645 InterVentricular mechanical delay during right ventricular; left ventricular and biventricular pacing

EP Europace ◽  
2005 ◽  
Vol 7 ◽  
pp. 149-149
Keyword(s):  
Right Ventricular ◽  
Biventricular Pacing ◽  
Left Ventricular

Pacing: a new look. Don’t be deceived

Heart ◽  
2018 ◽  
Vol 104 (18) ◽  
pp. 1491-1528 ◽  
Author(s):  
Chee Loong Chow ◽  
Barveen Abu Baker ◽  
Uwais Mohamed
Keyword(s):  
Right Ventricular ◽  
Sinus Bradycardia ◽  
Biventricular Pacing ◽  
Sinus Node ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Supplementary File ◽  
Electrode Position ◽  
List Type ◽  
Ventricular Ejection Fraction

Clinical introductionA 78-year-old man presents following a syncopal episode in the setting of intermittent sinus bradycardia and left bundle branch block (LBBB). With symptoms likely due to documented intermittent sinus node dysfunction, and finding of a diseased left bundle, a pacemaker was inserted (online supplementary figure 1 shows the electrode position in a PA fluroscopy view). His baseline ECG is shown in figure 1A, with a QRS width of 160 ms, and his echocardiogram revealed a left ventricular ejection fraction of 45%. His ECG day 1 postdevice insertion is shown in figure 1B. His device check confirmed excellent function. His QRS width on ECG postdevice insertion is now normalised to 80 ms.Supplementary file 1QuestionWhat type of device therapy has this patient received?Biventricular pacing.Right ventricular outflow septal pacing.His bundle pacing.Right ventricular apical pacing.Figure 1(A) Baseline ECG and (B) day 1 postpacemaker implantation.

P1236Revealing cardiac mechanics with CMR whilst CRT is active: the first step

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
A Koshy ◽  
J Gierula ◽  
M Paton ◽  
P Swoboda ◽  
A Toms ◽  
...  
Keyword(s):  
Heart Failure ◽  
Blood Pressure ◽  
Ejection Fraction ◽  
Systolic Blood Pressure ◽  
Right Ventricular ◽  
Biventricular Pacing ◽  
Left Ventricular ◽  
Heart Rates ◽  
Intrinsic Conduction ◽  
Mri Conditional

Abstract Introduction Cardiac resynchronisation therapy (CRT) is a routine treatment for heart failure with reduced ejection fraction and conduction delay to improve symptoms and prognosis. Technological advancements both in cardiac magnetic resonance (CMR) and devices (MRI-conditional modes) now enable investigation of the haemodynamic response to CRT over a range of heart rates. Methods Patients with a CRT-D device were enrolled from heart failure clinics at a single tertiary centre. A complete device system assessment and baseline device check was conducted to ensure MRI compatibility and suitability. Left ventricular (LV) volumes and systolic blood pressure were measured at baseline and heart rates of 75, 90, 100, 115, 125, and 140 bpm (randomised order) with CRT active and intrinsic conduction (AOO). MRI conditional mode parameters were replicated through standard parameter modification to ensure biventricular pacing during CRT active scans. All scans were conducted using a 3.0 T Siemens Prisma MRI scanner with analysis on commercially available software. Contractility was derived from the systolic blood pressure and left ventricular end systolic volume. A post scan device and lead assessment was conducted to assess for scanning safety. Results Scanning was conducted in 22 patients (safety cohort). Post scan battery voltage reduced by 2.9±1.0%. Mean change in atrial, right ventricular and left ventricular lead impedance was 0.5±0.06%, 3.0±0.04% and −1.7±0.05% respectively. Mean change in atrial, right ventricular and left ventricular pacing threshold was 0.0±0.3%, 8.3±0.3% and 5.6±0.3%. No patient experienced symptoms related to scanning or device failure. Preliminary data for patients with CRT on and off have been analysed (paired analysis cohort, n=8, 6 men). Mean age was 71.1±8.2, aetiology was primarily ischaemic (62.5%) with the remainder dilated cardiomyopathy. The mean LV ejection fraction at baseline was 29.4±12.9%. Biventricular pacing led to acute improvements in ejection fraction (p=0.005), left ventricular cardiac output (p<0.0001) and contractility (p=0.05) over the entire range of heart rates studied. We also noted an improvement in the force frequency relationship during biventricular pacing with a higher peak contractility (p=0.05), a higher heart rate at which this occurred (HR=130) and a generally up sloping relationship when compared with intrinsic conduction. Conclusion We have demonstrated for the first time, the mechanistic improvements in cardiac contractility consequent to CRT using CMR and also that MRI scans of conditional devices can be safe with CRT active. Acknowledgement/Funding Dr A Koshy is conducting a PhD supported by grant from Medtronic. Dr Klaus Witte has received honoraria from Medtronic

