BACKGROUND "Cardiac memory" refers to persistent T-wave changes on ECG that follow resumption of sinus rhythm after a period of altered activation sequence. Previous studies demonstrated that cardiac memory in intact dogs was abolished by 4-aminopyridine (4-AP), which blocks both the transient outward potassium current, Ito, and IK. METHODS AND RESULTS We used standard microelectrode techniqu...

BACKGROUND Previous studies have investigated the role of intrinsic conduction in optimizing cardiac resynchronization therapy. We investigated the role of fusing pacing-induced activation and intrinsic conduction in cardiac resynchronization therapy by evaluating the acute hemodynamic effects of simultaneous His-bundle (HIS) and left ventricular (LV) pacing. METHODS AND RESULTS We studied 11...

Cardiac pacing through a transvenous catheter located in the right ventricle usually produces a pattern of left bundle branch block (LBBB). When right bundle branch block (RBBB) occurs during apparent right ventricular pacing, a complication (perforation or malposition of the catheter) has usually occurred. In the patient reported here, uncomplicated right ventricular transvenous pacing produce...

This case describes a 65-year-old male with drug-resistant heart failure. Cardiac resynchronization therapy was performed. We evaluated cardiac function with volume curve differentiation software (VCDiff) from QGS data with Tc-99m sestamibi. Left ventricular parameters during atrial-right ventricular pacing were left ventricular ejection fraction (LVEF) 30%, end-diastolic volume (EDV) 156 ml, e...

1. Tse HF, Siu CW, Lee KL, et al. The incremental benefit of rateadaptive pacing on exercise performance during cardiac resynchronization therapy. J Am Coll Cardiol 2005;46:2292–7. 2. Lau CP. Normal exercise cardiopulmonary physiology and chronotropic incompetence. In: Lau CP, editor. Rate Adaptive Cardiac Pacing: Single and Dual Chamber. Mount Kisco, NY: Futura Publishing, 1993:7–23. 3. Fei L,...

Abstract Background Phrenic nerve stimulation is a well-recognized complication related to cardiac implantable electronic devices, in particular with left ventricular coronary sinus pacing leads for resynchronization therapy. Case presentation We report an unusual case of symptomatic phrenic due inadvertent placement right defibrillation lead posterior branch patient heart failure reduced eject...

BACKGROUND From the international long QT syndrome (LQTS) study, 30 patients with corrected QT interval (QTc) of more than 0.44 second 1/2 were identified who had permanent pacemakers implanted for management of recurrent syncope or aborted cardiac arrest. METHODS AND RESULTS Pacemakers were implanted on average 7 years after the onset of the first syncopal episode. Most of the patients were ...

ince the introduction of transvenous cardiac pacing S by Furman and Schwedell in 1959, numerous reports of unusual complications have appeared. To o w knowledge, rupture of a papillary muscle o r any valvular component has not been reported previously. This report describes a case of mitral valve papillary muscle rupture upon removal of a transvenous pacing electrode. Furthermore, this patient ...

A detailed description is given of a technique for the introduction of cardiac pacing catheters using a percutaneous supraclavicular route through the subclavian vein. In 91 attempts there was only one failure and the frequency of complications was low. Surface landmarks for the procedure were easy to define precisely, and stable pacing could usually be established rapidly without distress to t...

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether either right atrial or bi-atrial pacing effectively reduces the incidence of Atrial fibrillation post cardiac surgery. Altogether 458 papers were found using the reported search, of which 16 represented the best evidence on this topic. The author, journal, date and country...