Effective cardiac resynchronization therapy (CRT) requires an accurate atrio-biventricular pacing system. The innovative Quartet lead is a quadripolar, over-the-wire left ventricular lead with four electrodes and has recently been designed to provide more options and greater control in pacing vector selection. A lead with multiple pacing electrodes is a potential alternative to physical adjustm...

Clinical trials in patients with pacemakers for sinus node dysfunction or atrioventricular block have highlighted the fact that desynchronization of ventricular contraction induced by right ventricular apical pacing is associated with long-term morbidity and mortality. These clinical data confirm pathophysiological results indicating that right ventricular apical pacing causes abnormal ventricu...

Although the estimates from limited studies vary on the proportion of patients with heart failure who also have ventricular dyssynchrony as reflected by a prolonged QRS complex, often in the form of left bundle branch block, the number of such patients is large (27% to 53%) and it is certainly in excess of the rate for the general population. Among these patients, 10% to 15% are candidates for ...

AIMS Optimizing cardiac resynchronization therapy (CRT) devices has become more complex since modification of both atrioventricular (AV) and interventricular (VV) stimulation intervals has become possible. The current paper presents data from the routine use of impedance cardiography (IC)-based cardiac output (CO) measurements to guide the optimization of AV- and VV-interval timing of CRT devic...

Cardiac resynchronization therapy (CRT) has added a new dimension to the electrocardiographic evaluation of pacemaker function. During left ventricular (LV) pacing from the posterior or posterolateral coronary vein, a correctly positioned lead V1 registers a tall R wave and there is right axis deviation in the frontal plane with few exceptions. During simultaneous biventricular stimulation from...

AIMS Alternative forms of cardiac resynchronization therapy (CRT), including biventricular endocardial (BV-Endo) and multisite epicardial pacing (MSP), have been developed to improve response. It is unclear which form of stimulation is optimal. We aimed to compare the acute haemodynamic response (AHR) and electrophysiological effects of BV-Endo with MSP via two separate coronary sinus (CS) lead...

To investigate the influence of changes in activation on left ventricular ejection, the effects of right ventricular, left ventricular, and simultaneous pacing of both ventricles were studied in 6 patients immediately after replacement of the aortic valve with a Starr-Edwards prosthesis. Variation in pacing site caused little or no change in systemic arterial pressure or cardiac output. However...

Successful Implantation of the Left Ventricular Pacing Lead in the Postero-Lateral Cardiac Vein After Coronary Sinus Dissection During Biventricular Pacing SkevoS SideriS, StefanoS archontakiS, konStantinoS GatzouliS, PolychroniS dilaveriS, ioanniS vlaSeroS, ioanniS kallikazaroS, chriStodouloS StefanadiS State Cardiology Division, First University Department of Cardiology, Hippokration General ...