Variation in the Amount of Hemoglobin S in a Patient with Sickle Cell Trait and Megaloblastic Anemia

A patient with sickle cell trait and nutritional megaloblastic anemia wasfound to have a much smaller proportion of hemoglobin S during the megaloblastic phase than after recovery. This observation suggests preferential synthesis of hemoglobin A by megaloblastic bone marrow in the presence of theA-S trait.

Submitted on July 30, 1962 Accepted on November 9, 1962     

Asymptomatic Left Ventricular Malposition of a Transvenous Pacemaker Lead Through a Sinus Venosus Defect: Follow-up Over 17 Years

The case of a woman with an asymptomatic transvenous left ventricular endocardial pacemaker lead is presented. The chest X ray and the electrocardiogram suggested pacemaker catheter malposition. By two-dimensional echocardiography, the pacemaker lead was shown to cross from the left atrium through the mitral valve and implant in the left ventricular endocardium. The underlying sinus venosus defect and the passage of the electrode through this interatrial communication were directly visualized by transesophageal echocardiography. No thrombotic material attached to the lead was detected corresponding to the patient's uneventful course for surprisingly more than 17 years without evidence of past or present neurological deficiencies or of peripheral embolic phenomena. Thus, no operative correction was performed. Warfarin sodium therapy, however, was initiated.     

Clinical Impact of an Open‐Irrigated Radiofrequency Catheter with Direct Force Measurement on Atrial Fibrillation Ablation

Background: Electrode‐tissue contact is crucial for adequate lesion formation in radiofrequency catheter ablation (RFCA). Objective: We assessed the impact of direct catheter force measurement on acute procedural parameters during RFCA of atrial fibrillation (AF). Methods: Fifty consecutive patients (28 male) with paroxysmal AF who underwent their first procedure of circumferential pulmonary vein (PV) isolation (PVI) were assigned to either RFCA using (1) a standard 3.5‐mm open‐irrigated‐tip catheter or (2) a catheter with contact force measurement capabilities. Using the endpoint of PVI with entry and exit block, acute procedural parameters were assessed. Results: Procedural data showed a remarkable decline in ablation time (radiofrequency time needed for PVI) from 50.5 ± 15.9 to 39.0 ± 11.0 minutes (P = 0.007) with a reduction in overall procedure duration from 185 ± 46 to 154 ± 39 minutes (P = 0.022). In parallel, the total energy delivered could be significantly reduced from 70,926 ± 19,470 to 58,511 ± 14,655 Ws (P = 0.019). The number of acute PV reconnections declined from 36% to 12% (P = 0.095). Conclusions: The use of contact force sensing technology is able to significantly reduce ablation and procedure times in PVI. In addition, energy delivery is substantially reduced by avoiding radiofrequency ablation in positions with insufficient surface contact. Procedural efficacy and safety of this new feature have to be evaluated in larger cohorts. (PACE 2012; 35:1312–1318)