intrinsicoid Deflection

Aims: We hypothesized that the greater the intra- or interventricular dyssynchrony (intraD, interD), the more effective cardiac resynchronization therapy (CRT) is. We sought to improve patient selection for CRT by using novel ECG dyssynchrony criteria. Methods and results: Left ventricular (LV) intraD was estimated by the absolute time difference between the intrinsicoid deflections (ID) in leads aVL and aVF divided by the QRS duration (QRSd): [aVLID - aVFID]/QRSd (%)...

BACKGROUND: Time to intrinsicoid deflection (ID), the time from onset of the QRS complex to the peak of the R wave on the electrocardiogram, represents delayed ventricular activation and suggests that impaired myocardial function is present. It is unknown whether delayed time to ID is predictive of future heart failure (HF) events. HYPOTHESIS: Delayed time to ID is predictive of future HF events. METHODS: A total of 6394 participants (mean age, 62 ± 10 years; 54% women; 38% whites, 28% blacks, 22% Hispanics, 12% Chinese Americans) without clinically apparent cardiovascular disease or major ventricular conduction delay (QRS ≥120 ms) from the Multi-Ethnic Study of Atherosclerosis were included...

BACKGROUND: Estimating left ventricular electrical delay (Q-LV) from a 12-lead ECG may be important in evaluating cardiac resynchronization therapy (CRT). OBJECTIVE: The purpose of this study was to assess the impact of Q-LV interval on ECG configuration. METHODS: One hundred ninety-two consecutive patients undergoing CRT implantation were divided electrocardiographically into 3 groups: left bundle branch block (LBBB), right bundle branch block (RBBB), and nonspecific intraventricular conduction delay (IVCD)...

AIMS: The differentiation between idiopathic right ventricular outflow tract (RVOT) arrhythmias and early arrhythmogenic right ventricular cardiomyopathy (ARVC) can be challenging. We aimed to assess whether QRS morphological features and coupling interval of ventricular ectopic beats (VEBs) can improve differentiation between the two conditions. METHODS AND RESULTS: Twenty desmosomal-gene mutation carriers (13 females, mean age 43 years) with no or mild ARVC phenotypic expression and 33 age- and sex-matched subjects with idiopathic RVOT arrhythmias were studied...

BACKGROUND: Prolongation of initial ventricular depolarization on the 12-lead electrocardiogram (ECG), or delayed intrinsicoid deflection (DID), can indicate left ventricular hypertrophy (LVH). The possibility that this marker could convey distinct risk of sudden cardiac arrest (SCA) has not been evaluated. OBJECTIVE: To evaluate the association of DID and SCA in the community. METHODS: In the ongoing prospective, population-based Oregon Sudden Unexpected Death Study (Oregon SUDS; catchment area approximately 1 million), SCA cases were compared to geographic controls with no SCA...

In the 12-lead electrocardiogram (ECG), the time from the onset of the QRS complex (Q or R wave) to the apex or peak of R or to R' (when present), using indirect or semidirect surface unipolar precordial leads, bipolar limb leads or unipolar limb leads, is called ventricular activation time (VAT), R wave peak time (RWPT), R-peak time or intrinsicoid deflection (ID). The R-peak time in a specific ECG lead is the interval from the earliest onset of the QRS complex, preferably determined from multiple simultaneously recorded leads, to the peak (maximum) of the R wave or R' if present...

BACKGROUND: The same electrocardiographic (ECG) criteria that have been used for detection of left ventricular hypertrophy (LVH) have recently been recognized as predictors of adverse clinical outcomes, but this predictive ability is inadequately explored and understood. METHODS: A total of 14,984 participants from the ARIC study were included in this analysis. Romhilt-Estes (R-E) LVH score was measured from the automatically processed baseline (1987-1989) ECG data...

AIM: The aim of this study was to investigate the influence of geometrical factors on the ECG morphology and vectorcardiogram (VCG) parameters. METHODS: Patient-tailored models based on five heart-failure patients with intraventricular conduction defects (IVCDs) were created. The heart was shifted up to 6 cm to the left, right, up, and down and rotated ±30° around the anteroposterior axis. Precordial electrodes were shifted 3 cm down. RESULTS: Geometry modifications strongly altered ECG notching/slurring and intrinsicoid deflection time...

BACKGROUND: Cardiac resynchronization therapy (CRT) is an established treatment for heart failure patients. However, determinants of response to CRT remain elusive. The aim of the study was to assess the value of ECG parameters to predict super-response in CRT patients. METHODS: A 12-lead surface ECG was recorded at baseline and immediately after CRT-device implantation. Baseline ECG parameters (QRS duration, bundle branch morphology, axis, PR interval, QTc, intrinsicoid deflection) and post-implant paced QRS duration were analyzed; relative change in QRS duration was calculated...

BACKGROUND: Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is characterized by delay in depolarization of the right ventricle, detected by prolonged terminal activation duration (TAD) in V1-V3. However, manual ECG measurements have shown moderate-to-low intra- and inter-reader agreement. The goal of this study was to assess reproducibility of automated ECG measurements in the right precordial leads. METHODS: Pairs of ECGs recorded in the same day from Johns Hopkins ARVD/C Registry participants [n=247, mean age 35...

