OBJECTIVES Indirect evidence suggests a role for Ca(2+)-overload in electrical and mechanical alterations caused by atrial tachycardia. The present study assessed the alterations in cellular [Ca(2+)] and contractile function caused by rapid atrial cellular activation. METHODS Intracellular Ca(2+) transients (CaT) and cell shortening (CS) were measured by microfluorometry (Indo-1 AM) and video...

BACKGROUND The availability of implantable cardioverter-defibrillators (ICD) that are capable of antitachycardia pacing may lead to an increased use of ICDs in patients with haemodynamically tolerated ventricular tachycardia without a history of cardiac arrest. The frequency of potentially life-threatening fast ventricular tachycardias (cycle length < 250 ms) was investigated in patients who ha...

We performed a prospective, randomized crossover study to evaluate the comparative efficacy of transvenous cardioversion and rapid ventricular pacing for termination of induced ventricular tachycardia in patients with spontaneous ventricular tachycardia and organic heart disease. Sixty-two episodes of ventricular tachycardia were induced in 15 patients, mean age 60 +/- 10 years, during electrop...

It is not always easy to distinguish between supraventricular tachycardia with aberration and ventricular tachycardia by electrocardiographic analysis alone. M mode echocardiography can often help by providing direct or indirect evidence of the relation between atrial and ventricular contraction. Sixteen consecutive patients with spontaneous sustained broad QRS complex tachycardia with heart ra...

Five patients with chronic or recurrent ectopic supraventricular tachycardias unresponsive to drugs underwent programmed stimulation, endocardial mapping, and attempted catheter ablation of the arrhythmia focus. For attempted ablation, an intracardiac electrode catheter was positioned near the exit point of the tachycardia and served as the cathode while a chest wall patch served as the anode. ...

The clinical, electrocardiographic and electrophysiologic determinants and effects of antiarrhythmic agents on sustained sinus node reentrant tachycardia remain poorly defined. Of 65 consecutive men undergoing electrophysiologic studies for symptomatic paroxysmal supraventricular tachycardia over a 4 year period, 11 (16.9%), who ranged in age from 39 to 76 years, demonstrated sustained sinus no...

Tachycardia is associated with cardiovascular mortality. Tachycardia is also a known clozapine adverse effect. However, whether clozapine-associated tachycardia is persistent is not known. Thirty clozapine-treated patients with clinical tachycardia were investigated with 24-hour ambulatory electrocardiography (ECG). Baseline peripheral heart rate (HR) was 106.7±7.8. The ambulatory ECG 24-hour-H...

Supraventricular tachycardia in an isolated rabbit heart preparation was repeatedly initiated and terminated by carefully timed atrial premature beats. Transmembrane action potentials of AV nodal cells were recorded simultaneously by a "brush electrode" consisting of 10 microelectrodes. Surface electrograms of atrium and His bundle were also recorded. The moments of activation of 54 different A...

Introduction Wide complex tachycardias have a broad differential diagnosis including ventricular tachycardia (VT), antidromic reciprocating tachycardia (ART), supraventricular tachycardia (SVT) with aberrancy, atrial tachycardia (AT) or atrioventricular nodal reentry tachycardia (AVNRT) with a bystander accessory pathway, or unusual tachycardias involving nodoventricular or atriofascicular path...

Fragments of Holter monitoring a 64-year-old patient with paroxysms supraventricular tachycardia are presented, atrial ectopic activity during is recorded, which does not interrupt the tachycardia, but changes sequence RR intervals. The possibility remote analysis data 3-day patient’s electrocardiogram in 12-channel provided.