33 year old gentleman has undergone an electrophysiology study for recurrent paroxysmal palpitation. During one of the episodes of palpitation a regular narrow QRS tachycardia was documented which has terminated with intravenous adenosine. Baseline electrocardiogram did not show any pre-excitation. Atrial-His (AH) and His-Ventricular (HV) intervals were normal at baseline. There was no evidence of dual atrioventricular (AV) nodal physiology. Earliest atrial electrogram during ventricular pacing was recorded at coronary sinus (CS) 9,10 dipoles placed at CS OS region. Narrow QRS tachycardia with cycle length (TCL) of 400 ms and earliest retrograde atrial activation at CS 9,10 dipoles was induced with programmed ventricular stimulation. Ventricular overdrive (VOD) pacing was performed at 30 ms shorter than TCL during the tachycardia (Fig: 1). What is the mechanism of tachycardia?
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http://dx.doi.org/10.1016/j.ipej.2019.12.003 | DOI Listing |
Pacing Clin Electrophysiol
December 2024
Servei de Cardiologia, Hospital Universitari de Bellvitge, L'Hospitalet de Llobregat, Barcelona, España.
Introduction: Right ventricular (RV) pacing can impair left ventricular function and cause heart failure, known as pacing-induced cardiomyopathy (PICM). Upgrade to cardiac resynchronization (CRT) is its usual treatment; recently left bundle branch area pacing (LBBAP) has emerged as a potential alternative. Deep septal pacing (DSP), a simplified alternative to LBBAP, is still able to achieve narrower paced QRS than during conventional RV pacing.
View Article and Find Full Text PDFQJM
November 2024
Department of Cardiology, Aerospace Center Hospital, Haidian District, 15 Yuquan Road, Beijing, 100049, PR China.
J Electrocardiol
December 2024
Department of Cardiology, University Heart and Vascular Center Hamburg and Center for Population Health Innovation (POINT), Hamburg, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany; Department of Medicine-Cardiology, Zealand University Hospital, Nykoebing F, Denmark. Electronic address:
Background: There is still conflicting evidence regarding the prognostic implications of right bundle branch block (RBBB) in the general population but also in patients with heart diseases like acute coronary syndromes (ACS). In accordance with current guidelines, RBBB in ACS patients is considered as STEMI equivalent. However, recent studies indicate that further differentiation is necessary in this group, as we will outline below.
View Article and Find Full Text PDFEur Heart J Case Rep
November 2024
Division of Cardiology, Saiseikai Kumamoto Hospital, 5-3-1 Chikami, Minami-ku, Kumamoto 861-4193, Japan.
Background: Myocarditis is associated with an increased risk of conduction disturbances during the acute phase, which recovers in most cases but rarely recurs during the chronic phase.
Case Summary: A 50-year-old man who developed fulminant myocarditis after COVID-19 mRNA vaccination was discharged 24 days after admission. He was readmitted for heart failure associated with two P waves: one P wave (P1) had a normal amplitude and was dissociated from the QRS, and the other (P2) had a very low amplitude and was associated with the QRS.
Heart Rhythm
November 2024
Division of Cardiology, Peter Munk Cardiac Center, University Health Network, Toronto, Canada. Electronic address:
Background: Heterogeneous ventricular activation can provide the substrate for ventricular arrhythmias (VA), but its manifestation on the electrocardiogram (ECG) as a risk stratifier is not well-defined.
Objective: To characterize the spatiotemporal features of QRS peaks that best predict VA in patients with cardiomyopathy (CM) using machine learning (ML).
Methods: Prospectively enrolled CM patients with prophylactic defibrillators (n=95) underwent digital, high-resolution ECG recordings during intrinsic rhythm and ventricular pacing at 100 to 120 beats/min.
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