Transient Data Stream Dissociation in Computerized Data Acquisition System Masquerading as a Sensing Abnormality

During testing of a CPI model 1715 ICD, an apparent sensing abnormality was noted following shock delivery for VF. Close inspection of the recording prior to the defib-rillation attempt revealed that the surface leads spontaneously lost 848 ms of data while the event marker was unaffected. Computer simulations revealed that an inadequate buffer size for the ampHfied (surface ECC) data was the likely source of data loss. It is important to recognize tbat a discordance between surface leads and event marker may represent an abnormality in tlie data acquisition system and simulate an ICD or lead malfunction.     

Narrow QRS Tachycardia in a Patient with Tachycardiomyopathy: What Is the Mechanism?

A 50‐year‐old female presented with incessant palpitation of 2 weeks duration. She was hemodynamically stable and there was no evidence of heart failure. A transthoracic echocardiogram showed mild left ventricular (LV) dysfunction with LV ejection fraction of 45%. Electrocardiogram (12 lead and rhythm strip) was taken during the palpitation. What is the mechanism?     

Economic comparison of two strategies of oral cancer screening

Cancer is an important public health problem and new strategiesare needed for its prevention and control. Due to socioeconomicconstraints, a lack of adequate health care infrastructure andother competing health priorities in Trivandrum, there is apressing need to evaluate locally feasible and cost-effectivecancer control strategies. The Regional Cancer Centre, Thiruvananthapuram(RCCT), therefore developed and tested two innovative strategies.The first method used the mass media, the second trained unemployedyouth to carry out the initial screening process. Economic evaluationof both strategies was undertaken which showed that screeningusing young volunteers is more cost-effective, since more earlycancers and pre-cancers can be detected through this method.Screening using the mass media only, was found to be 4–9times more expensive in terms of costs per unit of outcome,than using trained volunteers. We therefore recommend the useof trained volunteers in oral cancer detection camps.     

Verapamil in Idiopathic Ventricular Tachycardia of Right Bundle Branch Block Morphology: Observations During Electrophysiologic and Exercise Testing

Electrophysiologic studies before and after administration of verapamil were performed in three young patients with recurrent sustained ventricular tachycardia (VT) of right bundle branch block morphology. VT was not provoked by maximal treadmill testing in any patient. Electrophysiologic findings at induction of VT suggested reentry in the first patient and triggered automaticity in the second. Findings were inconclusive in the third patient. Intravenous verapamil terminated the VT in all the three cases. Oral verapamil prevented laboratory induction of sustained VT in the latter two patients. However, VT could be provoked during exercise in both while on oral verapamil therapy. These findings suggest that different mechanisms may underlie ventricular tachycardia dependent upon slow-response tissue; the role of oral verapamil in the treatment of such VT needs further investigation.     

Diagnosis and Ablation of Multiform Fascicular Tachycardia

Ablation Multiform Fascicular Tachycardia . Introduction: Fascicular tachycardia (FT) is an uncommon cause of monomorphic sustained ventricular tachycardia (VT). We describe 6 cases of FT with multiform QRS morphologies. Methods and Results : Six of 823 consecutive VT cases were retrospectively analyzed and found attributable to FT with multiform QRS patterns, with 3 cases exhibiting narrow QRS VT as well. All underwent electrophysiology study including fascicular potential mapping, entrainment pacing, and electroanatomic mapping. The first 3 cases describe similar multiform VT patterns with successful ablation in the upper mid septum. Initially, a right bundle branch block (RBBB) VT with superior axis was induced. Radiofrequency catheter ablation (RFCA) targeting the left posterior fascicle (LPF) resulted in a second VT with RBBB inferior axis. RFCA in the upper septum just apical to the LBB potential abolished VT in all cases. Cases 4 and 5 showed RBBB VT with alternating fascicular block compatible with upper septal dependent VT, resulting in bundle branch reentrant VT (BBRT) after ablation of LPF and left anterior fascicle (LAF). Finally, Cases 5 and 6 demonstrated spontaneous shift in QRS morphology during VT, implicating participation of a third fascicle. In Case 6, successful ablation was achieved over the proximal LAF, likely representing insertion of the auxiliary fascicle near the proximal LAF. Conclusions : Multiform FTs show a reentrant mechanism using multiple fascicular branches. We hypothesize that retrograde conduction over the septal fascicle produces alternate fascicular patterns as well as narrow VT forms. Ablation of the respective fascicle was successful in abolishing FT but does not preclude development of BBRT unless septal fascicle is targeted and ablated. (J Cardiovasc Electrophysiol, Vol. 24, pp. 297‐304, March 2013)