PubMed Health⌕ Search

PubMed · 15272517

[Concealed phenomena in electrocardiography].

Abstract

Concealed phenomena in electrocardiography are events which, having no direct effect on the electrocardiogramme, nevertheless change the following sequences giving rise to very unusual appearances. They are diagnosed by deduction. First of all, there is concealed anterograde or retrograde conduction in the AV node, the consequences of which are either a block or the suppression of an escape rhythm or even facilitation of the transmission of activation. Concealed conduction is also possible in the Bundle of His and its branches, explaining the frequency of dependent blocks and aberrant conduction. There is also concealed conduction in accessory pathways. The second form is concealed rhythms: hisian extrasystoles giving rise to pseudo A-V block, and concealed extrasystoles and parasystoles. With temporary pacing of tachycardia, it has finally been possible to describe "visible" concealed phenomena, not on the surface but on the endocavitary electrogramme.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

R Grolleau, J L Pasquié, J C Macia, R Gervasoni, F Leclercq. 2003. [Concealed phenomena in electrocardiography].. https://pubmed.ncbi.nlm.nih.gov/15272517/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Safety of nerve conduction studies in patients with implanted cardiac devices.

Patients with implanted cardiac devices and their physicians may defer important electrodiagnostic testing because of anxiety about potential negative effects on the device. To determine the safety of routine nerve conduction studies (NCS) in this population, 10 patients with permanent dual-chamber pacemakers of various types and five patients with implanted cardiac defibrillators (ICD) underwent nerve stimulation at sites commonly used during NCS. The implanted cardiac device was interrogated before and after the study and there was continuous monitoring of the surface electrocardiogram (ECG) and atrial and ventricular electrograms. Electrical impulses generated during routine NCS were never detected by the sensing amplifier and did not affect the programmed settings of the implanted cardiac device. We conclude that routine NCS is safe in patients with implanted cardiac pacemakers with bipolar sensing configurations and defibrillators.

Arrhythmias, Cardiac↗

[Pulmonary diseases and heart function].

The most severe cardiac sequel to lung disease is the load on the right ventricle due to pulmonary hypertension with the development of a cor pulmonale. This is characterized by hypertrophy and/or dilatation of the right ventricle because of a primary impairment of lung function and/or lung structure. The most important pathomechanisms for the development of pulmonary hypertension are vessel obliteration, mechanical lesions, primary vascular or extra-vascular inflammation and hypoxic vasoconstriction. Chronic obstructive pulmonary disease (COPD) is one of the most important reasons for chronic cor pulmonale. A further very common reason is obstructive sleep apnea syndrome, especially if combined with a COPD. In this case, the prevalence of cor pulmonale can reach 80%. The development of a chronic cor pulmonale is the most striking negative prognostic factor for these patients. Only 30% of COPD patients with cor pulmonale survive longer than 5 years, and only early detection of the disturbances to respiration which might potentially lead to cor pulmonale and their subsequent therapy are able to improve the patient's prognosis. Furthermore, pulmonary diseases may also have an impact on the left heart side in terms of an impairment of left heart function or by inducing severe arrhythmias . Thus, lung diseases may have both a significant impact on right and left heart performance.

Arrhythmias, Cardiac↗