User Manual

Lumax Technical Manual 73
2.2 Cardiac Resynchronization Therapy
(CRT)
HF versions only
For Cardiac Resynchronization Therapy (CRT), a sensing/pacing
lead is placed in the right atrium, while an ICD lead is placed in
the right ventricle. The third lead is positioned to pace the left
ventricle. When connected together, this system provides
coordinated, simultaneous stimulation of the right and left
ventricles. This resynchronization therapy is designed to
coordinate the contraction of both ventricles, which allows the
heart to contract more efficiently. As a result, patients with CHF
and intraventricular conduction delay may have a greater ability to
complete physical activities thus improving their quality of life.
As a result of the device design and header configuration,
ventricular pacing pulses can be delivered between the right/left
ventricular lead tip electrodes simultaneously (cathode) and at
programmed intervals. In some configurations the ring of the right
ventricular lead works as LV anode. Ventricular sensing primarily
uses the poles of the right ventricular lead tip and ring. This
design avoids sensing of ventricular activity twice during a single
cardiac cycle (double counting) in patients with a wide QRS
complex. However, for diagnostic purposes and LV pacing
protection the Lumax HF devices can be programmed to sense in
the left ventricle.
Atrial Channel
The Lumax ICDs/CRT-Ds pace and sense in bipolar
configuration, between the atrial lead’s tip and ring electrodes. A
bipolar atrial lead must be used to ensure reliable sensing of atrial
activity.
Ventricular Channel
The Lumax HF devices can be programmed to pace in both the
right and left ventricle (as well as RV only). The Lumax HF
primarily senses in a bipolar configuration in the right ventricle.
However, for diagnostic purposes and LV pacing protection the
Lumax HF devices can be programmed to sense in the left
ventricle.
Potential Ventricular lead configurations are provided in Table 26
.