ELECTROPHYSIOLOGY
LEADLESS PACERS
Electrophysiologists on the medical staff at Baylor Hamilton Heart and Vascular Hospital are able to place the world ’ s smallest pacemaker called the Micra™ Transcatheter Pacing System produced by Medtronic in patients . Receiving FDA approval in fiscal year 2016 , cardiologists on the medical staff helped achieve U . S . approval for the commercial use of the leadless pacemaker , Micra . The size of a nickel or paperclip , Micra represents the first entry in what is a new class of slender , minimally invasive pacemakers that rest entirely inside the heart . Micra attaches to the inner heart wall directly , avoiding the need for insulated wires called leads to deliver the pacemaker ’ s electric pulses . Leads have been called the “ Achilles ’ heel ” of pacemakers because they can wear out and create infection risk .
Micra™ Transcatheter Pacing System Pictured at actual size . Micra is 93 % smaller than conventional pacemakers .
This type of leadless pacemaker is placed directly into the right ventricle . A traditional pacemaker is placed in a “ pocket ” of skin near the shoulder , and connects to leads strung through major blood vessels to deliver electric pulses to the heart . In contrast , leadless pacemakers fit in a flexible tube the size of a large drinking straw , which is advanced into the heart from a small incision in the leg . Tiny bits of metal on the end of the pacemaker hook or screw into the heart tissue .
LEFT ATRIAL APPENDAGE OCCLUSION ( LAAO )
MEASURING INNOVATION IN HEART AND VASCULAR CARE
Cardiologists on the medical staff at Baylor Hamilton Heart and Vascular Hospital have been instrumental in driving change and innovation for treatment strategies to prevent blood clot formation in patients suffering from atrial fibrillation . LAAO occlusion generally eliminates the risk of stroke without the need for blood thinners . Electrophysiologists on the medical staff have been successful with bringing the WATCHMAN™ device through clinical trials and post FDA approval . Approved by the FDA in 2016 after years of research and clinical trials proving its effectiveness , this device was a viable option for patients in 2017 .
A-Fib can decrease the heart ’ s pumping efficiency by as much as 30 percent . Poor pumping increases the risk of clots forming in the heart chambers , particularly the left atrial appendage ( LAA ). The LAA is pouch-shaped and about the size of your thumb . It is located on the top of the heart . The WATCHMAN device is designed to prevent blood clots that frequently form in the LAA from traveling in the blood stream to the brain , lungs and other parts of the body . Clots that travel to the brain cause strokes , one of the leading causes of death and disability .
“ The WATCHMAN device is implanted in the left atrial appendage using minimally invasive techniques ,” says James Choi , MD , cardiologist on the medical staff at Baylor Hamilton Heart and Vascular Hospital and one of the investigators involved in the WATCHMAN early studies . “ The parachute-shaped device is the size of a quarter and consists of a nitinol cage with a polytetrafluoroethylene membrane and includes a row of fixation barbs .”
“ The interventional cardiologist uses fluoroscopic imaging to guide a sheath into the LAA . The sheath serves as a duct for the delivery of a catheter that is pre-loaded with the WATCHMAN device . The catheter is advanced to the tip of the access sheath and is deployed by a gentle retraction of the sheath ,” says Dr . Choi .
With this device , patients are generally released from the hospital after 24 hours . Medical follow-up continues over the course of time as patients decrease their blood thinner medication under the supervision of a cardiologist . WATCHMAN device is suitable for patients with nonvalvular atrial fibrillation who :
• Are at increased risk for stroke and systemic embolism based on CHADS2 or CHADS2-VASc scores and are recommended for anticoagulation therapy
• Have an appropriate rationale to seek a nonpharmacologic alternative to oral anticoagulation , taking into account the safety and effectiveness of the device compared to warfarin
“ It is also important for patients to understand that , like blood thinning medications , the WATCHMAN device does not cure atrial fibrillation ,” says Dr . Choi . “ A stroke can occur as a result of factors not related to a clot traveling to the brain from the left atrial appendage . Other causes of stroke can include high blood pressure and narrowing of the blood vessels to the brain .”
WATCHMAN™ image courtesy of Boston Scientific
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