV) pacing impedance correlate with changes in left ventricular ejection fraction (LVEF) and New York Heart Association (NYHA) functional class during long-term follow-up in pacemaker recipients with CHF. The study included 67 patients, 70 ± 12 years of age, in NYHA class II or III, and with a mean LVEF = 29 ± 8% at implant. LVEF, NYHA class, and bipolar pacing impedance at the RV outflow tract (RVOT) and apex (RVA) were measured at implant and at 3, 6, 9, and 12 months of follow-up. At implant, impedance was similar in RVOT (548 ± 115 Ω) and RVA (571 ± 174 Ω). Between implant and 3 months, mean impedance decreased (P < 0.0001) at both the RVOT (472 ± 62 Ω) and RVA (488 ± 86 Ω), LVEF increased (43 ± 14%, P < 0.0001), and the NYHA class decreased from 2.4 ± 0.5 to 2.1 ± 0.6 (P = 0.0001). Changes in RVA impedance correlated with changes in LVEF (r = 0.45, P = 0.002). A 50 Ω decrease in RVA impedance corresponded to a 3% decrease in LVEF. RVA impedance decreased significantly as NYHA class increased from I to IV (P = 0.04). There was no correlation between impedance measured at the RVOT and LVEF or NYHA class. A decrease in bipolar pacing impedance at the RVA was associated with worsening LVEF and the NYHA class. The use of pacing impedance to monitor the clinical status in CHF is dependent on the RV pacing site.     

Effect of Right Ventricular Apical Pacing in Survivors of Myocardial Infarction

Background: Much information is available regarding the possible negative effects of long-term right ventricular (RV) apical pacing, which may cause worsening of heart failure. However, very limited data are available regarding the effects of RV pacing in patients with a previous myocardial infarction (MI).
Methods and Results: We screened 115 consecutive post-MI patients and matched a group of 29 pacemaker (PM) recipients with a group of 49 unpaced patients, for age, left ventricular (LV) ejection fraction, and site of MI. During a median follow-up of 54 months, echocardiograms showed a decrease in LV ejection fraction in the paced group, from 51 ± 10 to 39 ± 11 (P < 0.01), and a minimal change in the unpaced group, from 57 ± 8 to 56 ± 7 (P = 0.98). Similar change was observed in systolic and diastolic diameters and volumes.
Conclusions: The study showed that, in post-MI patients, RV apical pacing was associated with a worsening of LV function, suggesting that, among MI survivors, the need for a PM is a marker of worse outcome .     

Morphology of the RV electrogram during LV pacing is related to the hemodynamic effect in cardiac resynchronization therapy

Background: Biventricular (BiV) pacing and left ventricular (LV) pacing both improve LV function in patients with heart failure and LV dyssynchrony. We studied the hemodynamic effect of the atrioventricular (AV) interval and the associated changes in the right ventricular (RV) electrogram (EGM) during LV pacing and compared this with the hemodynamic effect of optimized sequential BiV pacing.
Methods: In 16 patients with New York Heart Association (NYHA) class II to IV, sinus rhythm with normal AV conduction, left bundle branch block (LBBB), QRS > 130 ms, and optimal medical therapy, the changes in RV EGM during LV pacing with varying AV intervals were studied. The hemodynamic effect associated with these changes was evaluated by invasive measurement of LVdP/dt_max and compared with the result of optimized sequential BiV pacing in the same patient.
Results: All patients showed electrocardiographic fusion during LV pacing. The morphology of the RV EGM showed changes in the RV activation that indicated a shift in the extent of fusion from LV pacing. These changes were associated with significant changes in LVdP/dt_max. Baseline LV dP/dt_max was 734 ± 177 mmHg/s, which increased to 927 ± 202 mmHg/s (P<0.0001) with optimized LV pacing and to 920 ± 209 mmHg/s (P<0.0001) with optimized sequential BiV pacing.
Conclusion: The RV EGM is a proper indicator for intrinsic activation over the right bundle during LV pacing and reveals the transition to fusion in the RV EGM that is associated with a decrease in LVdP/dt_max. The hemodynamic effect of optimized LV pacing is equal to optimized sequential BiV pacing.     

