Accuracy of left ventricular mechanical dyssynchrony indices for mechanical characteristics of left bundle branch block using cardiovascular magnetic resonance feature tracking.

Aims: More than 90% of patients with left bundle branch block (LBBB) and reduced left ventricular (LV) ejection fraction have LV dyssynchrony and a high probability of response to cardiac resynchronization therapy (CRT). A subgroup of patients with non-specific intraventricular conduction delay (IVCD) have a LBBB-like LV activation pattern when studied using invasive mapping and advanced echocardiographic techniques. These patients also frequently benefit from CRT but these patients have proven difficult to identify using ECG criteria.

Echocardiographic estimation of pulmonary artery wedge pressure: invasive derivation, validation, and prognostic association beyond diastolic dysfunction grading.

Aims: Grading of diastolic function can be useful, but indeterminate classifications are common. We aimed to invasively derive and validate a quantitative echocardiographic estimation of pulmonary artery wedge pressure (PAWP) and to compare its prognostic performance to diastolic dysfunction grading.

Methods And Results: Echocardiographic measures were used to derive an estimated PAWP (ePAWP) using multivariable linear regression in patients undergoing right heart catheterization (RHC).

Impact of Vasodilation on Oxygen-Enhanced Functional Lung MRI at 0.55 T.

Background: Oxygen-enhanced magnetic resonance imaging (OE-MRI) can be used to assess regional lung function without ionizing radiation. Inhaled oxygen acts as a T1-shortening contrast agent to increase signal in T1-weighted (T1w) images. However, increase in proton density from pulmonary hyperoxic vasodilation may also contribute to the measured signal enhancement.

An electrocardiography score predicts heart failure hospitalization or death beyond that of cardiovascular magnetic resonance imaging.

The electrocardiogram (ECG) and cardiovascular magnetic resonance imaging (CMR) provide powerful prognostic information. The aim was to determine their relative prognostic value. Patients (n = 783) undergoing CMR and 12-lead ECG with a QRS duration < 120 ms were included.

Lead one ratio in left bundle branch block predicts poor cardiac resynchronization therapy response.

Background: A low electrocardiogram (ECG) lead one ratio (LOR) of the maximum positive/negative QRS amplitudes is associated with lower left ventricular ejection fraction (LVEF) and worse outcomes in left bundle branch block (LBBB); however, the impact of LOR on cardiac resynchronization therapy (CRT) outcomes is unknown. We compared clinical outcomes and echocardiographic changes after CRT implantation by LOR.

Methods: Consecutive CRT-defibrillator recipients with LBBB implanted between 2006 and 2015 at Duke University Medical Center were included (N = 496).

The effect of levosimendan on survival and cardiac performance in an ischemic cardiac arrest model - A blinded randomized placebo-controlled study in swine.

Background: Survival after out-of-hospital cardiac arrest remains poor. Levosimendan could be a new intervention in this setting. Therefore, we conducted a blinded, placebo controlled randomized study investigating the effects of levosimendan on survival and cardiac performance in an ischemic cardiac arrest model in swine.

The electrical determinants of increased wall thickness and mass in left ventricular hypertrophy.

Introduction: Left ventricular hypertrophy (LVH), defined as an increased left ventricular mass (LVM), can manifest as increased wall thickness, ventricular dilatation, or both. Existing LVH criteria from the electrocardiogram (ECG) have poor sensitivity. However, it is unknown whether changes in wall thickness and mass, respectively, can be separately detected by the ECG.

Supine, prone, right and left gravitational effects on human pulmonary circulation.

Background: Body position can be optimized for pulmonary ventilation/perfusion matching during surgery and intensive care. However, positional effects upon distribution of pulmonary blood flow and vascular distensibility measured as the pulmonary blood volume variation have not been quantitatively characterized. In order to explore the potential clinical utility of body position as a modulator of pulmonary hemodynamics, we aimed to characterize gravitational effects upon distribution of pulmonary blood flow, pulmonary vascular distension, and pulmonary vascular distensibility.

Low lead one ratio predicts clinical outcomes in left bundle branch block.

Introduction: We evaluated the association between a novel electrocardiographic (ECG) marker of late, rightward electrocardiographic forces (termed the lead one ratio [LOR]), and left ventricular ejection fraction (LVEF), myocardial scar, and clinical outcomes in patients with left bundle branch block (LBBB).

Methods And Results: LOR was calculated in patients with LBBB from a derivation cohort (n = 240) and receiver operator characteristic curves identified optimal threshold values for predicting myocardial scar and LVEF less than 35%. An independent validation cohort of patients with LBBB (n = 196) was used to test the association of LOR with the myocardial scar, LVEF, and the likelihood of death, heart transplant or left ventricular assist device (LVAD) implantation.

Ejection fraction in left bundle branch block is disproportionately reduced in relation to amount of myocardial scar.

