Future may include CV
interventions
By Catherine
Carrington
Echocardiographers of the future will not just image cardiovascular problems,
they will treat them by guiding interventional procedures and delivering drugs,
genes, and primitive cells to target tissues.
“It’s quite exciting,” said Dr. Mario J. Garcia, who directs
echocardiography at the Cleveland Clinic. “As noninvasive cardiologists, we
have been seeking for years to perform interventions.”
Echocardiography already plays a central role in the treatment of such
conditions as cardiac tamponade, in which direct echo guidance makes it possible
to safely puncture the pericardial sac and relieve fluid pressing on the heart.
New research is also showing that echo can offer important help in the therapy
of arrhythmias by guiding epicardial mapping catheters through a small opening
in the chest into the pericardial space and to the external surface of the
heart.
Most intriguing, however, is echo’s potential to deliver therapeutic
agents that have been tucked into microbubbles. Once the microbubbles reach the
desired target, the echocardiographer can burst them with a blast of ultrasound
energy. One example would be delivery of a gene for promoting the growth of new
blood vessels, such as vascular endothelial growth factor. Microbubbles might
also be used to deliver myoblasts, stem cells that can be differentiated into
new myocardium, perhaps regenerating tissue destroyed during a heart attack.
“Ultrasound is unique in being able to destroy the surface of these
microbubbles so they release their contents, and also to generate heat in a way
that opens the pores of the cell membranes,” Garcia said. “Once the
pores are opened, these substances can get directly inside the cells.”