Long‐Term Nonoutflow Septal Versus Apical Right Ventricular Pacing: Relation to Left Ventricular Dyssynchrony

Background: Right ventricular (RV) apical pacing deteriorates left ventricular (LV) function. RV nonoutflow (low) septal pacing may better preserve ventricular performance, but this has not been systematically tested. Our aim was to assess (1) whether long‐term RV lower septal pacing is superior to RV apical pacing regarding LV volumes and ejection fraction (EF), and (2) if the changes in LV dyssynchrony imposed by pacing are related to the long‐term changes in LV volumes and EF. Methods: In thirty‐six patients with atrioventricular (AV) block, a dual‐chamber pacemaker was implanted. The ventricular electrode was placed either at the apex or at the lower septum, in a randomized sequence. Twenty‐four to 48 hours following implantation, we measured LV volumes, EF, and LV dyssynchrony (by tissue Doppler imaging), both with and without pacing. Patients were reassessed echocardiographically after 12 months. Results: Lower septal pacing induced a more synchronized pattern of LV contraction changes (P < 0.05). Following 12 months, differences were observed between groups regarding LV volumes and EF. EF increased within the septal group (from 52 ± 3.3% to 59 ± 3.0%, P < 0.05). A significant inverse relation was documented between changes in LV dyssynchrony and changes in EF (r =?0.64, P < 0.05). Conclusions: In patients with AV block, RV nonoutflow septal pacing represents an attractive alternative, since it preserves better and may even improve LV volumes and EF. Late changes in EF are associated with the changes in LV dyssynchrony imposed by pacing.     

Intracardiac Echocardiography-Guided Cardiac Resynchronization Therapy: Technique and Clinical Application

Background: We undertook a pilot investigation to evaluate the feasibility of a novel technique using intracardiac echocardiography (ICE) for intraoperative assessment of cardiac resynchronization therapy (CRT).
Methods: We evaluated ICE intraoperative imaging of left ventricular (LV) function and aortic valvular flow as well as safety of implementation. ICE was used to guide CRT system lead placement, assess impact of pacing modes, and optimization of device programming.
Results: Twenty-three patients underwent ICE imaging. ICE showed global hypokinesis in six patients, regional wall motion abnormality only in 10 patients, and both in seven patients. Optimized CRT modes included mean atrioventricular (AV) interval of 170 ms and interventricular timing using simultaneous right ventricular (RV)-LV pacing (five patients), LV pacing only (one patient), and sequential LV to RV stimulation (15 patients) or RV to LV stimulation (two patients). ICE-guided CRT acutely improved mean left ventricular ejection fraction (LVEF) from 24 ± 9% to 41 ± 1% (P < 0.00001). During follow-up of 3–24 (mean 11) months, New York Heart Association class improved in all patients from a mean of 3.2 ± 0.4 at implant to 1.6 ± 0.7 (P < 0.0001), with improvement of LVEF from 19 ± 7% to 34 ± 12% (P = 0.0001). Actuarial survival was 83% at 12 months.
Conclusions: (1) ICE imaging is reliable and safe for continuous intraoperative imaging of LV wall motion, and assesses baseline status and impact of CRT interventions. (2) Intraoperative ICE-guided CRT optimization resulted in an increase in LVEF acutely and consistent improvement in heart failure. (3) Sequential biventricular pacing and longer AV interval programming were more often used in ICE-guided CRT.     

Feasibility Of Temporary Biventricular Pacing In Patients With Reduced Left Ventricular Function After Coronary Artery Bypass Grafting