Introduction: The relationship between left ventricular (LV) ejection fraction (EF) and LV myocardial scar can identify potentially reversible causes of LV dysfunction. Left bundle branch block (LBBB) alters the electrical and mechanical activation of the LV. We hypothesized that the relationship between LVEF and scar extent is different in LBBB compared to controls.

The ability of the electrocardiogram in left bundle branch block to detect myocardial scar determined by cardiovascular magnetic resonance.

Aims: We aimed to improve the electrocardiographic 2009 left bundle branch block (LBBB) Selvester QRS score (2009 LBSS) for scar assessment.

Methods: We retrospectively identified 325 LBBB patients with available ECG and cardiovascular magnetic resonance imaging (CMR) with late gadolinium enhancement from four centers (142 [44%] with CMR scar). Forty-four semi-automatically measured ECG variables pre-selected based on the 2009 LBSS yielded one multivariable model for scar detection and another for scar quantification.

Evaluation of the ECG based Selvester scoring method to estimate myocardial scar burden and predict clinical outcome in patients with left bundle branch block, with comparison to late gadolinium enhancement CMR imaging.

Background: Myocardial scar burden quantification is an emerging clinical parameter for risk stratification of sudden cardiac death and prediction of ventricular arrhythmias in patients with left ventricular dysfunction. We investigated the relationships among semiautomated Selvester score burden and late gadolinium enhancement-cardiovascular magnetic resonance (LGE-CMR) assessed scar burden and clinical outcome in patients with underlying heart failure, left bundle branch block (LBBB) and implantable cardioverter-defibrillator (ICD) treatment.

Methods: Selvester QRS scoring was performed on all subjects with ischemic and nonischemic dilated cardiomyopathy at Skåne University Hospital Lund (2002-2013) who had undergone LGE-CMR and 12-lead ECG with strict LBBB pre-ICD implantation.

Diffuse Myocardial Fibrosis Reduces Electrocardiographic Voltage Measures of Left Ventricular Hypertrophy Independent of Left Ventricular Mass.

Background: Myocardial fibrosis quantified by myocardial extracellular volume fraction (ECV) and left ventricular mass (LVM) index (LVMI) measured by cardiovascular magnetic resonance might represent independent and opposing contributors to ECG voltage measures of left ventricular hypertrophy (LVH). Diffuse myocardial fibrosis can occur in LVH and interfere with ECG voltage measures. This phenomenon could explain the decreased sensitivity of LVH detectable by ECG, a fundamental diagnostic tool in cardiology.

Scar burden assessed by Selvester QRS score predicts prognosis, not CRT clinical benefit in preventing heart failure event and death: A MADIT-CRT sub-study.

Background: There is a need for improved selection criteria for Cardiac Resynchronization Therapy (CRT). High myocardial scar burden has been associated with worse outcome in CRT patients. It is, however, unclear whether high scar burden ameliorates CRT clinical benefit or is merely predictive of prognosis in heart failure (HF) patients regardless of CRT implantation.

Specificity for each of the 46 criteria of the Selvester QRS score for electrocardiographic myocardial scar sizing in left bundle branch block.

Background: The Selvester QRS score consists of a set of electrocardiographic criteria designed to identify, quantify and localize scar in the left ventricle using the morphology of the QRS complex. These criteria were updated in 2009 to expand their use to patients with underlying conduction abnormalities, but these versions have thus far only been validated in small and carefully selected populations.

Aim: To determine the specificity for each of the criteria of the left bundle branch block (LBBB) modified Selvester QRS Score (LB-SS) in a population with strict LBBB and no myocardial scar as verified by cardiovascular magnetic resonance imaging with late gadolinium enhancement (CMR-LGE).

Selvester scoring in patients with strict LBBB using the QUARESS software.

Background: Estimation of the infarct size from body-surface ECGs in post-myocardial infarction patients has become possible using the Selvester scoring method. Automation of this scoring has been proposed in order to speed-up the measurement of the score and improving the inter-observer variability in computing a score that requires strong expertise in electrocardiography. In this work, we evaluated the quality of the QuAReSS software for delivering correct Selvester scoring in a set of standard 12-lead ECGs.

ECG myocardial scar quantification predicts reverse left ventricular remodeling and survival after cardiac resynchronization therapy implantation: A retrospective pilot study.

Introduction: Electrocardiographic (ECG) LV scar quantification may improve prediction of CRT response.

Methods And Results: Data were abstracted in 76 patients who underwent a first CRT implantation at 2 US centers. Selvester QRS scar quantification was performed using the LBBB modified QRS scoring method.

Automatic QRS Selvester scoring system in patients with left bundle branch block.

Aims: The Selvester QRS scoring system uses quantitative criteria from the standard 12-lead electrocardiogram (ECG) to estimate the myocardial scar size of patients, including those with left bundle branch block (LBBB). Automation of the scoring system could facilitate the clinical use of this technique which requires a set of multiple QRS patterns to be identified and measured.

Methods And Results: We developed a series of algorithms to automatically detect and measure the QRS parameters required for Selvester scoring.