Circulation. 2007;115:2459
doi: 10.1161/CIRCULATIONAHA.107.183257
(Circulation. 2007;115:2459.)
© 2007 American Heart Association, Inc.
Issue Highlights
 |
ANNUAL RATE OF TRANSVENOUS DEFIBRILLATION LEAD DEFECTS IN IMPLANTABLE CARDIOVERTER-DEFIBRILLATORS OVER A PERIOD OF >10 YEARS, by Kleemann et al.
|
|---|
Implantable cardioverter-defibrillator systems consist of a
pulse generator and transvenous leads for sensing arrhythmias
and applying pacing and high-voltage shocks for treatment. Pulse
generator malfunctions, although rare, have received recent
attention. Like pacemaker leads, implantable cardioverter-defibrillator
leads are subject to continuous cardiac motion and susceptible
to failure from fracture of the conducting wires and insulation
breaks. In a single-center registry, Kleemann and colleagues
analyzed the frequency of lead malfunction in 990 patients who
received their transvenous implantable cardioverter-defibrillators
between 1992 and 2005. They observed that 15% of leads failed
over time, with 40% estimated to fail by 8 years of follow-up.
That only 4 subjects died suddenly suggests that lead failures
are often detected during follow-up before a potentially lethal
arrhythmia occurs. The findings show that transvenous leads
are a weak mechanical link in this life-saving therapy and support
the importance of close patient follow-up for the prompt detection
of these failures. See p 2474 (editorial p
2461).
|
HERITABILITY OF PLATELET RESPONSIVENESS TO ASPIRIN IN ACTIVATION PATHWAYS DIRECTLY AND INDIRECTLY RELATED TO CYCLOOXYGENASE-1, by Faraday et al.
|
|---|
A significant number of people have acute coronary syndrome
events despite being on aspirin or a platelet inhibitor. Little
is known, however, about what causes individual variability
in platelet function and thrombosis. In the current issue of
Circulation, Faraday and colleagues ask if measurable or inherited
conditions contribute to interindividual variability in platelet
function in the presence or absence of aspirin treatment. They
examined platelet function in 1908 subjects from 309 white and
208 black families and report an inherited basis for both platelet
function and aspirin response using select platelet function
tests. Further studies are needed to determine the specific
cause for the measured variability. See p 2490 (editorial p
2468).
|
CARDIAC IMPROVEMENT DURING MECHANICAL CIRCULATORY SUPPORT: A PROSPECTIVE, MULTICENTER STUDY OF THE LVAD WORKING GROUP, by Maybaum et al.
|
|---|
The frequency of myocardial recovery following left ventricular
assist device (LVAD) support is not clear. The LVAD Working
Group Recovery Study, a prospective, multicenter trial, assessed
the incidence of myocardial recovery in 67 patients bridged
to cardiac transplantation. At 30 days, echocardiography showed
improvements in left ventricular ejection fraction and dimensions
as compared to pre-LVAD. At 120 days, left ventricular ejection
fraction had returned to pre-LVAD levels, but heart size remained
reduced. Exercise capacity was improved at 30 and 120 days.
Histological analysis at explantation revealed reductions in
myocyte size, collagen content, and cardiac tumor necrosis factor-
.
Six subjects (9%) recovered sufficiently for LVAD explantation.
Thus, while LVAD therapy exerts beneficial effects on myocardial
structure and function, the degree of clinical recovery is insufficient
for device explantation in most patients. See p
2497.
Visit http://circ.ahajournals.org:
|
Images in Cardiovascular Medicine
|
|---|
The Use of 2 Contrast Filling Patterns in the Diagnosis of a
Giant Coronary Aneurysm. See p
e452.
"Elephant Trunk" Mimicking Thoracic Aortic Dissection: The Role of Intravascular Ultrasound. See p e455.
Intramural Dissecting Hemorrhage of the Myocardium. See p e457.
|
Correspondence
|
|---|
See p
e460.
Top
ANNUAL RATE OF TRANSVENOUS...
HERITABILITY OF PLATELET...