First study of cardiac resynchronization therapy using ultrasound and CT
18 November 2005
The Johns Hopkins Bayview Medical Center in California will use an Aplio
CV ultrasound system from Toshiba America Medical Systems for use in a
groundbreaking clinical trial to assess outcomes following cardiac
resynchronization therapy (CRT).
The all-digital ultrasound system for advanced cardiac applications will
enable clinicians in the Center's Department of Non-invasive Cardiac Imaging
to conduct a high-volume of cardiovascular echocardiography procedures.
Under the terms of the agreement, the Aplio CV will be used for 30 months
in a clinical study in conjunction with Toshiba’s Aquilion 64 CFX, a
volumetric 64-slice computerized tomography (CT) system. The clinical trial,
entitled "The Combined Use of Tissue Doppler Echo and Cardiac Multi-Detector
CT to Assess Outcome Following Resynchronization Therapy," commenced in
October and involves approximately 50-100 patients. According to
investigators, no other study has evaluated both ultrasound and CT.
The overall objective of the study is to utilize the combination of these
modalities to optimize cardiac resynchronization, predict the adequacy of
response to therapy and to study the effects of dyssynchrony.
The study aims to determine which echocardiography measurement or
combination of measurements best predicts CT-determined reverse-remodeling
in cardiac patients undergoing resynchronization therapy and exploring
whether coronary venous anatomy predicts CT determined reverse-remodeling in
cardiac patients undergoing resynchronization therapy.
“The combination of cardiac CT and Tissue-Doppler echocardiography has
the potential to obtain almost all clinically important cardiac information
needed to evaluate the patient, plan the implantation procedure and assess
the outcome,” said Gordon Parhar, director, Ultrasound Business Unit, TAMS.
“The decision by Johns Hopkins, the No. 1 rated hospital in the country, to
utilize not one, but two of our systems for this unique study, validates
Toshiba’s superior technology and excellent clinical support team.”
About cardiac resynchronization therapy
Cardiac resynchronization therapy (CRT), which is sometimes called
biventricular pacing, is a form of therapy for congestive heart failure
caused by dilated cardiomyopathy. CRT uses a specialized pacemaker to
coordinate the action of the right and left ventricles in patients with
heart failure. In approximately 30 percent of patients with heart failure,
an abnormality in the heart's electrical conducting system (called an
"intraventricular conduction delay" or bundle branch block) causes the two
ventricles to beat in an asynchronous fashion. That is, instead of beating
simultaneously, the two ventricles beat slightly out of phase. This
asynchrony greatly reduces the efficiency of the ventricles in patients with
CRT coordinates the beating of the two ventricles by pacing both
ventricles simultaneously. This differs from typical pacemakers, which pace
only the right ventricle1.