The influence of some pulmonary ventilation alterations (the normal ventilation at rest = control), the hyperventilation (HV) lasting 75 s, the hypoxic-hypercapnic ventilation (HXV) lasting 3 and 6 min) on the instantaneous QRS vectors was investigated in 42 young healthy women (19-24 years old). The magnitude and the direction of instantaneous QRS vectors in the 10th to the 70th ms and in QRS max were constructed from the Frank lead ECG. The significant alterations of the direction (angle) were found in the 30th ms and QRS max at HXV and in the 60th ms at HV. A significant decrease in the magnitude of instantaneous vectors was found in the 10th to 50th ms after 6 min of HXV, in the 30th to 50th ms at 3 min of HXV, in the 40th to 50th ms at HV. These alterations were the most marked in the horizontal plane. We suggest that the alterations of the instantaneous QRS vectors were caused by the influence of the autonomic nervous system or humoral agents, but not by heart position, Brody's effect or lung hyperinflation.
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JACC Clin Electrophysiol
November 2024
Geisinger Heart Institute, Geisinger Commonwealth School of Medicine, Wilkes-Barre, Pennsylvania, USA.
Background: Continuous deep septal pacing and signal recording during implantation of left bundle branch pacing (LBBP) lead enables to monitor beat-to-beat changes of electrocardiogram (ECG) and myocardial current of injury (COI) as the lead crosses the septum.
Objectives: This study aimed to characterize patterns of continuous QRS, ST-T, and COI change for monitoring of the lead depth and instantaneous determination of the obtained capture type (LBBP vs left ventricular septal pacing [LVSP]).
Methods: The ECG and COI during lead implantation were scrutinized for sudden changes of V R-wave peak time, V initial and terminal R-wave amplitude, V-V R-wave amplitude, repolarization pattern and S-wave amplitude in I, V-V, and COI drop.
Pacing Clin Electrophysiol
July 2024
Department of Cardiovascular Medicine, The University of Kansas Medical Center, Kansas City, Kansas, USA.
3DQRSarea is a strong marker for cardiac resynchronization therapy and can be obtained by taking the (i) summation or the (ii) difference of the areas subtended by positive and negative deflections in X, Y, Z vectorcardiographic electrocardiogram (ECG) leads. We correlated both methods with the instantaneous-absolute-3D-voltage-time-integral (VTI). 3DQRSarea consistently underestimated the VTI , but the summation method was a closer and more reliable approximation.
View Article and Find Full Text PDFFront Cardiovasc Med
June 2023
Cardiology Unit, Cardiac Thoracic and Vascular Department, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy.
Background: Electrocardiogram (ECG) has proven to be useful for early detection of cardiac involvement in Anderson-Fabry disease (AFD); however, little evidence is available on the association between ECG alterations and the progression of the disease.
Aim And Methods: To perform a cross sectional comparison of ECG abnormalities throughout different left ventricular hypertrophy (LVH) severity subgroups, providing ECG patterns specific of the progressive AFD stages. 189 AFD patients from a multicenter cohort underwent comprehensive ECG analysis, echocardiography, and clinical evaluation.
BMC Cardiovasc Disord
January 2023
Department of Cardiology, University Hospital "Sveti Duh", Zagreb, Croatia.
J Mol Cell Cardiol
February 2022
Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Germany. Electronic address:
Background: One third of heart failure patients exhibit dyssynchronized electromechanical activity of the heart (evidenced by a broad QRS-complex). Cardiac resynchronization therapy (CRT) in the form of biventricular pacing improves cardiac output and clinical outcome of responding patients. Technically demanding and laborious large animal models have been developed to better predict responders of CRT and to investigate molecular mechanisms of dyssynchrony and CRT.
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