Keywords: Sinus node Gene program Calcium clock Membrane clock Transcriptional control, repressor Biological pacemaker A group of approximately 10,000 cells in the sinoatrial node (SAN), which is located at the entry of the right superior caval vein into the right atrium, is responsible for regular heart beating under different physiological conditions [1]. While the SAN is reliably working for...

A 76-yr-old man with unipolar ventricular pacemaker, previously implanted in the right ventricular apex, presented with syncopal attack and twitching of the right pectoralis muscle. He finally was diagnosed as having Twiddler's syndrome. The patient had a pulse rate of 36/min and cannon waves in the neck veins. Chest radiography showed a dislodged pacing lead completely wrapped around the pulse...

Pacemaker infection has multiple risk factors. Its presentation is most often similar to infected endocarditis and the diagnosis is made through studying blood cultures. Transesophageal echocardiography can confirm the diagnosis. The most common microorganisms are staphylococcus speciesis. As a matter of fact, complete pacemaker removal appears to be the only definite treatment. We presented a ...

As implantable pacemakers last a variable time, it is desirable to be able to foretell when each individual pacemaker is nearing the end of its life. A test which detects a number of different impending electronic failures including battery depletion is described. The test requires only standard laboratory equipment and has been used for four years as a three-monthly procedure in an out-patient...

a field study was made to investigate the learning needs of patients with pacemaker in shahid rajaii heart hospital's out-patient clinic (1994). a total of 60 patients with pacemaker were selected sequentially from the total population that had a pacemaker and attended the out-patient clinic in shahid rajaii hospital. the subjects met the criteria for participating in this study. the tool ...

ince the introduction of electronic pacemakers, S a number of previously unencountered arrhythmias are now seen freq~ently.'.~ Among those more commonly observed is &cia1 ventricular parasystole which occurs when normal A-V conduction is resumed in patients with k e d rate pacemaker units.8 Spontaneous ventricular parasystole is occasionally encountered in patients with supraventricular mechani...

As an alternative to electronic pacemakers, we explored the feasibility of converting ventricular myocytes into pacemakers by somatic cell fusion. The idea is to create chemically induced fusion between myocytes and syngeneic fibroblasts engineered to express HCN1 pacemaker channels (HCN1-fibroblasts). HCN1-fibroblasts were fused with freshly isolated guinea pig ventricular myocytes using polye...

Erosive dermatitis is a skin reaction associated with implantable cardiac devices (ie, pacemakers and cardioverter defibrillators). We report a 65-year-old man with a history of several cerebrovascular attacks who developed an erythematous crusted erosive patch over the pacemaker site after implantation of two subsequent pacemakers. We suggest that physical irritation may be a trigger factor fo...