scholarly journals 645 InterVentricular mechanical delay during right ventricular; left ventricular and biventricular pacing

EP Europace ◽  
2005 ◽  
Vol 7 (Supplement_1) ◽  
pp. 149-149
Author(s):  
A. Tomaszewski ◽  
P. Rucinski ◽  
A. Kutarski ◽  
T. Widomska-Czekajska
Keyword(s):  
Right Ventricular ◽  
Biventricular Pacing ◽  
Left Ventricular

Effects of sequential biventricular pacing during acute right ventricular pressure overload

2006 ◽  
Vol 291 (5) ◽  
pp. H2380-H2387 ◽  
Author(s):  
T. Alexander Quinn ◽  
George Berberian ◽  
Santos E. Cabreriza ◽  
Lauren J. Maskin ◽  
Alan D. Weinberg ◽  
...  
Keyword(s):  
Right Ventricular ◽  
Diastolic Pressure ◽  
Biventricular Pacing ◽  
Interventricular Septum ◽  
Pressure Overload ◽  
Left Ventricular ◽  
Ventricular Pressure ◽  
Ventricular Contractility ◽  
Rate Of Increase ◽  
Control State

Temporary sequential biventricular pacing (BiVP) is a promising treatment for postoperative cardiac dysfunction, but the mechanism for improvement in right ventricular (RV) dysfunction is not understood. In the present study, cardiac output (CO) was optimized by sequential BiVP in six anesthetized, open-chest pigs during control and acute RV pressure overload (RVPO). Ventricular contractility was assessed by the maximum rate of increase of ventricular pressure (dP/d tmax). Mechanical interventricular synchrony was measured by the area of the normalized RV-left ventricular (LV) pressure diagram ( APP). Positive APP indicates RV pressure preceding LV pressure, whereas zero indicates complete synchrony. In the control state, CO was maximized with nearly simultaneous stimulation of the RV and LV, which increased RV ( P = 0.006) and LV dP/d tmax ( P = 0.002). During RVPO, CO was maximized with RV-first pacing, which increased RV dP/d tmax ( P = 0.007), but did not affect LV dP/d tmax, and decreased the left-to-right, end-diastolic pressure gradient ( P = 0.023). Percent increase of RV dP/d tmax was greater than LV dP/d tmax ( P = 0.014). There were no increases in end-diastolic pressure to account for increases in dP/d tmax. In control and RVPO, RV dP/dtmax was linearly related to APP ( r = 0.779, P < 0.001). The relation of CO to APP was curvilinear, with a peak in CO with positive APP in the control state ( P = 0.004) and with APP approaching zero during RVPO ( P = 0.001). These observations imply that, in our model, BiVP optimization improves CO by augmenting RV contractility. This is mediated by changes in mechanical interventricular synchrony. Afterload increases during RVPO exaggerate this effect, making CO critically dependent on simultaneous pressure generation in the RV and LV, with support of RV contractility by transmission of LV pressure across the interventricular septum.

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