Implantable Defibrillators Recommended For Patients With Cardiomyopathy
Plus Unexplained Fainting

	June 4, 1999 - New findings support the use of ICDs in patients
who have both nonischemic dilated cardiomyopathy and unexplained syncope
(fainting) but some questions remain unanswered. Dr. Bradley Knight and
colleagues, of the University of Michigan Medical Center in Ann Arbor,
studied the outcome of 14 patients with nonischemic cardiomyopathy, 
unexplained fainting and a negative EP test who had ICD implanted.
Nineteen heart attack patients with nonischemic cardiomyopathy who got
ICD were included in the trial as a comparison group.
	Dr. Knight found that 50% of the syncope group "...received
appropriate ICD shocks for ventricular arrhythmias during a 2 year
followup. Further fainting was mainly due to ventricular tachyarrhythmias,"
according to their report in the June issue of the Journal of the American
College of Cardiology. The rate of appropriate shocks during followup was
not much different between the syncope group and the control group.
	Patients with more severe cardiomyopathy appeared more likely to
receive appropriate shocks. "All patients in the syncope group with class 3
functional status before ICD implantation received appropriate shocks during
followup," the authors report. "No patient in the syncope group with an EF
of more than 35% received an appropriate shock." However, no clinical
characteristic identified patients who would get appropriate shocks from
those who did not.
	Further research is needed to establish ICDs' effect on mortality in
patients with nonischemic dilated cardiomyopathy and syncope of unknown
cause, say the researchers. They did conclude that the current findings and
the results of previous studies support the use of ICDs in this setting.
	Elsewhere in the journal, Dr. Mark Josephson writes that he is not
so convinced of the benefits of ICDs in this population. He cites the small
size of the study, the fact that it was not designed to measure an effect of
defibrillators on mortality, and the pitfalls of using a diagnosis of
"unexplained" syncope. Dr. Josephson adds that the lack of information on the
cost-effectiveness of the ICDs used, or on their relative benefits compared
with newer devices, such as those that provide dual chamber defibrillation,
are factors that need to be addressed.

J Am Coll Cardiol 1999;33:1964-1973