Electrocardiographic clues to identify nonresponders to cardiac resynchronization therapy.
BACKGROUND
The aim of cardiac resynchronization therapy (CRT) is to restore myocardial electromechanical synchrony. Achieving this in patients with chronic severe heart failure due to poor left ventricular (LV) systolic function and cardiac dyssynchrony on optimal medical therapy, is associated with improved clinical performance and outcomes. Up to one-third of patients undergoing CRT do not benefit from implantation. Ensuring LV capture is essential and can be at times difficult to confirm.


METHODS
Described herein, are six patients who underwent biventricular pacemaker implantation but failed to experience an improvement in LV systolic function or functional capacity.


RESULTS
In each case, the 12-lead electrocardiogram (ECG) was helpful in unmasking loss of LV capture in patients who were presumed to have biventricular pacing.


CONCLUSIONS
Despite the technical wizardry behind CRT and patient system analyzers, the surface ECG should continue to be an invaluable tool for evaluating patients who have undergone CRT.
El Sabbagh
Firas H
FH
Division of Cardiovascular Medicine, University of Missouri-Columbia, Five Hospital Drive, Columbia, MO 65212, USA. firass_77@yahoo.com
Guzon
Osler Jay J
OJ
Alpert
Martin A
MA
Flaker
Greg C
GC
D000368:Aged; D000369:Aged, 80 and over; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000503:physiopathology* / Q000628:therapy*; D006801:Humans; D008875:Middle Aged; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology / Q000628:therapy