Background and Methods: Biventricular pacing improves hemodynamics after weaning from cardiopulmonary bypass in patients with severely reduced left ventricular (LV) function undergoing coronary artery bypass grafting (CABG). We examined the feasibility of temporary biventricular pacing for 96 hours postoperatively. Unipolar epicardial wires were placed on the roof of the right atrium (RA), the right ventricular (RV) outflow tract, and the LV free lateral wall and connected to an external pacing device in 51 patients (mean LV ejection fraction 35 ± 4%). Pacing and sensing thresholds, lead survival and incidence of pacemaker dysfunction were determined.
Results: Atrial and RV pacing thresholds increased significantly by the 4th postoperative day, from 1.6 ± 0.2 to 2.5 ± 0.3 V at 0.5 ms (P = 0.03) at the RA, 1.4 ± 0.3 V to 2.7 ± 0.4 mV (P = 0.01) at the RV, and 1.9 ± 0.6 V to 2.9 ± 0.7 mV (P = 0.3) at the LV, while sensing thresholds decreased from 2.0 ± 0.2 to 1.7 ± 0.2 mV (P = 0.18) at the RA, 7.2 ± 0.8 to 5.1 ± 0.7 mV (P = 0.05) at the RV, and 9.4 ± 1.3 to 5.5 ± 1.1 mV (P = 0.02) at the LV. The cumulative overall incidence of lead failure was 24% by the 4th postoperative day, and was similar at the RV and LV. We observed no ventricular proarrhythmia due to pacing or temporary pacemaker malfunction.
Conclusions: Biventricular pacing after CABG using a standard external pacing system was feasible and safe.     

Relevance of Echocardiographic Evaluation of Right Ventricular Function in Patients Undergoing Cardiac Resynchronization Therapy

Aims: Right ventricular (RV) dysfunction is a marker of poor prognosis in heart failure (HF) patients. It is still unclear whether RV function might influence response to cardiac resynchronization therapy (CRT).
Methods: Forty-four consecutive patients with HF, large QRS, and either intraventricular or interventricular dyssynchrony underwent echocardiographic evaluation before, 1 month after, and 6 months after CRT. Response to CRT was considered in case of significant LV reverse remodeling, defined as the occurrence of LV end-systolic volume (LVESV) reduction ≥15% at 6 months.
Results: All echocardiographic indexes of baseline RV function and dimensions were significantly more impaired in nonresponders versus responders to CRT: tricuspid annular plane systolic excursion (TAPSE 15 ± 4 mm vs 20 ± 5 mm, P = 0.001), RV systolic pulmonary artery pressure (RVSP 39 ± 14 mmHg vs 27 ± 8 mmHg, P = 0.02), RV end-diastolic area (RVEDA 23 ± 6 cm² vs 16 ± 3 cm² P < 0.001), RV end-systolic area (RVESA 16 ± 6 cm² vs 8 ± 2 cm², P = 0.001), and RV fractional area change (30 ± 12% vs 48 ± 8%, P < 0.001). All the indexes of RV function significantly correlated with the percentage of LVESV reduction after CRT. Severe RV dysfunction was defined as TAPSE ≤14 mm and the population was stratified into two groups based on baseline TAPSE ≤ or > 14 mm. As compared to those with high TAPSE (n = 30), patients with low TAPSE (n = 14) were less likely to show LV reverse remodeling after CRT (76% vs 14%, P < 0.001).
Conclusions: Our study suggests that RV function significantly affects response to CRT. Poor LV reverse remodeling occurs after CRT in patients with HF having severe RV dysfunction at baseline.     

Heart Rate Turbulence after Ventricular Pacing Trains During Programmed Ventricular Stimulation

Background: This study tested the hypothesis that heart rate turbulence (HRT) following ventricular pacing trains depends on train cycle length, presence of retrograde ventriculoatrial (VA) conduction, and left ventricular (LV) function.
Methods: We analyzed digital recordings of programmed ventricular stimulation (PVS) performed in 82 patients (57 men) referred for electrophysiologic studies of ventricular arrhythmias, whose mean age was 64 ± 12 years and LV ejection fraction (EF) was 47 ± 15%. Profiles of sinus RR intervals after all available 8-beat ventricular pacing trains (600-and 400-ms) were averaged. Heart rate turbulence slope (HRTS) was analyzed as the maximum positive slope of a regression line through a sequence of 2–5 (HRTS2 - HRTS5) consecutive RR intervals within the first 5 RR intervals after the pacing train.
Results: Dynamics of RR intervals had biphasic and monophasic patterns, in patients with and without VA conduction, respectively. Sinus nodal response was less prominent after 600-ms than 400-ms pacing trains. After 400-ms pacing trains, HRTS was significantly shallower in patients with LVEF ≤40% than in those with LVEF >40%. HRTS4 was the best discriminator between the two groups (6.8 ± 8.6 ms/RR vs 19.6 ± 26.0 ms/RR, P = 0.017).
Conclusion: In patients with VA conduction, HRT after ventricular pacing trains reflects a combination of vagal withdrawal due to transient hypotension and suppression of sinus node automaticity. Attenuation of vagal modulation was detected in patients with LV dysfunction during standard PVS.     

