Cardiac Magnetic Resonance Identifies Responders to Cardiac Resynchronization Therapy with an Assessment of Septal Scar and Left Ventricular Dyssynchrony.

: The response to cardiac resynchronization therapy (CRT) depends on septal viability and correction of abnormal septal motion. This study investigates if cardiac magnetic resonance (CMR) as a single modality can identify CRT responders with combined imaging of pathological septal motion (septal flash) and septal scar. : In a prospective, multicenter, observational study of 136 CRT recipients, septal scar was assessed using late gadolinium enhancement (LGE) ( = 127) and septal flash visually from cine CMR sequences.

Scar imaging in the dyssynchronous left ventricle: Accuracy of myocardial metabolism by positron emission tomography and function by echocardiographic strain.

Purpose: Response to cardiac resynchronization therapy (CRT) is reduced in patients with high left ventricular (LV) scar burden, in particular when scar is located in the LV lateral wall or septum. Late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) can identity scar, but is not feasible in all patients. This study investigates if myocardial metabolism by F-fluorodeoxyglucose positron emission tomography (FDG-PET) and contractile function by echocardiographic strain are alternatives to LGE-CMR.

Determinants of LV dP/dt and QRS duration with different fusion strategies in cardiac resynchronisation therapy.

Background: We designed this study to assess the acute effects of different fusion strategies and left ventricular (LV) pre-excitation/post-excitation on LV dP/dt and QRS duration (QRSd).

Methods: We measured LV dP/dt and QRSd in 19 patients having cardiac resynchronisation therapy (CRT). Two groups of biventricular pacing were compared: pacing the left ventricle (LV) with FUSION with intrinsic right ventricle (RV) activation (FUSION), and pacing the LV and RV with NO FUSION with intrinsic RV activation.

Mechanical Effects on Right Ventricular Function From Left Bundle Branch Block and Cardiac Resynchronization Therapy.

Objectives: The purpose of this study was to investigate how LBBB and CRT modify RV free wall function by direct ventricular interaction.

Background: Right ventricular (RV) function influences prognosis in patients with left bundle branch block (LBBB) and cardiac resynchronization therapy (CRT). There is, however, limited insight into how LBBB and CRT affect RV function.

Septal contraction predicts acute haemodynamic improvement and paced QRS width reduction in cardiac resynchronization therapy.

Aims: Three distinct septal contraction patterns typical for left bundle branch block may be assessed using echocardiography in heart failure patients scheduled for cardiac resynchronization therapy (CRT). The aim of this study was to explore the association between these septal contraction patterns and the acute haemodynamic and electrical response to biventricular pacing (BIVP) in patients undergoing CRT implantation.

Methods And Results: Thirty-eight CRT candidates underwent speckle tracking echocardiography prior to device implantation.

Regional myocardial work by cardiac magnetic resonance and non-invasive left ventricular pressure: a feasibility study in left bundle branch block.

Aims: Regional myocardial work may be assessed by pressure-strain analysis using a non-invasive estimate of left ventricular pressure (LVP). Strain by speckle tracking echocardiography (STE) is not always accessible due to poor image quality. This study investigated the estimation of regional myocardial work from strain by feature tracking (FT) cardiac magnetic resonance (CMR) and non-invasive LVP.

Mechanism of Abnormal Septal Motion in Left Bundle Branch Block: Role of Left Ventricular Wall Interactions and Myocardial Scar.

Objectives: This study sought to investigate how regional left ventricular (LV) function modifies septal motion in left bundle branch block (LBBB).

Background: In LBBB, the interventricular septum often has marked pre-ejection shortening, followed by immediate relengthening (rebound stretch). This motion, often referred to as septal flash, is associated with positive response to cardiac resynchronization therapy (CRT).

Contractility surrogates derived from three-dimensional lead motion analysis and prediction of acute haemodynamic response to CRT.

Background: Patient-specific left ventricular (LV) lead optimisation strategies with immediate feedback on cardiac resynchronisation therapy (CRT) effectiveness are needed. The purpose of this study was to compare contractility surrogates derived from biventricular lead motion analysis to the peak positive time derivative of LV pressure (dP/dt in patients undergoing CRT implantation.

Methods: Twenty-seven patients underwent CRT implantation with continuous haemodynamic monitoring.

Left ventricular end-systolic volume is a more sensitive marker of acute response to cardiac resynchronization therapy than contractility indices: insights from an experimental study.

Aims: There are conflicting data and no consensus on how to measure acute response to cardiac resynchronization therapy (CRT). This study investigates, which contractility indices are best markers of acute CRT response.

Methods And Results: In eight anaesthetized dogs with left bundle branch block, we measured left ventricular (LV) pressure by micromanometer and end-diastolic volume (EDV) and end-systolic volume (ESV) by sonomicrometry.

Afterload Hypersensitivity in Patients With Left Bundle Branch Block.

Objectives: This study sought to investigate the hypothesis that patients with left bundle branch block (LBBB) are hypersensitive to elevated afterload.

Background: Epidemiological data suggest that LBBB can provoke heart failure in patients with hypertension.

Methods: In 11 asymptomatic patients with isolated LBBB and 11 age-matched control subjects, left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) were measured by echocardiography.

