Mapping propagation of mechanical activation  in the paced heart with MRI tagging

Wyman, Bradley T.; Hunter, William C.; Prinzen, Frits W.; McVeigh, Elliot R.

doi:10.1152/ajpheart.1999.276.3.h881

Cited by 197 publications

(202 citation statements)

References 30 publications

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“…This dysfunction can be offset by concomitant stimulation of the opposing wall to restore synchrony, and improvement depends on the extent of dyssynchrony generated by the first lead. 17,18 Such observations have suggested that patients with DCM and basal discoordination might benefit from LV or biventricular VDD pacing, and this was recently confirmed. [2][3][4][5] However, the response magnitude varies, highlighting the importance of identifying responsive individuals.…”

Section: Discussionmentioning

confidence: 85%

“…However, analogous data have been reported in animal studies, and these consistently demonstrate that single-site (LV or RV) pacing of a heart with normal conduction (narrow QRS) produces a significant decline in dP/dt max and other markers of systolic function. 14,15,17,18,27 We also limited our analysis to DCM patients with widened QRS complexes, and it remains possible that some individuals with more narrow complexes might also benefit. Previous studies have reported regional wall motion abnormalities, heterogeneous wall stress, and myocardial perfusion in DCM patients with normal-appearing epicardial vessels, 28,29 although none reported QRS durations to test correlations with these phenomena.…”

Section: Study Design Limitationsmentioning

confidence: 99%

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Predictors of Systolic Augmentation From Left Ventricular Preexcitation in Patients With Dilated Cardiomyopathy and Intraventricular Conduction Delay

et al. 2000

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Background-VDD pacing can enhance systolic function in patients with dilated cardiomyopathy and discoordinate contraction; however, identification of patients likely to benefit is unclear. We tested predictors of systolic responsiveness on the basis of global parameters as well as directly assessed mechanical dyssynchrony. Methods and Results-Twenty-two DCM patients with conduction delay were studied by cardiac catheterization with a dual-sensor micromanometer to measure LV and aortic pressures during sinus rhythm and LV free-wall pacing. Pacing enhanced isovolumetric (dP/dt max ) and ejection-phase (pulse pressure, PP) systolic function by 35Ϯ21% and 16.4Ϯ11%, respectively, and these changes correlated directly (rϭ0.7, Pϭ0.001). %⌬dP/dt max was weakly predicted by baseline QRS (rϭ0.6, PϽ0.02), more strongly by baseline dP/dt max (rϭ0.7, Pϭ0.001), and best by bidiscriminate analysis combining baseline dP/dt max Յ700 mm Hg/s and QRS Ն155 ms to predict %⌬dP/dt max Ն25% and %⌬PP Ն10% (PϽ0.0005, 2 ), with no false-positives. Benefit could not be predicted by %⌬QRS. To test whether basal mechanical dyssynchrony predicted responsiveness to LV pacing, circumferential strains were determined at Ϸ80 sites throughout the LV by tagged MRI in 8 DCM patients and 7 additional control subjects. Strain variance at time of maximal shortening indexed dyssynchrony, averaging 28.0Ϯ7.1% in normal subjects versus 201.4Ϯ84.3% in DCM patients (Pϭ0.001). Mechanical dyssynchrony also correlated directly with %⌬dP/dt max (rϭ0.85, Pϭ0.008). Conclusions-These results show that although mechanical dyssynchrony is a key predictor for pacing efficacy in DCM patients with conduction delay, combining information about QRS and basal dP/dt max provides an excellent tool to identify maximal responders.