Left Ventricular Ejection Fraction as Criterion for Implantation of an Implantable Cardioverter-Defibrillator in Heart Failure Patients Undergoing Surgical Left Ventricular Reconstruction

Background: Besides implantation of an implantable cardioverter-defibrillator (ICD), a proportion of patients with left ventricular (LV) dysfunction due to ischemic cardiomyopathy are potential candidates for surgical LV reconstruction (Dor procedure), which changes LV ejection fraction (LVEF) considerably. In these patients, LVEF as selection criterium for ICD implantation may be difficult. This study aimed to determine the value of LVEF as criterium for ICD implantation in heart failure patients undergoing surgical LV reconstruction.
Methods: Consecutive patients with end-stage heart failure who underwent ICD implantation and LV reconstruction were evaluated. During admission, two-dimensional (2D) echocardiography (LV volumes and LVEF) was performed before surgery and was repeated at 3 months after surgery. Over a median follow-up of 18 months, the incidence of ICD therapy was evaluated.
Results: The study population consisted of 37 patients (59 ± 11 years). At baseline, mean LVEF was 23 ± 5%. Mean left ventricular end-systolic volume (LVESV) and left ventricular end-diastolic volume (LVEDV) were 175 ± 73 mL and 225 ± 88 mL, respectively. At 3-month follow-up, mean LVEF was 41 ± 9% (P < 0.0001 vs. baseline), and mean LVESV and LVEDV were 108 ± 65 mL and 176 ± 73 mL, respectively (P < 0.0001 vs. baseline). During 18-month follow-up, 12 (32%) patients had ventricular arrhythmias, resulting in appropriate ICD therapy. No significant relations existed between baseline LVEF (P = 0.77), LVEF at 3-month follow-up (P = 0.34), change in LVEF from baseline to 3-month follow-up (P = 0.28), and the occurrence of ICD therapy during 18-month follow-up.
Conclusion: LVEF before and after surgical LV reconstruction is of limited use as criterium for ICD implantation in patients with end-stage heart failure.     

Clinical Significance of QRS Duration During Ventricular Pacing

To clarify the clinical significance of an abnormally prolonged paced QRS duration, we studied 114 patients who had undergone pacing for atrioventricular block (AVB). Patients were divided into two groups: group I consisted of 29 patients with at least one paced QRS duration greater than or equal to 180 msec during the follow-up period; group II consisted of 85 patients with paced QRS durations less than 180 msec. The clinical background, QRS complexes before pacing, and the echocardiographic findings were assessed. Males (P less than 0.05), those with H-V block (P less than 0.05) and a wider QRS complex of conducted and escape beats (both P less than 0.01) were dominant in group I. The incidence of underlying heart disease was greater in group I than in group II (83% vs 32%, P less than 0.01). Reduced left ventricular ejection fraction (LVEF) and increased left ventricular end-diastolic dimension (LVDd) were more prominent in group I than in group II (LVEF 0.49 +/- 0.17 vs 0.68 +/- 0.10, P less than 0.01, LVDd 57.1 +/- 7.9 mm vs 48.5 +/- 5.6 mm, P less than 0.01). The paced QRS duration correlated with LVEF (r = -0.61) and LVDd (r = 0.81). A paced QRS duration greater than or equal to 180 msec was sensitive and specific for a LVEF less than 0.5 (83.3% and 85.2%) and LVDd greater than or equal to 60 mm (100% and 81.4%). We conclude that patients with a prolonged paced QRS duration have more serious heart disease, and the paced QRS duration can be a useful indicator of impaired LV function.     

