Mortality rates were higher in ICD patients who received only ATP compared to no therapy, but ICD patients who received a shock had higher mortality compared to both groups. Furthermore, the data suggest that age, gender, device type, AF burden, and rate of arrhythmia do not change the trend of higher mortality in patients receiving ICD shock compared to ATP alone.

This study represents the largest prospective evaluation of LVL implantation to date, revealing a high LVL implant success rate and low complication rate using a single family of leads and delivery catheters.

No abstract

Loss of ventricular output resulting from an unexpected software error in a dual chamber implantable cardioverter defibrillator (ICD) is reported. A 70-year-old man with a dual chamber ICD implanted for a history of cardiac arrest and infra-Hisian block presented with acute onset of dizziness. He was found to have loss of ventricular output due to an internal software problem. The problem was corrected by software reprogramming via the programmer. This malfunction exemplifies the potential ability to correct current-generation ICD software problems noninvasively, thus avoiding the need for replacement.

We report a case of atrial tachycardia masquerading as atrial flutter in a man who had previously undergone catheter ablation for atrial flutter. The recurrent arrhythmia was electrocardiographically almost identical to the prior atrial flutter; at repeat electrophysiologic study, although bidirectional conduction block was observed in the tricuspid annulus-inferior vena caval isthmus, the atrial arrhythmia was readily initiated. Activation mapping suggested typical atrial flutter, but entrainment techniques demonstrated intra-atrial reentry not involving the ablated isthmus. This case illustrates the need to apply entrainment techniques even in cases of apparent "typical" atrial flutter to confirm that putative ablation targets are necessary for tachycardia perpetuation.