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Section: Discussionmentioning

confidence: 85%

Section: Study Design Limitationsmentioning

confidence: 99%

Predictors of Systolic Augmentation From Left Ventricular Preexcitation in Patients With Dilated Cardiomyopathy and Intraventricular Conduction Delay

et al. 2000

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“…Restoration of synchrony by biventricular pacing can improve symptoms and prognosis in selected patients. 6 Diagnostic and Prognostic implications of a newly diagnosed LBBB, in the presence or absence of these risk factors needs to be studied with respect to morbidity and mortality.The clinical manifestations, prognostic implications will be discussed here.…”

Section: Introductionmentioning

confidence: 99%

Diagnostic and prognostic value of left bundle branch block and its correlation with left ventricular functions: a prospective observational study

2017

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Background: Left bundle branch block (LBBB) indicates organic heart disease. It is commonly associated with ischemic heart disease (IHD), cardiomyopathies, intrinsic disease of conduction system, hypertensive heart disease and acute myocardial infarction can present as new onset LBBB. Purpose of the study was to find out the etiology, outcome in patients having LBBB with respect to left ventricular function coming to our hospital. Methods: All patients coming to our hospital as inpatient or outpatient basis with ECG suggestive of LBBB were studied. Their detailed history was taken and examination was done. 2D-Echocardiography (2D ECHO) was done in all patients and coronary angiogram (CAG) when indicated. Results: Total of 116 patients who had LBBB were studied. Mean age was 62.25±13.75 years. 62 of them were male (53.45%) and 54 were female (46.55%). On presentation 41 patients had dyspnea (35.34%) and 37 had chest pain (31.89%). 24 patients were asymptomatic (20.68%). 59 patients had hypertension (50.86%) and 35 patients had diabetes (30.17%). On 2D ECHO, 39 patients (33.6%) had left ventricular hypertrophy (LVH), with 29 having diastolic and 10 systolic dysfunctions. 26 patients (22.41%) had dilated cardiomyopathy (DCM) and 30 patients had evidence of myocardial infarction (25.86%). 17 patients had normal echocardiography (14.05%). In total 62 patients had systolic dysfunction (53.44%). Conclusions: Commonest clinical presentation was dyspnoea followed by chest pain in patients with LBBB. Most of them had hypertension. LVH was the commonest 2D ECHO finding followed by global hypokinesia and regional wall motion abnormality. Ventricular systolic dysfunction was present in more than 50% patients. CAG revealed coronary artery diseases in majority of cases in whom CAG was indicated. Bharath MS et al. Int J Adv Med. 2017 Jun;4(3):713-717 International Journal of Advances in Medicine | May-June 2017 | Vol 4 | Issue 3 Page 714 turn, results in significantly lower dP/dT, a greater LV end-systolic volume, and energy inefficient contraction. Keywords 3Left bundle branch block (LBBB), a pattern seen on the surface electrocardiogram (ECG), results when normal electrical activity in the His-Purkinje system is interrupted. LBBB most often occurs in patients with underlying heart disease such as, hypertension, valvular heart disease, cardiomyopathies, myocarditis, and coronary artery disease and may be associated with progressive conducting system disease. 5However, LBBB can also be seen in asymptomatic patients with a structurally normal heart in the absence of any of these risk factors. LBBB results in an altered pattern of LV activation and subsequent contraction. Under normal circumstances, impulse conduction spreads rapidly down the His bundle branches, followed by the Purkinje system and most of the LV endocardial surface is activated synchronously or within 40 ms. This results in efficient contraction at the expense of minimal energy. These dynamics are altered in the presence of LBBB, because conduction th...

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“…Sabemos que la estimulación ventricular derecha pura genera un patrón de activación ventricular asincrónico 19 . Estudios animales han mostrado que la estimulación derecha a largo plazo produce desorden de las miofibrillas, hipertrofia ventricular asimétrica y dilatación del VI [20][21][22] .…”

Section: Discussionunclassified

Terapia de resincronización en pacientes con insuficiencia cardiaca: experiencia acumulada de 10 años

et al. 2013

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Mapping propagation of mechanical activation in the paced heart with MRI tagging

Cited by 197 publications

References 30 publications

Predictors of Systolic Augmentation From Left Ventricular Preexcitation in Patients With Dilated Cardiomyopathy and Intraventricular Conduction Delay

Predictors of Systolic Augmentation From Left Ventricular Preexcitation in Patients With Dilated Cardiomyopathy and Intraventricular Conduction Delay

Diagnostic and prognostic value of left bundle branch block and its correlation with left ventricular functions: a prospective observational study

Terapia de resincronización en pacientes con insuficiencia cardiaca: experiencia acumulada de 10 años

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