Upgrading from Single Chamber Right Ventricular to Biventricular Pacing in Permanently Paced Patients with Worsening Heart Failure: The RD-CHF Study

Background: Biventricular (BiV) stimulation lowers morbidity and mortality in patients with drug-refractory congestive heart failure (CHF), depressed left ventricular (LV) function, and ventricular dyssynchrony in absence of indication for permanent cardiac pacing. This pilot, single-blind, randomized, cross-over study examined the safety and efficacy of upgrading conventional pacing systems to BiV stimulation in patients with advanced CHF .
Methods: We included 56 patients in New York Heart Association (NYHA) functional classes III or IV despite optimal drug treatment and ventricular dyssynchrony (interventriclar delay >40 ms or LV preejection delay >140 ms) in need of pacemaker replacement. We compared the patients' functional status, arrhythmias, and standard echocardiographic measurements during 3 months of conventional, single right ventricular (RV) versus 3 months of BiV stimulation .
Results: There were 44 patients in the cross-over phase. QRS duration was shortened by 23% and LV preejection delay by 16% with BiV stimulation. NYHA functional class, 6-minute hall walk and quality of life score were significantly improved with BiV stimulation compared with single RV pacing by 18%, 29%, and 19%, respectively. No significant difference was observed in the ventricular arrhythmia burden or LV reverse remodeling between the 2 periods .
Conclusions: This pilot study showed that upgrading from RV pacing to BiV pacing significantly improves symptoms and exercise tolerance in chronically paced patients with advanced CHF and mechanical dyssynchrony .     

实时三维超声心动图对两类不同病因心力衰竭患者左心室收缩同步性的临床研究

目的 比较缺血性心脏病与扩张型心肌病两类病因引起的慢性心力衰竭(心衰)患者左室收缩同步性.并分析两组患者不同步性指数(SDI)与左室射血分数(LVEF)的相关性.方法 43例心衰患者分为两组,A组为17例缺血性心脏病引起的心衰患者;B组为26例扩张型心肌病引起的心衰患者.应用实时三维超声心动图(RT一3DE)的全容积显像模式采集左室三维数据库,并用Qlab定量分析软件对其进行分析,获得左室舒张末容积(EDV)、收缩末容积(ESV)和左室射血分数(LVEF)、17节段"牛眼"图,16节段(除外心尖帽)收缩达最小容积时间的标准差并以心率校正后(Tmsv 16-SD/R-R)的百分数作为左室SDI.结果 A、B两组人选患者的年龄、心率、LVEF和EDV差异均无统计学意义(P>0.05);A组的SDI略低于B组,但差异无统计学意义,17节段"牛眼"图显示两组患者左室收缩延迟节段的位置分布各有不同;对数回归分析显示A、B两组的SDI与LVEF均呈良好的负相关(r=-0.83,r=-0.71,P< 0.01).结论 缺血性心脏病与扩张型心肌病心衰患者左室均存在一定程度的收缩不同步,SDI与左室整体收缩功能存在负相关,随收缩功能的减低而增加,两组收缩延迟节段的位置分布各有不同.     

实时三维超声心动图对两类不同病因心力衰竭患者左心室收缩同步性的临床研究

目的 比较缺血性心脏病与扩张型心肌病两类病因引起的慢性心力衰竭(心衰)患者左室收缩同步性.并分析两组患者不同步性指数(SDI)与左室射血分数(LVEF)的相关性.方法 43例心衰患者分为两组,A组为17例缺血性心脏病引起的心衰患者;B组为26例扩张型心肌病引起的心衰患者.应用实时三维超声心动图(RT一3DE)的全容积显像模式采集左室三维数据库,并用Qlab定量分析软件对其进行分析,获得左室舒张末容积(EDV)、收缩末容积(ESV)和左室射血分数(LVEF)、17节段"牛眼"图,16节段(除外心尖帽)收缩达最小容积时间的标准差并以心率校正后(Tmsv 16-SD/R-R)的百分数作为左室SDI.结果 A、B两组人选患者的年龄、心率、LVEF和EDV差异均无统计学意义(P>0.05);A组的SDI略低于B组,但差异无统计学意义,17节段"牛眼"图显示两组患者左室收缩延迟节段的位置分布各有不同;对数回归分析显示A、B两组的SDI与LVEF均呈良好的负相关(r=-0.83,r=-0.71,P< 0.01).结论 缺血性心脏病与扩张型心肌病心衰患者左室均存在一定程度的收缩不同步,SDI与左室整体收缩功能存在负相关,随收缩功能的减低而增加,两组收缩延迟节段的位置分布各有不同.     

