Circulation. 2006;113:2861
(Circulation. 2006;113:2861.)
© 2006 American Heart Association, Inc.
Issue Highlights
 |
DUAL-CHAMBER VERSUS SINGLE-CHAMBER DETECTION ENHANCEMENTS FOR IMPLANTABLE DEFIBRILLATOR RHYTHM DIAGNOSIS: THE DETECT SUPRAVENTRICULAR TACHYCARDIA STUDY, by Friedman et al.
|
|---|
Inappropriate shocks due to supraventricular tachycardias (SVT)
can adversely affect quality of life in patients with implantable
cardioverter defibrillators (ICDs). Incorporation of atrial
sensing into an ICD algorithm for arrhythmia identification
was compared to ventricular sensing alone in a 400-patient randomized
trial. SVTs were common in ICD recipients, accounting for more
than 40% of arrhythmia episodes and occurring in more than 30%
of patients. Atrial sensing did reduce inappropriate ICD classification
of SVT as ventricular tachycardia (VT), but more than 30% of
SVTs were still misclassified as VT. Inappropriate shocks were
not reduced because of differences in programming of antitachycardia
pacing among groups. These findings by Friedman et al show that
atrial sensing can improve SVT detection, but also support appropriate
programming of antitachycardia pacing to avoid ICD shocks. Dual
chamber ICDs are a reasonable consideration for patients who
have VTs with rates that may overlap with SVTs, even if the
atrial lead is not required for pacing. See p
2871.
|
RESIDUAL ARACHIDONIC ACID-INDUCED PLATELET ACTIVATION VIA AN ADENOSINE DIPHOSPHATE–DEPENDENT BUT CYCLOOXYGENASE-1– AND CYCLOOXYGENASE-2–INDEPENDENT PATHWAY: A 700-PATIENT STUDY OF ASPIRIN RESISTANCE, by Frelinger et al.
|
|---|
The absolute risk of recurrent vascular events among patients
treated with aspirin remains relatively high and has lead to
a concept known as "aspirin resistance." Aspirin resistance
has been defined as a clinical entity and by altered biomarkers/enhanced
platelet function testing. The mechanism for aspirin resistance
remains uncertain, however, and is likely multifactorial. In
this issue of
Circulation, Frelinger and colleagues study 700
patients treated with aspirin who were undergoing cardiac catheterization.
They report that aspirin noncompliance or underdosing was a
rare event, and that residual platelet activation after aspirin
treatment was by a cyclooxygenase-independent pathway. In patients
and normal subjects, they found that platelet activation while
taking aspirin occurs in direct proportion to the individuals’
baseline platelet function. These findings further our understanding
as to why patients continue to have thrombotic cardiovascular
events despite taking aspirin. See p 2888 (and editorial on
p
2865).
|
RISK OF DEATH OR REINFARCTION ASSOCIATED WITH THE USE OF SELECTIVE CYCLOOXYGENASE-2 INHIBITORS AND NONSELECTIVE NONSTEROIDAL ANTIINFLAMMATORY DRUGS AFTER ACUTE MYOCARDIAL INFARCTION, by Gislason et al.
|
|---|
Clinicians are now aware of multiple reports indicating an increased
risk of cardiovascular events when patients use nonsteroidal
antiinflammatory drugs (NSAIDs), including cyclooxygenase-2
(COX2) inhibitors. The array of articles in the medical and
lay press can be overwhelming and at times confusing. In August,
2005, a Special Report on Cyclooxygenase Inhibition and Cardiovascular
Risk was published in
Circulation (Antman, et al. Cyclooxygenase
Inhibition and Cardiovascular Risk. 2005;112:759-770). In this
issue, Gislason et al use their analysis of a remarkable database
in Denmark to provide much-needed information explicitly regarding
patients who have sustained a myocardial infarction and use
COX2-selective and -nonselective NSAIDs. They report an increased
risk of mortality with selective COX2 inhibitors in all dosages
and with nonselective NSAIDs in high dosage. Dr. Judith Hochman
provides an insightful editorial emphasizing the strengths and
limitations of this latest addition to an evolving story. She
concludes that clinicians should temper their enthusiasm for
all NSAIDs and provides helpful suggestions for how to use such
agents if necessary for pain relief. See p 2906 (and editorial
on p
2868).
Visit http://circ.ahajournals.org:
|
Clinician Update
|
|---|
South Asians and Cardiovascular Risk: What Clinicians Should
Know. See p
e924.
|
Images in Cardiovascular Medicine
|
|---|
Coronary-Subclavian Steal Syndrome Demonstrated by Cardiovascular
Magnetic Resonance. See p
e930.
Massive Biventricular Thrombosis as a Consequence of Myocarditis: Findings From 2-Dimensional and Real-Time 3-Dimensional Echocardiography. See p e932.
Transcatheter Right Ventricular Outflow Tract Intervention: The Risk to the Coronary Circulation. See p e934.
|
Correspondence
|
|---|
See p
e936.
Top
DUAL-CHAMBER VERSUS SINGLE...
RESIDUAL ARACHIDONIC ACID...