Utility and Validation of Corrected Left Ventricular Filling Time for Determining the Optimal AV Delay in Patients Receiving Cardiac Resynchronization Therapy

Introduction: Cardiac resynchronization therapy (CRT) is relatively new tool in treatment of chronic heart failure (HF), especially in dilated cardiomyopathy (DCM) with the left bundle branch block (LBBB). Objective: The Objective of our study was to assess the success of CRT in treatment of severe HF and the role of echocardiography in the evaluation of Results of such therapy. Method: The group consisted of 19 patients, 13 males and 6 females, mean age 58.0?8.22 years (47-65 years) with CRT applied for DCM, severe HF (NYHA III-IV), LBBB and ejection fraction (EF) <35%. The mean follow up was 17 months (6.5-30). Standard color Doppler echocardiography examination was performed in all patients before and after CRT. The parameters of systolic and diastolic left ventricular function, mitral insufficiency and the right ventricular pressure were evaluated. Results: Following the CRT, statistically significant improvement of the end-systolic LV dimension, cardiac output, cardiac index, myocardial performance index (p<0.01) and stroke index (p<0.05) was recorded. The mean value of EFLV was increased by 10% and LV fractional shortening improved by 6% in 10/16 (62%) patients. CRT resulted in decreased MR (p<0.01), prolonged LV diastolic filling time (p<0.02) and reduced RV pressure (p<0.05). Interventricular mechanical delay was shortened by 28% (18 msec) Conclusion: CRT has an important role in improvement of LV function and correction of ventricular asynchrony. The echocardiography is a useful tool for evaluation of HF treatment with CRT.

Download Full-text

149 Acute effects on left ventricular systolic and diastolic function of a post-implant echocardiographic biventricular pacemaker optimization protocol following cardiac resynchronization therapy

European Heart Journal ◽

10.1093/ehjci/ehz872.006 ◽

2020 ◽

Vol 41 (Supplement_1) ◽

Author(s):

P Barbier ◽

M Guglielmo ◽

C Agalbato ◽

I Viscone ◽

G Savioli

Keyword(s):

Cardiac Resynchronization Therapy ◽

Diastolic Function ◽

Left Ventricular ◽

Cardiac Resynchronization ◽

Diastolic Filling ◽

Acute Effects ◽

Resynchronization Therapy ◽

Biventricular Pacemaker ◽

Filling Time

Abstract Background Cardiac resynchronization therapy (CRT) has demonstrated efficacy in at least 60% of patients with left ventricular (LV) failure and guideline-based indication to CRT. Whereas lack of response to CRT in up to a third of patients is multifactorial, a relevant factor is thought to be inadequate biventricular pacemaker (BIV) optimization (OPT) of either the intraventricular (VVd) or atrioventricular (AVd) delay Purpose In this echocardiographic observational study, we compared the acute effects on LV contractility, output, and diastolic function of BIV intra-implant QRS duration-based (OPTq) and post-implant Doppler echocardiography-based (OPTe) OPT of VVd and AVd. Methods In 160 patients with ischemic (n = 86) or idiopathic (n = 74) dilated cardiomyopathy, guideline-based different de novo CRT systems were implanted followed by immediate OPTq. Post-implant (10 days) OPTe was performed measuring: transmitral velocity-time integral (MVFi), % diastolic filling time (MVFt%), and E/A ratio, LV outflow integral (LVOTi), ejection time (LVOTt), and stroke volume (SV), isovolumic contraction (IVCT) and relaxation (IVRT) times, and LV myocardial performance index (MPI). The protocol included, sequentially: 1) Doppler measurements with OPTq settings; 2) measurements (separated by 3’ intervals) during a range (80/200 ms) of AVd with synchronous VVd; 3) algorithm-based AVd selection (at least 2 of following: increase in MVFi or SV, decrease in MPI); 4) measurements, with set AVd, during range of VVd: LV-first (-20, -40ms); RV-first (20, 40ms); synchronous; 5) VVd selection based on same algorithm used for AVd selection. Results. At OPTq, 58.6% of patients were set synchronous, 38.6% LV-first and 3% RV-first, with a 126 ± 29 mean AVd. This increased to 137 ± 36 after OPTe, when 49.1% were set synchronous, 38% LV-first and 12.4% RV-first, resulting in modifications of AVd and VVd in 59% and 36% of patients. Further, gain in SV with OPTe, compared to OPTq, was 8.3% (p<.001), paralleled by an increase in MVFi (21.2 ± 8 cm vs 20.5 ± 8, p<.001) and decrease in E/A (1.25 vs 1.45, p<.001). The greatest increase in SV with OPTe was found in patients in whom both AVd and VVd were modified (n = 48; 81 ± 26 ml vs 71 ± 23, p<.001) vs. patients without modifications (n = 42), or with change of either AVd or VVd (n = 70; 77 ± 20 vs 72 ± 20, p<.01). Only in the first patient group both MVFi (22 ± 9 vs 20 ± 9, p<.001) and MVFt% (52 ± 7 vs 49 ± 8, p=.004) increased, along with a decrease in MPI (.82±.31 vs .92 ± 36, p=.007) and IVRT (144 ± 51 vs 156 ± 62, p=.02. Conclusions These preliminary results point to a significant incremental role of post-implant OPTe to enhance LV output, contractility, and diastolic function in patients with CRT. The prognostic role of OPTe-determined AVd and VVD changes remains to be determined.

