The potential role of cardiac magnetic resonance imaging in selecting patients with ischemic left ventricular dysfunction for the implantation of a cardioverter-defibrillator.
OBJECTIVE
To develop a protocol to risk stratify patients before ICD implantation in ischemic left ventricular dysfunction using magnetic resonance imaging and a gadolinium-based contrast agent. Ejection fraction as determined by other methods was reconfirmed using cardiac MRI.


METHODS
Five patients considered for implantation of an ICD were prospectively offered a cardiac MR exam between Novem-ber 2003 and June 2004. All had a history of MI and LV dysfunction, had undergone complete coronary revascularization or were considered ineligible for revascularization.


RESULTS
In three patients the MR ejection fractions were less than 30%, confirming the values detected by echocardiography. One patient had a larger EF by MRI compared to echo and ICD implantation was deferred. One patient thought to have an EF greater than 35% by echo on three studies was confirmed to have a much lower EF by MRI and was selected to undergo ICD implantation.


CONCLUSIONS
Cardiac MRI can be used to further stratify patients selected for an ICD. Ejection fraction can be more reliably estimated by MRI and the presence of extensive scar can be detected. The presence of extensive scar and a low ejection fraction, which are two factors known to predispose patients to sudden cardiac death in ischemic left ventricular dysfunction, can be studied reliably by MRI.
Thomas
Boban
B
RM Caselas, Lisboa, Portugal.
Tavares
Nuno Jalles
NJ
D000465:Algorithms; D017147:Defibrillators, Implantable; D006801:Humans; D008279:Magnetic Resonance Imaging; D017202:Myocardial Ischemia / Q000150:complications / Q000628:therapy*; D018579:Patient Selection; D011446:Prospective Studies; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000628:therapy*