Cardiac troponin concentrations following exercise and the association with cardiovascular disease and outcomes: rationale and design of the prospective TREAT cohort study.

Exercise can produce transient elevations of cardiac troponin (cTn) concentrations, which may resemble the cTn release profile of myocardial infarction. Consequently, clinical interpretation of postexercise cTn elevations (ie, values above the 99th percentile upper reference limit) remains challenging and may cause clinical confusion. Therefore, insight into the physiological versus pathological nature of postexercise cTn concentrations is warranted.

Radiation dose reduction of 50% in dynamic myocardial CT perfusion with skipped beat acquisition: a retrospective study.

Background: Dynamic myocardial computed tomography perfusion (CTP) is a novel imaging technique that increases the applicability of CT for cardiac imaging; however, the scanning requires a substantial radiation dose.

Purpose: To investigate the feasibility of dose reduction in dynamic CTP by comparing all-heartbeat acquisitions to periodic skipping of heartbeats.

Material And Methods: We retrieved imaging data of 38 dynamic CTP patients and created new datasets with every fourth, third or second beat (Skip1:4, Skip1:3, Skip1:2, respectively) removed.

Prognostic implications of invasive hemodynamics during cardiac resynchronization therapy: Stroke work outperforms dP/dt.

Background: Invasive measurements of left ventricular (LV) hemodynamic performance can evaluate acute response to cardiac resynchronization therapy (CRT).

Objective: The study sought to determine which metric, maximum rate of LV pressure rise (LV dP/dt) or LV stroke work (LVSW), is more strongly associated with long-term prognosis.

Methods: CRT patients were prospectively included from 3 academic centers.

Left ventricular strain-volume loops and myocardial fibrosis in pediatric patients with Duchenne muscular dystrophy.

Background: The left ventricular strain-volume loop (SVL) combines changes in global longitudinal strain (GLS) and LV volume across a cardiac cycle, providing insight into cardiac dynamics. This study explored the association between left ventricular SVL and presence of fibrosis, assessed with late gadolinium enhancement, in patients with Duchenne muscular dystrophy (DMD).

Methods And Results: 34 pediatric patients with DMD were included.

Left ventricular deformation and myocardial fibrosis in pediatric patients with Duchenne muscular dystrophy.

Background: Left ventricular (LV) strain and rotation are emerging functional markers for early detection of LV dysfunction and have been associated with the burden of myocardial fibrosis in several disease states. This study examined the association between LV deformation (i.e.

Comprehensive Evaluation of Pediatric Patients with Ebstein Anomaly Requires Both Echocardiography and Cardiac Magnetic Resonance Imaging.

With the trend towards childhood surgery in patients with Ebstein anomaly (EA), thorough imaging is crucial for patient selection. This study aimed to assess biventricular function by echocardiography and cardiac magnetic resonance (CMR) and compare EA severity classifications. Twenty-three patients (8-17 years) underwent echocardiography and CMR.

Synchronization of repolarization after cardiac resynchronization therapy: A combined clinical and modeling study.

Introduction: The changes in ventricular repolarization after cardiac resynchronization therapy (CRT) are poorly understood. This knowledge gap is addressed using a multimodality approach including electrocardiographic and echocardiographic measurements in patients and using patient-specific computational modeling.

Methods: In 33 patients electrocardiographic and echocardiographic measurements were performed before and at various intervals after CRT, both during CRT-ON and temporary CRT-OFF.

Does mechanical dyssynchrony in addition to QRS area ensure sustained response to cardiac resynchronization therapy?

Aims: Judicious patient selection for cardiac resynchronization therapy (CRT) may further enhance treatment response. Progress has been made by using improved markers of electrical dyssynchrony and mechanical discoordination, using QRSAREA, and systolic rebound stretch of the septum (SRSsept) or systolic stretch index (SSI), respectively. To date, the relation between these measurements has not yet been investigated.

Automated Assessment of COVID-19 Reporting and Data System and Chest CT Severity Scores in Patients Suspected of Having COVID-19 Using Artificial Intelligence.

Background The coronavirus disease 2019 (COVID-19) pandemic has spread across the globe with alarming speed, morbidity, and mortality. Immediate triage of patients with chest infections suspected to be caused by COVID-19 using chest CT may be of assistance when results from definitive viral testing are delayed. Purpose To develop and validate an artificial intelligence (AI) system to score the likelihood and extent of pulmonary COVID-19 on chest CT scans using the COVID-19 Reporting and Data System (CO-RADS) and CT severity scoring systems.

Hemodynamic Optimization in Cardiac Resynchronization Therapy: Should We Aim for dP/dt or Stroke Work?

Objectives: This study evaluated the acute effect of dP/dt- versus stroke work (SW)-guided cardiac resynchronization therapy (CRT) optimization and the related acute hemodynamic changes to long-term CRT response.

Background: Hemodynamic optimization may increase benefit from CRT. Typically, maximal left ventricular (LV) pressure rise dP/dt is used as an index of ventricular performance.

Multimodality imaging for real-time image-guided left ventricular lead placement during cardiac resynchronization therapy implantations.

This study was performed to evaluate the feasibility of intra-procedural visualization of optimal pacing sites and image-guided left ventricular (LV) lead placement in cardiac resynchronization therapy (CRT). In fifteen patients (10 males, 68 ± 11 years, 7 with ischemic cardiomyopathy and ejection fraction of 26 ± 5%), optimal pacing sites were identified pre-procedurally using cardiac imaging. Cardiac magnetic resonance (CMR) derived scar and dyssynchrony maps were created for all patients.