Download Full-text

Endocardial versus epicardial electrical synchrony during LV free-wall pacing

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00282.2003 ◽

2003 ◽

Vol 285 (5) ◽

pp. H1864-H1870 ◽

Cited By ~ 22

Author(s):

Owen P. Faris ◽

Frank J. Evans ◽

Alexander J. Dick ◽

Venkatesh K. Raman ◽

Daniel B. Ennis ◽

...

Keyword(s):

Cardiac Resynchronization Therapy ◽

Left Ventricular ◽

Cardiac Resynchronization ◽

Free Wall ◽

Resynchronization Therapy ◽

Lead Placement ◽

Intrinsic Conduction ◽

Endocardial Mapping ◽

Transition Delay ◽

Av Delay

Cardiac resynchronization therapy has been most typically achieved by biventricular stimulation. However, left ventricular (LV) free-wall pacing appears equally effective in acute and chronic clinical studies. Recent data suggest electrical synchrony measured epicardially is not required to yield effective mechanical synchronization, whereas endocardial mapping data suggest synchrony (fusion with intrinsic conduction) is important. To better understand this disparity, we simultaneously mapped both endocardial and epicardial electrical activation during LV free-wall pacing at varying atrioventricular delays (AV delay 0–150 ms) in six normal dogs with the use of a 64-electrode LV endocardial basket and a 128-electrode epicardial sock. The transition from dyssynchronous LV-paced activation to synchronous RA-paced activation was studied by constructing activation time maps for both endo- and epicardial surfaces as a function of increasing AV delay. The AV delay at the transition from dyssynchronous to synchronous activation was defined as the transition delay (AVt). AVt was variable among experiments, in the range of 44–93 ms on the epicardium and 47–105 ms on the endocardium. Differences in endo- and epicardial AVt were smaller (–17 to +12 ms) and not significant on average (–5.0 ± 5.2 ms). In no instance was the transition to synchrony complete on one surface without substantial concurrent transition on the other surface. We conclude that both epicardial and endocardial synchrony due to fusion of native with ventricular stimulation occur nearly concurrently. Assessment of electrical epicardial delay, as often used clinically during cardiac resynchronization therapy lead placement, should provide adequate assessment of stimulation delay for inner wall layers as well.

Download Full-text

Pacemaker optimization guided by echocardiography in cardiac resynchronization therapy

Srpski arhiv za celokupno lekarstvo ◽

10.2298/sarh0908416t ◽

2009 ◽

Vol 137 (7-8) ◽

pp. 416-422

Author(s):

Danijela Trifunovic ◽

Milan Petrovic ◽

Goran Milasinovic ◽

Bosiljka Vujisic-Tesic ◽

Marija Boricic ◽

...

Keyword(s):

Heart Failure ◽

Ejection Fraction ◽

Cardiac Resynchronization Therapy ◽

Left Ventricular ◽

Cardiac Resynchronization ◽

Resynchronization Therapy ◽

Delay Optimization ◽

Mitral Flow ◽

Av Delay

Introduction. Cardiac resynchronization therapy (CRT) or biventricular pacing is a contemporary treatment in the management of advanced heart failure. Echocardiography plays an evolving and important role in patient selection for CRT, follow-up of acute and chronic CRT effects and optimization of device settings after biventricular pacemaker implantation. In this paper we illustrate usefulness of echocardiography for successful AV and VV timing optimization in patients with CRT. A review of up-to-date literature concerning rationale for AV and VV delay optimization, echocardiographic protocols and current recommendations for AV and VV optimization after CRT are also presented. Outline of Cases. The first case is of successful AV delay optimization guided by echocardiography in a patient with dilated cardiomyopathy treated with CRT is presented. Pulsed blood flow Doppler was used to detect mitral inflow while programming different duration of AV delay. The AV delay with optimal transmittal flow was established. The optimal mitral flow was the one with clearly defined E and A waves and maximal velocity time integral (VTI) of the mitral flow. Improvement in clinical status and reverse left ventricle remodelling with improvement of ejection fraction was registered in our patient after a month. The second case presents a patient with heart failure caused by dilated cardiomyopathy; six months after CRT implantation the patient was still NYHA class III and with a significantly depressed left ventricular ejection fraction. Optimization of VV interval guided by echocardiography was undertaken measuring VTI of the left ventricular outflow tract (LVOT) during programming of different VV intervals. The optimal VV interval was determined using a maximal LVOT VTI. A month after VV optimization our patient showed improvement in LV ejection fraction. Conclusion. Optimal management of patients treated with CRT integrate both clinical and echocardiographic follow-up with, if needed, echocardiographically guided optimization of AV and VV delays, which offers the possibility of additional clinical improvement in such patients.

Download Full-text