Cardiac resynchronization therapy when no lateral pacing option exists: vectorcardiographic guided non-lateral left ventricular lead placement predicts acute hemodynamic response.

Aims: A difficult cardiac resynchronization therapy (CRT) implantation scenario emerges when no lateral pacing option exists. The aim of this study was to explore the effect of biventricular pacing (BIVP) on vectorcardiographic parameters in patients with a non-lateral left ventricular (LV) lead position. We hypothesized that perimeter and area reduction for both the QRS complex and T-wave would predict acute CRT response.

Left ventricular markers of mortality and ventricular arrhythmias in heart failure patients with cardiac resynchronization therapy.

Aims: Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in heart failure. However, prediction of the outcome remains difficult. We aimed to investigate for echocardiographic predictors of ventricular arrhythmias and fatal outcome and to explore how myocardial function is changed by biventricular pacing in heart failure.

A novel ECG-index for prediction of ventricular arrhythmias in patients after myocardial infarction.

Background: Risk prediction of ventricular arrhythmias after myocardial infarction (MI) is still insufficient. Prolonged QTc is a known risk marker of mortality and ventricular arrhythmias. QTc has not achieved clinical importance in predicting arrhythmic events in patients after MI.

Dynamic relationship of left-ventricular dyssynchrony and contractile reserve in patients undergoing cardiac resynchronization therapy.

Aims: Contradicting reports have been published regarding the relation between a dobutamine-induced increase in either cardiac dyssynchrony or left-ventricular ejection fraction (LVEF) and the response to cardiac resynchronization therapy (CRT). Using apical rocking (ApRock) as surrogate dyssynchrony parameter, we investigated the dobutamine stress echocardiography (DSE)-induced changes in left-ventricular (LV) dyssynchrony and LVEF and their potential pathophysiological interdependence.

Methods And Results: Fifty-eight guideline-selected CRT candidates were prospectively enrolled for low-dose DSE.

Peak oxygen uptake during cardiopulmonary exercise testing determines response to cardiac resynchronization therapy.

Background: Cardiac resynchronization therapy (CRT) is an established treatment modality for advanced heart failure (HF) but 20-30% of patients treated with CRT do not experience clinical improvement. Hence, in this study we aimed to investigate whether baseline cardiopulmonary exercise testing (CPX) can help improve the prediction of a positive functional CRT response.

Methods: This prospective observational study included 76 HF patients undergoing elective CRT implantation and clinical CPX and echocardiographic assessment were performed at baseline, 6, and 12 months.

Prognostic value of cardiac troponin T in patients with moderate to severe heart failure scheduled for cardiac resynchronization therapy.

Background: Predicting response to cardiac resynchronization therapy (CRT) is challenging. Highly sensitive cardiac troponin T (hsTnT) might predict response to CRT and identify patients at a high risk of experiencing severe cardiovascular events. We investigated whether baseline levels of hsTnT were associated with response to CRT and with severe cardiovascular events after long-term follow-up.

Right ventricular mechanical dispersion is related to malignant arrhythmias: a study of patients with arrhythmogenic right ventricular cardiomyopathy and subclinical right ventricular dysfunction.

Aims: We evaluated if right ventricular (RV) mechanical dispersion by strain was related to ventricular arrhythmias (VT/VF) in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) and if mechanical dispersion was increased in so far asymptomatic mutation carriers.

Methods And Results: We included 69 patients, 42 had symptomatic ARVC and 27 were mutation positive asymptomatic family members. Forty healthy individuals served as controls.

Mechanisms of abnormal systolic motion of the interventricular septum during left bundle-branch block.

Background: In a majority of patients with left bundle-branch block (LBBB), there is abnormal leftward motion of the interventricular septum during the preejection phase. This motion was considered to be passive, caused by early rise in right ventricular (RV) pressure, and has therefore been excluded from most indices of left ventricular (LV) dyssynchrony. If considered active, however, the leftward motion reflects onset of septal activation and should be included.

Evaluation of left ventricular dyssynchrony by onset of active myocardial force generation: a novel method that differentiates between electrical and mechanical etiologies.

Background: Better clinical tools for measuring left ventricular electrical dyssynchrony are needed. The present study investigates if onset of active myocardial force generation (AFG) may serve as a measure of electrical dyssynchrony.

Methods And Results: In anesthetized dogs, we evaluated left ventricular mechanical dyssynchrony by 2 different approaches.

Mechanical dispersion assessed by myocardial strain in patients after myocardial infarction for risk prediction of ventricular arrhythmia.

Objectives: The aim of this study was to investigate whether myocardial strain echocardiography can predict ventricular arrhythmias in patients after myocardial infarction (MI).

Background: Left ventricular (LV) ejection fraction (EF) is insufficient for selecting patients for implantable cardioverter-defibrillator (ICD) therapy after MI. Electrical dispersion in infarcted myocardium facilitates malignant arrhythmia.

Implantable cardioverter defibrillator dysfunction during and after magnetic resonance imaging.

This report describes a patient in whom a MRI of the brain was performed without realizing that an ICD had been implanted 8 days previously. Electromagnetic noise induced during the MRI was detected as ventricular fibrillation and nearly caused inappropriate shocks. Charge time during MRI was prolonged.