Atrioventricular optimization in cardiac resynchronization therapy with quadripolar leads: should we optimize every pacing configuration including multi-point pacing?

Aims: This study aims to define an atrioventricular (AV) delay optimization method for cardiac resynchronization therapy (CRT) with a quadripolar left ventricular (LV) lead based on intrinsic conduction intervals.

Methods And Results: Heart failure patients with a left bundle branch block underwent CRT implantation with a quadripolar LV lead. Invasive LV pressure-volume loops were recorded during four biventricular and three multi-point pacing (MPP) settings, using four patient-specific paced AV delays.

Strain imaging to predict response to cardiac resynchronization therapy: a systematic comparison of strain parameters using multiple imaging techniques.

Aims: Various strain parameters and multiple imaging techniques are presently available including cardiovascular magnetic resonance (CMR) tagging (CMR-TAG), CMR feature tracking (CMR-FT), and speckle tracking echocardiography (STE). This study aims to compare predictive performance of different strain parameters and evaluate results per imaging technique to predict cardiac resynchronization therapy (CRT) response.

Methods And Results: Twenty-seven patients were prospectively enrolled and underwent CMR and echocardiographic examination before CRT implantation.

Can We Use the Intrinsic Left Ventricular Delay (QLV) to Optimize the Pacing Configuration for Cardiac Resynchronization Therapy With a Quadripolar Left Ventricular Lead?

Background: Previous studies indicated the importance of the intrinsic left ventricular (LV) electric delay (QLV) for optimal benefit to cardiac resynchronization therapy. We investigated the use of QLV for achieving optimal acute hemodynamic response to cardiac resynchronization therapy with a quadripolar LV lead.

Methods And Results: Forty-eight heart failure patients with a left bundle branch block were prospectively enrolled (31 men; age, 66±10 years; LV ejection fraction, 28±8%; QRS duration, 176±14 ms).

Comparison of strain parameters in dyssynchronous heart failure between speckle tracking echocardiography vendor systems.

Background: Although mechanical dyssynchrony parameters derived by speckle tracking echocardiography (STE) may predict response to cardiac resynchronization therapy (CRT), comparability of parameters derived with different STE vendors is unknown.

Methods: In the MARC study, echocardiographic images of heart failure patients obtained before CRT implantation were prospectively analysed with vendor specific STE software (GE EchoPac and Philips QLAB) and vendor-independent software (TomTec 2DCPA). Response was defined as change in left ventricular (LV) end-systolic volume between examination before and six-months after CRT implantation.

Comparison of strain imaging techniques in CRT candidates: CMR tagging, CMR feature tracking and speckle tracking echocardiography.

Parameters using myocardial strain analysis may predict response to cardiac resynchronization therapy (CRT). As the agreement between currently available strain imaging modalities is unknown, three different modalities were compared. Twenty-seven CRT-candidates, prospectively included in the MARC study, underwent cardiac magnetic resonance (CMR) imaging and echocardiographic examination.

Echocardiographic Prediction of Cardiac Resynchronization Therapy Response Requires Analysis of Both Mechanical Dyssynchrony and Right Ventricular Function: A Combined Analysis of Patient Data and Computer Simulations.

Background: Pronounced echocardiographically measured mechanical dyssynchrony is a positive predictor of response to cardiac resynchronization therapy (CRT), whereas right ventricular (RV) dysfunction is a negative predictor. The aim of this study was to investigate how RV dysfunction influences the association between mechanical dyssynchrony and left ventricular (LV) volumetric remodeling following CRT.

Methods: One hundred twenty-two CRT candidates (mean LV ejection fraction, 19 ± 6%; mean QRS width, 168 ± 21 msec) were prospectively enrolled and underwent echocardiography before and 6 months after CRT.

Quadripolar Leads in Cardiac Resynchronization Therapy.

Despite the benefit of cardiac resynchronization therapy (CRT) in patients with heart failure and conduction delay, a considerable number of patients do not respond substantially. Left ventricular lead position is an important factor in response, restricted by the patient's specific anatomy and local pathophysiology. Quadripolar leads could enhance response to CRT, offering 4 pacing locations along the distal end of the lead.

Vectorcardiography for optimization of stimulation intervals in cardiac resynchronization therapy.

Current optimization of atrioventricular (AV) and interventricular (VV) intervals in cardiac resynchronization therapy (CRT) is time consuming and subject to noise. We aimed to prove the principle that the best hemodynamic effect of CRT is achieved by cancelation of opposing electrical forces, detectable from the QRS morphology in the 3D vectorcardiogram (VCG). Different degrees of left (LV) and right ventricular (RV) pre-excitation were induced, using variation in AV intervals during LV pacing in 20 patients with left bundle branch block (LBBB) and variation in VV intervals during biventricular pacing in 18 patients with complete AV block or atrial fibrillation.

Comparison of septal strain patterns in dyssynchronous heart failure between speckle tracking echocardiography vendor systems.

Aim: To analyze inter-vendor differences of speckle tracking echocardiography (STE) in imaging cardiac deformation in patients with dyssynchronous heart failure.

Methods And Results: Eleven patients (all with LBBB, median age 60.7 years, 9 males) with implanted cardiac resynchronization therapy devices were prospectively included.