Percutaneous pericardial access for epicardial mapping and ablation of ventricular arrhythmias has expanded considerably in recent years. After its description in patients with Chagas disease, the technique has provided relevant information on the arrhythmia substrate in other cardiomyopathies and has improved the results of ablation procedures in various clinical settings. Electrocardiographic criteria proposed for the recognition of the epicardial origin of ventricular tachycardias are mainly based on analysis of the first QRS components...

BACKGROUND: The ECG characteristics of premature ventricular contractions (PVCs) in subjects with Brugada syndrome (BrS) phenotype were investigated. METHODS AND RESULTS: A total of 96 patients with type 1 ECG pattern of BrS were screened for PVCs. The study population consisted of 10 male individuals (mean age 41.9±5.6 years) with spontaneous (n=2) or drug-induced (n=8) type 1 ECG phenotype of BrS and PVCs. Twenty patients (11 males, age 44.6±15.1 years) with idiopathic right ventricular outflow tract (RVOT) PVCs (LBBB/inferior axis morphology with a negative QRS complex in lead aVL) successfully ablated from an endocardial site were also included in the study, and served as comparative controls...

BACKGROUND: Several previous reports have revealed that idiopathic ventricular arrhythmias (VAs), including premature ventricular contractions (PVCs) and ventricular tachycardias (IVTs), can originate from endocardial mitral annulus (ENDO MA). However, these data are limited to ENDO MA VAs, and little is known about the electrocardiographic (ECG) characteristics and the efficacy of radiofrequency catheter ablation (RFCA) via the coronary venous system for the VAs arising from the epicardial MA (EPI MA)...

BACKGROUND: Up to one-third of the patients who undergo cardiac resynchronization therapy (CRT) are not responders. OBJECTIVE: To demonstrate that delayed lateral left ventricular activation time determined through time to intrinsicoid deflection onset (ID) predicts response after CRT. METHODS: The ID in leads I, aVL, V₁ and V₂, and V₅ and V₆ were measured in 135 patients who underwent CRT. A CRT response was defined as a decrease in left ventricular end-systolic volume (LVESV) exceeding 15% at 6 months...

AIM: To analyze electrocardiographic features of patients diagnosed with posttraumatic stress disorder (PTSD) after the Van-Erciş earthquake, with a shock measuring 7.2 on the Richter scale that took place in Turkey in October 2011. METHODS: Surface electrocardiograms of 12 patients with PTSD admitted to Van Erciş State Hospital (Van, Turkey) from February 2012 to May 2012 were examined. Psychiatric interviews of the sex and age matched control subjects, who had experienced the earthquake, confirmed the absence of any known diagnosable psychiatric conditions in the control group...

OBJECTIVES: We tested proposed algorithms for idiopathic and nonischemic tachycardias for their ability to identify epicardial LV-VT origins. BACKGROUND: Several ECG features have been reported to identify epicardial origins for left ventricular tachycardias (LV-VTs) in the absence of myocardial infarction. Only limited data exist in postinfarction patients. METHODS: The QRS features of 24 VTs that were ablated from the epicardium and 39 left ventricular VTs ablated from the endocardium were retrospectively analyzed for various 12-lead ECG features previously reported...

BACKGROUND: Frequent premature ventricular complexes (PVCs) can cause a decline in left ventricular ejection fraction (LVEF). We investigated whether the site of origin and other PVC characteristics are associated with LVEF. METHODS: We retrospectively studied 70 consecutive patients (mean age 42 ± 17 years, 40 [57%] female) with no other cause of cardiomyopathy undergoing ablation of PVCs. We analyzed the association of a reduced LVEF, defined by LVEF <50% on echocardiography, with features of PVCs obtained from electrocardiography, 24- or 48-hour Holter monitor and electrophysiology study...

BACKGROUND: ECG criteria identifying epicardial (EPI) origin for ventricular tachycardia (VT) in nonischemic cardiomyopathy have not been determined. Endocardial (ENDO) and EPI basal left ventricle fibrosis characterizes the VT substrate. METHODS AND RESULTS: We assessed the QRS from 102 basal-superior/lateral EPI and 67 comparable ENDO pace maps in 14 patients with nonischemic cardiomyopathy. Pace mapping focused on low bipolar voltage areas. Published morphology criteria: q wave in lead I (QWLI) and no q waves in inferior leads and interval criteria: pseudo-delta wave > or =34 ms, intrinsicoid deflection time > or =85 ms, shortest RS complex > or =121 ms, and maximum deflection index > or =0...

UNLABELLED: The increased QRS voltage is considered to be a specific electrocardiogram (ECG) sign of left ventricular hypertrophy (LVH), and it is expected that the QRS voltage reflects the increase in left ventricular mass (LVM). However, the increased QRS voltage is only one of QRS patterns observed in patients with LVH. According to the solid angle theory, the resultant QRS voltage is influenced not only by spatial (anatomic) but also by nonspatial (electrophysiologic) determinants...

BACKGROUND: Left ventricular hypertrophy (LVH) is a hallmark of chronic pressure or volume overload of the left ventricle and is associated with risk of cardiovascular morbidity and mortality. The purpose was to evaluate different electrocardiographic criteria for LVH as determined by cardiovascular magnetic resonance (CMR). Additionally, the effects of concentric and eccentric LVH on depolarization and repolarization were assessed. METHODS: 120 patients with aortic valve disease and 30 healthy volunteers were analysed...