Bidirectional ventricular tachycardia with myocardial infarction: a case report with insight on mechanism and treatment.

Bidirectional ventricular tachycardia (BVT) is a rare variety of tachycardia with morphologically distinct presentation: The QRS axis and/or morphology is alternating in the frontal plane leads. Since its original description in association with digitalis,(1) numerous cases of this fascinating tachycardia with disparate etiologies and mechanisms have been postulated. We report a patient with BVT in association with non-ST elevation myocardial infarction and severe cardiomyopathy in the absence of digoxin toxicity.

Spiked helmet sign: An under-recognized electrocardiogram finding in critically ill patients.

A 77-year-old male patient presented with rhabdomyolysis. He developed progressive respiratory failure and acute respiratory distress syndrome during his hospital stay requiring mechanical ventilation. An electrocardiogram during mechanical ventilation showed findings suggestive of ST elevation myocardial infarction. Closer review showed dome and spike findings that have been likened to a "spiked helmet." This finding has been associated with significant mortality. We discuss this under-recognized finding and the potential contributing mechanisms.

Comparison of endovascular versus epicardial lead placement for resynchronization therapy.

Cardiac resynchronization therapy (CRT) has been shown to improve survival and symptoms in patients with severe left ventricular (LV) dysfunction, congestive heart failure, and prolonged QRS duration. LV lead placement is achieved by placing the lead in the coronary sinus, an endovascular approach, or by a minimally invasive robotic-assisted thoracoscopic epicardial approach. There are no data directly comparing the 2 methods. Patients eligible for CRT were randomized to the endovascular and epicardial arms. Coronary sinus lead placement was achieved using the standard technique, and epicardial leads were placed using a minimally invasive robotic-assisted thoracoscopic approach. The primary end point was a decrease in LV end-systolic volume index at 6 months. The secondary end points included 30-day mortality rate, measures of clinical improvement, 1-year electrical lead performance, and 1-year survival rate. The relative improvement of LV end-systolic volume index from baseline to 6 months was similar between the arms (28.8% for the transvenous [n = 12] vs 30.5% for the epicardial (n = 9) arm, p = 0.93). There were no significant differences in the secondary end points between the 2 groups. In conclusion, there were no differences in echocardiographic and clinical outcomes comparing a conventional endovascular approach versus robotic-assisted surgical epicardial LV lead placement for CRT in patients with heart failure. Surgical approaches are still a viable alternative when a transvenous procedure has failed or is not technically feasible.

Clinical utility of a novel wireless implantable loop recorder in the evaluation of patients with unexplained syncope.

BACKGROUND: The implantable loop recorder (ILR) is particularly useful for monitoring patients with syncope, given the episodic nature and unpredictable pattern of recurrent episodes. Current practice guidelines advocate ILR implantation in select patients with unexplained syncope. OBJECTIVE: The purpose of this study was to evaluate the clinical utility and potential advantages of a novel wireless ILR in a consecutive cohort of patients with unexplained syncope. METHODS: Patients with unexplained syncope despite a comprehensive evaluation who underwent implantation of a Transoma Medical Sleuth ILR were examined. ILR implantation was considered in these patients if left ventricular function was ≥ 40% and if syncope was recurrent, associated with trauma, and/or associated with an abnormal ECG (e.g., bifascicular block). RESULTS: The Sleuth ILR was implanted in 50 patients. During mean follow-up 293 ± 211 days, 16 (32%) patients had recurrent near-syncope or syncope. Only half of the patients self-activated the ILR; in the other half, a diagnosis was established based on autoactivation-initiated storage of a significant arrhythmia event. Overall, there were 5 patients with complete heart block, 3 with sinus node dysfunction, 3 with supraventricular tachycardia, 2 with neurally mediated syncope, and 3 with a nonarrhythmic cause of syncope. The median time from an event to physician notification was 150 minutes (interquartile range 99, 297 min). Median time from ILR implantation to final diagnosis was 71 days (interquartile range 24, 143 days; range 3-683 days). CONCLUSION: A diagnosis of syncope was ultimately made in nearly one third of patients with unexplained syncope. Patients frequently did not activate their ILR at the time of recurrent syncope. However, the wireless ILR automatically transferred ECG data to a central monitoring station within minutes to hours of the arrhythmic event, virtually eliminating the possibility of data loss, thus greatly facilitating clinical decision making.