Is the diagnostic function of pacemakers a reliable source of information about ventricular arrhythmias?

Background: The aim of this study was to evaluate the reliability of pacemaker diagnostic function in diagnosing ventricular arrhythmias. Methods: We compared the occurrence of ventricular ectopic beats in 51 simultaneous 24-hour electrocardiogram (ECG) recordings and pacemaker event counters printouts. The diagnostic function of a pacemaker allowed also for a qualitative assessment in 38 patients. In these cases, the occurrence of complex forms of ventricular arrhythmias was cross-checked for accelerated ventricular rhythms together with ventricular tachycardia, and triplets and couplets. The detection of at least one type of complex ventricular form of arrhythmia, diagnosed by both methods, was considered as an agreement between the methods. Results: The results of ventricular ectopic beat counts differed significantly between the methods. In three (6%) patients, the results were consistent; in 20 (39%) the pacemaker underestimated results; in 28 (55%) they were overestimated. When more liberal criteria of agreement were applied, clinically significant differences were observed in 24 (47%) patients; in seven (29%) patients the count made by the pacemaker was lowered; and in 17 (71%) it was overestimated. Ventricular tachycardias were recorded in 24-hour ECG in eight patients. In three, they were identified by the pacemaker diagnostic function. In five, the pacemaker did not recognize tachycardia (because of its frequency being below 120/min). In nine, tachycardia was recognized falsely. The sensitivity in ventricular tachycardia diagnosis by pacemaker diagnostic function was 38%, specificity - 70%, the value of a positive result - 25%, negative - 81%. Conclusions: The evaluation of ventricular arrhythmias by pacemaker cannot serve as the only reliable diagnostic method of arrhythmias. The presence of a large number of sequences that may correspond to ventricular arrhythmia or failure to sense, should result in verification via 24-hour ECG monitoring. (Cardiol J 2010; 17, 5: 495-502

Czy głównym winowajcą omdleń jest mózg czy układ naczyniowy?

W artykule przybliżono problematykę omdleń. Zwrócono uwagę na rokowniczą rolę podziału omdleń na kardiogenne, niekardiogenne i o nieznanej etiologii. Do omdleń niekardiogennych zalicza się najczęściej występujące w praktyce omdlenia wazowagalne. Przedstawiono nowoczesne metody zgłębiania patomechanizmu tych omdleń, które koncentrują się na dwóch ich podstawowych aspektach: zachowania się ukrwienia i czynności elektrycznej mózgu (w odniesieniu do teorii ośrodkowych tych omdleń) lub zachowania się centralnego i obwodowego układu naczyniowego (teorie obwodowe). Pełniejsze zrozumienie tych elementów może w najbliższej przyszłości pomóc w celowanym leczeniu różnych postaci omdleń odruchowych. Forum Medycyny Rodzinnej 2008, tom 2, nr 1, 33-4

Morphology of the tendon of Todaro within the human heart in ontogenesis

The tendon of Todaro, found in the right atrium of the heart, has considerable clinical importance in the fields of both cardiac surgery and invasive cardiology. The goal of this study is to examine the occurrence and degree of development of the tendon of Todaro in humans. Research was conducted on material consisting of 160 human hearts of both sexes from the age of 14 Hbd to 87 years of age. Classical anatomical methods were used and histological sections were prepared from 100 hearts of various age groups stained in Masson’s method with Goldner’s modification. The tendon of Todaro occurred in all examined hearts. In foetal hearts, in the area typical of the course of the tendon of Todaro, a very well-developed, “white-like” structure was observed, convexed into the lumen of the atrium. Histologically, this was young fibrous tissue with a characteristically large number of fibroblasts. Evenly in infants and newborns, a visible convex structure was also observed extending into the lumen of the right ventricle, however, to a lesser degree than in foetuses. In the group of hearts of young adults, it was also possible to follow the course of the tendon of Todaro macroscopically. However, the older the heart was, the less the convex was visible, and in older adults it was completely invisible. In histological sections, it was observed that with ageing the number of connective tissue cells decreased, and fibres forming the lining increased. In the hearts of older adults the tendon of Todaro formed very small ribbons of connective tissue. Histologically, only small numbers of cellular elements were noticed. In the adult heart the examined tendon was located the deepest and did not connect to the endocardium. We can conclude that tendon of Todaro is a stable structure, occurring in all examined hearts even when it is not macroscopically visible. Due to the morphological changes that affect the tendon of Todaro in human ontogenesis, for the cardiac surgeon, its relevance as an important topographical structure in the hearts of older adults is minimal

Arrhythmias And Long-Term Hemodynamic Consequences In Patient With Repaired Tetralogy Of Fallot – A Case Study

The number of patients who underwent total correction of Tetralogy of Fallot (ToF) in early life or infancy is still rising. According to CDC ToF is the most prevalent cyanotic congenital heart disease with incidences of 1 in 2500 births. Rhythm disturbances and haemodynamic disturbances including valves disorders, heart failure, residual defects and more are new challenges for clinicians taking care of adult patients with repaired ToF. Our goal was to describe such a patient and highlight further complications which may be encountered among those patients