Cardiac resynchronization therapy (CRT) also called a bi-ventricular pacemaker an important device for treatment for symptoms associated with congestive heart failure (CHF) caused by weakening of the heart muscle (cardiomyopathy). This device is implanted in the body of the patient.
A CRT system consists of the pulse generator and three thin, insulated wires called leads.
The pulse generator is a small computer like device. It uses lead wires to deliver tiny amounts of electrical energy to the ventricles.
The energy impulses help the ventricles contract at the same time, or “resynchronize.”
When the ventricles pump together, the heart can work more efficiently. This helps the body get the blood it needs to live and work.
How does the heart’s electrical system work?
The heart is a muscular pump composed of 4 chambers. The 2 upper chambers are referred to as the atria, and 2 lower, or main pumping chambers, are known as the ventricles. The coordinated pumping action of these 4 chambers is controlled by an electrical system that is contained in the heart muscle. The normal heartbeat is stimulated by a tiny electrical signal that originates in a region of the right atrium known as the sinoatrial or SA node. The electrical signal then spreads through both atria, causing them to contract and squeeze blood into the ventricles.
The pacemaker continuously monitors the patient’s heartbeat and delivers a tiny, imperceptible electrical charge to stimulate the heartbeat when necessary. Most pacemakers typically have 2 electrodes (or leads), one in the right atrium and one in the right ventricle, which permit the pacemaker to maintain the normal coordinated pumping relationship between top and bottom of the heart. These leads are connected to a battery pack (pulse generator) placed under the skin in the upper chest. In addition to the 2 leads (right...
atrium and right ventricle) used by a common pacemaker, CRT pacemakers have a third lead that is positioned in a vein on the outer surface of the left ventricle. This allows the CRT pacemaker to simultaneously stimulate the left and right ventricles and restore a coordinated, or synchronous, pumping action.
New adaptive cardiac resynchronization therapy (CRT) system by Sorin Group
Sorin Group, a manufacturer of devices for the treatment of cardiovascular disease launched their new cardiac resynchronization therapy (CRT) system with CE approval. The SonR system comprises of the Paradym RF SonR CRT-D device, which generates and controls the resynchronization stimulus and the SonR tip atrial pacing lead which incorporates a hemodynamic sensor capable of estimating LV dP/dtmax, an index of cardiac contractility.
The system is able to optimize the delivery CRT by regularly estimating the contractility of the heart via the hemodynamic sensor and adjusting the delivery of stimulus accordingly. This system offer each patient a tailor-made programming of the timing between electrical impulses sent to different parts of the heart (CRT settings) on a regular basis. Current optimization methods include echocardiography and other device based timing features.
SonR sensor uniquely measures patient’s cardiac muscle vibrations. These real-time measurements are transmitted to the CRT-D device which uses them to determine the best settings for the patient. Every week, the system automatically optimizes to adapt to the patient’s changing condition.