实时三维超声心动图对两类不同病因心力衰竭患者左心室收缩同步性的临床研究

目的 比较缺血性心脏病与扩张型心肌病两类病因引起的慢性心力衰竭(心衰)患者左室收缩同步性.并分析两组患者不同步性指数(SDI)与左室射血分数(LVEF)的相关性.方法 43例心衰患者分为两组,A组为17例缺血性心脏病引起的心衰患者;B组为26例扩张型心肌病引起的心衰患者.应用实时三维超声心动图(RT一3DE)的全容积显像模式采集左室三维数据库,并用Qlab定量分析软件对其进行分析,获得左室舒张末容积(EDV)、收缩末容积(ESV)和左室射血分数(LVEF)、17节段"牛眼"图,16节段(除外心尖帽)收缩达最小容积时间的标准差并以心率校正后(Tmsv 16-SD/R-R)的百分数作为左室SDI.结果 A、B两组人选患者的年龄、心率、LVEF和EDV差异均无统计学意义(P>0.05);A组的SDI略低于B组,但差异无统计学意义,17节段"牛眼"图显示两组患者左室收缩延迟节段的位置分布各有不同;对数回归分析显示A、B两组的SDI与LVEF均呈良好的负相关(r=-0.83,r=-0.71,P< 0.01).结论 缺血性心脏病与扩张型心肌病心衰患者左室均存在一定程度的收缩不同步,SDI与左室整体收缩功能存在负相关,随收缩功能的减低而增加,两组收缩延迟节段的位置分布各有不同.     

实时三维超声心动图对两类不同病因心力衰竭患者左心室收缩同步性的临床研究

目的 比较缺血性心脏病与扩张型心肌病两类病因引起的慢性心力衰竭(心衰)患者左室收缩同步性.并分析两组患者不同步性指数(SDI)与左室射血分数(LVEF)的相关性.方法 43例心衰患者分为两组,A组为17例缺血性心脏病引起的心衰患者;B组为26例扩张型心肌病引起的心衰患者.应用实时三维超声心动图(RT一3DE)的全容积显像模式采集左室三维数据库,并用Qlab定量分析软件对其进行分析,获得左室舒张末容积(EDV)、收缩末容积(ESV)和左室射血分数(LVEF)、17节段"牛眼"图,16节段(除外心尖帽)收缩达最小容积时间的标准差并以心率校正后(Tmsv 16-SD/R-R)的百分数作为左室SDI.结果 A、B两组人选患者的年龄、心率、LVEF和EDV差异均无统计学意义(P>0.05);A组的SDI略低于B组,但差异无统计学意义,17节段"牛眼"图显示两组患者左室收缩延迟节段的位置分布各有不同;对数回归分析显示A、B两组的SDI与LVEF均呈良好的负相关(r=-0.83,r=-0.71,P< 0.01).结论 缺血性心脏病与扩张型心肌病心衰患者左室均存在一定程度的收缩不同步,SDI与左室整体收缩功能存在负相关,随收缩功能的减低而增加,两组收缩延迟节段的位置分布各有不同.     

