Northeast Ohio Medical University

Rootstown, Ohio, 44272

Mouse Microsurgery and echocardiography

workshop

Vahagn Ohanyan, MD, PhD

vohanyan@neomed.edu

Echo guided intra-myocardial and intra-ventricular injection

Stress echocardiography: measurement of cardiac function and blood pressure changes during stress test

A B

Surgical towel Ultrasound scanhead

Echo guided intra-myocardial and intra-ventricular injection

Preparation of mouse:

Selection of needle and syringes

CHamilton 10 l syrung

Intra-ventricular injectionVolume for bolus injection:Mice: < 50 ulRats~300g: <150 ulFor small volume injection use Hamilton needle(27-30G) and syringes (sterilize before using)

27 G Needle The tip of the needle

Echo guided insertion of 27G needle

LV Ventricle injectionVideo

Before Needle inside the LV Cavity

Injection of saline into LV VentricleVideo

Intra-myocardial Injection

• Use very small amount of solution to inject in one site. Large amount of the drug (solution can damage or rupture the ventricular wall).

• For mice 10-15 ul in one site • For rats 20-30 ul (~300 g rat)• Sterilize the needle before insertion.• Prepare the animal as described in intra-

ventricular injection section

The tip of the needle LV anterior wall

The tip of the needle

A

Positioning needle inside the LV wallVideo

Intra-myocardial injectionVedeo

Needle is inside the LV cavity Needle inside the LV Wall

PV Loop catheter insertion into LV ventricle trough carotid artery

• For carotid artery isolation, catheterization see page 53.

• Clean the mouse chest for echocardiography as described in transthoracic echocardiography section.

• Find parasternal long axis view and clear aortic root.

Parasternal long axis viewVideo

Pressure-volume catheter

Left ventricle

VideoPV catheter inside the LV cavity

Incorrect and correct position of the probe

Incorrect position Correct position

Stress echocardiography

• If you want to remove vagal reflex, treat the animals with ganglionic blocker Norepinephrine or Dobutaminecontinuous injection is commonly used for experimental protocols.

• Get all your measurement at plateau, which usually reaches after 30 second injection

Position of echo scanhead

• After finding the desirable position (M mode or Doppler) fix the probe and do not change any adjustments. All this must be constant.

Baseline During NE injection

SEE ONE , DO ONE ,

THEACH ONE, BECOME A CONTRIBUTRE

• For more information visit our website:• www.neomed.edu/microecho

• https://www.linkedin.com/groups/Microsurgery-Small-Animal-Echocardiography-5022068?home=&gid=5022068&trk=my_groups-tile-grp

• https://www.facebook.com/pages/Mouse-Microsurgery-and-Echocardiography-Workshop/398774443577599