Search results for " tachycardia"

Detection of ventricular fibrillation using the autocorrelation function analysis of the ECG

2003

A method is developed for the detection of ventricular fibrillation (VF) and life-threatening arrhythmias. The method is based on direct and simple peak analysis of the autocorrelation function (ACF). It can differentiate between VF (coarse and fine) and non-VH rhythms. ECG records during ventricular tachycardia (VT) and VF were obtained, and 4-s-long segments were digitized at 200 Hz and then split in three groups (VT, VF regular, and VF irregular). ACFs were computed, and positive peak P(j) (j=1, 2, . . .), RPL(j)=P(j)/2SE(1), TR(1)=P(1) width/lag P(1), and D(j)=P(j)-P(j+1) were measured and calculated for each sample. Results show that: (a) RPL(j)(j=1, 2, 3) together with D(j) present hi…

<i>In vitro</i> Modeling of Ryanodine Receptor 2 Dysfunction Using Human Induced Pluripotent Stem Cells

2011

Background/Aims: Induced pluripotent stem (iPS) cells generated from accessible adult cells of patients with genetic diseases open unprecedented opportunities for exploring the pathophysiology of human diseases in vitro. Catecholaminergic polymorphic ventricular tachycardia type 1 (CPVT1) is an inherited cardiac disorder that is caused by mutations in the cardiac ryanodine receptor type 2 gene (RYR2) and is characterized by stress-induced ventricular arrhythmia that can lead to sudden cardiac death in young individuals. The aim of this study was to generate iPS cells from a patient with CPVT1 and determine whether iPS cell-derived cardiomyocytes carrying patient specific RYR2 mutation recap…

Reduction of ICD Shock Burden by Eliminating Back-Up Pacing Induced Ventricular Tachyarrhythmias

2014

ICD Shock Reduction by Subthreshold Pacing Introduction Implantable cardioverter defibrillators (ICD) may have the capacity to provoke or worsen ventricular tachyarrhythmias (VT). It has been reported that ICD shocks by itself can increase mortality. This study aimed to determine the role of back-up pacing-induced VT (PIT) in the overall ICD shock burden by avoiding pause-related ventricular back-up pacing. Methods and Results A population of 550 single-chamber ICD patients was studied. Of them, 17 (3%, 69 ± 16 years, 14 male) patients had documented episodes of PIT. A total of 431 VT episodes were documented including 89 (21%) due to PIT. In 3 patients, VT events were exclusively PITs. Aft…

Mechanism of Sinoatrial Node Dysfunction in a RyR 2 R420Q Mouse Model Ofcatecholaminergic Polymorphic Ventricular Tachycardia

2017

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a genetic disease characterized by stress-induced syncope and/or sudden death in young individuals with structurally normal heart. More than 150 mutations located in the cardiac Ca2+ release channel (type-2 ryanodine receptor, RyR2) gene are related to CPVT. Besides ventricular tachycardia (VT) under stress, sinoatrial node (SAN) dysfunction is frequently observed in CPVT patients. However, the cellular mechanisms remain underexplored. We created a KI mice model bearing a mutation in the N-terminal portion of the RyR2 found in a CPVT family, RyR2(R420Q). ECGs were recorded in KI and WT littermates in resting condition and after…

Sensitivity and negative predictive value of treadmill exercise stress testing for the diagnosis of catecholaminergic polymorphic ventricular tachyca…

2015

Quasi-Conformal Technique for Integrating and Validating Myocardial Tissue Characterization in MRI with Ex-Vivo Human Histological Data

2017

Ventricular tachycardia caused by a circuit of re-entry is one of the most critical arrhythmias. It is usually related with heterogeneous scar regions where slow velocity of conduction tissue is mixed with non-conductive tissue, creating pathways (CC) responsible for the tachycardia. Pre-operative DE-MRI can provide information on myocardial tissue viability and then improve therapy planning. However, the current DE-MRI resolution is not sufficient for identifying small CCs and therefore they have to be identified during the intervention, which requires considerable operator experience. In this work, we studied the relationship of histological data (with 10 \(\mu \)m resolution), with in-vi…

Ventricular Fibrillation and Tachycardia detection from surface ECG using time-frequency representation images as input dataset for machine learning

2017

Parameter-less ventricular fibrillation detection with time-frequency representation.Time-frequency representations are treated as images for a classifier.A comparison for four classifiers demonstrates the validity of the proposed method.The proposed technique could be applied to any signal and research field.This is a novel approach to signal analysis. Background and objectiveTo safely select the proper therapy for Ventricullar Fibrillation (VF) is essential to distinct it correctly from Ventricular Tachycardia (VT) and other rhythms. Provided that the required therapy would not be the same, an erroneous detection might lead to serious injuries to the patient or even cause Ventricular Fibr…

The supraventricular tachycardias: Proposal of a diagnostic algorithm for the narrow complex tachycardias

2013

AbstractThe narrow complex tachycardias (NCTs) are defined by the presence in a 12-lead electrocardiogram (ECG) of a QRS complex duration less than 120ms and a heart rate greater than 100 beats per minute; those are typically of supraventricular origin, although rarely narrow complex ventricular tachycardias have been reported in the literature.As some studies document, to diagnose correctly the NCTs is an arduous exercise because sometimes those have similar presentation on the ECG. In this paper, we have reviewed the physiopathological, clinical, and ECG findings of all known supraventricular tachycardias and, in order to reduce the possible diagnostic errors on the ECG, we have proposed …

Ventricular paired pacing to control intractable junctional tachycardia following open heart surgery in a child.

1989

A 5-month-old girl presented postoperatively with an atrioventricular (A-V) junctional tachycardia at a rate of 245/min following surgical repair of tetralogy of Fallot. The systolic blood pressure dropped to 60 mmHg with this rapid heart rate, and the infant became shocked. Drugs and overdrive pacing were ineffective in suppressing the A-V junctional tachycardia and in improving cardiac output. Ventricular paired pacing was used successfully to halve the mechanically effective ventricular rate and to restore cardiac output. When ventricular paired pacing was stopped after 12 h, the spontaneous rhythm was an atrial rhythm with 1-1 A-V conduction. The patient was discharged in sinus rhythm o…

Exercise-Induced Sustained Ventricular Tachycardia without Structural Heart Disease: A Case Report

2020

Patient: Female, 51-year-old Final Diagnosis: Ventricular tachycardia Symptoms: Chest pain • shortness of breath Medication: — Clinical Procedure: Treadmill stress echocardiogram Specialty: Cardiology Objective: Unusual clinical course Background: Exercise-induced ventricular tachycardia (VT) has been widely reported in patients with preexisting structural heart disease or underlying ischemia and is attributed to reentry tachycardia and abnormal automaticity. However, studies regarding exercise-induced VT in individuals without evident structural heart disease are still limited. Case Report: A 51-year-old woman came to our practice for a treadmill stress echocardiogram. The patient experien…