实时三维超声心动图对两类不同病因心力衰竭患者左心室收缩同步性的临床研究

目的 比较缺血性心脏病与扩张型心肌病两类病因引起的慢性心力衰竭(心衰)患者左室收缩同步性.并分析两组患者不同步性指数(SDI)与左室射血分数(LVEF)的相关性.方法 43例心衰患者分为两组,A组为17例缺血性心脏病引起的心衰患者;B组为26例扩张型心肌病引起的心衰患者.应用实时三维超声心动图(RT一3DE)的全容积显像模式采集左室三维数据库,并用Qlab定量分析软件对其进行分析,获得左室舒张末容积(EDV)、收缩末容积(ESV)和左室射血分数(LVEF)、17节段"牛眼"图,16节段(除外心尖帽)收缩达最小容积时间的标准差并以心率校正后(Tmsv 16-SD/R-R)的百分数作为左室SDI.结果 A、B两组人选患者的年龄、心率、LVEF和EDV差异均无统计学意义(P>0.05);A组的SDI略低于B组,但差异无统计学意义,17节段"牛眼"图显示两组患者左室收缩延迟节段的位置分布各有不同;对数回归分析显示A、B两组的SDI与LVEF均呈良好的负相关(r=-0.83,r=-0.71,P< 0.01).结论 缺血性心脏病与扩张型心肌病心衰患者左室均存在一定程度的收缩不同步,SDI与左室整体收缩功能存在负相关,随收缩功能的减低而增加,两组收缩延迟节段的位置分布各有不同.     

Backup Right Ventricular Pacing with a 0.035" Guidewire during Implantation of Left Ventricular Leads

Introduction: During implantation of biventricular devices, manipulation of the guiding sheath during localization of the coronary sinus (CS) ostium may result in injury to the right bundle and complete heart block. A preventive measure is to implant the right ventricular (RV) lead first, though this may interfere with manipulation of the guiding sheath and dislodge the permanent lead . We tested the feasibility of backup pacing with a 0.035" guidewire, advanced through the guiding sheath during CS localization.
Methods: One hundred six consecutive patients (mean age = 70 ± 11 years, 81 men) undergoing biventricular device implantation were studied. A 0.035" guidewire with an uncoated tip was advanced into the right ventricle through the guiding sheath, and unipolar capture threshold, R-wave sensing amplitude, and pacing impedance were measured.
Results: RV pacing was successful in all patients. The mean capture threshold was 3.8 ± 2.1 V/0.5 ms, R-wave amplitude 5.4 ± 4.3 mV, and pacing impedance 226 ± 78 Ω. No arrhythmia was observed during the tests. Two patients developed complete heart block during the implant procedure and were successfully paced temporarily using the 0.035" guidewire.
Conclusion: Temporary RV pacing, using a 0.035" guidewire within the guiding sheath, is a simple, reliable, and safe method that allows backup pacing in case of traumatic complete heart block, developing during the implantation of biventricular devices.     

实时三维超声心动图对两类不同病因心力衰竭患者左心室收缩同步性的临床研究

目的 比较缺血性心脏病与扩张型心肌病两类病因引起的慢性心力衰竭(心衰)患者左室收缩同步性.并分析两组患者不同步性指数(SDI)与左室射血分数(LVEF)的相关性.方法 43例心衰患者分为两组,A组为17例缺血性心脏病引起的心衰患者;B组为26例扩张型心肌病引起的心衰患者.应用实时三维超声心动图(RT一3DE)的全容积显像模式采集左室三维数据库,并用Qlab定量分析软件对其进行分析,获得左室舒张末容积(EDV)、收缩末容积(ESV)和左室射血分数(LVEF)、17节段"牛眼"图,16节段(除外心尖帽)收缩达最小容积时间的标准差并以心率校正后(Tmsv 16-SD/R-R)的百分数作为左室SDI.结果 A、B两组人选患者的年龄、心率、LVEF和EDV差异均无统计学意义(P>0.05);A组的SDI略低于B组,但差异无统计学意义,17节段"牛眼"图显示两组患者左室收缩延迟节段的位置分布各有不同;对数回归分析显示A、B两组的SDI与LVEF均呈良好的负相关(r=-0.83,r=-0.71,P< 0.01).结论 缺血性心脏病与扩张型心肌病心衰患者左室均存在一定程度的收缩不同步,SDI与左室整体收缩功能存在负相关,随收缩功能的减低而增加,两组收缩延迟节段的位置分布各有不同.